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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #94a3b8;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.nav-brand .tagline {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    font-weight: 400;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    transition: color 0.2s;
    padding: 0.5rem 0;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.125rem;
    max-width: 800px;
    margin: 0 auto 2rem;
    opacity: 0.95;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin: 2rem 0;
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    text-decoration: none;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

.btn-large {
    padding: 1rem 2rem;
    font-size: 1rem;
}

/* Sections */
section {
    padding: 4rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 800px;
    margin-bottom: 2rem;
}

/* Benchmark Section */
.benchmark-section {
    background: var(--bg-secondary);
    padding: 3rem 0;
}

/* Dashboard Section */
.dashboard-section {
    background: var(--bg-secondary);
}

/* Benchmark Overview */
.benchmark-overview {
    background: linear-gradient(135deg, #667eea15 0%, #764ba215 100%);
    border-radius: 1rem;
    padding: 0;
    margin-bottom: 2.5rem;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.overview-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 2rem;
    text-align: center;
}

.overview-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1.5rem;
}

.overview-stats-highlight {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.highlight-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 1rem 2rem;
    border-radius: 0.75rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.highlight-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: white;
    line-height: 1;
}

.highlight-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    margin-top: 0.5rem;
}

.overview-content {
    padding: 2rem;
    background: var(--bg-primary);
}

.overview-section {
    margin-bottom: 2rem;
}

.overview-section:last-child {
    margin-bottom: 0;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--bg-tertiary);
}

.section-icon {
    color: var(--primary-color);
}

.category-grid-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem;
}

.category-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.category-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.category-icon {
    font-size: 2rem;
    line-height: 1;
    flex-shrink: 0;
}

.category-content {
    flex: 1;
    min-width: 0;
}

.category-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9375rem;
    margin-bottom: 0.25rem;
}

.category-count {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.category-desc {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.institution-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.institution-card {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    padding: 1.5rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: all 0.3s ease;
}

.institution-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.institution-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9375rem;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.institution-abbr {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.institution-count {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.contributors-footer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1.25rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    margin-top: 2rem;
    border: 1px solid var(--border-color);
}

.footer-icon {
    color: var(--primary-color);
    flex-shrink: 0;
}

.contributors-footer span {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.contributors-footer strong {
    color: var(--text-primary);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.category-card {
    background: var(--bg-primary);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.category-card-wide {
    grid-column: 1 / -1;
}

.category-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.category-stats {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.category-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 0.75rem;
}

.stat-item {
    display: flex;
    align-items: center;
    padding: 0.5rem;
    background: var(--bg-secondary);
    border-radius: 0.375rem;
}

.stat-item .count {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--primary-color);
    min-width: 3rem;
}

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

/* Contributors Section */
.contributors-section {
    margin-top: 3rem;
}

.contributors-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.table-container {
    background: var(--bg-primary);
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

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

.contributors-table thead {
    background: var(--bg-tertiary);
}

.contributors-table th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contributors-table td {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.875rem;
}

.contributors-table tbody tr:hover {
    background: var(--bg-secondary);
}

.empty-state td {
    text-align: center;
    color: var(--text-tertiary);
    padding: 3rem;
}

/* Submit Section */
.submit-section {
    background: var(--bg-primary);
}

.submission-form {
    max-width: 900px;
    margin: 0 auto;
}

.form-section {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 0.75rem;
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
}

.form-section h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-group label {
    font-weight: 500;
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="file"],
.form-group textarea,
.form-group select {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-family: inherit;
    background: var(--bg-primary);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input[type="text"]:focus,
.form-group input[type="email"]:focus,
.form-group input[type="file"]:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-group small {
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    cursor: pointer;
    padding: 0.75rem;
    border-radius: 0.5rem;
    transition: background-color 0.2s;
}

.checkbox-label:hover {
    background: var(--bg-primary);
}

.checkbox-label input[type="checkbox"],
.checkbox-label input[type="radio"] {
    margin-top: 0.25rem;
    width: 1rem;
    height: 1rem;
    cursor: pointer;
}

.checkbox-label span {
    flex: 1;
    font-size: 0.875rem;
    color: var(--text-primary);
}

.complexity-easy::before {
    content: "🟢 ";
}

.complexity-medium::before {
    content: "🟡 ";
}

.complexity-hard::before {
    content: "🔴 ";
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

/* About Section */
.about-section {
    background: var(--bg-secondary);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.about-text h3:first-child {
    margin-top: 0;
}

.about-text p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.about-text ul {
    list-style: none;
    margin-bottom: 1rem;
}

.about-text ul li {
    padding-left: 1.5rem;
    margin-bottom: 0.5rem;
    position: relative;
    color: var(--text-secondary);
}

.about-text ul li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

.paper-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section p {
    font-size: 0.875rem;
    opacity: 0.8;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: white;
    text-decoration: none;
    font-size: 0.875rem;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.footer-section ul li a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 0.875rem;
    opacity: 0.6;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .category-stats-grid {
        grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    }
}

@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }

    .hero-content h2 {
        font-size: 2rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }

    .category-grid {
        grid-template-columns: 1fr;
    }

    .category-stats-grid {
        grid-template-columns: 1fr;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .paper-links {
        flex-direction: column;
    }
}

/* Page-based Navigation */
.page {
    display: none;
}

.page.active {
    display: block;
}

/* Info Box */
.info-box {
    background: #fff3cd;
    border: 1px solid #ffc107;
    border-radius: 0.5rem;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.info-box h4 {
    margin-bottom: 0.75rem;
    color: #856404;
}

.info-box p {
    margin-bottom: 0.75rem;
    color: #856404;
}

.info-box ul {
    margin-left: 1.5rem;
    color: #856404;
}

.info-box ul li {
    margin-bottom: 0.5rem;
}

.info-box a {
    color: #004085;
    text-decoration: underline;
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Loading Animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Success Message */
.success-message {
    background: var(--success-color);
    color: white;
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    display: none;
}

.success-message.show {
    display: block;
}

/* Error Message */
.error-message {
    background: var(--danger-color);
    color: white;
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    display: none;
}

.error-message.show {
    display: block;
}