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

:root {
    /* Color Palette */
    --primary-bg: #0a0a0f;
    --secondary-bg: #1a1a2e;
    --accent-bg: #16213e;
    --surface-bg: #252550;
    
    --primary-text: #ffffff;
    --secondary-text: #b8b8cc;
    --accent-text: #4fc3f7;
    --success-text: #4caf50;
    --warning-text: #ff9800;
    --error-text: #f44336;
    
    --primary-accent: #00d4ff;
    --secondary-accent: #7c4dff;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Typography */
    --font-primary: 'Orbitron', monospace;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-xxl: 2rem;
    --font-size-xxxl: 3rem;
    
    /* Effects */
    --blur-sm: blur(4px);
    --blur-md: blur(8px);
    --blur-lg: blur(16px);
    
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(0, 212, 255, 0.3);
    
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 16px;
    --border-radius-xl: 24px;
}

body {
    font-family: var(--font-primary);
    background: var(--primary-bg);
    color: var(--primary-text);
    overflow: hidden;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
}

/* App Container */
#app {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

/* Screen Management */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: scale(0.95);
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.screen.active {
    opacity: 1;
    visibility: visible;
    transform: scale(1);
}

/* Game Canvas */
.game-container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: radial-gradient(circle at center, var(--secondary-bg) 0%, var(--primary-bg) 100%);
}

.game-canvas {
    display: block;
    max-width: 100%;
    max-height: 100%;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-lg);
    background: var(--accent-bg);
}

.game-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 10;
}

/* Modal Overlays */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: var(--blur-md);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    z-index: 1000;
    transition: all 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--secondary-bg);
    border: 1px solid var(--accent-bg);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    max-width: 90vw;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --font-size-xs: 0.7rem;
        --font-size-sm: 0.8rem;
        --font-size-md: 0.9rem;
        --font-size-lg: 1.1rem;
        --font-size-xl: 1.3rem;
        --font-size-xxl: 1.8rem;
        --font-size-xxxl: 2.5rem;
        
        --spacing-xs: 0.2rem;
        --spacing-sm: 0.4rem;
        --spacing-md: 0.8rem;
        --spacing-lg: 1.2rem;
        --spacing-xl: 1.6rem;
        --spacing-xxl: 2.4rem;
    }
    
    .modal-content {
        padding: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .modal-content {
        margin: var(--spacing-md);
        padding: var(--spacing-md);
    }
}

/* Performance Optimizations */
.game-canvas {
    will-change: auto;
}

.screen.transitioning {
    will-change: opacity, transform;
}

.screen:not(.transitioning) {
    will-change: auto;
}