/* CSS Variables */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #10b981;
    --background: #0f0f23;
    --surface: #1a1a2e;
    --surface-light: #252542;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --border: #334155;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--background);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Animated Background */
.gradient-bg {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 100vh;
    background: 
        radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(16, 185, 129, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(139, 92, 246, 0.08) 0%, transparent 70%);
    z-index: -1;
    pointer-events: none;
}

/* Header & Navigation */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(15, 15, 35, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}

header nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 1.25rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--primary-light);
}

/* Hero Section */
.hero {
    padding: 10rem 0 5rem;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
}

.hero .subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.student-info {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.badge {
    background: var(--surface);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.875rem;
    border: 1px solid var(--border);
}

/* Assignments Section */
.assignments {
    padding: 4rem 0;
}

.assignments h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

.assignment-card {
    background: var(--surface);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.assignment-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.assignment-card.featured {
    border-color: var(--primary);
    background: linear-gradient(135deg, var(--surface) 0%, rgba(99, 102, 241, 0.1) 100%);
}

.assignment-card.upcoming {
    opacity: 0.6;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.assignment-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    opacity: 0.5;
}

.status {
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.status.completed {
    background: rgba(16, 185, 129, 0.2);
    color: var(--secondary);
}

.status.upcoming-badge {
    background: rgba(99, 102, 241, 0.2);
    color: var(--primary-light);
}

.assignment-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
}

.assignment-card .description {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

/* Highlights Grid */
.highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.highlight-item {
    background: var(--surface-light);
    padding: 1rem;
    border-radius: 12px;
    text-align: center;
}

.highlight-value {
    display: block;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-light);
}

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

/* Tech Stack */
.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tech {
    background: var(--surface-light);
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Card Links */
.card-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.875rem;
    transition: all 0.3s ease;
}

.btn.primary {
    background: var(--gradient-1);
    color: white;
}

.btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

.btn.secondary {
    background: var(--surface-light);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn.secondary:hover {
    background: var(--border);
}

/* About Section */
.about {
    padding: 4rem 0;
}

.about h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

.about-content {
    background: var(--surface);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid var(--border);
}

.about-text p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.contact-links {
    display: flex;
    gap: 1rem;
}

.contact-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: var(--surface-light);
    border-radius: 8px;
    color: var(--text);
    text-decoration: none;
    transition: background 0.3s ease;
}

.contact-btn:hover {
    background: var(--border);
}

/* Footer */
footer {
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Detail Pages */
.section {
    padding: 2rem 0 3rem;
}

.back-link {
    display: inline-block;
    margin-bottom: 1.5rem;
    color: var(--primary-light);
    text-decoration: none;
    font-weight: 500;
}

.back-link:hover {
    color: var(--text);
}

.overview-grid,
.results-grid,
.insights-grid,
.notebooks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.25rem;
}

.overview-card,
.result-card,
.insight-card,
.notebook-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.5rem;
}

.overview-card h4,
.insight-card h4,
.notebook-card h4 {
    margin-bottom: 0.75rem;
}

.overview-card p,
.insight-card p,
.notebook-card p,
.table-note {
    color: var(--text-muted);
}

.result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-light);
}

.result-label {
    font-weight: 600;
    margin-top: 0.25rem;
}

.result-details {
    color: var(--text-muted);
    margin-top: 0.25rem;
    font-size: 0.95rem;
}

.table-section {
    margin-top: 2rem;
}

.table-section h3 {
    margin-bottom: 1rem;
}

.table-wrapper {
    overflow-x: auto;
    border: 1px solid var(--border);
    border-radius: 16px;
    background: var(--surface);
}

table {
    width: 100%;
    border-collapse: collapse;
}

th,
td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    color: var(--text);
    background: rgba(99, 102, 241, 0.08);
    font-weight: 600;
}

td {
    color: var(--text-muted);
}

tbody tr:last-child td {
    border-bottom: none;
}

.highlight-row {
    background: rgba(16, 185, 129, 0.08);
}

.best {
    color: var(--secondary);
    font-weight: 700;
}

.notebook-card {
    display: block;
    text-decoration: none;
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.notebook-card:hover {
    transform: translateY(-3px);
    border-color: var(--primary);
}

.notebook-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--primary-light);
    font-weight: 600;
}

pre {
    padding: 1rem 1.25rem;
    background: rgba(15, 15, 35, 0.75);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow-x: auto;
}

code {
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .highlights {
        grid-template-columns: 1fr;
    }
    
    .card-links {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }

    .overview-grid,
    .results-grid,
    .insights-grid,
    .notebooks-grid {
        grid-template-columns: 1fr;
    }

    th,
    td {
        padding: 0.85rem;
    }
}