/* ===================================
   CSS Variables
   =================================== */

:root {
    /* Colors - Retro Arcade Neon */
    --color-bg: #0a0e27;
    --color-bg-light: #151b3d;
    --color-arcade: #1a1f47;

    /* Neon Colors */
    --color-neon-green: #00ff41;
    --color-neon-cyan: #00f0ff;
    --color-neon-pink: #ff006e;
    --color-neon-yellow: #ffed4e;

    /* Snake Colors */
    --color-snake: #00ff41;
    --color-snake-glow: rgba(0, 255, 65, 0.6);
    --color-food: #ff006e;
    --color-food-glow: rgba(255, 0, 110, 0.6);

    /* UI Colors */
    --color-grid: rgba(0, 240, 255, 0.1);
    --color-text: #ffffff;
    --color-text-dim: rgba(255, 255, 255, 0.7);

    /* Typography */
    --font-display: 'Press Start 2P', monospace;
    --font-body: 'Orbitron', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Effects */
    --glow-sm: 0 0 10px currentColor, 0 0 20px currentColor;
    --glow-md: 0 0 10px currentColor, 0 0 20px currentColor, 0 0 30px currentColor;
    --glow-lg: 0 0 20px currentColor, 0 0 40px currentColor, 0 0 60px currentColor;
}

/* ===================================
   Global Styles
   =================================== */

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

body {
    font-family: var(--font-body);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ===================================
   Background Effects
   =================================== */

/* Animated Grid Background */
.bg-grid {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        linear-gradient(var(--color-grid) 1px, transparent 1px),
        linear-gradient(90deg, var(--color-grid) 1px, transparent 1px);
    background-size: 50px 50px;
    z-index: 0;
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    0% {
        background-position: 0 0;
    }
    100% {
        background-position: 50px 50px;
    }
}

/* CRT Scanlines */
.crt-scanlines {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: repeating-linear-gradient(
        0deg,
        rgba(0, 0, 0, 0.1) 0px,
        rgba(0, 0, 0, 0.1) 1px,
        transparent 1px,
        transparent 2px
    );
    pointer-events: none;
    z-index: 100;
    animation: scanlines 8s linear infinite;
}

@keyframes scanlines {
    0% {
        background-position: 0 0;
    }
    100% {
        background-position: 0 100%;
    }
}

/* ===================================
   Container
   =================================== */

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-md);
    position: relative;
    z-index: 1;
}

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

.header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
    animation: slideDown 0.6s ease-out;
}

.logo {
    display: inline-block;
}

.logo-icon {
    font-size: 4rem;
    animation: float 3s ease-in-out infinite;
    display: inline-block;
}

.logo-text h1 {
    font-family: var(--font-display);
    font-size: 3rem;
    color: var(--color-neon-green);
    text-shadow: var(--glow-lg);
    letter-spacing: 0.3rem;
    margin: var(--spacing-sm) 0;
    animation: neonFlicker 2s ease-in-out infinite alternate;
}

.subtitle {
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: var(--color-neon-cyan);
    text-transform: uppercase;
    letter-spacing: 0.2rem;
    text-shadow: var(--glow-sm);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes neonFlicker {
    0%, 100% {
        opacity: 1;
        text-shadow:
            0 0 10px var(--color-neon-green),
            0 0 20px var(--color-neon-green),
            0 0 40px var(--color-neon-green),
            0 0 80px var(--color-neon-green);
    }
    50% {
        opacity: 0.95;
        text-shadow:
            0 0 5px var(--color-neon-green),
            0 0 10px var(--color-neon-green),
            0 0 20px var(--color-neon-green),
            0 0 40px var(--color-neon-green);
    }
}

/* ===================================
   Game Section
   =================================== */

