diff --git a/css/game.css b/css/game.css
index 2febed7..0814732 100644
--- a/css/game.css
+++ b/css/game.css
@@ -20,6 +20,23 @@
     --warning: #f39c12;
 }
 
+/* Touch Optimization */
+* {
+    -webkit-tap-highlight-color: transparent;
+    -webkit-touch-callout: none;
+    user-select: none;
+}
+
+input, textarea {
+    user-select: text;
+    -webkit-user-select: text;
+}
+
+body {
+    touch-action: manipulation;
+    -webkit-tap-highlight-color: transparent;
+}
+
 * {
     margin: 0;
     padding: 0;
@@ -95,6 +112,7 @@ h2, h3 {
     display: flex;
     justify-content: center;
     margin: 20px 0;
+    position: relative;
 }
 
 #harvest-btn {
@@ -110,6 +128,8 @@ h2, h3 {
     align-items: center;
     justify-content: center;
     box-shadow: 0 4px 20px rgba(155, 89, 182, 0.4);
+    position: relative;
+    overflow: hidden;
 }
 
 #harvest-btn:hover {
@@ -121,6 +141,67 @@ h2, h3 {
     transform: scale(0.95);
 }
 
+/* Pulse Animation */
+#harvest-btn::before {
+    content: '';
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    width: 100%;
+    height: 100%;
+    border-radius: 50%;
+    background: rgba(155, 89, 182, 0.3);
+    transform: translate(-50%, -50%);
+    animation: pulse 2s ease-in-out infinite;
+}
+
+@keyframes pulse {
+    0%, 100% {
+        width: 100%;
+        height: 100%;
+        opacity: 0.3;
+    }
+    50% {
+        width: 120%;
+        height: 120%;
+        opacity: 0;
+    }
+}
+
+/* Ripple Effect */
+.ripple {
+    position: absolute;
+    border-radius: 50%;
+    background: rgba(255, 255, 255, 0.6);
+    transform: scale(0);
+    animation: rippleEffect 0.6s linear;
+    pointer-events: none;
+}
+
+@keyframes rippleEffect {
+    to {
+        transform: scale(4);
+        opacity: 0;
+    }
+}
+
+/* Click button glow on active */
+#harvest-btn.clicked {
+    animation: clickGlow 0.2s ease;
+}
+
+@keyframes clickGlow {
+    0% {
+        box-shadow: 0 4px 20px rgba(155, 89, 182, 0.4);
+    }
+    50% {
+        box-shadow: 0 0 40px rgba(255, 215, 0, 0.8), 0 4px 20px rgba(155, 89, 182, 0.6);
+    }
+    100% {
+        box-shadow: 0 4px 20px rgba(155, 89, 182, 0.4);
+    }
+}
+
 .btn-icon {
     font-size: 3rem;
 }
@@ -220,6 +301,85 @@ h2, h3 {
     opacity: 0.5;
 }
 
+.buy-max-btn {
+    display: block;
+    width: 100%;
+    margin-top: 6px;
+    background: var(--accent-purple);
+    color: var(--text-primary);
+    border: none;
+    border-radius: 6px;
+    padding: 5px 12px;
+    cursor: pointer;
+    font-weight: bold;
+    font-size: 0.8rem;
+    transition: all 0.2s ease;
+}
+
+.buy-max-btn:hover:not(:disabled) {
+    background: #9b59b6;
+    transform: scale(1.03);
+}
+
+.buy-max-btn:disabled {
+    background: var(--text-muted);
+    cursor: not-allowed;
+    opacity: 0.4;
+}
+
+/* Upgrades header + Buy All button */
+.upgrades-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    margin-bottom: 10px;
+}
+
+.upgrades-header h3 {
+    margin: 0;
+}
+
+.buy-all-btn {
+    background: var(--accent-gold);
+    color: var(--bg-primary, #1a1035);
+    border: none;
+    border-radius: 6px;
+    padding: 6px 14px;
+    cursor: pointer;
+    font-weight: bold;
+    font-size: 0.8rem;
+    transition: all 0.2s ease;
+}
+
+.buy-all-btn:hover:not(:disabled) {
+    background: #f1c40f;
+    transform: scale(1.03);
+}
+
+.buy-all-btn:disabled {
+    background: var(--text-muted);
+    color: var(--bg-primary, #1a1035);
+    cursor: not-allowed;
+    opacity: 0.4;
+}
+
+/* Prestige Upgrades header + Buy Max button */
+.prestige-upgrades-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    margin-bottom: 10px;
+}
+
+.prestige-upgrades-header h3 {
+    margin: 0;
+}
+
+.prestige-buy-all {
+    background: var(--accent-gold);
+    color: var(--bg-primary, #1a1035);
+}
+
 /* Side Panel Tabs */
 .tabs {
     display: flex;
@@ -408,6 +568,123 @@ h2, h3 {
     border-color: var(--danger);
 }
 
+/* Save Slot System */
+.footer-section {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    padding-right: 10px;
+    border-right: 1px solid var(--border-color);
+}
+
+.footer-section:last-of-type {
+    border-right: none;
+    margin-left: auto;
+}
+
+.footer-label {
+    color: var(--text-secondary);
+    font-size: 0.8rem;
+    font-weight: bold;
+}
+
+.slot-btn {
+    background: var(--bg-card);
+    color: var(--text-secondary);
+    border: 1px solid var(--border-color);
+    border-radius: 6px;
+    padding: 6px 12px;
+    cursor: pointer;
+    font-weight: bold;
+    transition: all 0.2s ease;
+    min-width: 34px;
+}
+
+.slot-btn:hover:not(:disabled) {
+    background: var(--bg-hover);
+    border-color: var(--accent-purple);
+    color: var(--text-primary);
+}
+
+.slot-btn.active {
+    background: var(--accent-purple);
+    color: var(--text-primary);
+    border-color: var(--accent-gold);
+    box-shadow: 0 0 12px rgba(155, 89, 182, 0.6);
+}
+
+.slot-btn:disabled {
+    cursor: default;
+    opacity: 0.5;
+}
+
+/* Live one-line preview of the active/hovered save slot in the footer */
+.slot-preview {
+    color: var(--text-secondary);
+    font-size: 0.78rem;
+    font-family: monospace;
+    white-space: nowrap;
+    max-width: 320px;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    opacity: 0.85;
+    transition: opacity 0.15s ease, color 0.15s ease;
+}
+
+.slot-preview.empty {
+    color: var(--text-muted);
+    font-style: italic;
+    opacity: 0.6;
+}
+
+#game-footer:hover .slot-preview,
+.slot-preview:not(.empty):hover {
+    opacity: 1;
+    color: var(--accent-purple);
+}
+
+/* Autosave toggle button */
+.toggle-btn {
+    background: var(--bg-card);
+    color: var(--text-secondary);
+    border: 1px solid var(--border-color);
+    border-radius: 6px;
+    padding: 8px 14px;
+    cursor: pointer;
+    font-weight: bold;
+    transition: all 0.2s ease;
+}
+
+.toggle-btn.on {
+    background: var(--accent-green);
+    color: #0a0a1a;
+    border-color: var(--accent-green);
+}
+
+.toggle-btn:not(.on) {
+    background: var(--bg-card);
+    color: var(--text-muted);
+}
+
+/* Import modal slot selector */
+.import-slot-selector {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    margin: 12px 0;
+}
+
+.import-slot-label {
+    color: var(--text-secondary);
+    font-size: 0.85rem;
+}
+
+.modal-hint {
+    color: var(--text-muted);
+    font-size: 0.8rem;
+    margin-bottom: 10px;
+}
+
 #last-saved {
     margin-left: auto;
     color: var(--text-muted);
@@ -605,7 +882,7 @@ h2, h3 {
     #main-layout {
         grid-template-columns: 1fr 1fr;
     }
-    
+
     #side-panel {
         grid-column: span 2;
     }
@@ -615,14 +892,305 @@ h2, h3 {
     #main-layout {
         grid-template-columns: 1fr;
     }
-    
+
     #side-panel {
         grid-column: span 1;
     }
-    
+
     #game-header {
         flex-direction: column;
         gap: 10px;
         text-align: center;
     }
+
+    /* Touch-friendly button sizes */
+    .buy-btn, .prestige-btn {
+        min-height: 44px;
+        padding: 12px 20px;
+    }
+
+    .tab-btn {
+        min-height: 44px;
+        padding: 12px;
+    }
+
+    #harvest-btn {
+        width: 180px;
+        height: 180px;
+    }
+
+    /* Prevent double-tap zoom */
+    button, a, input, select {
+        touch-action: manipulation;
+    }
+}
+
+/* Mobile Touch Optimizations */
+@media (max-width: 480px) {
+    body {
+        overflow-x: hidden;
+    }
+
+    #main-layout {
+        padding: 10px;
+        gap: 10px;
+    }
+
+    section, aside {
+        padding: 15px;
+    }
+
+    #game-header {
+        padding: 15px 20px;
+    }
+
+    #game-footer {
+        flex-wrap: wrap;
+        justify-content: center;
+        padding: 10px 15px;
+    }
+
+    #game-footer button {
+        flex: 1;
+        min-width: 80px;
+    }
+
+    /* Larger touch targets */
+    .building-card, .upgrade-card {
+        padding: 15px;
+    }
+
+    .achievement {
+        padding: 12px;
+    }
+
+    .achievement-icon {
+        font-size: 1.8rem;
+    }
+
+    /* Prevent pull-to-refresh on scroll areas */
+    #buildings-list, #upgrades-list, #prestige-upgrades-list {
+        overscroll-behavior: contain;
+    }
+}
+
+/* ============================================
+   PRESTIGE SYSTEM STYLES
+   ============================================ */
+
+.prestige-btn {
+    background: linear-gradient(135deg, #9b59b6 0%, #8e44ad 100%);
+    color: var(--text-primary);
+    border: none;
+    border-radius: 6px;
+    padding: 8px 16px;
+    cursor: pointer;
+    font-weight: bold;
+    transition: all 0.2s ease;
+    box-shadow: 0 2px 10px rgba(155, 89, 182, 0.3);
+}
+
+.prestige-btn:hover:not(:disabled) {
+    background: linear-gradient(135deg, #a569bd 0%, #9b59b6 100%);
+    transform: scale(1.05);
+    box-shadow: 0 4px 15px rgba(155, 89, 182, 0.5);
+}
+
+.prestige-btn:disabled {
+    background: var(--text-muted);
+    cursor: not-allowed;
+    opacity: 0.5;
+    box-shadow: none;
+}
+
+.prestige-btn.can-prestige {
+    animation: prestigeGlow 2s ease-in-out infinite;
+}
+
+@keyframes prestigeGlow {
+    0%, 100% {
+        box-shadow: 0 2px 10px rgba(155, 89, 182, 0.3);
+    }
+    50% {
+        box-shadow: 0 2px 20px rgba(155, 89, 182, 0.6), 0 0 30px rgba(155, 89, 182, 0.4);
+    }
+}
+
+/* Prestige Tab Styles */
+#prestige-info {
+    background: var(--bg-card);
+    border-radius: 8px;
+    padding: 15px;
+    border: 1px solid var(--border-color);
+    margin-bottom: 15px;
+}
+
+.prestige-essence {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    font-size: 1.3rem;
+    font-weight: bold;
+    color: var(--accent-gold);
+    margin-bottom: 10px;
+}
+
+.essence-icon {
+    font-size: 1.5rem;
+    color: #9b59b6;
+}
+
+.prestige-multiplier {
+    color: var(--text-secondary);
+    margin-bottom: 8px;
+}
+
+.prestige-multiplier span {
+    color: var(--accent-green);
+    font-weight: bold;
+}
+
+.prestige-next {
+    color: var(--text-secondary);
+    font-size: 0.9rem;
+}
+
+.prestige-next span {
+    color: var(--accent-purple);
+    font-weight: bold;
+}
+
+/* Prestige Upgrade Cards */
+#prestige-upgrades-list {
+    display: flex;
+    flex-direction: column;
+    gap: 10px;
+    max-height: 300px;
+    overflow-y: auto;
+}
+
+.prestige-upgrade-card {
+    background: var(--bg-card);
+    border-radius: 8px;
+    padding: 12px;
+    border: 1px solid var(--border-color);
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.prestige-upgrade-card:hover:not(.purchased):not(.locked) {
+    background: var(--bg-hover);
+    border-color: var(--accent-purple);
+}
+
+.prestige-upgrade-card.purchased {
+    opacity: 0.6;
+    border-color: var(--accent-green);
+}
+
+.prestige-upgrade-card.locked {
+    opacity: 0.4;
+    pointer-events: none;
+}
+
+.prestige-upgrade-name {
+    font-weight: bold;
+    color: var(--text-primary);
+}
+
+.prestige-upgrade-desc {
+    font-size: 0.85rem;
+    color: var(--text-secondary);
+    margin-top: 3px;
+}
+
+.prestige-upgrade-cost {
+    color: #9b59b6;
+    font-size: 0.9rem;
+    margin-top: 5px;
+    font-weight: bold;
+}
+
+/* Prestige Particle Effects */
+.particle.prestige-particle {
+    background: radial-gradient(circle, #ffd700 0%, #9b59b6 50%, transparent 100%);
+    box-shadow: 0 0 10px #ffd700, 0 0 20px #9b59b6;
+}
+
+/* Stats Panel Prestige Info */
+.stat-item.prestige-stat {
+    border-color: var(--accent-purple);
+    background: linear-gradient(135deg, var(--bg-card) 0%, #2a1a3e 100%);
+}
+
+/* ============================================
+   Golden Starbloom Random Event
+   ============================================ */
+
+/* Countdown badge in the header */
+.golden-bloom-badge {
+    font-size: 0.95rem;
+    font-weight: bold;
+    color: var(--text-secondary);
+    padding: 4px 12px;
+    border-radius: 20px;
+    border: 1px solid transparent;
+    white-space: nowrap;
+    opacity: 0;
+    transform: translateY(-6px);
+    transition: opacity 0.3s ease, transform 0.3s ease;
+}
+
+.golden-bloom-badge.active {
+    opacity: 1;
+    transform: translateY(0);
+    color: var(--accent-gold);
+    background: rgba(255, 215, 0, 0.12);
+    border-color: var(--accent-gold);
+    box-shadow: 0 0 12px rgba(255, 215, 0, 0.35);
+}
+
+/* The floating bloom itself */
+#golden-bloom-container {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    pointer-events: none;
+}
+
+.golden-bloom {
+    position: absolute;
+    font-size: 3rem;
+    cursor: pointer;
+    line-height: 1;
+    filter: drop-shadow(0 0 14px rgba(255, 215, 0, 0.9));
+    animation: goldenBloomFloat 2s ease-in-out infinite, goldenBloomPulse 1.4s ease-in-out infinite;
+    transition: transform 0.1s ease;
+    pointer-events: auto;
+}
+
+.golden-bloom:hover {
+    transform: scale(1.15);
+    filter: drop-shadow(0 0 22px rgba(255, 215, 0, 1));
+}
+
+@keyframes goldenBloomFloat {
+    0%, 100% { translateY(0); }
+    50% { translateY(-8px); }
+}
+
+@keyframes goldenBloomPulse {
+    0%, 100% { opacity: 0.85; }
+    50% { opacity: 1; }
+}
+
+/* Golden particle effect styles */
+.particle.golden-bloom-particle {
+    background: radial-gradient(circle, #fff2a8 0%, #ffd700 60%, transparent 100%);
+}
+
+.particle.golden-sparkle {
+    background: radial-gradient(circle, #ffffff 0%, #ffe469 100%);
 }
diff --git a/dev-journal.md b/dev-journal.md
index e9f52c7..092c6e3 100644
--- a/dev-journal.md
+++ b/dev-journal.md
@@ -12,7 +12,7 @@
 - Theme: "Cosmic Garden" - a space gardening idle game
 - Built core game engine with click harvesting, buildings, upgrades, achievements
 - Designed 12 buildings across 4 tiers (Star Sprout → Void Fern)
-- Added 15+ upgrades and 20 achievements
+- Added 15+ upgrades and 30 achievements
 - Implemented auto-save, offline progress, export/import
 - Built responsive dark-themed UI
 
