/* ===== Global Styles ===== */
:root {
    --primary-color: #2563eb;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --dark-bg: #0f172a;
    --light-bg: #f8fafc;
    --gray-bg: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.1);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
}

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

body {
    font-family: var(--font-main);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--light-bg);
    overflow-x: hidden;
}

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

/* ===== Navigation ===== */
.navbar {
    background: white;
    box-shadow: var(--shadow-sm);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* ===== Hero Section ===== */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,133.3C960,128,1056,96,1152,90.7C1248,85,1344,107,1392,117.3L1440,128L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
    opacity: 0.3;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
    position: relative;
    z-index: 1;
}

.gradient-text {
    background: linear-gradient(45deg, #fff, #f0f0f0);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 2rem;
    animation: fadeInUp 0.8s ease 0.2s both;
    position: relative;
    z-index: 1;
}

.authors {
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease 0.4s both;
    position: relative;
    z-index: 1;
}

.authors a {
    color: white;
    text-decoration: none;
    margin: 0 10px;
    font-size: 1.1rem;
    transition: opacity 0.3s ease;
}

.authors a:hover {
    opacity: 0.8;
    text-decoration: underline;
}

.affiliations {
    margin-bottom: 2rem;
    font-size: 0.95rem;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease 0.5s both;
    position: relative;
    z-index: 1;
}

.conference {
    margin-bottom: 2rem;
    animation: fadeInUp 0.8s ease 0.6s both;
    position: relative;
    z-index: 1;
}

.conference-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 20px;
    border-radius: 25px;
    font-weight: 600;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.7s both;
    position: relative;
    z-index: 1;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ===== Sections ===== */
.section {
    padding: 80px 0;
}

.section-gray {
    background: var(--gray-bg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--primary-color);
    margin: 1rem auto;
    border-radius: 2px;
}

/* ===== Abstract Section ===== */
.abstract-content {
    max-width: 900px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.abstract-content p {
    margin-bottom: 1.5rem;
}

.abstract-content strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* ===== Method Section ===== */
.method-overview {
    margin-bottom: 3rem;
}

.method-image {
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    display: block;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.image-caption {
    text-align: center;
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-style: italic;
}

.method-details h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.feature-list {
    list-style: none;
    max-width: 800px;
    margin: 0 auto;
}

.feature-list li {
    padding: 1rem;
    margin-bottom: 1rem;
    background: white;
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-list li:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

.feature-list i {
    color: var(--secondary-color);
    font-size: 1.2rem;
    margin-top: 0.2rem;
}

/* ===== Results Section ===== */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.result-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.result-card h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.table-responsive {
    overflow-x: auto;
}

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

.results-table th,
.results-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.results-table th {
    background: var(--gray-bg);
    font-weight: 600;
    color: var(--text-primary);
}

.results-table tr:hover {
    background: var(--gray-bg);
}

.results-table tr.highlight {
    background: rgba(37, 99, 235, 0.1);
}

.visualization-section h3 {
    margin-bottom: 2rem;
    text-align: center;
    font-size: 1.5rem;
}

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

.vis-item {
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease;
}

.vis-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.vis-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.vis-item p {
    padding: 1rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ===== Dataset Section ===== */
.dataset-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.stat-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.stat-card h3 {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.stat-card p {
    color: var(--text-secondary);
}

.dataset-description {
    background: white;
    padding: 3rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.dataset-description h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.download-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

/* ===== Demo Section ===== */
.demo-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.demo-player {
    background: #000;
    border-radius: 8px;
    overflow: hidden;
}

.demo-player video {
    width: 100%;
    height: auto;
}

.demo-controls {
    padding: 1rem;
}

.demo-controls h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.input-group select,
.input-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.input-group select:focus,
.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.demo-output {
    margin-top: 2rem;
    padding: 1rem;
    background: var(--gray-bg);
    border-radius: 6px;
}

.demo-output h4 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

#demo-result {
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

/* ===== Citation Section ===== */
.citation-box {
    position: relative;
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow-md);
}

.citation-box pre {
    background: var(--dark-bg);
    color: #e2e8f0;
    padding: 1.5rem;
    border-radius: 6px;
    overflow-x: auto;
    font-size: 0.9rem;
}

.citation-box code {
    font-family: var(--font-mono);
}

.copy-btn {
    position: absolute;
    top: 2.5rem;
    right: 2.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: background 0.3s ease;
}

.copy-btn:hover {
    background: #1d4ed8;
}

/* ===== Footer ===== */
.footer {
    background: var(--dark-bg);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.footer-content p {
    margin-bottom: 1rem;
}

.footer-content a {
    color: white;
    text-decoration: none;
    margin: 0 10px;
    font-size: 1.2rem;
    transition: opacity 0.3s ease;
}

.footer-content a:hover {
    opacity: 0.7;
}

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

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .demo-container {
        grid-template-columns: 1fr;
    }
    
    .dataset-stats {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .vis-grid {
        grid-template-columns: 1fr;
    }
}