/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    --primary-color: #4a90d9;
    --primary-dark: #3a7bc8;
    --primary-light: #6ba3e0;
    --secondary-color: #5c6bc0;
    --accent-color: #ff6b6b;
    --text-primary: #2c3e50;
    --text-secondary: #5a6c7d;
    --text-light: #8896a4;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #eef2f7;
    --border-color: #e1e8ef;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
    --max-width: 1000px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

/* ===================================
   Container
   =================================== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===================================
   Header Section
   =================================== */
.header {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    padding: 60px 0 50px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.title {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
    margin-bottom: 16px;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.title .highlight {
    color: var(--primary-color);
    background: linear-gradient(120deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.venue {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: 0.5px;
}

/* Authors */
.authors {
    margin-bottom: 12px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px 20px;
}

.author {
    font-size: 1.05rem;
}

.author a {
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition);
}

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

.author sup {
    color: var(--primary-color);
    font-weight: 600;
}

/* Affiliations */
.affiliations {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px 24px;
    margin-bottom: 8px;
}

.affiliation {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.affiliation sup {
    color: var(--primary-color);
}

.equal-contribution {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 28px;
}

/* Buttons (for BibTeX copy) */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--bg-primary);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

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

.btn i {
    font-size: 1rem;
}

/* ===================================
   Teaser Section
   =================================== */
.teaser {
    padding: 50px 0;
    background: var(--bg-secondary);
}

.teaser-image {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-md);
    overflow: hidden;
}

.teaser-image img {
    width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    display: block;
}

.teaser-caption {
    text-align: center;
    margin-top: 20px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ===================================
   Section Styles
   =================================== */
section {
    padding: 60px 0;
}

section:nth-child(even) {
    background: var(--bg-secondary);
}

section h2 {
    font-size: 1.8rem;
    color: var(--text-primary);
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

section h2 i {
    color: var(--primary-color);
    font-size: 1.4rem;
}

section h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin: 32px 0 16px;
}

/* ===================================
   Abstract Section
   =================================== */
.abstract p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    text-align: justify;
    margin-bottom: 16px;
}

.abstract .metric {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.1rem;
}

/* ===================================
   Method Section
   =================================== */
.method-content {
    margin-bottom: 32px;
}

.method-image {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.method-image img {
    width: 100%;
    height: auto;
    border-radius: var(--radius-md);
}

.method-caption {
    text-align: center;
    margin-top: 16px;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.method-description ul {
    list-style: none;
    padding: 0;
}

.method-description li {
    padding: 12px 0;
    padding-left: 24px;
    position: relative;
    color: var(--text-secondary);
}

.method-description li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===================================
   Results Section
   =================================== */
.results-table {
    margin-bottom: 40px;
}

.results-table table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.results-table th,
.results-table td {
    padding: 14px 20px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

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

.results-table td {
    color: var(--text-secondary);
}

.results-table .highlight-row {
    background: linear-gradient(90deg, rgba(74, 144, 217, 0.1) 0%, rgba(92, 107, 192, 0.1) 100%);
}

.results-table .highlight-row td {
    color: var(--primary-color);
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 20px;
}

/* Video Grid 3x2 for 6 videos */
.video-grid-6 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 20px;
}

.results-intro {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-bottom: 24px;
    text-align: center;
}

.video-item {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.video-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.video-item video {
    width: 100%;
    height: auto;
    display: block;
    aspect-ratio: 16/9;
    object-fit: cover;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
}

.video-info {
    padding: 14px 16px;
    background: var(--bg-tertiary);
}

.video-info h4 {
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 6px;
    font-weight: 600;
}

.video-info p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.video-caption {
    padding: 12px 16px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
}

/* Qualitative Results */
.comparison-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 20px;
}

.comparison-item {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.comparison-item img {
    width: 100%;
    height: auto;
    display: block;
}

.comparison-item p {
    padding: 12px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
}

/* ===================================
   Dataset Section
   =================================== */
.dataset-content {
    text-align: center;
}

.dataset-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    margin-bottom: 30px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1.2;
}

.stat-label {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.dataset-content p {
    max-width: 700px;
    margin: 0 auto 24px;
    color: var(--text-secondary);
}

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

.dataset-btn:hover {
    background: var(--primary-dark);
}

/* ===================================
   BibTeX Section
   =================================== */
.bibtex p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.bibtex-box {
    position: relative;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 20px;
    border: 1px solid var(--border-color);
}

.bibtex-box pre {
    margin: 0;
    overflow-x: auto;
}

.bibtex-box code {
    font-family: 'Source Code Pro', monospace;
    font-size: 0.9rem;
    color: var(--text-primary);
    line-height: 1.5;
}

.copy-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    padding: 8px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
}

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

/* ===================================
   Related Projects Section
   =================================== */
.related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.related-item {
    background: var(--bg-primary);
    padding: 24px;
    border-radius: var(--radius-md);
    text-decoration: none;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.related-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.related-item h4 {
    color: var(--primary-color);
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.related-item p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

/* ===================================
   Footer (Hidden)
   =================================== */

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    .title {
        font-size: 1.8rem;
    }

    .venue {
        font-size: 1rem;
    }

    .authors {
        gap: 6px 16px;
    }

    .author {
        font-size: 0.95rem;
    }

    .buttons {
        gap: 10px;
    }

    .btn {
        padding: 8px 16px;
        font-size: 0.9rem;
    }

    section {
        padding: 40px 0;
    }

    section h2 {
        font-size: 1.5rem;
    }

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

    .video-grid-6 {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

    .dataset-stats {
        flex-direction: column;
        gap: 30px;
    }

    .stat-number {
        font-size: 2rem;
    }

    .bibtex-box {
        padding: 16px;
        padding-top: 50px;
    }

    .bibtex-box code {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .header {
        padding: 40px 0 30px;
    }

    .title {
        font-size: 1.5rem;
    }

    .video-grid-6 {
        grid-template-columns: 1fr;
    }

    .results-table th,
    .results-table td {
        padding: 10px 12px;
        font-size: 0.85rem;
    }
}

/* ===================================
   Animations
   =================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

section {
    animation: fadeIn 0.6s ease-out;
}

/* ===================================
   Utility Classes
   =================================== */
.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

/* Image placeholder styling */
.teaser-image img[src="images/teaser.png"],
.method-image img[src="images/method.png"],
.comparison-item img {
    min-height: 200px;
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}