# Health UI Display - What Changed

## Before ❌

```
Problem: Health UI not visible
- Emoji hearts (❤️ 💔 🖤)
- Inline CSS styles (position: fixed; z-index: 100)
- Z-index too low (100 < inventory's 1000)
- Never appears on screen
```

## After ✅

```
Solution: Health UI now displays properly
- PNG icon hearts (assets/icons/heart.png)
- Proper CSS file (css/health-ui.css)
- Z-index: 1100 (above inventory)
- Appears above inventory when damaged
```

## Visual Layout

```
┌──────────────────────────────────────────────────────────┐
│                                                          │
│           ❤️  ❤️  ❤️  ❤️  💔                            │
│         (Health UI - NEW z-index: 1100)                │
│                                                          │
│  ┌────────────────────────────────────────────────────┐ │
│  │                                                    │ │
│  │              [Game World]                         │ │
│  │         Player running around                     │ │
│  │                                                    │ │
│  │                                                    │[I] │
│  │                                                    │[n] │
│  │                                                    │[v] │
│  │                                                    │[e] │
│  └────────────────────────────────────────────────────┘ │
│         Inventory UI (z-index: 1000)          │
│                                               │
└──────────────────────────────────────────────┘
```

## Code Changes Summary

### Change 1: Image-Based Hearts

**Before:**
```javascript
const heart = document.createElement('div');
heart.textContent = '❤️';  // Emoji
```

**After:**
```javascript
const heart = document.createElement('img');
heart.src = 'assets/icons/heart.png';  // PNG icon
```

### Change 2: Proper CSS Styling

**Before:**
```javascript
this.container.style.cssText = `
  z-index: 100;  // TOO LOW
  display: none;
`;
```

**After:**
```css
#health-ui-container {
  z-index: 1100;  /* ABOVE inventory (z-index: 1000) */
  display: flex;
}
```

### Change 3: CSS File Created

**New file:** `css/health-ui.css`
```css
z-index: 1100;              /* Key fix */
pointer-events: none;       /* Don't block clicks */
background: rgba(0, 0, 0, 0.8);  /* Dark background */
border: 2px solid #333;     /* Pixel-art style */
image-rendering: pixelated; /* Crisp icons */
```

## Heart Display Examples

### Full Health (Hidden)
```
Status: No damage taken
Display: [HIDDEN]
Console: (health-ui not showing)
```

### Partially Damaged
```
Player HP: 60 / 100 (3/5 hearts)
Display: ❤️  ❤️  ❤️  🖤  🖤
Status: UI visible above inventory
```

### Half Damage
```
Player HP: 50 / 100 (2.5/5 hearts)
Display: ❤️  ❤️  💔  🖤  🖤
Status: UI visible above inventory
```

### Nearly Dead
```
Player HP: 10 / 100 (0.5/5 hearts)
Display: 💔  🖤  🖤  🖤  🖤
Status: UI visible above inventory
```

## Z-Index Hierarchy

```
2000  ┌─────────────────────────┐
      │  Minigames (laptop)     │
      │  person-chat, phone     │
1100  ├─────────────────────────┤
      │  Health UI ← NEW!       │
1000  ├─────────────────────────┤
      │  Inventory UI           │
      │  Notifications          │
 100  ├─────────────────────────┤
      │  Other elements         │
  0   └─────────────────────────┘
```

## Asset Files

```
assets/icons/
├── heart.png       ← Full heart (used for full AND empty with opacity)
├── heart-half.png  ← Half heart (for remainder)
└── (other icons)
```

## Files Changed

✏️ **js/ui/health-ui.js** - Updated to use PNG icons
🆕 **css/health-ui.css** - New CSS file with proper styling
📝 **index.html** - Added CSS link

## Event Flow

```
Combat happens
    ↓
Player takes damage
    ↓
combatSystem emits: CombatEvents.PLAYER_HP_CHANGED
    ↓
HealthUI.updateHP() called
    ↓
Health UI shows (if hp < maxHP)
    ↓
Hearts update: ❤️ ❤️ 💔 🖤 🖤
    ↓
Health UI displays above inventory ✅
```

## Testing Checklist

- [ ] Load index.html in browser
- [ ] Take damage (get hit by hostile NPC)
- [ ] Health UI appears above inventory
- [ ] Hearts update correctly (full/half/empty)
- [ ] UI hides when health restored to full
- [ ] Icons are crisp and pixelated
- [ ] No console errors

## Quick Reference

| Element | Value |
|---------|-------|
| Z-Index | 1100 |
| Position | Top center, 60px from top |
| Positioning | Fixed (always visible when shown) |
| Full Heart Icon | assets/icons/heart.png |
| Half Heart Icon | assets/icons/heart-half.png |
| Empty Heart | heart.png at 0.2 opacity |
| Max Hearts | 5 (configurable via COMBAT_CONFIG.ui.maxHearts) |
| Max HP | 100 (20 HP per heart) |

## Pixel-Art Style

All images use:
```css
image-rendering: pixelated;        /* Standard */
image-rendering: -moz-crisp-edges; /* Firefox */
image-rendering: crisp-edges;      /* Chrome/Safari */
```

This ensures icons look crisp even when scaled, maintaining the pixel-art aesthetic.
