/* ========== Root / Layout ========== */

#snake-game-wrapper {
    max-width: 100%;
    margin: 16px auto;
    padding: 16px;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.12);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    text-align: center;
    user-select: none;
    -webkit-user-select: none;
    overflow: hidden;
    position: relative;
    touch-action: none;
    -webkit-touch-callout: none;
}

/* ========== Themes ========== */

.snake-theme-green {
    background: #f0f7f0;
    border: 2px solid #4a7c59;
}
.snake-theme-green .snake-header { color: #2d5a3f; }
.snake-theme-green .snake-title { margin: 0 0 8px; font-size: 1.5rem; }
.snake-theme-green .snake-stats { font-size: 0.95rem; color: #4a7c59; }
.snake-theme-green .snake-stats strong { color: #2d5a3f; }
.snake-theme-green .snake-difficulty-btn { border-color: #4a7c59; color: #4a7c59; }
.snake-theme-green .snake-difficulty-btn.active { background: #4a7c59; color: #fff; }
.snake-theme-green .snake-pause-btn { border-color: #4a7c59; color: #4a7c59; }
.snake-theme-green .snake-pause-btn:hover { background: rgba(74,124,89,0.1); }
.snake-theme-green .snake-speed-fill { background: #4a7c59; }
.snake-theme-green .snake-board-frame { border-color: #4a7c59; }

.snake-theme-dark {
    background: #1a1a2e;
    border: 2px solid #16213e;
    color: #eee;
}
.snake-theme-dark .snake-title { margin: 0 0 8px; color: #e94560; }
.snake-theme-dark .snake-stats strong { color: #e94560; }
.snake-theme-dark #snake-start-btn { background: #e94560; }
.snake-theme-dark #snake-start-btn:hover { background: #c73a52; }
.snake-theme-dark .snake-dpad-btn { border-color: #e94560; background: rgba(233, 69, 96, 0.15); }
.snake-theme-dark .snake-dpad-btn:active { background: rgba(233, 69, 96, 0.4); }
.snake-theme-dark .snake-difficulty-btn { border-color: #e94560; color: #e94560; }
.snake-theme-dark .snake-difficulty-btn.active { background: #e94560; color: #fff; }
.snake-theme-dark .snake-pause-btn { border-color: #e94560; color: #e94560; }
.snake-theme-dark .snake-pause-btn:hover { background: rgba(233,69,96,0.15); }
.snake-theme-dark .snake-leaderboard-table th { color: #ffd93d; }
.snake-theme-dark .snake-leaderboard-table tr:nth-child(even) { background: rgba(255,255,255,0.05); }
.snake-theme-dark .snake-speed-fill { background: #e94560; }
.snake-theme-dark .snake-board-frame { border-color: #e94560; }
.snake-theme-dark .snake-food-legend { background: rgba(255,255,255,0.06); }

.snake-theme-retro {
    background: #f5e6c8;
    border: 3px solid #8b7355;
    border-radius: 4px;
    color: #5c4a32;
}
.snake-theme-retro .snake-title { margin: 0 0 8px; font-family: 'Courier New', monospace; color: #5c4a32; }
.snake-theme-retro .snake-stats strong { color: #5c4a32; }
.snake-theme-retro #snake-start-btn { background: #5c4a32; border-radius: 2px; }
.snake-theme-retro #snake-start-btn:hover { background: #3b2f1e; }
.snake-theme-retro .snake-dpad-btn { border-color: #5c4a32; background: rgba(92, 74, 50, 0.15); border-radius: 2px; }
.snake-theme-retro .snake-dpad-btn:active { background: rgba(92, 74, 50, 0.4); }
.snake-theme-retro .snake-difficulty-btn { border-color: #5c4a32; color: #5c4a32; border-radius: 2px; }
.snake-theme-retro .snake-difficulty-btn.active { background: #5c4a32; color: #fff; }
.snake-theme-retro .snake-pause-btn { border-color: #5c4a32; color: #5c4a32; border-radius: 2px; }
.snake-theme-retro .snake-pause-btn:hover { background: rgba(92,74,50,0.1); }
.snake-theme-retro .snake-leaderboard-table th { color: #5c4a32; }
.snake-theme-retro .snake-leaderboard-table tr:nth-child(even) { background: rgba(92,74,50,0.08); }
.snake-theme-retro .snake-speed-fill { background: #5c4a32; }
.snake-theme-retro .snake-board-frame { border-color: #5c4a32; }
.snake-theme-retro .snake-food-legend { background: rgba(92,74,50,0.08); }

