:root {
    /* Themes will override these */
    --bg-color: #050505;
    --grid-color: rgba(0, 255, 255, 0.05);
    --snake-head: #00ffff;
    --snake-body: #00ccff;
    --food-normal: #ff0055;
    --text-glow: #00ffff;
    
    --font-ui: 'Orbitron', sans-serif;
    --font-pixel: 'Press Start 2P', cursive;
}

[data-theme="neon"] {
    --bg-color: #050505;
    --grid-color: rgba(0, 255, 255, 0.05);
    --snake-head: #00ffff;
    --snake-body: #0088ff;
    --food-normal: #ff0055;
    --text-glow: #00ffff;
}

[data-theme="retro"] {
    --bg-color: #0f380f;
    --grid-color: rgba(48, 98, 48, 0.2);
    --snake-head: #9bbc0f;
    --snake-body: #8bac0f;
    --food-normal: #306230;
    --text-glow: #9bbc0f;
}

[data-theme="forest"] {
    --bg-color: #1a2315;
    --grid-color: rgba(76, 175, 80, 0.05);
    --snake-head: #4caf50;
    --snake-body: #2e7d32;
    --food-normal: #ff9800;
    --text-glow: #4caf50;
}

[data-theme="ocean"] {
    --bg-color: #001f3f;
    --grid-color: rgba(0, 116, 217, 0.1);
    --snake-head: #0074d9;
    --snake-body: #39cccc;
    --food-normal: #ff851b;
    --text-glow: #7fdbff;
}

* {
    box-sizing: border-box;
    margin: 0; padding: 0;
    user-select: none;
    -webkit-user-drag: none;
}

body {
    background-color: #000;
    color: #fff;
    font-family: var(--font-ui);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
    transition: background-color 0.5s ease;
}

#game-container {
    position: relative;
    width: 100%;
    max-width: 800px;
    height: 100%;
    max-height: 800px;
    background-color: var(--bg-color);
    box-shadow: 0 0 50px rgba(0,0,0,0.8);
    transition: background-color 0.5s ease;
}

@media(min-aspect-ratio: 1/1) {
    #game-container { aspect-ratio: 1/1; height: 90vh; width: 90vh; }
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    image-rendering: pixelated; /* Sharp edges */
}

/* UI Layer */
#ui-layer {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    pointer-events: none;
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.top-bar {
    display: flex;
    justify-content: space-between;
}

.score-container {
    background: rgba(0,0,0,0.6);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 10px 15px;
    display: flex;
    flex-direction: column;
    align-items: center;
    backdrop-filter: blur(4px);
}

.label {
    font-size: 10px;
    letter-spacing: 2px;
    color: #888;
    margin-bottom: 5px;
}

.value {
    font-family: var(--font-pixel);
    font-size: 16px;
    color: #fff;
    text-shadow: 0 0 10px var(--text-glow);
}

.powerup-display {
    align-self: flex-start;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.powerup-item {
    background: rgba(0,0,0,0.7);
    border-left: 4px solid #fff;
    padding: 8px 15px;
    font-size: 12px;
    letter-spacing: 1px;
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.powerup-bar-bg {
    width: 100px;
    height: 4px;
    background: #333;
    border-radius: 2px;
    overflow: hidden;
}

.powerup-bar-fill {
    height: 100%;
    background: #fff;
    transition: width 0.1s linear;
}

/* Screens */
.screen {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 20;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    padding: 20px;
}

.screen.active {
    opacity: 1;
    pointer-events: auto;
}

.glass-panel {
    background: rgba(0,0,0,0.85);
    backdrop-filter: blur(10px);
}

.glow-text {
    font-size: 48px;
    font-weight: 900;
    letter-spacing: 4px;
    text-align: center;
    margin-bottom: 40px;
    color: #fff;
    text-shadow: 0 0 20px var(--text-glow);
    line-height: 1.2;
}

.text-red {
    color: #ff2a55;
    text-shadow: 0 0 20px #ff2a55;
}

.settings-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
    margin-bottom: 30px;
    width: 100%;
    max-width: 400px;
}

.setting {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255,255,255,0.05);
    padding: 10px 15px;
    border-radius: 8px;
}

.setting label {
    font-size: 14px;
    letter-spacing: 1px;
    color: #aaa;
}

.setting select {
    background: #000;
    color: var(--text-glow);
    border: 1px solid rgba(255,255,255,0.2);
    padding: 8px;
    font-family: var(--font-ui);
    border-radius: 4px;
    outline: none;
    cursor: pointer;
}

.btn {
    font-family: var(--font-ui);
    font-size: 16px;
    font-weight: 700;
    padding: 15px 40px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    letter-spacing: 2px;
}

.btn-primary {
    background: rgba(255,255,255,0.1);
    color: #fff;
    border: 2px solid var(--text-glow);
    box-shadow: 0 0 15px rgba(255,255,255,0.1) inset, 0 0 20px var(--text-glow);
}

.btn-primary:active {
    transform: scale(0.95);
}

.btn-secondary {
    background: transparent;
    color: #888;
    border: 1px solid #555;
}

.controls-hint {
    margin-top: 20px;
    font-size: 12px;
    color: #666;
}

.results-box {
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--text-glow);
    padding: 30px 50px;
    border-radius: 12px;
    text-align: center;
    margin-bottom: 30px;
}

.big-score {
    font-family: var(--font-pixel);
    font-size: 36px;
    margin-top: 15px;
    color: #fff;
    text-shadow: 0 0 15px var(--text-glow);
}

.leaderboard-preview {
    margin-top: 30px;
    width: 100%;
    max-width: 400px;
}

.leaderboard-preview h3 {
    text-align: center;
    font-size: 12px;
    color: #888;
    letter-spacing: 2px;
    margin-bottom: 10px;
}

#leaderboard-list {
    list-style: none;
    font-size: 14px;
    display: flex;
    flex-direction: column;
    gap: 5px;
}

#leaderboard-list li {
    display: flex;
    justify-content: space-between;
    background: rgba(255,255,255,0.03);
    padding: 8px 12px;
    border-radius: 4px;
}

/* Shake Effect */
.shake {
    animation: screenshake 0.2s cubic-bezier(.36,.07,.19,.97) both;
}

@keyframes screenshake {
    0% { transform: translate(0, 0); }
    25% { transform: translate(-10px, 8px); }
    50% { transform: translate(10px, -8px); }
    75% { transform: translate(-10px, -8px); }
    100% { transform: translate(0, 0); }
}