:root {
    --bg-color: #0d1117;
    --screen-bg: #001100;
    --snake-color: #33ff00;
    --food-color: #ff3333;
    --text-color: #33ff00;
    --glow: 0 0 10px rgba(51, 255, 0, 0.7);
    --crt-flicker: rgba(18, 16, 16, 0.1);
}

/* Themes */
body.theme-amber {
    --screen-bg: #1a1100;
    --snake-color: #ffb000;
    --text-color: #ffb000;
    --glow: 0 0 10px rgba(255, 176, 0, 0.7);
}

body.theme-blue {
    --screen-bg: #00111a;
    --snake-color: #00ccff;
    --text-color: #00ccff;
    --glow: 0 0 10px rgba(0, 204, 255, 0.7);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none;
    -webkit-user-select: none;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Press Start 2P', cursive;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    position: relative;
    transition: color 0.3s;
}

/* CRT Effects */
.crt-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: radial-gradient(circle, rgba(0, 0, 0, 0) 60%, rgba(0, 0, 0, 0.6) 100%);
    pointer-events: none;
    z-index: 10;
}

.scanlines {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: linear-gradient(to bottom,
            rgba(255, 255, 255, 0),
            rgba(255, 255, 255, 0) 50%,
            rgba(0, 0, 0, 0.2) 50%,
            rgba(0, 0, 0, 0.2));
    background-size: 100% 4px;
    pointer-events: none;
    z-index: 11;
    animation: scroll 10s linear infinite;
}

@keyframes scroll {
    0% {
        background-position: 0 0;
    }

    100% {
        background-position: 0 100%;
    }
}

/* Game Container */
.game-container {
    position: relative;
    z-index: 5;
    text-align: center;
    width: 100%;
    max-width: 500px;
    padding: 20px;
}

header {
    margin-bottom: 20px;
}

h1 {
    font-size: 2.5rem;
    text-shadow: var(--glow);
    margin-top: 10px;
    transition: text-shadow 0.3s;
}

.back-link {
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.8rem;
    opacity: 0.7;
    transition: opacity 0.2s;
    display: inline-block;
    margin-bottom: 10px;
}

.back-link:hover {
    opacity: 1;
    text-shadow: var(--glow);
}

/* Score Board */
.score-board {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
    padding: 0 10px;
}

.score-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.label {
    font-size: 0.7rem;
    opacity: 0.8;
}

#score,
#high-score {
    font-size: 1.2rem;
    text-shadow: var(--glow);
    transition: text-shadow 0.3s;
}

/* Canvas Wrapper */
.canvas-wrapper {
    position: relative;
    border: 4px solid var(--text-color);
    box-shadow: var(--glow), inset 0 0 20px rgba(51, 255, 0, 0.2);
    /* Fallback glow color */
    box-shadow: var(--glow), inset 0 0 20px var(--text-color);
    /* Use variable */
    background-color: var(--screen-bg);
    margin: 0 auto;
    width: fit-content;
    transition: border-color 0.3s, box-shadow 0.3s, background-color 0.3s;
}

canvas {
    display: block;
    image-rendering: pixelated;
}

/* Overlays */
.overlay-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 15px;
    padding: 20px;
}

.hidden {
    display: none;
}

.overlay-screen h2 {
    font-size: 1.5rem;
    color: #fff;
    text-shadow: 2px 2px #000;
    margin-bottom: 10px;
}

.overlay-screen p {
    font-size: 0.8rem;
    line-height: 1.5;
    margin-bottom: 15px;
}

.retro-btn {
    background: var(--text-color);
    color: var(--screen-bg);
    border: none;
    padding: 15px 20px;
    font-family: 'Press Start 2P', cursive;
    font-size: 1rem;
    cursor: pointer;
    box-shadow: 0 0 10px var(--text-color);
    transition: transform 0.1s, background-color 0.3s, color 0.3s, box-shadow 0.3s;
    width: 200px;
}

.retro-btn.small-btn {
    padding: 10px 15px;
    font-size: 0.8rem;
    width: 150px;
    margin-top: 5px;
    background: transparent;
    border: 2px solid var(--text-color);
    color: var(--text-color);
}

.retro-btn.small-btn:hover {
    background: var(--text-color);
    color: var(--screen-bg);
}

.retro-btn:active {
    transform: scale(0.95);
}

.retro-btn:hover {
    background: #fff;
}

/* Settings Styles */
.setting-group {
    width: 100%;
    margin-bottom: 15px;
    text-align: center;
}

.setting-group label {
    display: block;
    font-size: 0.7rem;
    margin-bottom: 8px;
    color: #fff;
    opacity: 0.8;
}

.toggle-group {
    display: flex;
    justify-content: center;
    gap: 10px;
}

.toggle-group button {
    background: transparent;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    font-family: inherit;
    font-size: 0.6rem;
    cursor: pointer;
    transition: all 0.2s;
}

.toggle-group button.active {
    background: var(--text-color);
    color: var(--screen-bg);
}

.toggle-group button:hover:not(.active) {
    background: rgba(255, 255, 255, 0.1);
}

/* Controls Hint */
.controls-hint {
    margin-top: 20px;
    font-size: 0.7rem;
    opacity: 0.6;
    line-height: 1.6;
}

/* Responsive */
@media (max-width: 500px) {
    h1 {
        font-size: 1.8rem;
    }

    canvas {
        width: 300px;
        height: 300px;
    }

    .game-container {
        padding: 10px;
    }
}