/* ========== Header ========== */

.snake-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    flex-wrap: wrap;
    gap: 8px;
}

.snake-header-left {
    display: flex;
    align-items: center;
    gap: 8px;
}

.snake-header-icon {
    font-size: 1.8rem;
    line-height: 1;
}

.snake-title {
    margin: 0;
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.snake-stats {
    font-size: 0.95rem;
    display: flex;
    gap: 12px;
    align-items: center;
}

.snake-stats strong {
    font-size: 1.15rem;
    font-variant-numeric: tabular-nums;
}

/* ========== Difficulty Selector ========== */

.snake-difficulty-selector {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 6px;
    margin-bottom: 10px;
}

.snake-difficulty-btn {
    padding: 8px 18px;
    border: 2px solid #4a7c59;
    border-radius: 999px;
    background: transparent;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.snake-difficulty-btn:hover {
    opacity: 0.8;
}
.snake-difficulty-btn.active {
    color: #fff;
}
.snake-difficulty-btn.locked {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
}

.snake-lock-icon {
    display: none;
    font-size: 0.9rem;
    opacity: 0.5;
    margin-right: 2px;
}
.snake-lock-icon.visible {
    display: inline;
}

/* ========== Speed Indicator ========== */

.snake-speed-indicator {
    display: none;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 10px;
    font-size: 0.8rem;
}
.snake-speed-indicator.visible {
    display: flex;
}

.snake-speed-bar {
    width: 100px;
    height: 6px;
    background: rgba(0,0,0,0.1);
    border-radius: 3px;
    overflow: hidden;
}

.snake-speed-fill {
    height: 100%;
    width: 10%;
    border-radius: 3px;
    transition: width 0.3s, background 0.3s;
}

.snake-speed-value {
    font-weight: 700;
    min-width: 20px;
}

/* ========== Pause Button ========== */

.snake-pause-btn {
    padding: 6px 14px;
    border: 2px solid #4a7c59;
    border-radius: 999px;
    background: transparent;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
    margin-left: 4px;
}

/* ========== Canvas / Board ========== */

.snake-board-container {
    position: relative;
    display: flex;
    justify-content: center;
    margin-bottom: 16px;
}

.snake-board-frame {
    border: 3px solid rgba(74, 124, 89, 0.3);
    border-radius: 8px;
    box-shadow:
        0 2px 8px rgba(0,0,0,0.1),
        inset 0 1px 3px rgba(0,0,0,0.05);
    padding: 2px;
    background: rgba(0,0,0,0.03);
    display: inline-block;
    line-height: 0;
}

.snake-board-frame.snake-shake {
    animation: snakeShake 0.5s ease-in-out;
}

@keyframes snakeShake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-4px); }
    20%, 40%, 60%, 80% { transform: translateX(4px); }
}

#snake-canvas {
    display: block;
    border-radius: 6px;
    max-width: 100%;
    height: auto;
}

/* ========== Overlay ========== */

.snake-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.25s;
}
.snake-overlay.snake-hidden {
    opacity: 0;
    pointer-events: none;
}

.snake-overlay-content {
    text-align: center;
    color: #fff;
    padding: 16px;
}

.snake-overlay-icon {
    font-size: 3rem;
    margin-bottom: 8px;
    line-height: 1;
}

.snake-overlay-content h3 {
    margin: 0 0 8px;
    font-size: 1.8rem;
    font-weight: 800;
}

.snake-overlay-content p {
    margin: 0 0 16px;
    font-size: 0.95rem;
    opacity: 0.85;
}

#snake-start-btn {
    padding: 14px 48px;
    font-size: 1.2rem;
    font-weight: 700;
    color: #fff;
    background: #4a7c59;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.15s;
    box-shadow: 0 4px 12px rgba(74,124,89,0.3);
}
#snake-start-btn:hover {
    background: #3a6649;
    box-shadow: 0 6px 16px rgba(74,124,89,0.4);
}
#snake-start-btn:active {
    transform: scale(0.97);
}

.snake-overlay-difficulty {
    margin-top: 12px;
    font-size: 0.8rem;
    opacity: 0.6;
}

/* ========== Level Up Animation ========== */

.snake-level-up {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2rem;
    font-weight: 700;
    color: #ffd93d;
    text-shadow: 0 0 10px rgba(255,217,61,0.5);
    pointer-events: none;
    animation: snakeLevelUp 1s ease-out forwards;
    z-index: 10;
}

