:root {
    --bg-color: #0f172a;
    --grid-line: #1e293b;
    --snake-color: #00ff88;
    --snake-head: #ccffdd;
    --snake-glow: 0 0 10px #00ff88, 0 0 20px #00ff88;
    --food-color: #ff0055;
    --food-glow: 0 0 10px #ff0055, 0 0 20px #ff0055;
    --text-color: #f8fafc;
    --overlay-bg: rgba(15, 23, 42, 0.9);
    --font-main: 'Outfit', sans-serif;
    --accent-color: #38bdf8;
    --level-hue: 0deg;
}

.game-container {
    text-align: center;
    position: relative;
    width: 100%;
    max-width: 500px;
    filter: hue-rotate(var(--level-hue));
    transition: filter 0.8s ease;
}

[data-theme="cyberpunk"] {
    --bg-color: #1a1a2e;
    --grid-line: #16213e;
    --snake-color: #f0a500;
    --snake-head: #f9d371;
    --snake-glow: 0 0 10px #f0a500;
    --food-color: #e94560;
    --accent-color: #0f3460;
}

[data-theme="classic"] {
    --bg-color: #000;
    --grid-line: #001a00;
    --snake-color: #00ff00;
    --snake-head: #88ff88;
    --snake-glow: none;
    --food-color: #ffffff;
    --accent-color: #003300;
}

[data-theme="sunset"] {
    --bg-color: #2d132c;
    --grid-line: #522546;
    --snake-color: #ffde7d;
    --snake-head: #fff4e0;
    --snake-glow: 0 0 10px #ffde7d;
    --food-color: #f67280;
    --accent-color: #c06c84;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.2);
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
    margin-bottom: 1rem;
}

.header-controls {
    display: flex;
    gap: 0.5rem;
}

#main-home-btn,
#pause-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

#main-home-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--snake-color);
    color: var(--snake-color);
    box-shadow: 0 0 15px rgba(0, 255, 136, 0.2);
}

.score-board {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    padding: 0 2rem;
    font-size: 1.1rem;
    font-weight: 300;
}

.canvas-wrapper {
    position: relative;
    box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    display: inline-block;
}

canvas {
    background-color: #111;
    background-image:
        linear-gradient(var(--grid-line) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
    background-size: 20px 20px;
    display: block;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: var(--bg-color);
    /* Solid background to completely hide game */
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.3s ease;
    z-index: 9999;
}

.menu-card {
    width: 90%;
    max-width: 400px;
    padding: 3rem 2rem;
    background: #1e293b;
    /* Solid, non-transparent background */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border-radius: 24px;
    border: 2px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.8);
}

.overlay.active {
    opacity: 1;
    pointer-events: all;
}

.overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.overlay h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-transform: uppercase;
}

.danger-text {
    color: #ff3366;
    text-shadow: 0 0 15px rgba(255, 51, 102, 0.6);
}

.overlay p {
    margin-bottom: 2rem;
    opacity: 0.8;
}

.glow-btn {
    background: transparent;
    border: 2px solid var(--snake-color);
    color: var(--snake-color);
    padding: 12px 32px;
    font-family: inherit;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
    border-radius: 50px;
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.2);
}

.glow-btn:hover {
    background: var(--snake-color);
    color: #000;
    box-shadow: 0 0 20px rgba(0, 255, 136, 0.6);
}

.glow-btn.small {
    padding: 8px 24px;
    font-size: 0.9rem;
    margin-top: 1rem;
}

.glass-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    padding: 12px 32px;
    font-family: inherit;
    font-weight: 400;
    font-size: 1rem;
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
    border-radius: 50px;
    backdrop-filter: blur(10px);
}

.glass-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.2);
}

.menu-actions {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.mode-selection {
    display: flex;
    background: rgba(0, 0, 0, 0.3);
    padding: 5px;
    border-radius: 10px;
    margin-bottom: 0.5rem;
}

.mode-btn {
    background: transparent;
    border: none;
    color: var(--text-color);
    padding: 8px 16px;
    cursor: pointer;
    border-radius: 6px;
    opacity: 0.5;
    transition: all 0.2s ease;
    font-family: inherit;
    font-weight: 600;
}

.mode-btn.active {
    opacity: 1;
    background: var(--accent-color);
    color: white;
}

#mode-desc {
    font-size: 0.9rem;
    height: 1.2rem;
    margin-bottom: 2rem;
}

.difficulty-selection {
    margin-bottom: 2rem;
    width: 100%;
}

.difficulty-selection h3 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    opacity: 0.6;
    margin-bottom: 0.5rem;
}

.diff-btns {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
}

.diff-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    padding: 6px 16px;
    cursor: pointer;
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.8rem;
    font-weight: 600;
    transition: all 0.2s ease;
}

.diff-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.diff-btn.active {
    background: var(--snake-color);
    color: #000;
    border-color: var(--snake-color);
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.3);
}

.custom-section {
    width: 80%;
    margin-bottom: 1.5rem;
}

.custom-section h3 {
    font-size: 1rem;
    margin-bottom: 0.8rem;
    text-align: left;
    opacity: 0.7;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.8rem;
}

.option {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.9rem;
}

.option:hover {
    background: rgba(255, 255, 255, 0.08);
}

.option.selected {
    border-color: var(--snake-color);
    background: rgba(0, 255, 136, 0.1);
    color: var(--snake-color);
}

.level-notice {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 3.5rem;
    font-weight: 600;
    color: white;
    text-shadow: 0 0 30px var(--snake-color);
    pointer-events: none;
    z-index: 100;
    animation: zoomIn 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.level-notice.fade-out {
    opacity: 0;
    transform: translate(-50%, -60%) scale(1.1);
    transition: all 0.5s ease;
}

@keyframes zoomIn {
    from {
        transform: translate(-50%, -50%) scale(0.5);
        opacity: 0;
    }

    to {
        transform: translate(-50%, -50%) scale(1);
        opacity: 1;
    }
}

/* Toggle Switch Styles */
.toggle-control {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.03);
    padding: 12px 16px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 10px;
}

.switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.1);
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked+.slider {
    background-color: var(--snake-color);
}

input:checked+.slider:before {
    transform: translateX(20px);
}

/* Summary Screen Styles */
.summary-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    width: 100%;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: rgba(0, 0, 0, 0.3);
    /* Slight contrast background for stats */
    border-radius: 16px;
}

.summary-item {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
}

.summary-item.full-width {
    grid-column: span 2;
}

.summary-item .label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    opacity: 0.6;
}

.summary-item .value {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--accent-color);
    text-shadow: 0 0 10px rgba(56, 189, 248, 0.3);
}

.summary-item:nth-child(1) .value {
    color: #38bdf8;
}

/* Score - Cyan */
.summary-item:nth-child(2) .value {
    color: #f472b6;
}

/* Level - Pink */
.summary-item:nth-child(3) .value {
    color: #fbbf24;
}

/* Length - Amber */
.summary-item:nth-child(4) .value {
    color: #34d399;
}

/* Occupancy - Emerald */
.summary-item:nth-child(5) .value {
    color: #818cf8;
}

/* Mode - Indigo */

.summary-item.highlight .value {
    color: var(--snake-color);
    text-shadow: 0 0 15px rgba(0, 255, 136, 0.5);
    font-size: 1.6rem;
}

/* Specific styling for the summary screen h2 */
#game-over-screen h2 {
    margin-bottom: 2rem;
    letter-spacing: 4px;
}