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

:root {
    --bg: #1a1a2e;
    --card-bg: #16213e;
    --text: #e0e0e0;
    --text-secondary: #a0a0b8;
    --accent: #e2b04a;
    --accent-hover: #f0c860;
    --danger: #e05555;
    --success: #4caf84;
    --border: rgba(255, 255, 255, 0.08);
    --board-bg: #d4a056;
    --board-line: #5a3825;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Microsoft YaHei", sans-serif;
    background: var(--bg);
    background-image:
        radial-gradient(ellipse at 50% 0%, rgba(226, 176, 74, 0.08) 0%, transparent 60%),
        radial-gradient(ellipse at 80% 80%, rgba(76, 175, 132, 0.04) 0%, transparent 60%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--text);
}

.container {
    width: 100%;
    max-width: 960px;
    padding: 24px;
}

.header {
    text-align: center;
    margin-bottom: 32px;
}

.title {
    font-size: 36px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), #f5d782);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 4px;
}

.subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 4px;
    letter-spacing: 2px;
}

.game-wrapper {
    display: flex;
    gap: 28px;
    justify-content: center;
    align-items: flex-start;
    flex-wrap: wrap;
}

.board-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

#board-canvas {
    display: block;
    cursor: pointer;
    border-radius: 8px;
}

.panel {
    display: flex;
    flex-direction: column;
    gap: 14px;
    width: 220px;
}

.panel-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 16px;
    border: 1px solid var(--border);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.panel-title {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.status-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 15px;
    font-weight: 600;
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--success);
    animation: pulse 2s infinite;
}

.status-badge.ended .status-dot {
    background: var(--danger);
    animation: none;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.turn-indicator {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    font-weight: 500;
}

.piece-icon {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    flex-shrink: 0;
    box-shadow: inset -2px -2px 4px rgba(0,0,0,0.3), inset 2px 2px 4px rgba(255,255,255,0.2);
}

.piece-icon.black {
    background: radial-gradient(circle at 35% 35%, #555, #111 50%, #000 100%);
}

.piece-icon.white {
    background: radial-gradient(circle at 35% 35%, #fff, #e8e8e8 40%, #c0c0c0 100%);
}

.difficulty-selector {
    display: flex;
    gap: 6px;
}

.diff-btn {
    flex: 1;
    padding: 8px 4px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: transparent;
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.diff-btn:hover {
    border-color: var(--accent);
    color: var(--text);
}

.diff-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #1a1a2e;
    font-weight: 600;
}

.game-info {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.info-row {
    display: flex;
    justify-content: space-between;
    font-size: 13px;
}

.info-row span:first-child {
    color: var(--text-secondary);
}

.info-row span:last-child {
    font-weight: 500;
    font-variant-numeric: tabular-nums;
}

#game-id {
    font-family: "SF Mono", "Fira Code", monospace;
    font-size: 12px;
    color: var(--text-secondary);
}

.btn-new-game {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--accent), #c9943a);
    color: #1a1a2e;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
    letter-spacing: 1px;
    box-shadow: 0 4px 12px rgba(226, 176, 74, 0.3);
}

.btn-new-game:hover {
    background: linear-gradient(135deg, var(--accent-hover), #dba44a);
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(226, 176, 74, 0.4);
}

.btn-new-game:active {
    transform: translateY(0);
}

@media (max-width: 700px) {
    .game-wrapper {
        flex-direction: column;
        align-items: center;
    }
    .panel {
        width: 100%;
        max-width: 400px;
    }
}