/* CSS Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-bg: #0a0a0f;
    --secondary-bg: #141420;
    --card-bg: #1a1a2e;
    --accent-color: #00ff88;
    --accent-secondary: #ff0080;
    --text-primary: #ffffff;
    --text-secondary: #b0b0c4;
    --text-muted: #6b6b7d;
    --border-color: #2a2a3e;
    --success-color: #00ff88;
    --warning-color: #ffaa00;
    --error-color: #ff4444;
    
    /* Game Colors */
    --snake-color: #00ff88;
    --snake-head: #00cc6a;
    --food-color: #ff0080;
    --grid-color: #1a1a2e;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 20px rgba(0, 255, 136, 0.3);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
}

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, var(--primary-bg) 0%, var(--secondary-bg) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    font-smooth: always;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Game Container */
.game-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
}

/* Game Header */
.game-header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.game-title {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.title-snake {
    font-size: 3rem;
    animation: snake-wiggle 2s infinite ease-in-out;
}

@keyframes snake-wiggle {
    0%, 100% { transform: rotate(0deg); }
    25% { transform: rotate(-5deg); }
    75% { transform: rotate(5deg); }
}

.game-stats {
    display: flex;
    gap: var(--spacing-xl);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-color);
    text-shadow: 0 0 10px rgba(0, 255, 136, 0.5);
}

/* Canvas Container */
.canvas-container {
    position: relative;
    margin-bottom: var(--spacing-xl);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    border: 2px solid var(--accent-color);
}

#game-canvas {
    display: block;
    background: var(--primary-bg);
    background-image: 
        radial-gradient(circle at 25% 25%, rgba(0, 255, 136, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(255, 0, 128, 0.1) 0%, transparent 50%);
}

/* Overlays */
.game-overlay,
.pause-overlay,
.game-over-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.game-overlay.hidden,
.pause-overlay.hidden,
.game-over-overlay.hidden {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.95);
}

.overlay-content,
.pause-content,
.game-over-content {
    text-align: center;
    padding: var(--spacing-xxl);
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    animation: slide-up 0.5s ease;
}

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

.overlay-title,
.game-over-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.overlay-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

/* Controls */
.overlay-controls {
    margin-bottom: var(--spacing-xl);
}

.control-group h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.controls-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    max-width: 300px;
    margin: 0 auto;
}

.control-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md);
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.control-key {
    font-family: 'Courier New', monospace;
    font-weight: 700;
    color: var(--accent-color);
    font-size: 0.875rem;
}

.control-desc {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Buttons */
.start-button,
.restart-button,
.menu-button {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.125rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    position: relative;
    overflow: hidden;
}

.start-button,
.restart-button {
    background: linear-gradient(135deg, var(--accent-color), var(--success-color));
    color: var(--primary-bg);
    box-shadow: 0 4px 15px rgba(0, 255, 136, 0.3);
}

.menu-button {
    background: linear-gradient(135deg, var(--accent-secondary), var(--error-color));
    color: var(--text-primary);
    box-shadow: 0 4px 15px rgba(255, 0, 128, 0.3);
    margin-left: var(--spacing-md);
}

.start-button:hover,
.restart-button:hover,
.menu-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 255, 136, 0.4);
}

.start-button:active,
.restart-button:active,
.menu-button:active {
    transform: translateY(0);
}

/* Game Over Stats */
.final-stats {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.final-stat {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.final-stat-label {
    color: var(--text-secondary);
}

.final-stat-value {
    font-weight: 700;
    color: var(--accent-color);
}

.game-over-buttons {
    display: flex;
    justify-content: center;
}

/* Mobile Controls */
.mobile-controls {
    display: none;
    width: 100%;
    justify-content: space-between;
    align-items: flex-end;
    margin-top: var(--spacing-lg);
    padding: var(--spacing-lg);
}

.mobile-dpad {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.dpad-middle {
    display: flex;
    gap: var(--spacing-lg);
}

.dpad-button {
    width: 60px;
    height: 60px;
    font-size: 1.5rem;
    border: 2px solid var(--accent-color);
    background: var(--card-bg);
    color: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.dpad-button:hover,
.dpad-button:active {
    background: var(--accent-color);
    color: var(--primary-bg);
    transform: scale(0.95);
}

.mobile-actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.action-button {
    width: 50px;
    height: 50px;
    font-size: 1.25rem;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-primary);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.action-button:hover {
    background: var(--accent-color);
    color: var(--primary-bg);
}

/* Footer */
.game-footer {
    width: 100%;
    text-align: center;
    padding: var(--spacing-lg);
    color: var(--text-muted);
}

.footer-content p {
    margin-bottom: var(--spacing-md);
}

.tip {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Particle Canvas */
.particle-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity 0.5s ease;
}

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

.loading-content {
    text-align: center;
}

.loading-snake {
    font-size: 4rem;
    margin-bottom: var(--spacing-lg);
    animation: loading-bounce 1s infinite ease-in-out;
}

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

.loading-content h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--accent-color);
}

.loading-bar {
    width: 200px;
    height: 4px;
    background: var(--secondary-bg);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin: 0 auto;
}

.loading-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-secondary));
    border-radius: var(--radius-sm);
    animation: loading-progress 2s ease-in-out;
}

@keyframes loading-progress {
    0% { width: 0%; }
    100% { width: 100%; }
}

/* Responsive Design */
@media (max-width: 768px) {
    .game-container {
        padding: var(--spacing-md);
    }
    
    .game-header {
        flex-direction: column;
        gap: var(--spacing-lg);
        text-align: center;
    }
    
    .game-title {
        font-size: 2rem;
    }
    
    .game-stats {
        gap: var(--spacing-lg);
    }
    
    #game-canvas {
        width: 100%;
        height: auto;
        max-width: 400px;
        max-height: 300px;
    }
    
    .mobile-controls {
        display: flex;
    }
    
    .overlay-content,
    .pause-content,
    .game-over-content {
        padding: var(--spacing-lg);
        margin: var(--spacing-md);
    }
    
    .overlay-title,
    .game-over-title {
        font-size: 2rem;
    }
    
    .controls-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .game-title {
        font-size: 1.5rem;
    }
    
    .title-snake {
        font-size: 2rem;
    }
    
    .stat-value {
        font-size: 1.25rem;
    }
    
    .game-stats {
        gap: var(--spacing-md);
    }
    
    .dpad-button {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --primary-bg: #000000;
        --secondary-bg: #111111;
        --card-bg: #222222;
        --text-primary: #ffffff;
        --border-color: #555555;
    }
}

/* Focus styles for accessibility */
button:focus,
.dpad-button:focus,
.action-button:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .loading-screen,
    .particle-canvas,
    .mobile-controls {
        display: none;
    }
}