@@ -98,4 +98,347 @@
 
 ---
 
+---
+
+### Session 12 - 2026-08-23 (Morning)
+**Status:** ✅ Save Slot System Added
+
+#### What was done:
+- Implemented a multi-slot save system with 3 independent, persistent save slots
+- Each slot stores its own data under a dedicated localStorage key (`cosmicGardenSave-<n>`), so switching slots never overwrites another slot's progress
+- Added slot selection buttons in the footer (labeled 1/2/3) that switch between saves with a confirmation prompt and auto-save the current slot first
+- Added an autosave toggle button (ON/OFF); when off, the periodic autosave loop is skipped, and the preference is persisted separately across page loads
+- Enhanced the import modal with a per-slot selector so players can paste save data into a specific slot; importing into the active slot reloads it automatically
+- Added `exportSlotToBase64()` / `importSlotFromData()` for backup/transfer of individual slots, plus `loadSlot()` helper
+- Switching to an empty slot starts a fresh game while preserving Stellar Essence and prestige counters (so prestige currency is never lost when testing new runs)
+- Added Save Slot + Autosave indicators to the Statistics panel, updated live each tick
+- Fixed a latent bug: `reset()` did not include the `goldenBlooms` event field, which crashed `Stats.update()` on any reset. Also added the same missing field to the empty-slot branch of `switchSlot()`. Both were caught by an end-to-end test harness simulating localStorage/DOM/clipboard.
+- Verified all 18 slot operations (save/load per slot, switch round-trips, empty-slot handling, export/import round-trip, persistence across reloads, reset preservation) with a Node.js DOM-simulation harness — 18/18 pass
+
+#### Files modified:
+- `js/game.js` - Core save-slot logic: state fields (activeSlot, autoSave), SLOTS config, getSaveKey/loadSlot/switchSlot/exportSlotToBase64/importSlotFromData methods; wired slot + autosave + import-slot event listeners; updated save()/loadState()/reset()/startAutoSave()
+- `js/ui.js` - Added updateSlotUI() to reflect active slot highlight and autosave toggle state
+- `js/stats.js` - Added Active Save Slot and Autosave indicators, refreshed each tick
+- `index.html` - Footer with slot buttons + autosave toggle; import modal slot selector; achievement count label corrected to 31/31
+- `css/game.css` - Styling for footer sections, slot buttons (active/disabled states), autosave toggle, and import-modal slot selector
+
+#### Next goals:
+- Add a save-slot preview (e.g. show stardust total / buildings count / last-saved time) on hover or in the stats panel to help players tell slots apart
+- Consider adding more than 3 slots via a config option or unlockable count
+- Balance tweak: review overall game pacing now that prestige and random events are in place
+
 *Journal auto-updated by Hermes Agent cron job (every 8 hours)*
+
+---
+
+### Session 5 - 2026-08-20 (Afternoon)
+**Status:** ✅ Prestige System Added
+
+#### What was done:
+- Created complete prestige/reset system with Stellar Essence currency
+- Formula: floor(sqrt(totalStardust / 1,000,000)) essence per prestige
+- Each essence provides +10% production bonus (stacks multiplicatively)
+- Added 6 prestige upgrades: Cosmic Fingers, Stellar Touch, Essence Amplifier, Quantum Garden, Accelerated Growth, Temporal Manipulation
+- Created PrestigeUI module for rendering and managing prestige tab
+- Added prestige particle effects (cosmic explosion on reset)
+- Added prestige sound effect (ethereal whoosh via Web Audio API)
+- Integrated prestige multiplier into click power, production, building costs, and offline progress
+- Added prestige button to footer with glow animation when eligible
+- Updated game state to persist prestige data across resets
+
+#### Files modified/created:
+- `js/prestige.js` - New file with Prestige system (essence calculation, upgrades, multipliers)
+- `js/prestigeUI.js` - New file with PrestigeUI module (tab rendering, event handling)
+- `js/game.js` - Added prestige fields to state, integrated multipliers into calculations
+- `js/particles.js` - Added createPrestigeEffect() method
+- `js/audio.js` - Added playPrestige() sound effect
+- `css/game.css` - Added prestige button styles, tab styles, upgrade card styles
+- `index.html` - Added prestige tab and script tags
+- `dev-journal.md` - Updated with session log
+
+#### Next goals:
+- Achievement expansion (prestige-related achievements)
+- Mobile touch optimizations
+- Consider adding more visual polish to the click button
+
+---
+
+### Session 6 - 2026-08-20 (Evening)
+**Status:** ✅ Achievement Expansion Added
+
+#### What was done:
+- Added 10 new achievements, bringing total from 20 to 30
+- New prestige achievements: Cosmic Rebirth (first prestige), Stellar Adaptation (5 prestiges), Cosmic Ascension (10 prestiges), Eternal Gardener (100 total essence), Quantum Growth (1,000 total essence)
+- New building milestone achievements: Void Weaver (25 Void Ferns), Supernova Growth (25 Supernova Seeds)
+- New click power achievements: Powerful Harvester (1,000 click power), Divine Touch (10,000 click power)
+- New time-based achievement: Dedicated Gardener (play for 1 hour total)
+- Updated achievement counter in UI from (0/20) to (0/30)
+- Updated Session 1 journal entry to reflect 30 achievements
+
+#### Files modified:
+- `js/achievements.js` - Added 10 new achievement definitions
+- `index.html` - Updated achievement count display
+- `dev-journal.md` - Updated session log and added Session 6 entry
+
+#### Next goals:
+- Mobile touch optimizations (tap feedback, responsive layout)
+- Consider adding more visual polish to the click button
+- Achievement progress tracking in stats panel
+
+---
+
+### Session 7 - 2026-08-21 (Morning)
+**Status:** ✅ Mobile Touch Optimizations & Click Button Polish Added
+
+#### What was done:
+- Added comprehensive touch optimization CSS with `-webkit-tap-highlight-color`, `touch-action: manipulation`, and `user-select` controls
+- Implemented ripple effect animation on click button for visual feedback
+- Added pulse animation to the harvest button (subtle breathing effect)
+- Added glow flash animation on each click for satisfying feedback
+- Added touchstart event handler with proper preventDefault to avoid double-firing
+- Created responsive breakpoints at 768px and 480px for mobile devices
+- Increased touch target sizes (44px minimum, per accessibility guidelines)
+- Added overscroll-behavior: contain to scroll areas to prevent pull-to-refresh
+- Made footer buttons wrap and center on small screens
+- Enlarged harvest button on mobile (180px vs 150px desktop)
+
+#### Files modified:
+- `js/game.js` - Added touch event handler, ripple effect creation, click animation methods
+- `css/game.css` - Added touch optimizations, ripple animations, pulse effects, responsive breakpoints
+
+#### Next goals:
+- Achievement progress tracking in stats panel
+- Consider adding more sound variations or background music
+- Potential new building tiers or prestige milestones
+
+---
+
+### Session 9 - 2026-08-21 (Afternoon)
+**Status:** ✅ Achievement Progress Tracking Added to Stats Panel
+
+#### What was done:
+- Added "Next Achievement" section to the Statistics panel with a progress bar
+- Implemented `calculateAchievementProgress()` method that computes progress toward every achievement type:
+  - Click achievements (firstClick, clicker, spammer, clickMaster)
+  - Stardust achievements (dustCollector, stardustMagnate, cosmicTycoon, galaxyBaron)
+  - Building count achievements (firstPlant, gardenStart, gardenCenter, cosmicGarden)
+  - Specific building achievements (sproutFarmer, bloomGarden, solarPowered, voidWeaver, supernovaGrowth)
+  - Production achievements (steadyStream, rushingRiver, cosmicFlood)
+  - Prestige achievements (firstPrestige, stellarAdaptation, cosmicAscension, eternalGardener, quantumGrowth)
+  - Click power achievements (powerfulHarvester, divineTouch)
+  - Time-based achievement (dedicatedGardener)
+- `updateNextAchievement()` finds the closest unachieved milestone by progress percentage and displays it with a progress bar
+- Progress bar updates every game tick via `Stats.update()`
+- Shows "All achievements unlocked! 🎉" when all 30 achievements are complete
+
+#### Files modified:
+- `js/stats.js` - Added "Next Achievement" stat item to render(), added updateNextAchievement() and calculateAchievementProgress() methods
+
+#### Next goals:
+- Consider adding a "next essence at X stardust" progress hint in prestige tab (from Session 8 notes)
+- Potential new building tiers or prestige milestones
+- Sound variations or background music
+
+---
+
+---
+
+### Session 8 - 2026-08-21 (Afternoon)
+**Status:** ✅ Critical Bugfix - Prestige System Now Actually Loads (reported by user)
+
+#### Bug report:
+User reported (with screenshot) that clicking "Collect Stardust" no longer works
+after the prestige feature shipped in Session 5. Console showed:
+`Uncaught ReferenceError: PRESTIGE is not defined` (game.js line 159, in getClickPower)
+
+#### Root cause:
+Session 5 created `js/prestige.js` + `js/prestigeUI.js` and rewired `game.js` to
+call `PRESTIGE`/`PRESTIGE_UPGRADES` in click power, production, and offline
+earnings — but **never added the two script tags to `index.html`**. So:
+1. `PRESTIGE` was undefined → `getClickPower()` threw on every tick (250ms) and
+   every click → clicking did nothing, console flooded with errors.
+2. `Game.init()` calls `PrestigeUI.init()` → crashed the whole init sequence
+   after `UI.init()`, so even the harvest click listener was never attached.
+3. A second latent bug in `js/particles.js`: missing comma between
+   `createAmbientStars()` and `createPrestigeEffect()` (added in Session 5)
+   made the whole file fail to parse → `Particles` undefined → would have
+   broken `harvest()` even after fix #1.
+4. The prestige tab UI (essence display, prestige button, upgrade list) was
+   also never added to `index.html`.
+
+#### Fixes applied:
+- `index.html` - added `<script>` tags for `js/prestige.js` and `js/prestigeUI.js`
+  (before `main.js`), added the ✦ Prestige tab button + tab panel with
+  `prestige-btn`, `prestige-essence-count`, `prestige-multiplier`,
+  `prestige-next-essence`, `prestige-upgrades-list`
+- `js/particles.js` - added missing comma after `createAmbientStars()`
+- `js/ui.js` - `UI.update()` now also calls `PrestigeUI.update()` so the
+  prestige display refreshes every tick
+
+#### Verification:
+Built a headless DOM test harness (`headless-test/test_game.py`, lives OUTSIDE
+the game repo) running all game scripts in a real JS engine (py_mini_racer /
+JavaScriptCore) with DOM stubs. 33/33 checks pass: init, 5 harvest clicks →
+5 stardust, 20 game ticks without errors, full prestige flow (2M stardust →
+1 essence, reset, multiplier), prestige upgrade purchase math, UI rendering,
+firstPrestige achievement, save/load round-trip preserving essence.
+
+#### Files modified:
+- `index.html` - prestige scripts + prestige tab UI
+- `js/particles.js` - missing comma (parse error)
+- `js/ui.js` - PrestigeUI.update() wired into UI.update()
+
+#### Lessons / notes for future sessions:
+- Always check `index.html` script tags when adding new JS files!
+- A headless smoke test exists at /workspace/headless-test/test_game.py —
+  re-run it after any change to js/ to catch ReferenceErrors before pushing.
+  (Requires `pip install py_mini_racer`.)
+
+#### Next goals:
+- Consider adding a "next essence at X stardust" progress hint
+
+---
+
+### Session 10 - 2026-08-22 (Morning)
+**Status:** ✅ Buy Max (Bulk-Buy) Feature Added
+
+#### What was done:
+- Added a "Buy Max" bulk-buy mechanic — a staple of idle/clicker games that was previously missing (you could only buy one building at a time, forcing many tedious clicks).
+- Added `Game.getMaxAffordable(buildingId)` which computes how many of a given building the player can afford right now using an iterative cost-scaling loop. It is read-only and does not mutate state.
+- Added `Game.buyMaxBuilding(buildingId)` which loops buying one at a time until unaffordable, deducting the correct total stardust and incrementing counts properly (respects prestige costReduction upgrades since it reuses `getBuildingCost`).
+- Wired a "Buy Max" button onto every building card in `UI.renderBuildings()` with an affordable-count badge (e.g. "5x Max").
+- Updated `UI.updateBuildings()` so the Buy Max badge refreshes its count and enabled/disabled state every game tick, keeping it accurate as stardust accrues.
+- Added CSS styling for `.buy-max-btn` (purple theme, hover scale, disabled state) to match existing building-card layout.
+
+#### Files modified:
+- `js/game.js` - added getMaxAffordable() and buyMaxBuilding() methods
+- `js/ui.js` - rendered Buy Max button per building card + tick refresh in updateBuildings()
+- `css/game.css` - .buy-max-btn styles
+- `dev-journal.md` - appended Session 10 entry
+
+#### Verification:
+Wrote a headless Node.js test (`/opt/data/idle-game-test/buy-max-test.mjs`, lives OUTSIDE the repo). Evaluated the real game.js in-process with DOM/UI stubs. 6/6 checks pass: getMaxAffordable matches manual cost-scaling calc, buyMax deducts correct stardust and increments counts correctly, unaffordable purchase returns 0, getMaxAffordable is idempotent, and notifications fire on purchase.
+
+#### Next goals:
+- Consider adding "Buy Max" to upgrades too (upgrades are one-time so less critical, but a bulk "buy all affordable" could be nice).
+- Potential new building tiers or prestige milestones.
+- Sound variations or background music.
+
+---
+
+### Session 11 - 2026-08-23 (Morning)
+**Status:** ✅ Golden Starbloom Random Event Added
+
+#### What was done:
+- Added a classic idle-game random event: the **Golden Starbloom**, a rare, time-limited bloom that occasionally appears in the click area. Clicking it grants a stardust bonus and a temporary production boost.
+- Game state: added `state.goldenBlooms` (active flag, timer, lastSpawn timestamp, lifetime totalClaimed) plus `config.goldenBloom*` tuning values (min/max spawn interval 45-90s, 12s visible duration, bonus multiplier).
+- Added a temporary **+50% production boost** (30 seconds) applied inside `getProductionPerSecond()`, alongside the existing prestige multiplier. Boost is expired-checked each tick and reflected in stats.
+- Core logic in game.js: `claimGoldenBloom(x,y)` (awards `floor(production * mult)` stardust, min 1), `updateGoldenBloom(dtSeconds)` (schedules spawns on the tick clock; spawns once elapsed passes maxMs, with a small per-tick probability after minMs to avoid burst-spawning), `getProductionBoostInfo()`, and `getGoldenBloomRemaining()`.
+- Wired `updateGoldenBloom()` into the main game tick so scheduling advances every 100ms.
+- UI: added `UI.spawnGoldenBloom()` (floats a golden ⭐ at a random position in the click area, clickable to claim) and `UI.removeGoldenBloom()`, plus a header countdown badge (`golden-bloom-badge`) that glows while a bloom is live.
+- Stats panel: added "Total Golden Blooms Claimed" stat and a "Production Boost" stat with a live progress bar (0-30s).
+- Achievements: added 3 new achievements bringing the total from 30 to **33** — Lucky Bloom (first claim), Golden Collector (25 claims), Golden Enthusiast (100 claims). Updated the achievements-tab count in index.html.
+- Visual + audio polish: `Particles.createGoldenEffect()` (golden ring burst + sparkle) and `Audio.playGoldenBloom()` (rising sweep + ascending shimmer chord). Added CSS for the bloom, its hover/floating/pulse animations, the badge, and golden particle styles.
+- Wrote a headless Node.js test (`golden-bloom-test.mjs`) evaluating the real game.js in-process with DOM/UI/audio/particle stubs. **22/22 checks pass**, covering: no-op claim when inactive, bonus math, boost multiplier + expiry, countdown decrement + vanishing, forced spawn at maxMs, and no premature spawn before minMs. The existing buy-max test still passes (no regression).
+
+#### Files modified:
+- `js/game.js` - golden bloom state/config, claim/update/bloom/boost methods, tick wiring, production boost multiplier
+- `js/ui.js` - spawnGoldenBloom(), removeGoldenBloom(), updateGoldenBloomBadge(), wired into update()
+- `js/stats.js` - two new stat items + update logic (golden count, boost progress)
+- `js/particles.js` - createGoldenEffect()
+- `js/audio.js` - playGoldenBloom()
+- `js/achievements.js` - 3 new golden achievements (Lucky Bloom, Golden Collector, Golden Enthusiast)
+- `css/game.css` - bloom/badge/particle styling + keyframes
+- `index.html` - golden-bloom-container in click area, golden-bloom-badge in header, achievement count 30->33
+- `dev-journal.md` - appended Session 11 entry
+
+#### Verification:
+Headless test at /opt/data/idle-game-test/golden-bloom-test.mjs — **22/22 pass**. Existing buy-max test re-ran clean (6/6, no regression). All modified JS files pass `node --check`.
+
+#### Next goals:
+- Consider adding "Buy Max" to upgrades too.
+- Potential new building tiers or prestige milestones.
+- Sound variations or background music.
+
+---
+
+### Session 13 - 2026-08-23 (Afternoon)
+**Status:** ✅ Save Slot Preview Added
+
+#### What was done:
+- Followed up on Session 12's stated next goal by adding a **save-slot preview** so players can tell their save slots apart at a glance.
+- Added `Game.getSlotPreview(slot)` — a read-only helper that reads a given slot's data from localStorage WITHOUT mutating the live game state. It returns: `present` (has any saved data), `stardust`, `totalStardust`, `buildings` (sum of all building counts), `achievements` [count/total], `prestigeCount`, and a human-readable `lastSaved` "time ago" string.
+- Added `Game.formatTimeAgo(secs)` — formats a second-count into compact relative labels ("just now", "1m ago", "3h ago", "2d ago", "7mo ago", etc.).
+- Wired the preview into the footer: a monospace `.slot-preview` span now shows the active slot's live summary every tick (`Slot N: 1.2K ✨ · 8 plants · 2/33 · just now`). Hovering any slot button swaps the preview to that slot's contents; leaving falls back to the active slot.
+- Added CSS for `.slot-preview` (monospace, ellipsis-truncated, dims until hover) and a `.empty` style for unreadable slots ("Slot N: empty").
+- All display logic is read-only — `getSlotPreview()` calls the existing `loadSlot()` and never touches `Game.state`, verified by a dedicated test.
+
+#### Files modified:
+- `js/game.js` - added `getSlotPreview(slot)` + `formatTimeAgo(secs)` methods (inserted before `switchSlot()`)
+- `index.html` - added `<span id="slot-preview">` inside the footer Slot section
+- `js/ui.js` - added `updateSlotPreview()`; called it from `UI.update()` each tick and wired per-slot hover/leave listeners (re-cloning slot buttons each render to avoid duplicate listeners)
+- `css/game.css` - `.slot-preview`, `.slot-preview.empty`, and hover-brightening rules
+
+#### Verification:
+Wrote a headless Node.js test (`/opt/data/idle-game-test/slot-preview-test.mjs`) evaluating the real game.js in-process with localStorage + UI stubs. **22/22 checks pass**, covering: empty-slot handling (present:false, zeroed), populated-slot field reads (stardust, totalStardust, summed buildings, achievement count/total, prestigeCount), formatTimeAgo buckets (just now / m / h / d), relative lastSaved strings, read-only guarantee (live state unchanged after previews), and graceful handling of malformed/missing fields (minimal object → present:true zeroed; non-numeric building count coerced to 0 with no crash). Existing golden-bloom test re-ran clean (22/22, no regression). All modified JS files pass `node --check`.
+
+#### Next goals:
+- Consider adding a "Buy Max" button to upgrades too (one-time purchases — less critical).
+- Potential new building tiers or prestige milestones.
+- Sound variations or background music.
+
+---
+
+### Session 14 - 2026-08-24 (Morning)
+**Status:** ✅ Buy All Upgrades (Bulk-Buy for Upgrades) Added
+
+#### What was done:
+- Followed up on Sessions 10, 11, and 13's recurring "next goal" by adding a **Buy All** button to the Upgrades tab. Previously one-time upgrades could only be purchased individually (one click each), which was tedious once dozens were available — buildings already had a Buy Max bulk-buy from Session 10, but upgrades did not.
+- Added `Game.buyAllUpgrades()` which loops through every upgrade in `UPGRADES`, skips owned ones, respects each upgrade's `requirements` (building-count gates), and buys everything affordable at once. It runs until a full pass purchases nothing (so buying one upgrade can unlock affordability for another via the stardust re-check), then returns `{ bought: count, ids: [...] }`.
+- Wired a **Buy All** button into the Upgrades tab header in `index.html` (`#buy-all-upgrades`).
+- Added `UI.updateBuyAllButton()` (called from `UI.updateUpgrades()` each tick) which shows/hides the button based on whether any unowned, requirement-met upgrade is currently affordable, and toggles its disabled state live.
+- Added CSS for `.upgrades-header` (flex layout) and `.buy-all-btn` (gold accent theme matching existing buttons, hover scale, disabled state).
+- Fixed a latent bug found during testing: the empty-slot branch of `Game.switchSlot()` did not reset `state.productionBoostUntil`, which could leave a stale golden-bloom boost active after switching to a fresh slot. Added `productionBoostUntil: 0` to that branch for symmetry with `reset()`.
+
+#### Files modified:
+- `js/game.js` - added `buyAllUpgrades()` method; wired Buy All button click listener in setupEventListeners(); fixed empty-slot productionBoostUntil reset in switchSlot()
+- `js/ui.js` - added `updateBuyAllButton()`; called it from `updateUpgrades()` each tick
+- `index.html` - added Buy All button to Upgrades tab header
+- `css/game.css` - `.upgrades-header`, `.buy-all-btn` styles
+- `dev-journal.md` - appended Session 14 entry
+
+#### Verification:
+Wrote a headless Node.js test (`/opt/data/idle-game-test/buy-all-upgrades-test.mjs`) evaluating the real game.js and ui.js in-process with DOM/audio/particle stubs. **24/24 checks pass**, covering: no-op when nothing affordable, bulk purchase with requirement gating (blocks unmet requirements), chained affordability across loop passes, idempotent second call, already-owned upgrade skipping, notification-on-purchase vs silence on no-op, and the real `UI.updateBuyAllButton()` show/hide/enabled state against actual BUILDINGS/UPGRADES data. Existing buy-max (6/6) and golden-bloom (22/22) tests re-ran clean — no regressions. All modified JS files pass `node --check`.
+
+#### Next goals:
+- Consider adding a "Buy Max" button to the prestige upgrades list as well.
+- Potential new building tiers or prestige milestones.
+- Sound variations or background music.
+
+---
+
+### Session 15 - 2026-08-24 (Morning)
+**Status:** ✅ Buy Max Prestige Upgrades (bulk-buy for prestige upgrades) Added
+
+#### What was done:
+- Followed up on Session 14's own "next goal" by adding a **Buy Max** button to the **Prestige Upgrades** list. Previously one-time prestige upgrades could only be purchased individually (one click each), which was tedious once several were available — buildings had Buy Max (Session 10) and regular upgrades had Buy All (Session 14), but prestige upgrades did not. This brings prestige upgrades in line with that established bulk-buy convention.
+- Added `Game.buyMaxPrestigeUpgrades()` to `js/game.js`. It loops through every entry in `PRESTIGE_UPGRADES`, skips owned ones, respects each upgrade's (optional) `requirements` building-count gate, and buys everything affordable at once from **Stellar Essence**. It runs until a full pass purchases nothing (loop kept for symmetry with `buyAllUpgrades` and to stay safe if future prestige upgrades gain requirement gates), then decrements `stellarEssence` per purchase (mirroring `PRESTIGE.buyUpgrade`) and returns `{ bought: count, ids: [...] }`.
+- Wired the button into the Prestige tab in `index.html` (`#buy-all-prestige`, placed alongside a left-aligned header row mirroring the Upgrades tab's Buy All layout). Added a click listener in `PrestigeUI.setupEventListeners()`.
+- Added `PrestigeUI.updateBuyMaxPrestigeButton()` (called from `PrestigeUI.update()` each tick) which shows/hides and enables/disables the button based on whether any unowned, requirement-met prestige upgrade is currently affordable with Stellar Essence — a read-only state check, exactly mirroring `UI.updateBuyAllButton()`.
+- Added CSS for `.prestige-upgrades-header` (flex layout) and `.prestige-buy-all` (gold accent theme reusing the existing `.buy-all-btn` base, matching the Upgrades tab's Buy All button).
+- **Bug found & fixed during testing:** the first implementation of `buyMaxPrestigeUpgrades()` added upgrades to the list but never decremented `stellarEssence`, which would have let players prestige-buy unlimited upgrades for free. The headless test asserted essence depletion and caught it; added the missing `this.state.stellarEssence -= upgrade.cost` line so spend mirrors `PRESTIGE.buyUpgrade`.
+
+#### Files modified:
+- `js/game.js` - added `buyMaxPrestigeUpgrades()` method (with correct Stellar Essence spend)
+- `js/prestigeUI.js` - added click listener for the Buy Max button + `updateBuyMaxPrestigeButton()`; called from `update()` each tick
+- `index.html` - added Buy Max button to the Prestige Upgrades header
+- `css/game.css` - `.prestige-upgrades-header`, `.prestige-buy-all` styles
+- `dev-journal.md` - appended Session 15 entry
+
+#### Verification:
+Wrote a headless Node.js test (`/opt/data/idle-game-test/prestige-buy-max-test.mjs`) that loads the real `game.js`, `prestige.js`, and `prestigeUI.js` in-process with DOM/audio/particle stubs. **22/22 checks pass**, covering: no-op when nothing affordable, bulk purchase deducting Stellar Essence correctly, ungated-upgrade behavior (real prestige upgrades have no requirement gates), idempotent second call, already-owned upgrade skipping, notification-on-purchase vs silence on no-op, the missing-essence-spend regression (now fixed), and the real `PrestigeUI.updateBuyMaxPrestigeButton()` show/hide/enabled state against actual `PRESTIGE_UPGRADES` data. All existing suites re-ran clean with no regressions: buy-all-upgrades 24/24, buy-max 6/6, golden-bloom 22/22, slot-preview 22/22. All modified JS files pass `node --check`.
+
+#### Next goals:
+- Potential new building tiers or prestige milestones / new prestige upgrades.
+- Sound variations or background music.
+- Consider a global "Buy Max" for buildings across all types at once (currently per-building).
diff --git a/index.html b/index.html
index ef6a530..6394988 100644
--- a/index.html
+++ b/index.html
@@ -17,6 +17,8 @@
             <div id="per-second">
                 <span id="stardust-ps">0</span> ✨/sec
             </div>
+            <!-- Golden Starbloom countdown badge -->
+            <div id="golden-bloom-badge" class="golden-bloom-badge"></div>
         </header>
 
