:root {
    --bg: #0a0a12;
    --bg-card: #0f0f1e;
    --bg-board: #080810;
    --text: #e4e4ef;
    --text-dim: #6e6e8e;
    --text-muted: #3a3a5a;
    --accent: #8b5cf6;
    --accent-glow: #a78bfa;
    --border: #1c1c38;
    --grid-line: #111125;

    /* Piece colors */
    --piece-I: #06b6d4;
    --piece-O: #eab308;
    --piece-T: #a855f7;
    --piece-S: #22c55e;
    --piece-Z: #ef4444;
    --piece-J: #3b82f6;
    --piece-L: #f97316;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 20px 20px 8px;
    flex-shrink: 0;
}

header h1 {
    font-size: clamp(1.4rem, 4vw, 2rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--text) 0%, var(--accent-glow) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: clamp(0.8rem, 2vw, 1rem);
    color: var(--accent-glow);
    font-weight: 300;
}

/* Game layout */
.game-layout {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 16px;
    padding: 16px 20px;
    flex: 1;
    min-height: 0;
}

/* Side panels */
.side-panel {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 140px;
    flex-shrink: 0;
}

.panel-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 10px;
    text-align: center;
}

.panel-box h3 {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.6rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.12em;
    margin-bottom: 6px;
}

.panel-box canvas {
    display: block;
    margin: 0 auto;
}

.model-name {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-glow);
}

.model-ctx {
    font-size: 0.65rem;
    color: var(--text-dim);
    margin-top: 2px;
}

.score-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text);
    line-height: 1;
}

.score-value.small {
    font-size: 1.2rem;
}

.stat-detail {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--text-dim);
}

/* Controls info */
.controls-info {
    text-align: left;
}

.control-row {
    font-size: 0.62rem;
    color: var(--text-dim);
    margin-bottom: 3px;
    display: flex;
    align-items: center;
    gap: 3px;
}

kbd {
    display: inline-block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.55rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 1px 4px;
    min-width: 18px;
    text-align: center;
    color: var(--accent-glow);
}

/* Game center */
.game-center {
    flex-shrink: 0;
}

.board-wrapper {
    position: relative;
    background: var(--bg-board);
    border: 2px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    line-height: 0;
}

#board-canvas {
    display: block;
}

/* Overlay */
.game-overlay {
    position: absolute;
    inset: 0;
    background: rgba(8, 8, 16, 0.92);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    backdrop-filter: blur(4px);
}

.overlay-content {
    text-align: center;
    padding: 30px;
}

.overlay-content h2 {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--accent-glow);
    margin-bottom: 6px;
}

.overlay-content p {
    font-size: 0.82rem;
    color: var(--text-dim);
    margin-bottom: 20px;
}

.btn-primary {
    padding: 10px 32px;
    font-size: 0.9rem;
    font-weight: 600;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.btn-primary:hover {
    background: #7c3aed;
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(139, 92, 246, 0.3);
}

/* Mobile controls */
.mobile-controls {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 12px 20px 20px;
}

.mobile-row {
    display: flex;
    gap: 8px;
}

.mobile-btn {
    width: 56px;
    height: 56px;
    font-size: 1.3rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text);
    cursor: pointer;
    font-family: inherit;
    display: flex;
    align-items: center;
    justify-content: center;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.mobile-btn.wide {
    width: 120px;
    font-size: 0.8rem;
    font-weight: 600;
}

.mobile-btn:active {
    background: var(--accent);
    border-color: var(--accent);
}

/* Hidden */
.hidden { display: none !important; }

/* Footer */
footer {
    text-align: center;
    padding: 16px 20px;
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

footer p { color: var(--text-dim); font-size: 0.72rem; margin-bottom: 4px; }
.footer-note { font-size: 0.65rem !important; opacity: 0.5; }

/* Line clear flash */
@keyframes lineClear {
    0% { background: rgba(139, 92, 246, 0.3); }
    50% { background: rgba(139, 92, 246, 0.6); }
    100% { background: transparent; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* Responsive */
@media (max-width: 768px) {
    .game-layout { gap: 8px; padding: 8px 8px; }
    .side-panel { width: 90px; }
    .panel-box { padding: 6px; }
    .panel-box h3 { font-size: 0.5rem; }
    .score-value { font-size: 1.2rem; }
    .score-value.small { font-size: 0.95rem; }
    .controls-info { display: none; }
    .mobile-controls { display: flex; }
    header { padding: 12px 12px 4px; }
}

@media (max-width: 480px) {
    .left-panel { display: none; }
    .game-layout { gap: 6px; }
    .side-panel { width: 70px; }
    .panel-box canvas { width: 60px !important; height: auto !important; }
}