.game-board {
    display: grid;
    grid-template-columns: repeat(20, 1fr);
    gap: 1px;
    background-color: var(--fallback-b3,oklch(var(--b3)/1));
    padding: 1px;
    border-radius: 8px;
    aspect-ratio: 1;
    max-width: min(90vw, 600px);
    margin: 0 auto;
    position: relative;
    overflow: hidden;
    transition: background-color 0.3s ease;
}

.cell {
    aspect-ratio: 1;
    background-color: var(--fallback-b1,oklch(var(--b1)/1));
    border-radius: 2px;
    transition: all 0.15s ease-out;
}

.cell.snake {
    background-color: var(--fallback-p,oklch(var(--p)/1));
    border-radius: 4px;
    transform: scale(0.9);
    transition: all 0.15s ease-out;
}

.cell.snake-head {
    background-color: var(--fallback-s,oklch(var(--s)/1));
    transform: scale(0.95);
    animation: headPulse 2s ease-in-out infinite;
}

.cell.food {
    background-color: var(--fallback-su,oklch(var(--su)/1));
    border-radius: 50%;
    animation: foodPulse 2s ease-in-out infinite;
    transition: all 0.15s ease-out;
}

.cell.power-up {
    border-radius: 50%;
    animation: powerUpFloat 2s ease-in-out infinite;
    transition: all 0.15s ease-out;
}

.cell.power-up.speed {
    background-color: var(--fallback-wa,oklch(var(--wa)/1));
}

.cell.power-up.shield {
    background-color: var(--fallback-in,oklch(var(--in)/1));
}

.cell.power-up.score {
    background-color: var(--fallback-ac,oklch(var(--ac)/1));
}

.shield-effect {
    position: absolute;
    inset: 0;
    border: 4px solid var(--fallback-in,oklch(var(--in)/0.5));
    border-radius: 8px;
    animation: shieldPulse 1s infinite;
    pointer-events: none;
}

.speed-boost {
    animation: speedBoostBg 1s ease-in-out infinite;
}

.game-controls {
    position: relative;
    z-index: 10;
}

.game-controls button {
    transition: transform 0.1s ease;
}

.game-controls button:active {
    transform: scale(0.9);
}

@keyframes headPulse {
    0% { transform: scale(0.95); }
    50% { transform: scale(0.98); }
    100% { transform: scale(0.95); }
}

@keyframes foodPulse {
    0% { transform: scale(0.9); }
    50% { transform: scale(1); }
    100% { transform: scale(0.9); }
}

@keyframes powerUpFloat {
    0% { transform: translateY(0) scale(0.9); }
    50% { transform: translateY(-2px) scale(1); }
    100% { transform: translateY(0) scale(0.9); }
}

@keyframes shieldPulse {
    0% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.02); opacity: 0.7; }
    100% { transform: scale(1); opacity: 0.5; }
}

@keyframes speedBoostBg {
    0% { background-color: var(--fallback-b3,oklch(var(--b3)/1)); }
    50% { background-color: var(--fallback-wa,oklch(var(--wa)/0.1)); }
    100% { background-color: var(--fallback-b3,oklch(var(--b3)/1)); }
}

@media (max-width: 640px) {
    .game-board {
        max-width: min(90vw, 400px);
    }

    .game-controls {
        margin-top: 2rem;
    }

    .game-controls button {
        font-size: 1.5rem;
        padding: 1rem;
    }
}

.stats {
    transition: all 0.3s ease;
}

.stat-value {
    animation: valueChange 0.3s ease;
}

@keyframes valueChange {
    0% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

.collapse-title {
    transition: background-color 0.3s ease;
}

.collapse-content {
    transition: all 0.3s ease;
}

.paused .game-board::after {
    content: "已暂停";
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.5);
    color: white;
    font-size: 2rem;
    font-weight: bold;
}

/* 添加按钮动画样式 */
.btn {
    transition: all 0.3s ease;
}

.btn[onclick="startGame()"] {
    opacity: 1;
    transform: scale(1);
}

.btn[onclick="startGame()"][style*="display: none"] {
    opacity: 0;
    transform: scale(0.8);
}