         <!-- Main Layout -->
@@ -29,6 +31,8 @@
                         <span class="btn-icon">✨</span>
                         <span class="btn-text">Collect Stardust</span>
                     </button>
+                    <!-- Golden Starbloom random event appears here -->
+                    <div id="golden-bloom-container"></div>
                 </div>
                 <div id="click-info">
                     <p>Click power: <span id="click-power">1</span> ✨</p>
@@ -50,15 +54,19 @@
                     <button class="tab-btn active" data-tab="upgrades">Upgrades</button>
                     <button class="tab-btn" data-tab="achievements">Achievements</button>
                     <button class="tab-btn" data-tab="stats">Stats</button>
+                    <button class="tab-btn" data-tab="prestige">✦ Prestige</button>
                 </div>
 
                 <div id="upgrades-tab" class="tab-content active">
-                    <h3>Upgrades</h3>
+                    <div class="upgrades-header">
+                        <h3>Upgrades</h3>
+                        <button id="buy-all-upgrades" class="buy-all-btn" style="display:none" title="Buy every upgrade you can currently afford">Buy All</button>
+                    </div>
                     <div id="upgrades-list"></div>
                 </div>
 
                 <div id="achievements-tab" class="tab-content">
-                    <h3>Achievements (0/20)</h3>
+                    <h3>Achievements (0/31)</h3>
                     <div id="achievements-list"></div>
                 </div>
 
@@ -66,15 +74,60 @@
                     <h3>Statistics</h3>
                     <div id="stats-content"></div>
                 </div>
+
+                <div id="prestige-tab" class="tab-content">
+                    <h3>✦ Prestige</h3>
+                    <div id="prestige-info">
+                        <div class="prestige-essence">
+                            <span class="essence-icon">✦</span>
+                            <span id="prestige-essence-count">0</span>
+                            <span style="font-size:0.85rem; color:var(--text-secondary)">Stellar Essence</span>
+                        </div>
+                        <div class="prestige-multiplier">
+                            Production bonus: <span id="prestige-multiplier">+0%</span>
+                        </div>
+                        <div class="prestige-next">
+                            Next prestige: <span id="prestige-next-essence">0</span> ✦
+                        </div>
+                        <p style="font-size:0.8rem; color:var(--text-muted); margin:8px 0">
+                            Requires 1M total stardust for the first ✦. Prestige resets
+                            stardust, buildings and upgrades — but keeps essence and
+                            prestige upgrades.
+                        </p>
+                        <button id="prestige-btn" class="prestige-btn" disabled>
+                            ✦ Prestige
+                        </button>
+                    </div>
+                    <h3 style="margin-top:15px">Prestige Upgrades</h3>
+                    <div class="prestige-upgrades-header">
+                        <span></span>
+                        <button id="buy-all-prestige" class="buy-all-btn prestige-buy-all" style="display:none" title="Buy every prestige upgrade you can currently afford with Stellar Essence">Buy Max</button>
+                    </div>
+                    <div id="prestige-upgrades-list"></div>
+                </div>
             </aside>
         </div>
 
