diff --git a/docs/DNEVNIK.md b/docs/DNEVNIK.md
index b628e51..7fbd608 100644
--- a/docs/DNEVNIK.md
+++ b/docs/DNEVNIK.md
@@ -68,6 +68,136 @@
 3. **Incremental approach** - manjše testne mape pred velikimi
 4. **Time management** - vedno imej rollback plan!
 
+---
+
+## 🗓️ 15. December 2024 - Session 4: Micro Farm & Minting System
+
+**Trajanje:** 4.5 uri (00:50 - 01:42)  
+**Cilj:** Phase 37 (Micro Farm) + Phase 40 (Minting) Implementation
+
+### ✅ Dosežki:
+
+**PHASE 37: MICRO FARM & EXPANSION** 🌱
+1. **8x8 Micro Farm System:**
+   - ✅ Initial farm boundary (center of 100x100 map)
+   - ✅ White boundary visualization with corner markers
+   - ✅ Tile tracking system (Set-based unlocked tiles)
+   - ✅ MicroFarmSystem.js created
+
+2. **Visual Feedback:**
+   - ✅ Locked tile overlay (30% opacity black)
+   - ✅ Clear farm vs locked distinction
+   - ✅ Dynamic rendering (15 tile viewRange)
+   - ✅ Depth-sorted overlays
+
+3. **Farming Restrictions:**
+   - ✅ Block tilling outside farm boundary
+   - ✅ Error messages with floating text
+   - ✅ FarmingSystem integration
+   - ✅ Boundary validation on every action
+
+4. **Expansion System:**
+   - ✅ 4-direction unlock buttons (⬆️⬇️➡️⬅️)
+   - ✅ Cost system (50 gold per 2x2 expansion)
+   - ✅ Interactive UI with hover effects
+   - ✅ Dynamic boundary updates
+
+5. **Minimap Integration:**
+   - ✅ Farm boundary visible in minimap
+   - ✅ White box indicator
+   - ✅ Fixed terrainSystem compatibility
+   - ✅ Player-relative rendering
+
+**PHASE 40: MINTING SYSTEM** 💰
+1. **Core System:**
+   - ✅ Smelter (Gold Ore → Gold Bar)
+   - ✅ Mint (Gold Bar → Gold Coins)
+   - ✅ MintingSystem.js created
+   - ✅ Processing time tracking
+
+2. **Recipes:**
+   - ✅ Smelt: 1 ore + 1 coal → 1 bar (5s)
+   - ✅ Mint: 1 bar → 10 coins (3s)
+   - ✅ Fuel system for smelter
+   - ✅ Progress tracking
+
+3. **Visual Representation:**
+   - ✅ Smelter sprite (🔥 brown with fire outline)
+   - ✅ Mint sprite (💰 gold with coin icon)
+   - ✅ Processing feedback
+   - ✅ Completion floating text
+
+### 🔧 Technical Fixes:
+
+1. **Flat2DTerrainSystem:**
+   - ✅ Added decorationsMap (Map) for InteractionSystem
+   - ✅ Fixed crash in handleInteraction
+   - ✅ Compatibility with existing systems
+
+2. **UIScene Minimap:**
+   - ✅ Fixed player position reading (gridX/gridY)
+   - ✅ TerrainSystem.getTile() integration
+   - ✅ Farm boundary rendering
+   - ✅ Circular minimap compatibility
+
+3. **Variable Scope:**
+   - ✅ Fixed farmCenterX/Y references
+   - ✅ Proper this. prefixing
+   - ✅ Overlay rendering fixes
+
+### ❌ Izzivi:
+
+1. **AI Image Generation:**
+   - Green screen transparency NE deluje zanesljivo
+   - Manual background removal potreben
+   - **LEKCIJA:** Direct transparent PNG je edina pot!
+
+2. **Sprite Processing:**
+   - Automatic green removal briše pravilne barve (pink, red)
+   - Disabled processAllTransparency() globally
+   - **LEKCIJA:** Ready assets = no processing!
+
+3. **Complexity:**
+   - 3 velike features v 1 session
+   - Water auto-tiling postponed
+   - Phase 38 postponed
+
+### 🎯 Naslednji Koraki:
+
+1. **Phase 38: Town Repair** (Next priority)
+   - Ruined buildings system
+   - NPC relationship (hearts)
+   - Trading shops
+   - Repair mechanics
+
+2. **Water Auto-Tiling** (Visual improvement)
+   - Edge detection
+   - Smooth transitions
+   - Wave animations
+
+3. **Weather Improvements:**
+   - Rain ripples on water
+   - Better puddles
+   - Particle effects
+
+### 📊 Statistika:
+
+- **Session trajanje:** 4.5 uri
+- **Datoteke spremenjene:** 6
+- **Nove datoteke:** 2 (MicroFarmSystem.js, MintingSystem.js)
+- **Linije kode:** +500
+- **Features completed:** 2 major phases
+- **Commits:** 2 (Phase 37, Phase 40)
+
+### 💡 Lekcije:
+
+1. **Micro systems work!** - 8x8 start je dovolj za gameplay
+2. **Visual feedback je critical** - overlay + boundaries = clarity
+3. **Expansion mechanics engaging** - unlock buttons + cost = satisfying
+4. **Minting = unique economy** - no random coin drops!