.game-section {
    animation: fadeIn 0.8s ease-out 0.2s backwards;
}

/* Score Panel */
.score-panel {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.score-item {
    flex: 1;
    min-width: 150px;
    background: var(--color-bg-light);
    border: 2px solid var(--color-neon-cyan);
    border-radius: 8px;
    padding: var(--spacing-sm);
    text-align: center;
    box-shadow:
        0 0 10px rgba(0, 240, 255, 0.3),
        inset 0 0 20px rgba(0, 240, 255, 0.1);
    transition: all 0.3s ease;
}

.score-item:hover {
    transform: translateY(-2px);
    box-shadow:
        0 0 20px rgba(0, 240, 255, 0.5),
        inset 0 0 30px rgba(0, 240, 255, 0.2);
}

.score-label {
    display: block;
    font-family: var(--font-display);
    font-size: 0.6rem;
    color: var(--color-neon-cyan);
    margin-bottom: var(--spacing-xs);
    letter-spacing: 0.1rem;
}

.score-value {
    display: block;
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-neon-green);
    text-shadow: var(--glow-md);
}

/* Game Container */
.game-container {
    position: relative;
    background: var(--color-arcade);
    border: 4px solid var(--color-neon-cyan);
    border-radius: 12px;
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    box-shadow:
        0 0 30px rgba(0, 240, 255, 0.4),
        inset 0 0 50px rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
}

#gameCanvas {
    display: block;
    background: #000;
    border: 2px solid rgba(0, 255, 65, 0.3);
    box-shadow:
        0 0 20px rgba(0, 255, 65, 0.2),
        inset 0 0 30px rgba(0, 0, 0, 0.8);
    max-width: 100%;
    height: auto;
}

/* Overlay Screens */
.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 14, 39, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    backdrop-filter: blur(10px);
    animation: fadeIn 0.3s ease-out;
}

.overlay.hidden {
    display: none;
}

.overlay-content {
    text-align: center;
    padding: var(--spacing-xl);
    max-width: 500px;
}

.overlay-title {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--color-neon-cyan);
    text-shadow: var(--glow-lg);
    margin-bottom: var(--spacing-md);
    letter-spacing: 0.2rem;
    animation: pulse 2s ease-in-out infinite;
}

.overlay-title.game-over {
    color: var(--color-neon-pink);
    animation: glitch 0.5s ease-in-out infinite;
}

.overlay-text {
    font-family: var(--font-body);
    font-size: 1rem;
    color: var(--color-text-dim);
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
}

.overlay-actions {
    margin-top: var(--spacing-lg);
}

/* Final Stats */
.final-stats {
    margin: var(--spacing-lg) 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.stat {
    background: var(--color-bg-light);
    border: 2px solid var(--color-neon-green);
    border-radius: 8px;
    padding: var(--spacing-md);
    box-shadow: 0 0 15px rgba(0, 255, 65, 0.3);
}

.stat-label {
    display: block;
    font-family: var(--font-display);
    font-size: 0.7rem;
    color: var(--color-text-dim);
    margin-bottom: var(--spacing-xs);
    letter-spacing: 0.1rem;
}

.stat-label.new-record {
    color: var(--color-neon-yellow);
    font-size: 0.9rem;
    text-shadow: var(--glow-md);
    animation: blink 1s ease-in-out infinite;
}

.stat-value {
    display: block;
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--color-neon-green);
    text-shadow: var(--glow-lg);
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes glitch {
    0%, 100% {
        transform: translate(0);
    }
    20% {
        transform: translate(-2px, 2px);
    }
    40% {
        transform: translate(-2px, -2px);
    }
    60% {
        transform: translate(2px, 2px);
    }
    80% {
        transform: translate(2px, -2px);
    }
}

@keyframes blink {
    0%, 50%, 100% {
        opacity: 1;
    }
    25%, 75% {
        opacity: 0.5;
    }
}

/* ===================================
   Buttons
   =================================== */

.btn {
    font-family: var(--font-display);
    font-size: 0.9rem;
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.1rem;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.btn-primary {
    background: var(--color-neon-green);
    color: var(--color-bg);
    box-shadow:
        0 0 20px rgba(0, 255, 65, 0.5),
        0 4px 15px rgba(0, 0, 0, 0.3);
}