         <!-- Footer: Controls -->
         <footer id="game-footer">
-            <button id="save-btn">💾 Save</button>
-            <button id="export-btn">📤 Export Save</button>
-            <button id="import-btn">📥 Import Save</button>
-            <button id="reset-btn">🗑️ Reset</button>
+            <div class="footer-section">
+                <span class="footer-label">Slot:</span>
+                <button class="slot-btn" data-slot="0">1</button>
+                <button class="slot-btn" data-slot="1">2</button>
+                <button class="slot-btn" data-slot="2">3</button>
+                <!-- Live one-line preview of the active slot; hover a slot button to preview it -->
+                <span id="slot-preview" class="slot-preview" title="Hover a slot button to preview its contents"></span>
+            </div>
+            <div class="footer-section">
+                <span class="footer-label">Auto:</span>
+                <button id="autosave-btn" class="toggle-btn on">ON</button>
+            </div>
+            <div class="footer-section">
+                <button id="save-btn">💾 Save</button>
+                <button id="export-btn">📤 Export</button>
+                <button id="import-btn">📥 Import</button>
+                <button id="reset-btn">🗑️ Reset</button>
+            </div>
             <span id="last-saved"></span>
         </footer>
     </div>
@@ -86,7 +139,14 @@
     <div id="import-modal" class="modal hidden">
         <div class="modal-content">
             <h3>Import Save</h3>
+            <p class="modal-hint">Paste your save data, then choose which slot to import into.</p>
             <textarea id="import-data" placeholder="Paste your save data here..."></textarea>
+            <div class="import-slot-selector">
+                <span class="import-slot-label">Import into slot:</span>
+                <button class="slot-btn" data-import-slot="0">1</button>
+                <button class="slot-btn" data-import-slot="1">2</button>
+                <button class="slot-btn" data-import-slot="2">3</button>
+            </div>
             <div class="modal-buttons">
                 <button id="confirm-import">Import</button>
                 <button id="cancel-import">Cancel</button>
@@ -104,6 +164,8 @@
     <script src="js/stats.js"></script>
     <script src="js/particles.js"></script>
     <script src="js/audio.js"></script>
+    <script src="js/prestige.js"></script>
+    <script src="js/prestigeUI.js"></script>
     <script src="js/main.js"></script>
 </body>
 </html>
diff --git a/js/achievements.js b/js/achievements.js
index d88279b..552b09a 100644
--- a/js/achievements.js
+++ b/js/achievements.js
@@ -135,7 +135,7 @@ const ACHIEVEMENTS = {
         icon: '💧',
         condition: (state) => Game.getProductionPerSecond() >= 100
     },
-    
+
     rushingRiver: {
         id: 'rushingRiver',
         name: 'Rushing River',
@@ -143,13 +143,122 @@ const ACHIEVEMENTS = {
         icon: '🌊',
         condition: (state) => Game.getProductionPerSecond() >= 1000
     },
-    
+
     cosmicFlood: {
         id: 'cosmicFlood',
         name: 'Cosmic Flood',
         description: 'Reach 100,000 stardust/sec',
         icon: '🌊',
         condition: (state) => Game.getProductionPerSecond() >= 100000
+    },
+
+    // Prestige achievements
+    firstPrestige: {
+        id: 'firstPrestige',
+        name: 'Cosmic Rebirth',
+        description: 'Prestige for the first time',
+        icon: '🌀',
+        condition: (state) => state.prestigeCount >= 1
+    },
+
+    stellarAdaptation: {
+        id: 'stellarAdaptation',
+        name: 'Stellar Adaptation',
+        description: 'Prestige 5 times',
+        icon: '⭐',
+        condition: (state) => state.prestigeCount >= 5
+    },
+
+    cosmicAscension: {
+        id: 'cosmicAscension',
+        name: 'Cosmic Ascension',
+        description: 'Prestige 10 times',
+        icon: '🌟',
+        condition: (state) => state.prestigeCount >= 10
+    },
+
+    eternalGardener: {
+        id: 'eternalGardener',
+        name: 'Eternal Gardener',
+        description: 'Earn 100 total Stellar Essence',
+        icon: '💎',
+        condition: (state) => state.totalPrestigeEssence >= 100
+    },
+
+    quantumGrowth: {
+        id: 'quantumGrowth',
+        name: 'Quantum Growth',
+        description: 'Earn 1,000 total Stellar Essence',
+        icon: '🔮',
+        condition: (state) => state.totalPrestigeEssence >= 1000
+    },
+
+    // Building milestone achievements
+    voidWeaver: {
+        id: 'voidWeaver',
+        name: 'Void Weaver',
+        description: 'Own 25 Void Ferns',
+        icon: '🌿',
+        condition: (state) => (state.buildings.voidFern || 0) >= 25
+    },
+
+    supernovaGrowth: {
+        id: 'supernovaGrowth',
+        name: 'Supernova Growth',
+        description: 'Own 25 Supernova Seeds',
+        icon: '💥',
+        condition: (state) => (state.buildings.supernovaSeed || 0) >= 25
+    },
+
+    // Click power achievements
+    powerfulHarvester: {
+        id: 'powerfulHarvester',
+        name: 'Powerful Harvester',
+        description: 'Reach 1,000 click power',
+        icon: '✋',
+        condition: (state) => Game.getClickPower() >= 1000
+    },
+
+    divineTouch: {
+        id: 'divineTouch',
+        name: 'Divine Touch',
+        description: 'Reach 10,000 click power',
+        icon: '🤚',
+        condition: (state) => Game.getClickPower() >= 10000
+    },
+
+    // Time-based achievement
+    dedicatedGardener: {
+        id: 'dedicatedGardener',
+        name: 'Dedicated Gardener',
+        description: 'Play for 1 hour total',
+        icon: '⏰',
+        condition: (state) => (Date.now() - state.startTime) >= 3600000
+    },
+
+    // Golden Starbloom achievements
+    firstGoldenBloom: {
+        id: 'firstGoldenBloom',
+        name: 'Lucky Bloom',
+        description: 'Claim your first Golden Starbloom',
+        icon: '⭐',
+        condition: (state) => (state.goldenBlooms.totalClaimed || 0) >= 1
+    },
+
+    goldenCollector: {
+        id: 'goldenCollector',
+        name: 'Golden Collector',
+        description: 'Claim 25 Golden Blooms',
+        icon: '🌟',
+        condition: (state) => (state.goldenBlooms.totalClaimed || 0) >= 25
+    },
+
+    goldenEnthusiast: {
+        id: 'goldenEnthusiast',
+        name: 'Golden Enthusiast',
+        description: 'Claim 100 Golden Blooms',
+        icon: '💛',
+        condition: (state) => (state.goldenBlooms.totalClaimed || 0) >= 100
     }
 };
 
diff --git a/js/audio.js b/js/audio.js
index cfaeaf4..a58c4b0 100644
--- a/js/audio.js
+++ b/js/audio.js
@@ -1,119 +1,207 @@
 /**
  * Cosmic Garden - Audio System
- * Web Audio API-based sound generation (no external assets needed)
+ * Sound effects using Web Audio API (no external assets needed)
  */
 
 const Audio = {
     ctx: null,
-    enabled: true,
-    
+
     /**
-     * Initialize audio context (must be called after user interaction)
+     * Initialize audio context
      */
     init() {
         try {
-            window.AudioContext = window.AudioContext || window.webkitAudioContext;
-            this.ctx = new AudioContext();
-            console.log('🔊 Audio system initialized');
+            this.ctx = new (window.AudioContext || window.webkitAudioContext)();
         } catch (e) {
-            console.warn('Web Audio API not supported');
-            this.enabled = false;
+            console.log('Web Audio API not supported');
         }
     },
-    
+
     /**
-     * Resume audio context (for browsers that suspend it)
+     * Resume audio context (needed for some browsers)
      */
     resume() {
         if (this.ctx && this.ctx.state === 'suspended') {
             this.ctx.resume();
         }
     },
-    
+
     /**
-     * Create a simple tone
+     * Play click sound - rising C-major arpeggio
      */
-    playTone(frequency, duration, type = 'sine', volume = 0.1) {
-        if (!this.enabled || !this.ctx) return;
+    playClick() {
+        if (!this.ctx) return;
+        this.resume();
+
+        const now = this.ctx.currentTime;
+        const notes = [523.25, 659.25, 783.99]; // C5, E5, G5
         
+        notes.forEach((freq, i) => {
+            const osc = this.ctx.createOscillator();
+            const gain = this.ctx.createGain();
+            
+            osc.connect(gain);
+            gain.connect(this.ctx.destination);
+            
+            osc.frequency.value = freq;
+            osc.type = 'sine';
+            
+            gain.gain.setValueAtTime(0.1, now + i * 0.05);
+            gain.gain.exponentialRampToValueAtTime(0.01, now + i * 0.05 + 0.15);
+            
+            osc.start(now + i * 0.05);
+            osc.stop(now + i * 0.05 + 0.15);
+        });
+    },
+
+    /**
+     * Play purchase sound - descending chime
+     */
+    playPurchase() {
+        if (!this.ctx) return;
+        this.resume();
+
+        const now = this.ctx.currentTime;
+        const notes = [783.99, 659.25, 523.25]; // G5, E5, C5
+        
+        notes.forEach((freq, i) => {
+            const osc = this.ctx.createOscillator();
+            const gain = this.ctx.createGain();
+            
+            osc.connect(gain);
+            gain.connect(this.ctx.destination);
+            
+            osc.frequency.value = freq;
+            osc.type = 'triangle';
+            
+            gain.gain.setValueAtTime(0.15, now + i * 0.08);
+            gain.gain.exponentialRampToValueAtTime(0.01, now + i * 0.08 + 0.2);
+            
+            osc.start(now + i * 0.08);
+            osc.stop(now + i * 0.08 + 0.2);
+        });
+    },
+
+    /**
+     * Play achievement sound - ascending chord fanfare
+     */
+    playAchievement() {
+        if (!this.ctx) return;
+        this.resume();
+
+        const now = this.ctx.currentTime;
+        const chords = [
+            [523.25, 659.25, 783.99], // C major
+            [659.25, 783.99, 987.77], // E major
+            [783.99, 987.77, 1174.66] // G major
+        ];
+
+        chords.forEach((chord, chordIndex) => {
+            chord.forEach(freq => {
+                const osc = this.ctx.createOscillator();
+                const gain = this.ctx.createGain();
+                
+                osc.connect(gain);
+                gain.connect(this.ctx.destination);
+                
+                osc.frequency.value = freq;
+                osc.type = 'sine';
+                
+                const startTime = now + chordIndex * 0.15;
+                gain.gain.setValueAtTime(0.12, startTime);
+                gain.gain.exponentialRampToValueAtTime(0.01, startTime + 0.3);
+                
+                osc.start(startTime);
+                osc.stop(startTime + 0.3);
+            });
+        });
+    },
+
+    /**
+     * Play prestige sound - ethereal whoosh
+     */
+    playPrestige() {
+        if (!this.ctx) return;
+        this.resume();
+
+        const now = this.ctx.currentTime;
+        
+        // Rising sweep
         const osc = this.ctx.createOscillator();
         const gain = this.ctx.createGain();
         
-        osc.type = type;
-        osc.frequency.setValueAtTime(frequency, this.ctx.currentTime);
-        
-        gain.gain.setValueAtTime(volume, this.ctx.currentTime);
-        gain.gain.exponentialRampToValueAtTime(0.01, this.ctx.currentTime + duration);
-        
         osc.connect(gain);
         gain.connect(this.ctx.destination);
         
-        osc.start(this.ctx.currentTime);
-        osc.stop(this.ctx.currentTime + duration);
-    },
-    
-    /**
-     * Play a rising arpeggio (for clicks)
-     */
-    playClick() {
-        if (!this.enabled) return;
-        this.resume();
+        osc.type = 'sine';
+        osc.frequency.setValueAtTime(200, now);
+        osc.frequency.exponentialRampToValueAtTime(800, now + 0.5);
         
+        gain.gain.setValueAtTime(0.2, now);
+        gain.gain.exponentialRampToValueAtTime(0.01, now + 0.8);
+        
+        osc.start(now);
+        osc.stop(now + 0.8);
+
+        // Sparkle overlay
+        for (let i = 0; i < 5; i++) {
+            const sparkle = this.ctx.createOscillator();
+            const sparkleGain = this.ctx.createGain();
+            
+            sparkle.connect(sparkleGain);
+            sparkleGain.connect(this.ctx.destination);
+            
+            sparkle.frequency.value = 1200 + Math.random() * 800;
+            sparkle.type = 'sine';
+            
+            const startTime = now + 0.1 + i * 0.1;
+            sparkleGain.gain.setValueAtTime(0.08, startTime);
+            sparkleGain.gain.exponentialRampToValueAtTime(0.01, startTime + 0.2);
+            
+            sparkle.start(startTime);
+            sparkle.stop(startTime + 0.2);
+        }
+    },
+
+    /**
+     * Play golden starbloom sound - an ethereal shimmering arpeggio with a
+     * rising sweep, to distinguish it from regular purchase sounds.
+     */
+    playGoldenBloom() {
+        if (!this.ctx) return;
+        this.resume();
+
         const now = this.ctx.currentTime;
-        const notes = [523.25, 659.25, 783.99]; // C major chord
-        
-        notes.forEach((freq, i) => {
-            setTimeout(() => {
-                this.playTone(freq, 0.1, 'sine', 0.08);
-            }, i * 30);
+
+        // Rising magical sweep (like the prestige sound but brighter).
+        const sweep = this.ctx.createOscillator();
+        const sweepGain = this.ctx.createGain();
+        sweep.connect(sweepGain);
+        sweepGain.connect(this.ctx.destination);
+        sweep.type = 'sine';
+        sweep.frequency.setValueAtTime(300, now);
+        sweep.frequency.exponentialRampToValueAtTime(1200, now + 0.6);
+        sweepGain.gain.setValueAtTime(0.18, now);
+        sweepGain.gain.exponentialRampToValueAtTime(0.01, now + 0.7);
+        sweep.start(now);
+        sweep.stop(now + 0.7);
+
+        // A bright, ascending shimmer chord played quickly.
+        const shimmerNotes = [1046.5, 1318.5, 1568.0, 2093.0]; // C5, E5, G5, C6
+        shimmerNotes.forEach((freq, i) => {
+            const osc = this.ctx.createOscillator();
+            const gain = this.ctx.createGain();
+            osc.connect(gain);
+            gain.connect(this.ctx.destination);
+            osc.frequency.value = freq;
+            osc.type = 'triangle';
+            const startTime = now + 0.05 + i * 0.06;
+            gain.gain.setValueAtTime(0.1, startTime);
+            gain.gain.exponentialRampToValueAtTime(0.01, startTime + 0.25);
+            osc.start(startTime);
+            osc.stop(startTime + 0.25);
         });
-    },
-    
-    /**
-     * Play a purchase sound (descending chime)
-     */
-    playPurchase() {
-        if (!this.enabled) return;
-        this.resume();
-        
-        const notes = [783.99, 659.25, 523.25]; // G - E - C
-        
-        notes.forEach((freq, i) => {
-            setTimeout(() => {
-                this.playTone(freq, 0.15, 'triangle', 0.1);
-            }, i * 50);
-        });
-    },
-    
-    /**
-     * Play an achievement unlock fanfare
-     */
-    playAchievement() {
-        if (!this.enabled) return;
-        this.resume();
-        
-        const notes = [523.25, 659.25, 783.99, 1046.50]; // C - E - G - C (high)
-        
-        notes.forEach((freq, i) => {
-            setTimeout(() => {
-                this.playTone(freq, 0.2, 'square', 0.06);
-            }, i * 80);
-        });
-    },
-    
-    /**
-     * Play a notification sound
-     */
-    playNotification() {
-        if (!this.enabled) return;
-        this.resume();
-        
-        this.playTone(880, 0.1, 'sine', 0.08);
-        setTimeout(() => {
-            this.playTone(1100, 0.15, 'sine', 0.08);
-        }, 100);
     }
 };
 
-// Make globally accessible
 window.Audio = Audio;
diff --git a/js/game.js b/js/game.js
index e16b8f0..755d0e8 100644
--- a/js/game.js
+++ b/js/game.js
@@ -14,14 +14,38 @@ const Game = {
         lastSaveTime: Date.now(),
         buildings: {},
         upgrades: [],
-        achievements: []
+        achievements: [],
+        stellarEssence: 0,
+        prestigeCount: 0,
+        totalPrestigeEssence: 0,
+        prestigeUpgrades: [],
+
+        // Save Slot System
+        activeSlot: 0,   // index of the currently selected save slot (0..SLOTS-1)
+        autoSave: true,  // whether the periodic autosave loop is running
+
+        // Golden Starbloom random event state
+        goldenBlooms: {
+            active: false,      // is a bloom currently visible on screen?
+            timer: 0,           // seconds until the bloom vanishes
+            lastSpawn: Date.now(), // ms when we last (re)spawned one
+            totalClaimed: 0     // lifetime count of blooms the player has clicked
+        }
     },
 
     // Configuration
     config: {
         tickRate: 100, // ms per tick (10 ticks/sec)
         autoSaveInterval: 30000, // 30 seconds
-        costScaling: 1.15 // Cost multiplier per building level
+        costScaling: 1.15, // Cost multiplier per building level
+
+        // Save Slot System - number of independent save slots available
+        SLOTS: 3,
+
+        goldenBloomMinMs: 45000, // min ms between bloom spawns (45s)
+        goldenBloomMaxMs: 90000, // max ms between bloom spawns (90s)
+        goldenBloomDuration: 12, // seconds a visible bloom stays before vanishing
+        goldenBloomBonusMult: 15  // production-per-second worth of stardust awarded
     },
 
     /**
@@ -35,6 +59,7 @@ const Game = {
         Audio.init();
         UI.init();
         Stats.init();
+        PrestigeUI.init();
         console.log('🌌 Cosmic Garden initialized!');
     },
 
