/* MOK Education - Modern UI Foundation Design System */
:root {
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e1b4b 50%, #0f172a 100%);
    --card-bg: rgba(30, 41, 59, 0.7);
    --card-border: rgba(255, 255, 255, 0.1);
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-glow: rgba(99, 102, 241, 0.35);
    --accent: #06b6d4;
    --accent-glow: rgba(6, 182, 212, 0.35);
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --glass-blur: blur(16px);
    --radius-lg: 16px;
    --radius-md: 10px;
    --transition-fast: all 0.25s ease-in-out;
    --font-stack: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

body {
    font-family: var(--font-stack);
    background: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    line-height: 1.6;
    overflow-x: hidden;
}

/* Glassmorphism Container */
.app-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    flex: 1;
}

/* Header & Navigation */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2rem;
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    margin-bottom: 2.5rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: #fff;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.brand-badge {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 800;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    list-style: none;
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
    color: #fff;
    text-shadow: 0 0 10px var(--primary-glow);
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    margin-bottom: 3rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: 50%;
    transform: translateX(-50%);
    width: 300px;
    height: 300px;
    background: var(--primary-glow);
    filter: blur(100px);
    border-radius: 50%;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.25rem;
    background: linear-gradient(135deg, #ffffff 0%, #cbd5e1 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 650px;
    margin: 0 auto 2rem;
}

/* UI Cards Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.card {
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 1.75rem;
    transition: var(--transition-fast);
}

.card:hover {
    transform: translateY(-5px);
    border-color: rgba(99, 102, 241, 0.4);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5), 0 0 20px var(--primary-glow);
}

.card-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(6, 182, 212, 0.2));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1.25rem;
    color: var(--accent);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.card-text {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.75rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: var(--transition-fast);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-hover));
    color: #fff;
    box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--primary-glow);
}

.btn-outline {
    background: transparent;
    color: var(--text-main);
    border: 1px solid var(--card-border);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: #fff;
}

/* Status Badges */
.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.status-badge.success {
    background: rgba(16, 185, 129, 0.15);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    border-top: 1px solid var(--card-border);
    margin-top: auto;
    font-size: 0.9rem;
}

/* 404 Error Display */
.error-page {
    text-align: center;
    padding: 5rem 2rem;
    max-width: 600px;
    margin: 0 auto;
}

.error-code {
    font-size: 6rem;
    font-weight: 900;
    background: linear-gradient(135deg, #ef4444, #f59e0b);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1;
    margin-bottom: 1rem;
}