@keyframes snakeLevelUp {
    0% { opacity: 1; transform: translate(-50%, -50%) scale(0.5); }
    50% { opacity: 1; transform: translate(-50%, -50%) scale(1.2); }
    100% { opacity: 0; transform: translate(-50%, -80%) scale(1); }
}

/* ========== Food Legend ========== */

.snake-food-legend {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 12px;
    font-size: 0.8rem;
    flex-wrap: wrap;
    background: rgba(0,0,0,0.04);
    border-radius: 8px;
    padding: 8px 12px;
}

.snake-food-legend-item {
    display: flex;
    align-items: center;
    gap: 4px;
}

.snake-food-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: inline-block;
}

/* ========== D-pad (mobile) ========== */

.snake-controls {
    margin-top: 8px;
}

.snake-dpad {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.snake-dpad-btn {
    width: 72px;
    height: 72px;
    font-size: 1.6rem;
    border: 2px solid #4a7c59;
    background: rgba(74, 124, 89, 0.12);
    border-radius: 50%;
    cursor: pointer;
    color: inherit;
    display: flex;
    align-items: center;
    justify-content: center;
    -webkit-tap-highlight-color: transparent;
    transition: all 0.1s;
    touch-action: manipulation;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    position: relative;
    overflow: hidden;
}
.snake-dpad-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50%;
    background: radial-gradient(circle at center, rgba(255,255,255,0.15), transparent 70%);
    pointer-events: none;
}
.snake-dpad-btn:active {
    background: rgba(74, 124, 89, 0.35);
    transform: scale(0.92);
    box-shadow: 0 1px 3px rgba(0,0,0,0.15);
}

.snake-dpad-row {
    display: flex;
    gap: 8px;
    justify-content: center;
}

/* ========== Leaderboard ========== */

.snake-leaderboard {
    margin-top: 16px;
    border-top: 1px solid rgba(0,0,0,0.1);
    padding-top: 12px;
}

.snake-leaderboard-toggle {
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    background: none;
    border: none;
    color: inherit;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background 0.15s;
}
.snake-leaderboard-toggle:hover {
    background: rgba(0,0,0,0.05);
}

.snake-leaderboard-content {
    margin-top: 8px;
}
.snake-leaderboard-content.snake-hidden {
    display: none;
}

.snake-leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid rgba(0,0,0,0.08);
}
.snake-leaderboard-table th {
    padding: 8px 10px;
    text-align: left;
    font-weight: 600;
    border-bottom: 1px solid rgba(0,0,0,0.1);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.snake-leaderboard-table td {
    padding: 6px 10px;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}
.snake-leaderboard-table tr:nth-child(even) {
    background: rgba(0,0,0,0.02);
}
.snake-leaderboard-table tbody tr:first-child td {
    font-weight: 700;
}

/* ========== Stats Panel ========== */

.snake-stats-panel {
    margin-top: 12px;
    border-top: 1px solid rgba(0,0,0,0.1);
    padding-top: 12px;
    font-size: 0.8rem;
    opacity: 0.7;
}

.snake-stats-panel-toggle {
    cursor: pointer;
    background: none;
    border: none;
    color: inherit;
    font-size: 0.8rem;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background 0.15s;
}
.snake-stats-panel-toggle:hover {
    background: rgba(0,0,0,0.05);
}

.snake-stats-panel-content {
    margin-top: 4px;
    display: flex;
    justify-content: center;
    gap: 16px;
}
.snake-stats-panel-content.snake-hidden {
    display: none;
}

/* ========== Hidden ========== */

.snake-hidden {
    display: none !important;
}

/* ========== Responsive ========== */

@media (min-width: 768px) {
    .snake-controls {
        display: none;
    }
}

@media (max-width: 400px) {
    #snake-game-wrapper {
        padding: 12px;
        margin: 10px auto;
    }
    .snake-dpad-btn {
        width: 64px;
        height: 64px;
        font-size: 1.4rem;
    }
    .snake-difficulty-btn {
        padding: 6px 14px;
        font-size: 0.8rem;
    }
    .snake-speed-bar {
        width: 70px;
    }
    .snake-overlay-content h3 {
        font-size: 1.5rem;
    }
    #snake-start-btn {
        padding: 12px 36px;
        font-size: 1.1rem;
    }
}