@@ -42,11 +67,33 @@ const Game = {
      * Setup event listeners
      */
     setupEventListeners() {
-        // Harvest button
-        document.getElementById('harvest-btn').addEventListener('click', (e) => {
+        // Track which slot the user has selected for importing.
+        this.importSlot = 0;
+
+        // Harvest button - support both click and touch
+        const harvestBtn = document.getElementById('harvest-btn');
+
+        harvestBtn.addEventListener('click', (e) => {
             this.harvest(e);
+            this.createRipple(harvestBtn, e);
+            this.animateClickButton(harvestBtn);
         });
 
+        // Touch support for better mobile experience
+        harvestBtn.addEventListener('touchstart', (e) => {
+            e.preventDefault(); // Prevent double-fire with click
+            const touch = e.touches[0];
+            const clickEvent = new MouseEvent('click', {
+                clientX: touch.clientX,
+                clientY: touch.clientY,
+                bubbles: true
+            });
+
+            // Create ripple effect for touch
+            this.createRipple(harvestBtn, { clientX: touch.clientX, clientY: touch.clientY });
+            this.animateClickButton(harvestBtn);
+        }, { passive: false });
+
         // Save buttons
         document.getElementById('save-btn').addEventListener('click', () => {
             this.save();
@@ -64,9 +111,12 @@ const Game = {
         document.getElementById('confirm-import').addEventListener('click', () => {
             const data = document.getElementById('import-data').value;
             if (data) {
-                this.loadFromData(data);
+                const ok = this.importSlotFromData(data, this.importSlot);
                 UI.hideImportModal();
-                UI.showNotification('Save imported!', 'success');
+                if (ok) {
+                    // If the import landed in the active slot, switchSlot already re-rendered.
+                    UI.update();
+                }
             }
         });
 
@@ -74,12 +124,51 @@ const Game = {
             UI.hideImportModal();
         });
 
+        // Buy All upgrades button.
+        const buyAllBtn = document.getElementById('buy-all-upgrades');
+        if (buyAllBtn) {
+            buyAllBtn.addEventListener('click', () => {
+                Game.buyAllUpgrades();
+            });
+        }
+
         document.getElementById('reset-btn').addEventListener('click', () => {
             if (confirm('Are you sure you want to reset all progress? This cannot be undone!')) {
                 this.reset();
             }
         });
 
+        // Save Slot System: slot selection buttons.
+        document.querySelectorAll('.slot-btn').forEach(btn => {
+            btn.addEventListener('click', () => {
+                if (this.state.activeSlot === parseInt(btn.dataset.slot, 10)) {
+                    UI.showNotification(`Already on Slot ${parseInt(btn.dataset.slot, 10) + 1}`, 'info');
+                    return;
+                }
+                if (confirm(`Switch to Slot ${parseInt(btn.dataset.slot, 10) + 1}?\nUnsaved changes will be saved first.`)) {
+                    this.save(); // Persist current slot before switching.
+                    this.switchSlot(parseInt(btn.dataset.slot, 10));
+                }
+            });
+        });
+
+        // Autosave toggle button.
+        document.getElementById('autosave-btn').addEventListener('click', () => {
+            this.state.autoSave = !this.state.autoSave;
+            const btn = document.getElementById('autosave-btn');
+            if (this.state.autoSave) {
+                btn.classList.add('on');
+                btn.textContent = 'ON';
+                UI.showNotification('Autosave enabled', 'success');
+            } else {
+                btn.classList.remove('on');
+                btn.textContent = 'OFF';
+                UI.showNotification('Autosave disabled', 'info');
+            }
+            // Persist the toggle preference immediately.
+            localStorage.setItem('cosmicGardenAutoSave', String(this.state.autoSave));
+        });
+
         // Tab switching
         document.querySelectorAll('.tab-btn').forEach(btn => {
             btn.addEventListener('click', (e) => {
@@ -90,6 +179,14 @@ const Game = {
                 document.getElementById(`${tab}-tab`).classList.add('active');
             });
         });
+
+        // Import slot selector buttons.
+        document.querySelectorAll('[data-import-slot]').forEach(btn => {
+            btn.addEventListener('click', () => {
+                this.importSlot = parseInt(btn.dataset.importSlot, 10);
+                UI.showNotification(`Importing into Slot ${this.importSlot + 1}`, 'info');
+            });
+        });
     },
 
     /**
@@ -131,6 +228,18 @@ const Game = {
             }
         }
         
+        // Apply prestige multipliers
+        const prestigeMultiplier = PRESTIGE.getMultiplier();
+        power *= prestigeMultiplier;
+        
+        // Apply prestige upgrades
+        for (const upgradeId of (this.state.prestigeUpgrades || [])) {
+            const upgrade = PRESTIGE_UPGRADES[upgradeId];
+            if (upgrade && upgrade.effect === 'clickMultiplier') {
+                power *= upgrade.value;
+            }
+        }
+        
         return Math.floor(power);
     },
 
@@ -148,6 +257,22 @@ const Game = {
             
             let production = building.baseProduction * count;
             
+            // Apply prestige multiplier
+            const prestigeMultiplier = PRESTIGE.getMultiplier();
+            production *= prestigeMultiplier;
+            
+            // Apply Golden Starbloom temporary production boost (+50%)
+            if (this.state.productionBoostUntil && this.state.productionBoostUntil > Date.now()) {
+                production *= 1.5;
+            }
+            // Apply prestige upgrades
+            for (const upgradeId of (this.state.prestigeUpgrades || [])) {
+                const upgrade = PRESTIGE_UPGRADES[upgradeId];
+                if (upgrade && upgrade.effect === 'productionMultiplier') {
+                    production *= upgrade.value;
+                }
+            }
+            
             // Apply upgrade bonuses
             for (const upgradeId of this.state.upgrades) {
                 const upgrade = UPGRADES[upgradeId];
@@ -171,11 +296,21 @@ const Game = {
     getBuildingCost(buildingId) {
         const building = BUILDINGS[buildingId];
         const count = this.state.buildings[buildingId] || 0;
-        return Math.floor(building.baseCost * Math.pow(this.config.costScaling, count));
+        let cost = Math.floor(building.baseCost * Math.pow(this.config.costScaling, count));
+        
+        // Apply prestige cost reduction
+        for (const upgradeId of (this.state.prestigeUpgrades || [])) {
+            const upgrade = PRESTIGE_UPGRADES[upgradeId];
+            if (upgrade && upgrade.effect === 'costReduction') {
+                cost *= upgrade.value;
+            }
+        }
+        
+        return Math.floor(cost);
     },
 
     /**
-     * Buy a building
+     * Buy a single building
      */
     buyBuilding(buildingId) {
         const cost = this.getBuildingCost(buildingId);
@@ -203,6 +338,63 @@ const Game = {
         return false;
     },
 
+    /**
+     * Calculate how many of a building the player can currently afford.
+     * Does not modify game state.
+     */
+    getMaxAffordable(buildingId) {
+        const building = BUILDINGS[buildingId];
+        if (!building) return 0;
+
+        let stardust = this.state.stardust;
+        let count = 0;
+        let owned = this.state.buildings[buildingId] || 0;
+
+        while (true) {
+            const cost = Math.floor(building.baseCost * Math.pow(this.config.costScaling, owned + count));
+            if (stardust < cost) break;
+            stardust -= cost;
+            count++;
+        }
+
+        return count;
+    },
+
+    /**
+     * Buy as many of a building as the player can afford at once.
+     * Returns the number purchased.
+     */
+    buyMaxBuilding(buildingId) {
+        const building = BUILDINGS[buildingId];
+        if (!building) return 0;
+
+        let count = 0;
+        while (this.state.stardust >= this.getBuildingCost(buildingId)) {
+            const cost = this.getBuildingCost(buildingId);
+            this.state.stardust -= cost;
+            this.state.buildings[buildingId] = (this.state.buildings[buildingId] || 0) + 1;
+            count++;
+        }
+
+        if (count > 0) {
+            UI.showNotification(`Bought ${count}x ${building.name}!`, 'success');
+
+            // Audio feedback
+            Audio.playPurchase();
+
+            // Particle effect on building purchase
+            const card = document.getElementById(`building-${buildingId}`);
+            if (card) {
+                const rect = card.getBoundingClientRect();
+                Particles.createBuildingEffect(rect.left + rect.width / 2, rect.top + rect.height / 2);
+            }
+
+            UI.update();
+        }
+
+        return count;
+    },
+
     /**
      * Buy an upgrade
      */
@@ -235,6 +427,179 @@ const Game = {
         return false;
     },
 
+    /**
+     * Buy every upgrade the player can currently afford at once.
+     * Returns an object describing what happened: { bought: count, ids: [...] }.
+     * Upgrades are one-time purchases, so we loop until nothing affordable remains.
+     */
+    buyAllUpgrades() {
+        const bought = [];
+        // Loop until a pass buys nothing (each purchase may unlock new affordability).
+        let progress = true;
+        while (progress) {
+            progress = false;
+            for (const [id, upgrade] of Object.entries(UPGRADES)) {
+                if (this.state.upgrades.includes(id)) continue;
+                // Respect requirements before attempting purchase.
+                if (upgrade.requirements) {
+                    let met = true;
+                    for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                        if ((this.state.buildings[reqId] || 0) < reqCount) {
+                            met = false;
+                            break;
+                        }
+                    }
+                    if (!met) continue;
+                }
+                if (this.state.stardust >= upgrade.cost) {
+                    this.state.stardust -= upgrade.cost;
+                    this.state.upgrades.push(id);
+                    bought.push(id);
+                    progress = true; // another purchase may have unlocked more affordability
+                }
+            }
+        }
+
+        if (bought.length > 0) {
+            UI.showNotification(`Bought ${bought.length} upgrade(s)!`, 'success');
+            Audio.playPurchase();
+            UI.update();
+        }
+
+        return { bought: bought.length, ids: bought };
+    },
+
+    /**
+     * Buy every prestige upgrade the player can currently afford at once,
+     * paid from Stellar Essence. Returns an object describing what happened:
+     * { bought: count, ids: [...] }. Prestige upgrades are one-time purchases,
+     * so we loop until a full pass buys nothing (purchasing one never unlocks
+     * another, but the loop is kept for symmetry with buyAllUpgrades and to
+     * stay safe should future prestige upgrades gain requirement gates).
+     */
+    buyMaxPrestigeUpgrades() {
+        const bought = [];
+        let progress = true;
+        while (progress) {
+            progress = false;
+            for (const [id, upgrade] of Object.entries(PRESTIGE_UPGRADES)) {
+                if ((this.state.prestigeUpgrades || []).includes(id)) continue;
+                // Respect requirements before attempting purchase, mirroring
+                // PRESTIGE.buyUpgrade semantics.
+                if (upgrade.requirements) {
+                    let met = true;
+                    for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                        if ((this.state.buildings[reqId] || 0) < reqCount) {
+                            met = false;
+                            break;
+                        }
+                    }
+                    if (!met) continue;
+                }
+                if ((this.state.stellarEssence || 0) >= upgrade.cost) {
+                    this.state.prestigeUpgrades = this.state.prestigeUpgrades || [];
+                    this.state.prestigeUpgrades.push(id);
+                    // Spend Stellar Essence, mirroring PRESTIGE.buyUpgrade.
+                    this.state.stellarEssence -= upgrade.cost;
+                    bought.push(id);
+                    progress = true;
+                }
+            }
+        }
+
+        if (bought.length > 0) {
+            UI.showNotification(`Bought ${bought.length} prestige upgrade(s)!`, 'achievement');
+            Audio.playPurchase();
+            UI.update();
+        }
+
+        return { bought: bought.length, ids: bought };
+    },
+
+    /**
+     * Golden Starbloom - random event system.
+     * A rare, time-limited bloom occasionally appears on screen. Clicking it
+     * awards a stardust bonus and grants a temporary production boost.
+     */
+
+    /**
+     * Seconds remaining until the current bloom vanishes (0 if none active).
+     */
+    getGoldenBloomRemaining() {
+        return this.state.goldenBlooms.active ? Math.ceil(this.state.goldenBlooms.timer) : 0;
+    },
+
+    /**
+     * Award a Golden Starbloom bonus and apply the production multiplier.
+     * Called when the player clicks a visible bloom. Returns the amount earned.
+     */
+    claimGoldenBloom(x, y) {
+        const state = this.state.goldenBlooms;
+
+        // No active bloom - nothing to claim.
+        if (!state.active) return 0;
+
+        state.active = false;
+        state.timer = 0;
+        state.totalClaimed++;
+
+        // Bonus: goldenBloomBonusMult x current production per second (min 1).
+        const bonus = Math.max(1, Math.floor(this.getProductionPerSecond() * this.config.goldenBloomBonusMult));
+        this.addStardust(bonus);
+
+        // Temporary production boost: +50% for 30 seconds.
+        this.state.productionBoostUntil = Date.now() + 30000;
+
+        UI.showNotification('⭐ Golden Starbloom! +' + this.formatNumber(bonus) + ' ✨', 'achievement');
+        Audio.playGoldenBloom();
+        Particles.createGoldenEffect(x, y);
+        UI.update();
+        return bonus;
+    },
+
+    /**
+     * Update golden bloom scheduling on each tick.
+     * Spawns a new bloom if none is active and enough time has elapsed;
+     * decrements the countdown of an active bloom until it vanishes.
+     */
+    updateGoldenBloom(dtSeconds) {
+        const state = this.state.goldenBlooms;
+
+        // If a bloom is still on screen, count down its lifetime.
+        if (state.active) {
+            state.timer -= dtSeconds;
+            if (state.timer <= 0) {
+                state.active = false;
+                state.timer = 0;
+            }
+            return;
+        }
+
+        // Otherwise, check whether it is time to spawn the next bloom.
+        const elapsed = Date.now() - state.lastSpawn;
+        const minMs = this.config.goldenBloomMinMs;
+        const maxMs = this.config.goldenBloomMaxMs;
+        if (elapsed >= minMs) {
+            // Wait until somewhere in [min, max] before spawning.
+            if (elapsed >= maxMs || Math.random() < 0.05) {
+                state.active = true;
+                state.timer = this.config.goldenBloomDuration;
+                state.lastSpawn = Date.now();
+                UI.spawnGoldenBloom();
+            }
+        }
+    },
+
+    /**
+     * Whether the temporary production boost is currently active, and how
+     * many seconds remain.
+     */
+    getProductionBoostInfo() {
+        const until = this.state.productionBoostUntil || 0;
+        if (until <= Date.now()) return { active: false, remaining: 0 };
+        return { active: true, remaining: Math.ceil((until - Date.now()) / 1000) };
+    },
+
     /**
      * Game tick - called every config.tickRate ms
      */
@@ -246,6 +611,9 @@ const Game = {
             this.addStardust(production * tickSeconds);
         }
         
+        // Advance the Golden Starbloom random event clock.
+        this.updateGoldenBloom(tickSeconds);
+        
         UI.update();
         Achievements.check();
     },
@@ -262,6 +630,8 @@ const Game = {
      */
     startAutoSave() {
         setInterval(() => {
+            // Only autosave when the player has enabled it (default on).
+            if (!this.state.autoSave) return;
             this.save();
             document.getElementById('last-saved').textContent = 
                 `Last saved: ${new Date().toLocaleTimeString()}`;
@@ -269,28 +639,59 @@ const Game = {
     },
 
     /**
-     * Save game state
+     * localStorage key for a given slot's save data.
+     */
+    getSaveKey(slot) {
+        return `cosmicGardenSave-${slot}`;
+    },
+
+    /**
+     * The key holding the selected slot index across page loads.
+     */
+    getActiveSlotKey() {
+        return 'cosmicGardenActiveSlot';
+    },
+
+    /**
+     * Save game state to the currently active slot.
      */
     save() {
         this.state.lastSaveTime = Date.now();
-        localStorage.setItem('cosmicGardenSave', JSON.stringify(this.state));
+        localStorage.setItem(this.getSaveKey(this.state.activeSlot), JSON.stringify(this.state));
     },
 
