/* Modern Brain Games Design System */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

:root {
    /* NIGHT MODE (Default) */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #ec4899;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.3);
    
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* DAY MODE */
body.day-mode {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --secondary: #f43f5e;
    --success: #16a34a;
    
    --bg-primary: #f8fafc;
    --bg-secondary: #e2e8f0;
    --bg-tertiary: #cbd5e1;
    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    
    --glass-bg: rgba(0, 0, 0, 0.03);
    --glass-border: rgba(0, 0, 0, 0.1);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    transition: background var(--transition-base), color var(--transition-base);
}

/* Navbar */
.modern-nav {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all var(--transition-base);
}

body.day-mode .modern-nav {
    background: rgba(248, 250, 252, 0.8);
}

.modern-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    transition: all var(--transition-base);
    font-weight: 500;
}

.modern-nav a:hover {
    color: var(--text-primary);
    background: var(--glass-bg);
}

.modern-nav .brand {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 250ms;
}

.modern-nav .brand:hover {
    filter: brightness(1.2);
    transform: scale(1.05);
}

/* Theme Toggle Button */
.theme-toggle {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all var(--transition-base);
}

.theme-toggle:hover {
    background: var(--glass-border);
    border-color: var(--primary);
}

/* Glass Card */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.glass-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(255, 255, 255, 0.15);
}

body.day-mode .glass-card:hover {
    border-color: rgba(0, 0, 0, 0.15);
}

/* Gradient Cards */
.gradient-card {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 1.5rem;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.gradient-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, transparent 0%, rgba(255, 255, 255, 0.1) 100%);
    opacity: 0;
    transition: opacity var(--transition-base);
    pointer-events: none;
}

.gradient-card:hover::before {
    opacity: 1;
}

.gradient-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-xl), 0 0 40px rgba(99, 102, 241, 0.3);
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 1rem;
    position: relative;
}

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 900;
    background: linear-gradient(135deg, #fff 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
    line-height: 1.2;
}

body.day-mode .hero h1 {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Stat Cards */
.stat-card {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
    border: 1px solid var(--glass-border);
    border-radius: 1rem;
    padding: 1.5rem;
    text-align: center;
    transition: all var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
    box-shadow: 0 8px 32px rgba(99, 102, 241, 0.2);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

/* Game Cards */
.game-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
    padding: 2.5rem;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.game-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--secondary) 100%);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.game-card:hover::before {
    transform: scaleX(1);
}

.game-card:hover {
    transform: translateY(-8px);
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: var(--shadow-xl);
}

body.day-mode .game-card:hover {
    border-color: rgba(0, 0, 0, 0.2);
}

.game-icon {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    display: inline-block;
    animation: float 3s ease-in-out infinite;
}

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

.game-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.game-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.game-stats {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--glass-border);
}

.game-stat {
    flex: 1;
}

.game-stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.game-stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-light);
}

/* Buttons */
.btn {
    padding: 0.875rem 2rem;
    border-radius: 0.75rem;
    font-weight: 600;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    display: inline-block;
    text-align: center;
    position: relative;
    z-index: 10;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
}

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

.btn-success {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: white;
    box-shadow: 0 4px 16px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(16, 185, 129, 0.4);
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: 2rem;
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
    overflow: visible;
    box-shadow: var(--shadow-xl);
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

.cta-section h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
}

.cta-section p {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
    position: relative;
    z-index: 1;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    animation: fadeInUp 0.6s ease-out;
}

.animate-in-delay-1 { animation-delay: 0.1s; animation-fill-mode: both; }
.animate-in-delay-2 { animation-delay: 0.2s; animation-fill-mode: both; }
.animate-in-delay-3 { animation-delay: 0.3s; animation-fill-mode: both; }

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .game-card {
        padding: 1.5rem;
    }
    
    .cta-section {
        padding: 3rem 1.5rem;
    }
}