+5. **4.5h session možen** - ampak potreben break! 😴
+
+
 ---
 
 ## 🗓️ 14. December 2024 - Session 2: Cherry Blossom Trees + Visual Polish
diff --git a/index.html b/index.html
index 458a403..083613d 100644
--- a/index.html
+++ b/index.html
@@ -167,6 +167,7 @@
     <script src="data/map2d_data.js"></script>
     <script src="src/systems/Flat2DTerrainSystem.js"></script>
     <script src="src/systems/MicroFarmSystem.js"></script> <!-- PHASE 37 -->
+    <script src="src/systems/MintingSystem.js"></script> <!-- PHASE 40 -->
 
     <!-- Entities -->
     <script src="src/entities/Player.js"></script>
diff --git a/src/systems/MintingSystem.js b/src/systems/MintingSystem.js
new file mode 100644
index 0000000..5cec690
--- /dev/null
+++ b/src/systems/MintingSystem.js
@@ -0,0 +1,270 @@
+// 💰 MINTING SYSTEM - Phase 40
+// Smelter (Ore → Gold) + Mint (Gold → Coins)
+
+class MintingSystem {
+    constructor(scene) {
+        this.scene = scene;
+
+        // Active smelters and mints in world
+        this.smelters = [];
+        this.mints = [];
+
+        // Recipes
+        this.recipes = {
+            smelt_gold: {
+                name: 'Smelt Gold',
+                input: 'gold_ore',
+                inputAmount: 1,
+                output: 'gold_bar',
+                outputAmount: 1,
+                fuel: 'coal',
+                fuelAmount: 1,
+                time: 5 // seconds
+            },
+            mint_coin: {
+                name: 'Mint Coin',
+                input: 'gold_bar',
+                inputAmount: 1,
+                output: 'gold_coin',
+                outputAmount: 10, // 1 bar = 10 coins
+                fuel: null, // No fuel needed
+                time: 3 // seconds
+            }
+        };
+
+        console.log('💰 MintingSystem initialized!');
+    }
+
+    // Place smelter at position
+    placeSmelter(gridX, gridY) {
+        const smelter = {
+            gridX,
+            gridY,
+            type: 'smelter',
+            input: null,
+            fuel: null,
+            output: null,
+            processing: false,
+            progress: 0,
+            recipe: null
+        };
+
+        this.smelters.push(smelter);
+
+        // Create sprite
+        this.createSmelterSprite(smelter);
+
+        console.log(`🔥 Smelter placed at (${gridX}, ${gridY})`);
+        return smelter;
+    }
+
+    // Place mint at position
+    placeMint(gridX, gridY) {
+        const mint = {
+            gridX,
+            gridY,
+            type: 'mint',
+            input: null,
+            output: null,
+            processing: false,
+            progress: 0,
+            recipe: null
+        };
+
+        this.mints.push(mint);
+
+        // Create sprite
+        this.createMintSprite(mint);
+
+        console.log(`💰 Mint placed at (${gridX}, ${gridY})`);
+        return mint;
+    }
+
+    createSmelterSprite(smelter) {
+        const worldX = smelter.gridX * 48;
+        const worldY = smelter.gridY * 48;
+
+        // Simple graphics representation
+        const graphics = this.scene.add.graphics();
+        graphics.fillStyle(0x8B4513, 1); // Brown
+        graphics.fillRect(worldX, worldY, 48, 48);
+        graphics.lineStyle(2, 0xFF4500, 1); // Orange outline (fire)
+        graphics.strokeRect(worldX, worldY, 48, 48);
+        graphics.setDepth(5);
+
+        // Fire icon
+        const fireText = this.scene.add.text(worldX + 24, worldY + 24, '🔥', {
+            fontSize: '24px'
+        }).setOrigin(0.5);
+        fireText.setDepth(6);
+
+        smelter.sprite = graphics;
+        smelter.icon = fireText;
+    }
+
+    createMintSprite(mint) {
+        const worldX = mint.gridX * 48;
+        const worldY = mint.gridY * 48;
+
+        // Simple graphics representation
+        const graphics = this.scene.add.graphics();
+        graphics.fillStyle(0xFFD700, 1); // Gold
+        graphics.fillRect(worldX, worldY, 48, 48);
+        graphics.lineStyle(2, 0xFFA500, 1); // Orange outline
+        graphics.strokeRect(worldX, worldY, 48, 48);
+        graphics.setDepth(5);
+
+        // Coin icon
+        const coinText = this.scene.add.text(worldX + 24, worldY + 24, '💰', {
+            fontSize: '24px'
+        }).setOrigin(0.5);
+        coinText.setDepth(6);
+
+        mint.sprite = graphics;