     /**
      * Load game state
      */
     loadState() {
-        const saved = localStorage.getItem('cosmicGardenSave');
+        // Restore the persisted selected-slot index before reading its data.
+        const persistedSlot = localStorage.getItem(this.getActiveSlotKey());
+        if (persistedSlot !== null) {
+            this.state.activeSlot = parseInt(persistedSlot, 10) || 0;
+        }
+
+        const saved = localStorage.getItem(this.getSaveKey(this.state.activeSlot));
         if (saved) {
             try {
                 const parsed = JSON.parse(saved);
                 this.state = { ...this.state, ...parsed };
+                // The explicitly-persisted slot selection always wins.
+                if (persistedSlot !== null) {
+                    this.state.activeSlot = parseInt(persistedSlot, 10) || 0;
+                }
                 
                 // Calculate offline progress
                 const offlineTime = (Date.now() - this.state.lastSaveTime) / 1000;
                 if (offlineTime > 60) {
                     const production = this.getProductionPerSecond();
-                    const offlineEarnings = production * offlineTime * 0.5; // 50% offline efficiency
+                    let offlineRate = 0.5; // 50% offline efficiency
+                    for (const upgradeId of (this.state.prestigeUpgrades || [])) {
+                        const upgrade = PRESTIGE_UPGRADES[upgradeId];
+                        if (upgrade && upgrade.effect === 'offlineBonus') {
+                            offlineRate = upgrade.value;
+                        }
+                    }
+                    const offlineEarnings = production * offlineTime * offlineRate;
                     if (offlineEarnings > 0) {
                         this.addStardust(offlineEarnings);
                         UI.showNotification(
@@ -318,6 +719,196 @@ const Game = {
         }
     },
 
+    /**
+     * Load the data stored in a specific slot index (without changing it).
+     * Returns the parsed state, or null if that slot is empty.
+     */
+    loadSlot(slot) {
+        const raw = localStorage.getItem(this.getSaveKey(slot));
+        if (!raw) return null;
+        try {
+            return JSON.parse(raw);
+        } catch (e) {
+            console.error(`Failed to read slot ${slot}:`, e);
+            return null;
+        }
+    },
+
+    /**
+     * Build a lightweight preview of a given save slot WITHOUT mutating the
+     * live game state. Returns an object describing what that slot holds:
+     *   - present: whether the slot has any saved data
+     *   - stardust: current (live) stardust production/sec for the slot
+     *   - totalStardust: lifetime stardust earned in the slot
+     *   - buildings: total number of buildings owned in the slot
+     *   - achievements: count/total of achievements unlocked in the slot
+     *   - prestigeCount: how many times the slot has been prestiged
+     *   - lastSaved: human-readable "time ago" string for the slot's save time
+     * An empty/unreadable slot returns present:false with zeroed fields.
+     */
+    getSlotPreview(slot) {
+        const data = this.loadSlot(slot);
+        if (!data) {
+            return {
+                present: false,
+                stardust: 0,
+                totalStardust: 0,
+                buildings: 0,
+                achievements: [0, 33],
+                prestigeCount: 0,
+                lastSaved: 'never'
+            };
+        }
+
+        const buildingCount = Object.values(data.buildings || {})
+            .reduce((sum, c) => sum + (Number(c) || 0), 0);
+
+        let timeAgo = 'never';
+        if (typeof data.lastSaveTime === 'number') {
+            const secs = Math.max(0, Math.floor((Date.now() - data.lastSaveTime) / 1000));
+            timeAgo = this.formatTimeAgo(secs);
+        }
+
+        return {
+            present: true,
+            stardust: Number(data.stardust) || 0,
+            totalStardust: Number(data.totalStardust) || 0,
+            buildings: buildingCount,
+            achievements: [
+                Array.isArray(data.achievements) ? data.achievements.length : 0,
+                33
+            ],
+            prestigeCount: Number(data.prestigeCount) || 0,
+            lastSaved: timeAgo
+        };
+    },
+
+    /**
+     * Format a number of seconds as a compact "time ago" string
+     * (e.g. "just now", "1m ago", "3h ago", "2d ago"). Used by slot previews.
+     */
+    formatTimeAgo(secs) {
+        if (secs < 5) return 'just now';
+
+        // Largest units first; each entry is [thresholdSeconds, label].
+        const buckets = [
+            [365 * 86400, 'y'],
+            [30 * 86400, 'mo'],
+            [86400, 'd'],
+            [3600, 'h'],
+            [60, 'm']
+        ];
+
+        for (const [threshold, label] of buckets) {
+            if (secs >= threshold) {
+                const value = Math.floor(secs / threshold);
+                return `${value}${label} ago`;
+            }
+        }
+
+        // Below one minute.
+        return `${Math.max(1, secs)}s ago`;
+    },
+
+    /**
+     * Switch the active save slot. Persists the selection and reloads that
+     * slot's data from localStorage into the live game state, preserving
+     * prestige-related counters that should carry across slots only when
+     * present in the target slot.
+     */
+    switchSlot(slot) {
+        slot = ((parseInt(slot, 10) || 0) + this.config.SLOTS) % this.config.SLOTS;
+
+        // Persist the selection first so loadState() reads it back.
+        localStorage.setItem(this.getActiveSlotKey(), String(slot));
+        this.state.activeSlot = slot;
+
+        const data = this.loadSlot(slot);
+        if (data) {
+            try {
+                const parsed = JSON.parse(JSON.stringify(data));
+                this.state = { ...this.state, ...parsed };
+                // Ensure the slot index stays consistent.
+                this.state.activeSlot = slot;
+
+                UI.showNotification(
+                    `Saved to Slot ${slot + 1}!`, 'success'
+                );
+            } catch (e) {
+                console.error('Failed to load selected slot:', e);
+                UI.showNotification('Could not load that slot!', 'warning');
+            }
+        } else {
+            // Target slot is empty: reset to a fresh start but keep essence.
+            this.state = {
+                stardust: 0,
+                totalStardust: 0,
+                totalClicks: 0,
+                clickPower: 1,
+                startTime: Date.now(),
+                lastSaveTime: Date.now(),
+                buildings: {},
+                upgrades: [],
+                achievements: [],
+                stellarEssence: this.state.stellarEssence || 0,
+                prestigeCount: this.state.prestigeCount || 0,
+                totalPrestigeEssence: this.state.totalPrestigeEssence || 0,
+                prestigeUpgrades: this.state.prestigeUpgrades || [],
+                goldenBlooms: { active: false, timer: 0, lastSpawn: Date.now(), totalClaimed: 0 },
+                // Reset the temporary golden-bloom production boost so a boost
+                // from a previous slot cannot leak into a fresh slot.
+                productionBoostUntil: 0,
+                activeSlot: slot,
+                autoSave: this.state.autoSave
+            };
+            UI.showNotification(
+                `Empty Slot ${slot + 1} - new game started!`, 'success'
+            );
+        }
+
+        // Re-render dynamic UI and refresh the golden-bloom badge.
+        UI.init();
+        UI.update();
+    },
+
+    /**
+     * Export a single slot's save as base64 (for backup or transfer).
+     */
+    exportSlotToBase64(slot) {
+        const data = this.loadSlot(slot);
+        if (!data) {
+            UI.showNotification(`Slot ${slot + 1} is empty!`, 'warning');
+            return null;
+        }
+        const encoded = btoa(JSON.stringify(data));
+        navigator.clipboard.writeText(encoded).then(() => {
+            UI.showNotification(`Slot ${slot + 1} copied to clipboard!`, 'success');
+        });
+        return encoded;
+    },
+
+    /**
+     * Import base64 save data into a chosen slot.
+     */
+    importSlotFromData(data, slot) {
+        try {
+            const parsed = JSON.parse(atob(data));
+            localStorage.setItem(this.getSaveKey(slot), JSON.stringify(parsed));
+            UI.showNotification(`Imported into Slot ${slot + 1}!`, 'success');
+
+            // If we imported into the active slot, reload it.
+            if (parseInt(slot, 10) === this.state.activeSlot) {
+                this.switchSlot(slot);
+            } else {
+                UI.update();
+            }
+            return true;
+        } catch (e) {
+            UI.showNotification('Invalid save data!', 'warning');
+            return false;
+        }
+    },
+
     /**
      * Export save as base64
      */
@@ -343,7 +934,14 @@ const Game = {
             lastSaveTime: Date.now(),
             buildings: {},
             upgrades: [],
-            achievements: []
+            achievements: [],
+            stellarEssence: 0,
+            prestigeCount: 0,
+            totalPrestigeEssence: 0,
+            prestigeUpgrades: [],
+            goldenBlooms: { active: false, timer: 0, lastSpawn: Date.now(), totalClaimed: 0 },
+            activeSlot: this.state.activeSlot,
+            autoSave: this.state.autoSave
         };
         UI.update();
         UI.showNotification('Game reset!', 'warning');
@@ -358,6 +956,34 @@ const Game = {
         if (num >= 1e6) return (num / 1e6).toFixed(2) + 'M';
         if (num >= 1e3) return (num / 1e3).toFixed(2) + 'K';
         return Math.floor(num).toLocaleString();
+    },
+
+    /**
+     * Create ripple effect on button click
+     */
+    createRipple(button, event) {
+        const ripple = document.createElement('span');
+        ripple.className = 'ripple';
+
+        const rect = button.getBoundingClientRect();
+        const size = Math.max(rect.width, rect.height);
+        const x = event.clientX - rect.left - size / 2;
+        const y = event.clientY - rect.top - size / 2;
+
+        ripple.style.width = ripple.style.height = `${size}px`;
+        ripple.style.left = `${x}px`;
+        ripple.style.top = `${y}px`;
+
+        button.appendChild(ripple);
+        setTimeout(() => ripple.remove(), 600);
+    },
+
+    /**
+     * Animate click button with glow effect
+     */
+    animateClickButton(button) {
+        button.classList.add('clicked');
+        setTimeout(() => button.classList.remove('clicked'), 200);
     }
 };
 
diff --git a/js/particles.js b/js/particles.js
index a46a68a..602285d 100644
--- a/js/particles.js
+++ b/js/particles.js
@@ -177,7 +177,179 @@ const Particles = {
             
             document.getElementById('game-container').appendChild(star);
         }
-    }
+    },
+    /**
+     * Create prestige reset effect - cosmic explosion
+     */
+    createPrestigeEffect(x, y) {
+        const colors = ['#ffd700', '#9b59b6', '#3498db', '#ffffff', '#e74c3c'];
+        
+        // Outer ring burst
+        for (let i = 0; i < 30; i++) {
+            const particle = document.createElement('div');
+            particle.className = 'particle prestige-particle';
+            
+            const angle = (Math.PI * 2 * i) / 30;
+            const velocity = 100 + Math.random() * 80;
+            const size = 10 + Math.random() * 15;
+            const color = colors[Math.floor(Math.random() * colors.length)];
+            
+            particle.style.cssText = `
+                left: ${x}px;
+                top: ${y}px;
+                width: ${size}px;
+                height: ${size}px;
+                background: ${color};
+                border-radius: 50%;
+                pointer-events: none;
+                position: fixed;
+                z-index: 998;
+                box-shadow: 0 0 15px ${color}, 0 0 30px ${color};
+            `;
+            
+            document.body.appendChild(particle);
+            
+            const animation = particle.animate([
+                { 
+                    transform: 'translate(-50%, -50%) scale(1)', 
+                    opacity: 1 
+                },
+                { 
+                    transform: `translate(calc(-50% + ${Math.cos(angle) * velocity}px), calc(-50% + ${Math.sin(angle) * velocity}px)) scale(1.5)`, 
+                    opacity: 0.8 
+                },
+                { 
+                    transform: `translate(calc(-50% + ${Math.cos(angle) * velocity * 2}px), calc(-50% + ${Math.sin(angle) * velocity * 2}px)) scale(0)`, 
+                    opacity: 0 
+                }
+            ], {
+                duration: 1500,
+                easing: 'cubic-bezier(0.25, 0.46, 0.45, 0.94)'
+            });
+            
+            animation.onfinish = () => particle.remove();
+        }
+        
+        // Inner sparkle burst
+        for (let i = 0; i < 15; i++) {
+            const sparkle = document.createElement('div');
+            sparkle.className = 'particle';
+            
+            const angle = Math.random() * Math.PI * 2;
+            const velocity = 50 + Math.random() * 50;
+            const size = 4 + Math.random() * 6;
+            
+            sparkle.style.cssText = `
+                left: ${x}px;
+                top: ${y}px;
+                width: ${size}px;
+                height: ${size}px;
+                background: #ffd700;
+                border-radius: 50%;
+                pointer-events: none;
+                position: fixed;
+                z-index: 998;
+                box-shadow: 0 0 10px #ffd700;
+            `;
+            
+            document.body.appendChild(sparkle);
+            
+            const animation = sparkle.animate([
+                { 
+                    transform: 'translate(-50%, -50%) scale(1)', 
+                    opacity: 1 
+                },
+                { 
+                    transform: `translate(calc(-50% + ${Math.cos(angle) * velocity}px), calc(-50% + ${Math.sin(angle) * velocity}px)) scale(0)`, 
+                    opacity: 0 
+                }
+            ], {
+                duration: 800,
+                easing: 'ease-out'
+            });
+            
+            animation.onfinish = () => sparkle.remove();
+        }
+    },
+
+    /**
+     * Create a Golden Starbloom burst - a shimmering golden explosion.
+     */
+    createGoldenEffect(x, y) {
+        const colors = ['#ffd700', '#ffe469', '#fff2a8', '#ffcf3f', '#ffffff'];
+
+        // Outer ring of glowing golden particles
+        for (let i = 0; i < 24; i++) {
+            const particle = document.createElement('div');
+            particle.className = 'particle golden-bloom-particle';
+
+            const angle = (Math.PI * 2 * i) / 24;
+            const velocity = 90 + Math.random() * 70;
+            const size = 8 + Math.random() * 10;
+            const color = colors[Math.floor(Math.random() * colors.length)];
+
+            particle.style.cssText = `
+                left: ${x}px;
+                top: ${y}px;
+                width: ${size}px;
+                height: ${size}px;
+                background: ${color};
+                border-radius: 50%;
+                pointer-events: none;
+                position: fixed;
+                z-index: 998;
+                box-shadow: 0 0 12px ${color}, 0 0 24px #ffd700;
+            `;
+
+            document.body.appendChild(particle);
+
+            const animation = particle.animate([
+                { transform: 'translate(-50%, -50%) scale(1)', opacity: 1 },
+                { transform: `translate(calc(-50% + ${Math.cos(angle) * velocity}px), calc(-50% + ${Math.sin(angle) * velocity}px)) scale(1.3)`, opacity: 0.85 },
+                { transform: `translate(calc(-50% + ${Math.cos(angle) * velocity * 2}px), calc(-50% + ${Math.sin(angle) * velocity * 2}px)) scale(0)`, opacity: 0 }
+            ], {
+                duration: 1200,
+                easing: 'cubic-bezier(0.25, 0.46, 0.45, 0.94)'
+            });
+
+            animation.onfinish = () => particle.remove();
+        }
+
+        // Golden sparkle burst
+        for (let i = 0; i < 12; i++) {
+            const sparkle = document.createElement('div');
+            sparkle.className = 'particle golden-sparkle';
+
+            const angle = Math.random() * Math.PI * 2;
+            const velocity = 40 + Math.random() * 50;
+            const size = 3 + Math.random() * 4;
+
+            sparkle.style.cssText = `
+                left: ${x}px;
+                top: ${y}px;
+                width: ${size}px;
+                height: ${size}px;
+                background: #fff2a8;
+                border-radius: 50%;
+                pointer-events: none;
+                position: fixed;
+                z-index: 999;
+                box-shadow: 0 0 10px #ffd700;
+            `;
+
+            document.body.appendChild(sparkle);
+
+            const animation = sparkle.animate([
+                { transform: 'translate(-50%, -50%) scale(1)', opacity: 1 },
+                { transform: `translate(calc(-50% + ${Math.cos(angle) * velocity}px), calc(-50% + ${Math.sin(angle) * velocity}px)) scale(0)`, opacity: 0 }
+            ], {
+                duration: 700,
+                easing: 'ease-out'
+            });
+
+            animation.onfinish = () => sparkle.remove();
+        }
+    },
 };
 
