/*
 * 贪吃蛇网页版样式。
 *
 * 现代简洁风格：浅色页面、深色棋盘、圆角卡片与柔和阴影。
 * 布局纵向居中，棋盘按宽度自适应（正方形），触屏设备额外显示虚拟方向键。
 */

:root {
    --page-bg: #f1f5f9;
    --card-bg: #ffffff;
    --ink: #0f172a;
    --ink-soft: #64748b;
    --ink-faint: #94a3b8;
    --accent: #10b981;
    --accent-hover: #059669;
    --overlay-bg: rgba(15, 23, 42, 0.55);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    background: var(--page-bg);
    color: var(--ink);
    font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC",
        "Microsoft YaHei", sans-serif;
    -webkit-tap-highlight-color: transparent;
}

.page {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    width: 100%;
    max-width: 520px;
    padding: 24px 16px 40px;
}

.page-header h1 {
    margin: 0;
    font-size: 28px;
    letter-spacing: 0.12em;
}

/* 分数栏 */

.score-bar {
    display: flex;
    gap: 12px;
}

.score-item {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 6px 16px;
    font-size: 14px;
    color: var(--ink-soft);
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.08);
}

.score-item span {
    font-weight: 700;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

/* 棋盘与覆盖层 */

.board-wrap {
    position: relative;
    width: 100%;
    max-width: 480px;
    aspect-ratio: 1 / 1;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(15, 23, 42, 0.18);
}

#board {
    display: block;
    width: 100%;
    height: 100%;
    touch-action: none;
}

.overlay {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 24px;
    text-align: center;
    background: var(--overlay-bg);
    backdrop-filter: blur(4px);
    color: #f8fafc;
}

.overlay[hidden] {
    display: none;
}

.overlay h2 {
    margin: 0;
    font-size: 30px;
    letter-spacing: 0.08em;
}

.overlay p {
    margin: 0;
    color: #cbd5e1;
    font-size: 14px;
}

.overlay strong {
    color: #f8fafc;
    font-variant-numeric: tabular-nums;
}

.record-line {
    color: #fbbf24 !important;
    font-weight: 700;
}

.btn {
    border: none;
    border-radius: 999px;
    background: var(--accent);
    color: #ffffff;
    font-size: 16px;
    padding: 10px 28px;
    margin-top: 6px;
    cursor: pointer;
    transition: background 0.15s ease;
}

.btn:hover {
    background: var(--accent-hover);
}

.btn:active {
    transform: scale(0.97);
}

.overlay-hint {
    font-size: 12px !important;
    color: var(--ink-faint) !important;
}

/* 底部提示 */

.hint {
    margin: 0;
    font-size: 13px;
    color: var(--ink-soft);
}

/* 虚拟方向键（仅触屏设备显示） */

.touch-controls {
    display: grid;
    grid-template-columns: repeat(3, 68px);
    grid-template-rows: repeat(3, 58px);
    gap: 8px;
    justify-content: center;
    margin-top: 4px;
}

.touch-controls[hidden] {
    display: none;
}

.pad {
    border: none;
    border-radius: 14px;
    background: var(--card-bg);
    color: #334155;
    font-size: 18px;
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.12);
    cursor: pointer;
    touch-action: manipulation;
    user-select: none;
}

.pad:active {
    background: #e2e8f0;
    transform: scale(0.96);
}

.pad-up {
    grid-column: 2;
    grid-row: 1;
}

.pad-left {
    grid-column: 1;
    grid-row: 2;
}

.pad-primary {
    grid-column: 2;
    grid-row: 2;
    color: var(--accent);
}

.pad-right {
    grid-column: 3;
    grid-row: 2;
}

.pad-down {
    grid-column: 2;
    grid-row: 3;
}