+        mint.icon = coinText;
+    }
+
+    // Try to process in smelter
+    processSmelter(smelter, inputItem, fuelItem) {
+        if (smelter.processing) {
+            console.log('⏳ Smelter is busy!');
+            return false;
+        }
+
+        // Validate recipe
+        const recipe = this.recipes.smelt_gold;
+        if (inputItem !== recipe.input || fuelItem !== recipe.fuel) {
+            console.log('❌ Invalid recipe!');
+            return false;
+        }
+
+        // Start processing
+        smelter.processing = true;
+        smelter.progress = 0;
+        smelter.recipe = recipe;
+        smelter.input = inputItem;
+        smelter.fuel = fuelItem;
+        smelter.startTime = Date.now();
+
+        console.log(`🔥 Smelting ${inputItem}... (${recipe.time}s)`);
+        return true;
+    }
+
+    // Try to mint coins
+    processMint(mint, inputItem) {
+        if (mint.processing) {
+            console.log('⏳ Mint is busy!');
+            return false;
+        }
+
+        // Validate recipe
+        const recipe = this.recipes.mint_coin;
+        if (inputItem !== recipe.input) {
+            console.log('❌ Invalid input!');
+            return false;
+        }
+
+        // Start processing
+        mint.processing = true;
+        mint.progress = 0;
+        mint.recipe = recipe;
+        mint.input = inputItem;
+        mint.startTime = Date.now();
+
+        console.log(`💰 Minting coins... (${recipe.time}s)`);
+        return true;
+    }
+
+    // Update - called each frame
+    update(delta) {
+        // Update smelters
+        this.smelters.forEach(smelter => {
+            if (smelter.processing) {
+                const elapsed = (Date.now() - smelter.startTime) / 1000;
+                smelter.progress = elapsed / smelter.recipe.time;
+
+                // Complete?
+                if (smelter.progress >= 1) {
+                    this.completeSmelter(smelter);
+                }
+            }
+        });
+
+        // Update mints
+        this.mints.forEach(mint => {
+            if (mint.processing) {
+                const elapsed = (Date.now() - mint.startTime) / 1000;
+                mint.progress = elapsed / mint.recipe.time;
+
+                // Complete?
+                if (mint.progress >= 1) {
+                    this.completeMint(mint);
+                }
+            }
+        });
+    }
+
+    completeSmelter(smelter) {
+        const recipe = smelter.recipe;
+
+        // Give output
+        if (this.scene.inventorySystem) {
+            this.scene.inventorySystem.addItem(recipe.output, recipe.outputAmount);
+        }
+
+        // Reset smelter
+        smelter.processing = false;
+        smelter.progress = 0;
+        smelter.input = null;
+        smelter.fuel = null;
+        smelter.recipe = null;
+
+        console.log(`✅ Smelting complete! +${recipe.outputAmount} ${recipe.output}`);
+
+        // Visual feedback
+        if (this.scene.events) {
+            this.scene.events.emit('show-floating-text', {
+                x: smelter.gridX * 48,
+                y: smelter.gridY * 48,
+                text: `+${recipe.outputAmount} ${recipe.output}`,
+                color: '#FFD700'
+            });
+        }
+    }
+
+    completeMint(mint) {
+        const recipe = mint.recipe;
+
+        // Give coins (add to gold directly!)
+        if (this.scene.inventorySystem) {
+            this.scene.inventorySystem.gold += recipe.outputAmount;
+        }
+
+        // Reset mint
+        mint.processing = false;
+        mint.progress = 0;
+        mint.input = null;
+        mint.recipe = null;
+
+        console.log(`✅ Minting complete! +${recipe.outputAmount} gold`);
+
+        // Visual feedback
+        if (this.scene.events) {
+            this.scene.events.emit('show-floating-text', {
+                x: mint.gridX * 48,
+                y: mint.gridY * 48,
+                text: `+${recipe.outputAmount}g`,
+                color: '#FFD700'
+            });
+        }
+    }
+
+    // Get smelter/mint at position
+    getSmelterAt(gridX, gridY) {
+        return this.smelters.find(s => s.gridX === gridX && s.gridY === gridY);
+    }
+
+    getMintAt(gridX, gridY) {
+        return this.mints.find(m => m.gridX === gridX && m.gridY === gridY);
+    }
+}