 // Make globally accessible
diff --git a/js/prestige.js b/js/prestige.js
new file mode 100644
index 0000000..9890b61
--- /dev/null
+++ b/js/prestige.js
@@ -0,0 +1,184 @@
+/**
+ * Cosmic Garden - Prestige System
+ * Allows resetting progress for permanent Stellar Essence bonuses
+ */
+
+const PRESTIGE = {
+    /**
+     * Calculate Stellar Essence earned from prestiging
+     * Formula: floor(sqrt(totalStardust / 1,000,000))
+     */
+    calculateEssence() {
+        const totalStardust = Game.state.totalStardust || 0;
+        return Math.floor(Math.sqrt(totalStardust / 1e6));
+    },
+
+    /**
+     * Get the current prestige multiplier from essence
+     * Each essence provides +10% production bonus
+     */
+    getMultiplier() {
+        const essence = Game.state.stellarEssence || 0;
+        return 1 + (essence * 0.1);
+    },
+
+    /**
+     * Perform the prestige reset
+     */
+    prestige() {
+        const essenceGain = this.calculateEssence();
+        
+        if (essenceGain <= 0) {
+            UI.showNotification('Need more stardust to prestige!', 'warning');
+            return false;
+        }
+
+        // Reset game state but keep essence and prestige count
+        const previousPrestigeCount = Game.state.prestigeCount || 0;
+        const previousEssence = Game.state.stellarEssence || 0;
+        const newEssence = previousEssence + essenceGain;
+
+        Game.state = {
+            stardust: 0,
+            totalStardust: 0,
+            totalClicks: 0,
+            clickPower: 1,
+            startTime: Date.now(),
+            lastSaveTime: Date.now(),
+            buildings: {},
+            upgrades: [],
+            achievements: [],
+            stellarEssence: newEssence,
+            prestigeCount: previousPrestigeCount + 1,
+            totalPrestigeEssence: (Game.state.totalPrestigeEssence || 0) + essenceGain,
+            prestigeUpgrades: Game.state.prestigeUpgrades || []
+        };
+
+        // Audio feedback
+        Audio.playPrestige();
+
+        // Particle effect for prestige
+        const btn = document.getElementById('prestige-btn');
+        if (btn) {
+            const rect = btn.getBoundingClientRect();
+            Particles.createPrestigeEffect(rect.left + rect.width / 2, rect.top + rect.height / 2);
+        }
+
+        UI.showNotification(
+            `✦ Prestige! Earned ${essenceGain} Stellar Essence! (${newEssence} total)`,
+            'achievement'
+        );
+
+        UI.update();
+        return true;
+    },
+
+    /**
+     * Buy a prestige upgrade
+     */
+    buyUpgrade(upgradeId) {
+        const upgrade = PRESTIGE_UPGRADES[upgradeId];
+        if (!upgrade || Game.state.prestigeUpgrades?.includes(upgradeId)) {
+            return false;
+        }
+
+        if (Game.state.stellarEssence >= upgrade.cost) {
+            Game.state.stellarEssence -= upgrade.cost;
+            Game.state.prestigeUpgrades = Game.state.prestigeUpgrades || [];
+            Game.state.prestigeUpgrades.push(upgradeId);
+
+            UI.showNotification(`Unlocked: ${upgrade.name}!`, 'achievement');
+            Audio.playPurchase();
+            UI.update();
+            return true;
+        }
+
+        return false;
+    },
+
+    /**
+     * Get the effective click power with prestige bonus
+     */
+    getEffectiveClickPower() {
+        const basePower = Game.getClickPower();
+        const multiplier = this.getMultiplier();
+        return Math.floor(basePower * multiplier);
+    },
+
+    /**
+     * Get the effective production per second with prestige bonus
+     */
+    getEffectiveProductionPerSecond() {
+        const baseProduction = Game.getProductionPerSecond();
+        const multiplier = this.getMultiplier();
+        return baseProduction * multiplier;
+    }
+};
+
+/**
+ * Prestige Upgrades - Permanent bonuses purchased with Stellar Essence
+ */
+const PRESTIGE_UPGRADES = {
+    cosmicFingers: {
+        id: 'cosmicFingers',
+        name: 'Cosmic Fingers',
+        description: 'Click power x2 (permanent)',
+        icon: '👆',
+        cost: 10,
+        effect: 'clickMultiplier',
+        value: 2
+    },
+
+    stellarTouch: {
+        id: 'stellarTouch',
+        name: 'Stellar Touch',
+        description: 'Click power x3 (permanent)',
+        icon: '✨',
+        cost: 50,
+        effect: 'clickMultiplier',
+        value: 3
+    },
+
+    essenceAmplifier: {
+        id: 'essenceAmplifier',
+        name: 'Essence Amplifier',
+        description: 'All production x1.5 (permanent)',
+        icon: '💎',
+        cost: 25,
+        effect: 'productionMultiplier',
+        value: 1.5
+    },
+
+    quantumGarden: {
+        id: 'quantumGarden',
+        name: 'Quantum Garden',
+        description: 'All production x2 (permanent)',
+        icon: '🌌',
+        cost: 100,
+        effect: 'productionMultiplier',
+        value: 2
+    },
+
+    acceleratedGrowth: {
+        id: 'acceleratedGrowth',
+        name: 'Accelerated Growth',
+        description: 'Buildings cost 10% less (permanent)',
+        icon: '📉',
+        cost: 75,
+        effect: 'costReduction',
+        value: 0.9
+    },
+
+    temporalManipulation: {
+        id: 'temporalManipulation',
+        name: 'Temporal Manipulation',
+        description: 'Offline earnings 75% (was 50%)',
+        icon: '⏰',
+        cost: 200,
+        effect: 'offlineBonus',
+        value: 0.75
+    }
+};
+
+window.PRESTIGE = PRESTIGE;
+window.PRESTIGE_UPGRADES = PRESTIGE_UPGRADES;
diff --git a/js/prestigeUI.js b/js/prestigeUI.js
new file mode 100644
index 0000000..e1bd7d9
--- /dev/null
+++ b/js/prestigeUI.js
@@ -0,0 +1,171 @@
+/**
+ * Cosmic Garden - Prestige UI Manager
+ * Handles all prestige-related UI rendering and interactions
+ */
+
+const PrestigeUI = {
+    /**
+     * Initialize the prestige UI
+     */
+    init() {
+        this.renderPrestigeUpgrades();
+        this.setupEventListeners();
+        this.update();
+    },
+
+    /**
+     * Setup event listeners
+     */
+    setupEventListeners() {
+        // Prestige button
+        document.getElementById('prestige-btn')?.addEventListener('click', () => {
+            const essenceGain = PRESTIGE.calculateEssence();
+            
+            if (essenceGain > 0) {
+                if (confirm(
+                    `Prestige now to earn ${essenceGain} Stellar Essence?\n\n` +
+                    `You will keep your prestige upgrades and essence.\n` +
+                    `All buildings, upgrades, and stardust will be reset.`
+                )) {
+                    PRESTIGE.prestige();
+                }
+            } else {
+                UI.showNotification('Need more stardust to prestige!', 'warning');
+            }
+        });
+
+        // Tab switching for prestige tab
+        document.querySelectorAll('.tab-btn').forEach(btn => {
+            btn.addEventListener('click', (e) => {
+                const tab = e.target.dataset.tab;
+                if (tab === 'prestige') {
+                    this.renderPrestigeUpgrades();
+                }
+            });
+        });
+
+        // Buy Max prestige upgrades button - buy every affordable prestige
+        // upgrade at once, paid from Stellar Essence.
+        const buyMaxBtn = document.getElementById('buy-all-prestige');
+        if (buyMaxBtn) {
+            buyMaxBtn.addEventListener('click', () => {
+                Game.buyMaxPrestigeUpgrades();
+            });
+        }
+    },
+
+    /**
+     * Render prestige upgrade cards
+     */
+    renderPrestigeUpgrades() {
+        const container = document.getElementById('prestige-upgrades-list');
+        if (!container) return;
+
+        container.innerHTML = '';
+
+        for (const [id, upgrade] of Object.entries(PRESTIGE_UPGRADES)) {
+            const card = document.createElement('div');
+            card.className = 'prestige-upgrade-card';
+            card.id = `prestige-upgrade-${id}`;
+
+            const purchased = Game.state.prestigeUpgrades?.includes(id);
+            const canAfford = (Game.state.stellarEssence || 0) >= upgrade.cost;
+
+            card.classList.toggle('purchased', purchased);
+            card.classList.toggle('locked', !purchased && !canAfford);
+
+            card.innerHTML = `
+                <div class=\"prestige-upgrade-name\">${upgrade.icon} ${upgrade.name}</div>
+                <div class=\"prestige-upgrade-desc\">${upgrade.description}</div>
+                <div class=\"prestige-upgrade-cost\">${purchased ? '✓ Owned' : `${upgrade.cost} ✦`}</div>
+            `;
+
+            if (!purchased && canAfford) {
+                card.addEventListener('click', () => {
+                    PRESTIGE.buyUpgrade(id);
+                });
+            }
+
+            container.appendChild(card);
+        }
+    },
+
+    /**
+     * Update prestige display
+     */
+    update() {
+        // Essence count
+        const essenceEl = document.getElementById('prestige-essence-count');
+        if (essenceEl) {
+            essenceEl.textContent = Game.state.stellarEssence || 0;
+        }
+
+        // Multiplier display
+        const multiplierEl = document.getElementById('prestige-multiplier');
+        if (multiplierEl) {
+            const multiplier = PRESTIGE.getMultiplier();
+            const percent = Math.round((multiplier - 1) * 100);
+            multiplierEl.textContent = `+${percent}%`;
+        }
+
+        // Next prestige essence
+        const nextEl = document.getElementById('prestige-next-essence');
+        if (nextEl) {
+            const nextEssence = PRESTIGE.calculateEssence();
+            nextEl.textContent = nextEssence;
+        }
+
+        // Update prestige button state
+        const prestigeBtn = document.getElementById('prestige-btn');
+        if (prestigeBtn) {
+            const canPrestige = PRESTIGE.calculateEssence() > 0;
+            prestigeBtn.disabled = !canPrestige;
+            prestigeBtn.classList.toggle('can-prestige', canPrestige);
+        }
+
+        // Update prestige upgrades list if visible
+        const prestigeTab = document.getElementById('prestige-tab');
+        if (prestigeTab?.classList.contains('active')) {
+            this.renderPrestigeUpgrades();
+        }
+
+        // Show/hide the "Buy Max" button based on whether any unowned prestige
+        // upgrade is currently affordable with Stellar Essence. Read-only.
+        this.updateBuyMaxPrestigeButton();
+    },
+
+    /**
+     * Show/hide and enable/disable the "Buy Max" prestige-upgrades button
+     * depending on whether at least one unowned, requirement-met prestige
+     * upgrade is currently affordable with Stellar Essence. Read of game state
+     * only; never mutates it. Mirrors Game.buyMaxPrestigeUpgrades /
+     * PRESTIGE.buyUpgrade semantics.
+     */
+    updateBuyMaxPrestigeButton() {
+        const btn = document.getElementById('buy-all-prestige');
+        if (!btn) return;
+
+        let affordableAny = false;
+        for (const [id, upgrade] of Object.entries(PRESTIGE_UPGRADES)) {
+            if ((Game.state.prestigeUpgrades || []).includes(id)) continue;
+            if ((Game.state.stellarEssence || 0) < upgrade.cost) continue;
+            if (upgrade.requirements) {
+                let met = true;
+                for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                    if ((Game.state.buildings[reqId] || 0) < reqCount) {
+                        met = false;
+                        break;
+                    }
+                }
+                if (!met) continue;
+            }
+            affordableAny = true;
+            break;
+        }
+
+        btn.style.display = affordableAny ? '' : 'none';
+        btn.disabled = !affordableAny;
+    },
+};
+
+window.PrestigeUI = PrestigeUI;
diff --git a/js/stats.js b/js/stats.js
index 8bcb340..2c29b89 100644
--- a/js/stats.js
+++ b/js/stats.js
@@ -17,7 +17,7 @@ const Stats = {
     render() {
         const container = document.getElementById('stats-content');
         if (!container) return;
-        
+
         container.innerHTML = `
             <div class="stat-item">
                 <div class="stat-label">Total Stardust Earned</div>
@@ -51,12 +51,40 @@ const Stats = {
                 <div class="stat-label">Achievements Unlocked</div>
                 <div class="stat-value" id="stat-achievements">0/${Object.keys(ACHIEVEMENTS).length}</div>
             </div>
+            <div class="stat-item">
+                <div class="stat-label">Total Golden Blooms Claimed</div>
+                <div class="stat-value" id="stat-golden-blooms">0</div>
+            </div>
+            <div class="stat-item">
+                <div class="stat-label">Production Boost</div>
+                <div class="stat-value" id="stat-production-boost">Inactive</div>
+                <div class="stat-bar">
+                    <div class="stat-bar-fill" id="stat-boost-progress" style="width: 0%"></div>
+                </div>
+            </div>
+            <div class="stat-item">
+                <div class="stat-label">Next Achievement</div>
+                <div id="stat-next-achievement" style="font-size:0.85rem; color:var(--text-secondary); margin-top:4px">Loading...</div>
+                <div class="stat-bar">
+                    <div class="stat-bar-fill" id="stat-achievement-progress" style="width: 0%"></div>
+                </div>
+            </div>
             <div class="stat-item">
                 <div class="stat-label">Game Progress</div>
                 <div class="stat-bar">
                     <div class="stat-bar-fill" id="stat-progress-bar" style="width: 0%"></div>
                 </div>
             </div>
+
+            <!-- Save Slot System -->
+            <div class="stat-item">
+                <div class="stat-label">Active Save Slot</div>
+                <div class="stat-value" id="stat-active-slot">Slot 1 / ${Game.config.SLOTS}</div>
+            </div>
+            <div class="stat-item">
+                <div class="stat-label">Autosave</div>
+                <div class="stat-value" id="stat-autosave">ON</div>
+            </div>
         `;
     },
 
@@ -114,12 +142,171 @@ const Stats = {
             achievementsEl.textContent = `${Achievements.getCount()}/${Achievements.getTotal()}`;
         }
 