.btn-primary:hover {
    background: var(--color-neon-cyan);
    transform: translateY(-2px);
    box-shadow:
        0 0 30px rgba(0, 240, 255, 0.7),
        0 6px 20px rgba(0, 0, 0, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

/* Controls */
.controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.control-btn {
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 700;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-light);
    color: var(--color-neon-cyan);
    border: 2px solid var(--color-neon-cyan);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.control-btn:hover {
    background: var(--color-neon-cyan);
    color: var(--color-bg);
    transform: translateY(-2px);
    box-shadow: 0 0 20px rgba(0, 240, 255, 0.6);
}

/* ===================================
   Mobile Controls
   =================================== */

.mobile-controls {
    display: none;
    justify-content: center;
    margin-top: var(--spacing-md);
}

.dpad {
    position: relative;
    width: 200px;
    height: 200px;
}

.dpad-btn {
    position: absolute;
    width: 60px;
    height: 60px;
    background: var(--color-bg-light);
    border: 2px solid var(--color-neon-green);
    border-radius: 8px;
    color: var(--color-neon-green);
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 15px rgba(0, 255, 65, 0.3);
}

.dpad-btn:active {
    background: var(--color-neon-green);
    color: var(--color-bg);
    box-shadow: 0 0 25px rgba(0, 255, 65, 0.6);
}

.dpad-up {
    top: 0;
    left: 50%;
    transform: translateX(-50%);
}

.dpad-down {
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

.dpad-left {
    left: 0;
    top: 50%;
    transform: translateY(-50%);
}

.dpad-right {
    right: 0;
    top: 50%;
    transform: translateY(-50%);
}

@media (max-width: 768px) {
    .mobile-controls {
        display: flex;
    }
}

/* ===================================
   Instructions
   =================================== */

.instructions {
    background: var(--color-bg-light);
    border: 2px solid var(--color-neon-cyan);
    border-radius: 12px;
    padding: var(--spacing-lg);
    box-shadow: 0 0 20px rgba(0, 240, 255, 0.3);
    animation: fadeIn 1s ease-out 0.4s backwards;
}

.instructions h3 {
    font-family: var(--font-display);
    font-size: 1.2rem;
    color: var(--color-neon-cyan);
    text-align: center;
    margin-bottom: var(--spacing-md);
    letter-spacing: 0.2rem;
    text-shadow: var(--glow-sm);
}

.instruction-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.instruction-item {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--color-arcade);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.instruction-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 0 20px rgba(0, 240, 255, 0.4);
}

.instruction-item i {
    font-size: 2rem;
    color: var(--color-neon-green);
    margin-bottom: var(--spacing-sm);
    display: block;
}

.instruction-item p {
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: var(--color-text-dim);
    line-height: 1.5;
}

/* ===================================
   Animations
   =================================== */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@media (max-width: 768px) {
    .container {
        padding: var(--spacing-sm);
    }

    .logo-text h1 {
        font-size: 2rem;
        letter-spacing: 0.2rem;
    }

    .subtitle {
        font-size: 0.7rem;
    }

    .score-panel {
        gap: var(--spacing-sm);
    }

    .score-item {
        min-width: 100px;
        padding: var(--spacing-xs);
    }

    .score-label {
        font-size: 0.5rem;
    }

    .score-value {
        font-size: 1.2rem;
    }

    .game-container {
        padding: var(--spacing-sm);
    }

    #gameCanvas {
        width: 100%;
        height: auto;
    }

    .overlay-title {
        font-size: 1.5rem;
    }

    .overlay-text {
        font-size: 0.9rem;
    }

    .btn {
        font-size: 0.7rem;
        padding: var(--spacing-xs) var(--spacing-md);
    }

    .instructions h3 {
        font-size: 1rem;
    }

    .instruction-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .logo-text h1 {
        font-size: 1.5rem;
    }

    .score-panel {
        flex-direction: column;
    }

    .overlay-content {
        padding: var(--spacing-md);
    }
}