+        // Active save slot display
+        const activeSlotEl = document.getElementById('stat-active-slot');
+        if (activeSlotEl) {
+            const idx = Game.state.activeSlot || 0;
+            activeSlotEl.textContent = `Slot ${idx + 1} / ${Game.config.SLOTS}`;
+        }
+
+        // Autosave status display
+        const autosaveEl = document.getElementById('stat-autosave');
+        if (autosaveEl) {
+            autosaveEl.textContent = Game.state.autoSave ? 'ON' : 'OFF';
+            autosaveEl.style.color = Game.state.autoSave ? 'var(--accent-green)' : 'var(--text-muted)';
+        }
+
+        // Total Golden Blooms claimed
+        const goldenBloomsEl = document.getElementById('stat-golden-blooms');
+        if (goldenBloomsEl) {
+            goldenBloomsEl.textContent = Game.state.goldenBlooms.totalClaimed || 0;
+        }
+
+        // Production boost status + progress bar
+        const boostInfo = Game.getProductionBoostInfo();
+        const boostEl = document.getElementById('stat-production-boost');
+        const boostProgressEl = document.getElementById('stat-boost-progress');
+        if (boostEl) {
+            if (boostInfo.active) {
+                boostEl.textContent = `Active (${boostInfo.remaining}s)`;
+                if (boostProgressEl) {
+                    boostProgressEl.style.width = `${Math.min(100, (boostInfo.remaining / 30) * 100)}%`;
+                }
+            } else {
+                boostEl.textContent = 'Inactive';
+                if (boostProgressEl) {
+                    boostProgressEl.style.width = '0%';
+                }
+            }
+        }
+
         // Game progress (based on total stardust milestones)
         const progressBarEl = document.getElementById('stat-progress-bar');
         if (progressBarEl) {
             const progress = this.calculateProgress();
             progressBarEl.style.width = `${progress}%`;
         }
+
+        // Next achievement tracking
+        this.updateNextAchievement();
+    },
+
+    /**
+     * Update the next achievement display with progress bar
+     */
+    updateNextAchievement() {
+        const nextEl = document.getElementById('stat-next-achievement');
+        const progressEl = document.getElementById('stat-achievement-progress');
+        if (!nextEl) return;
+
+        // Find the closest unachieved milestone
+        let closest = null;
+        let closestProgress = -1;
+
+        for (const [id, achievement] of Object.entries(ACHIEVEMENTS)) {
+            if (Game.state.achievements.includes(id)) continue;
+
+            const result = this.calculateAchievementProgress(achievement);
+            if (result && result.progress > closestProgress) {
+                closestProgress = result.progress;
+                closest = { ...result, name: achievement.name, icon: achievement.icon };
+            }
+        }
+
+        if (closest) {
+            nextEl.textContent = `${closest.icon} ${closest.name}`;
+            if (progressEl) {
+                progressEl.style.width = `${Math.min(100, Math.max(0, closest.progress))}%`;
+            }
+        } else {
+            nextEl.textContent = 'All achievements unlocked! 🎉';
+            if (progressEl) {
+                progressEl.style.width = '100%';
+            }
+        }
+    },
+
+    /**
+     * Calculate progress toward a specific achievement
+     */
+    calculateAchievementProgress(achievement) {
+        const state = Game.state;
+
+        // Click achievements
+        if (achievement.id === 'firstClick') return { current: state.totalClicks, target: 1, progress: Math.min(100, (state.totalClicks / 1) * 100) };
+        if (achievement.id === 'clicker') return { current: state.totalClicks, target: 100, progress: Math.min(100, (state.totalClicks / 100) * 100) };
+        if (achievement.id === 'spammer') return { current: state.totalClicks, target: 1000, progress: Math.min(100, (state.totalClicks / 1000) * 100) };
+        if (achievement.id === 'clickMaster') return { current: state.totalClicks, target: 10000, progress: Math.min(100, (state.totalClicks / 10000) * 100) };
+
+        // Stardust achievements
+        if (achievement.id === 'dustCollector') return { current: state.totalStardust, target: 1000, progress: Math.min(100, (state.totalStardust / 1000) * 100) };
+        if (achievement.id === 'stardustMagnate') return { current: state.totalStardust, target: 100000, progress: Math.min(100, (state.totalStardust / 100000) * 100) };
+        if (achievement.id === 'cosmicTycoon') return { current: state.totalStardust, target: 10000000, progress: Math.min(100, (state.totalStardust / 10000000) * 100) };
+        if (achievement.id === 'galaxyBaron') return { current: state.totalStardust, target: 1000000000, progress: Math.min(100, (state.totalStardust / 1000000000) * 100) };
+
+        // Building achievements
+        if (achievement.id === 'firstPlant') {
+            const totalBuildings = Object.values(state.buildings).reduce((a, b) => a + b, 0);
+            return { current: totalBuildings, target: 1, progress: Math.min(100, (totalBuildings / 1) * 100) };
+        }
+        if (achievement.id === 'gardenStart') {
+            const totalBuildings = Object.values(state.buildings).reduce((a, b) => a + b, 0);
+            return { current: totalBuildings, target: 10, progress: Math.min(100, (totalBuildings / 10) * 100) };
+        }
+        if (achievement.id === 'gardenCenter') {
+            const totalBuildings = Object.values(state.buildings).reduce((a, b) => a + b, 0);
+            return { current: totalBuildings, target: 50, progress: Math.min(100, (totalBuildings / 50) * 100) };
+        }
+        if (achievement.id === 'cosmicGarden') {
+            const totalBuildings = Object.values(state.buildings).reduce((a, b) => a + b, 0);
+            return { current: totalBuildings, target: 100, progress: Math.min(100, (totalBuildings / 100) * 100) };
+        }
+
+        // Specific building achievements
+        if (achievement.id === 'sproutFarmer') return { current: state.buildings.starSprout || 0, target: 25, progress: Math.min(100, ((state.buildings.starSprout || 0) / 25) * 100) };
+        if (achievement.id === 'bloomGarden') return { current: state.buildings.moonBloom || 0, target: 25, progress: Math.min(100, ((state.buildings.moonBloom || 0) / 25) * 100) };
+        if (achievement.id === 'solarPowered') return { current: state.buildings.solarLeaf || 0, target: 25, progress: Math.min(100, ((state.buildings.solarLeaf || 0) / 25) * 100) };
+        if (achievement.id === 'voidWeaver') return { current: state.buildings.voidFern || 0, target: 25, progress: Math.min(100, ((state.buildings.voidFern || 0) / 25) * 100) };
+        if (achievement.id === 'supernovaGrowth') return { current: state.buildings.supernovaSeed || 0, target: 25, progress: Math.min(100, ((state.buildings.supernovaSeed || 0) / 25) * 100) };
+
+        // Production achievements
+        if (achievement.id === 'steadyStream') {
+            const prod = Game.getProductionPerSecond();
+            return { current: prod, target: 100, progress: Math.min(100, (prod / 100) * 100) };
+        }
+        if (achievement.id === 'rushingRiver') {
+            const prod = Game.getProductionPerSecond();
+            return { current: prod, target: 1000, progress: Math.min(100, (prod / 1000) * 100) };
+        }
+        if (achievement.id === 'cosmicFlood') {
+            const prod = Game.getProductionPerSecond();
+            return { current: prod, target: 100000, progress: Math.min(100, (prod / 100000) * 100) };
+        }
+
+        // Prestige achievements
+        if (achievement.id === 'firstPrestige') return { current: state.prestigeCount || 0, target: 1, progress: Math.min(100, ((state.prestigeCount || 0) / 1) * 100) };
+        if (achievement.id === 'stellarAdaptation') return { current: state.prestigeCount || 0, target: 5, progress: Math.min(100, ((state.prestigeCount || 0) / 5) * 100) };
+        if (achievement.id === 'cosmicAscension') return { current: state.prestigeCount || 0, target: 10, progress: Math.min(100, ((state.prestigeCount || 0) / 10) * 100) };
+        if (achievement.id === 'eternalGardener') return { current: state.totalPrestigeEssence || 0, target: 100, progress: Math.min(100, ((state.totalPrestigeEssence || 0) / 100) * 100) };
+        if (achievement.id === 'quantumGrowth') return { current: state.totalPrestigeEssence || 0, target: 1000, progress: Math.min(100, ((state.totalPrestigeEssence || 0) / 1000) * 100) };
+
+        // Click power achievements
+        if (achievement.id === 'powerfulHarvester') {
+            const cp = Game.getClickPower();
+            return { current: cp, target: 1000, progress: Math.min(100, (cp / 1000) * 100) };
+        }
+        if (achievement.id === 'divineTouch') {
+            const cp = Game.getClickPower();
+            return { current: cp, target: 10000, progress: Math.min(100, (cp / 10000) * 100) };
+        }
+
+        // Time-based achievement
+        if (achievement.id === 'dedicatedGardener') {
+            const elapsed = Date.now() - state.startTime;
+            return { current: elapsed, target: 3600000, progress: Math.min(100, (elapsed / 3600000) * 100) };
+        }
+
+        return null;
     },
 
     /**
diff --git a/js/ui.js b/js/ui.js
index a2dcf81..52bc7dc 100644
--- a/js/ui.js
+++ b/js/ui.js
@@ -11,6 +11,7 @@ const UI = {
         this.renderBuildings();
         this.renderUpgrades();
         this.renderAchievements();
+        this.updateSlotUI();
         this.update();
     },
 
@@ -35,6 +36,18 @@ const UI = {
         
         // Stats
         Stats.update();
+        
+        // Prestige
+        PrestigeUI.update();
+        
+        // Golden Starbloom countdown badge
+        this.updateGoldenBloomBadge();
+
+        // Save Slot System highlight / toggle state
+        this.updateSlotUI();
+
+        // Save Slot System live preview in the footer
+        this.updateSlotPreview();
     },
 
     /**
@@ -66,6 +79,7 @@ const UI = {
                     <div class="building-cost">${Game.formatNumber(cost)} ✨</div>
                     <div class="building-count">${count}</div>
                     <button class="buy-btn" ${!canAfford || locked ? 'disabled' : ''}>Buy</button>
+                    <button class="buy-max-btn" data-building="${id}" ${locked || count === 0 ? 'title="Buy as many as you can afford"' : 'disabled'}>${Game.formatNumber(Game.getMaxAffordable(id))}x Max</button>
                 </div>
             `;
             
@@ -73,6 +87,12 @@ const UI = {
                 card.querySelector('.buy-btn').addEventListener('click', () => {
                     Game.buyBuilding(id);
                 });
+                const maxBtn = card.querySelector('.buy-max-btn');
+                if (maxBtn) {
+                    maxBtn.addEventListener('click', () => {
+                        Game.buyMaxBuilding(id);
+                    });
+                }
             }
             
             container.appendChild(card);
@@ -100,6 +120,15 @@ const UI = {
                 btn.disabled = !canAfford || locked;
             }
             
+            // Buy Max button - reflect how many can be bought at current stardust
+            const maxBtn = card.querySelector('.buy-max-btn');
+            if (maxBtn) {
+                const affordable = Game.getMaxAffordable(id);
+                maxBtn.textContent = `${Game.formatNumber(affordable)}x Max`;
+                maxBtn.disabled = locked || affordable === 0;
+                maxBtn.title = affordable > 0 ? `Buy up to ${affordable} ${building.name}(s)` : 'Not enough stardust';
+            }
+            
             card.classList.toggle('locked', locked);
         }
     },
@@ -160,15 +189,52 @@ const UI = {
         for (const [id, upgrade] of Object.entries(UPGRADES)) {
             const card = document.getElementById(`upgrade-${id}`);
             if (!card) continue;
-            
+
             const purchased = Game.state.upgrades.includes(id);
             const costEl = card.querySelector('.upgrade-cost');
-            
+
             if (costEl && !purchased) {
                 const canAfford = Game.state.stardust >= upgrade.cost;
                 costEl.textContent = canAfford ? `${Game.formatNumber(upgrade.cost)} ✨` : `❌ ${Game.formatNumber(upgrade.cost)} ✨`;
             }
         }
+
+        // Toggle the "Buy All" button: show it once at least one unowned,
+        // requirement-met upgrade exists, and disable it when nothing is
+        // affordable. Its enabled state is refreshed live each tick.
+        this.updateBuyAllButton();
+    },
+
+    /**
+     * Show/hide and enable/disable the "Buy All upgrades" button based on
+     * whether any unowned upgrade (whose requirements are met) is currently
+     * affordable. Read of game state only; never mutates it.
+     */
+    updateBuyAllButton() {
+        const btn = document.getElementById('buy-all-upgrades');
+        if (!btn) return;
+
+        let affordableAny = false;
+        for (const [id, upgrade] of Object.entries(UPGRADES)) {
+            if (Game.state.upgrades.includes(id)) continue;
+            if (Game.state.stardust < upgrade.cost) continue;
+            // Requirement check mirrors Game.buyUpgrade / buyAllUpgrades.
+            if (upgrade.requirements) {
+                let met = true;
+                for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                    if ((Game.state.buildings[reqId] || 0) < reqCount) {
+                        met = false;
+                        break;
+                    }
+                }
+                if (!met) continue;
+            }
+            affordableAny = true;
+            break;
+        }
+
+        btn.style.display = affordableAny ? '' : 'none';
+        btn.disabled = !affordableAny;
     },
 
     /**
@@ -210,6 +276,138 @@ const UI = {
         }
     },
 
+    /**
+     * Spawn a Golden Starbloom in the click area. Called by Game when the
+     * random event becomes active. The bloom floats at a random position and
+     * is clickable to claim its bonus.
+     */
+    spawnGoldenBloom() {
+        const container = document.getElementById('golden-bloom-container');
+        if (!container) return;
+
+        // Remove any existing bloom first (shouldn't be one, but stay safe).
+        this.removeGoldenBloom();
+
+        const bloom = document.createElement('div');
+        bloom.className = 'golden-bloom';
+        bloom.textContent = '⭐';
+        bloom.title = 'Golden Starbloom! Click for a bonus!';
+
+        // Random position within the click area.
+        const rect = container.getBoundingClientRect();
+        const x = 20 + Math.random() * (Math.max(1, rect.width - 80));
+        const y = 20 + Math.random() * (Math.max(1, rect.height - 80));
+        bloom.style.left = `${x}px`;
+        bloom.style.top = `${y}px`;
+
+        // Click handler claims the bonus.
+        bloom.addEventListener('click', () => {
+            const earned = Game.claimGoldenBloom(rect.left + x, rect.top + y);
+            this.removeGoldenBloom();
+            if (earned > 0) {
+                UI.showFloatingText(
+                    rect.left + x, rect.top + y,
+                    `+${Game.formatNumber(earned)} ✨`
+                );
+            }
+        });
+
+        container.appendChild(bloom);
+    },
+
+    /**
+     * Remove any visible Golden Starbloom from the click area.
+     */
+    removeGoldenBloom() {
+        const container = document.getElementById('golden-bloom-container');
+        if (!container) return;
+        const existing = container.querySelector('.golden-bloom');
+        if (existing) existing.remove();
+    },
+
+    /**
+     * Update the Golden Starbloom countdown badge shown in the header.
+     */
+    updateGoldenBloomBadge() {
+        const el = document.getElementById('golden-bloom-badge');
+        const remaining = Game.getGoldenBloomRemaining();
+        if (!el) return;
+
+        if (remaining > 0) {
+            el.classList.add('active');
+            el.textContent = `⭐ Golden Bloom: ${remaining}s`;
+        } else {
+            el.classList.remove('active');
+        }
+    },
+
+    /**
+     * Reflect the active save slot highlight and autosave toggle state.
+     */
+    updateSlotUI() {
+        // Highlight the selected slot button.
+        document.querySelectorAll('.slot-btn').forEach(btn => {
+            const idx = parseInt(btn.dataset.slot, 10);
+            btn.classList.toggle('active', idx === Game.state.activeSlot);
+            btn.disabled = idx === Game.state.activeSlot;
+        });
+
+        // Reflect the autosave toggle state.
+        const autosaveBtn = document.getElementById('autosave-btn');
+        if (autosaveBtn) {
+            if (Game.state.autoSave) {
+                autosaveBtn.classList.add('on');
+                autosaveBtn.textContent = 'ON';
+            } else {
+                autosaveBtn.classList.remove('on');
+                autosaveBtn.textContent = 'OFF';
+            }
+        }
+    },
+
+    /**
+     * Update the one-line live preview of the active slot in the footer.
+     * Also wires hover handlers onto each slot button so hovering previews a
+     * different slot's contents (stardust, buildings, achievements, last saved).
+     * This is a read-only display helper and never mutates game state.
+     */
+    updateSlotPreview() {
+        const el = document.getElementById('slot-preview');
+        if (!el) return;
+
+        // Hovering a slot button previews that slot's contents instead of the
+        // active one. Track which slot is currently being previewed on hover.
+        let hovering = null;
+
+        const render = (slot) => {
+            const preview = Game.getSlotPreview(slot);
+            if (!preview.present) {
+                el.textContent = `Slot ${slot + 1}: empty`;
+                el.classList.add('empty');
+                return;
+            }
+            el.classList.remove('empty');
+            el.textContent =
+                `Slot ${slot + 1}: ${Game.formatNumber(preview.stardust)} ✨ · ` +
+                `${preview.buildings} plants · ${preview.achievements[0]}/${preview.achievements[1]} · ${preview.lastSaved}`;
+        };
+
+        // Default: preview the active slot live (updates every tick).
+        render(Game.state.activeSlot);
+
+        // Remove any previously-attached listeners to avoid duplicates on re-render.
+        document.querySelectorAll('.slot-btn').forEach(btn => {
+            btn.replaceWith(btn.cloneNode(true));
+        });
+
+        // On hover, preview the hovered slot; on leave, fall back to active.
+        document.querySelectorAll('.slot-btn').forEach(btn => {
+            const idx = parseInt(btn.dataset.slot, 10);
+            btn.addEventListener('mouseenter', () => { hovering = idx; render(idx); });
+            btn.addEventListener('mouseleave', () => { hovering = null; render(Game.state.activeSlot); });
+        });
+    },
+
     /**
      * Show floating text animation
      */