/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 12px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: 0.75rem 0;
}

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

.nav-brand a {
    font-size: 2rem;
    font-weight: 700;
    color: #1f2937;
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-brand a:hover {
    color: #2563eb;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.nav-menu a {
    text-decoration: none;
    color: #4b5563;
    font-weight: 500;
    transition: color 0.3s ease;
    font-size: 1.5rem;
}

.nav-menu a:hover {
    color: #2563eb;
}

/* Hero Section */
.hero {
    padding: 120px 0 20px;
    background: white;
    color: #1f2937;
    text-align: center;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    color: #1f2937;
}

.hero-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 1.2rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 900;
    transition: all 0.2s;
    border: 2px solid transparent;
    font-size: 1.75rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.btn-primary {
    background: #2563eb;
    color: #fff;
}
.btn-primary:hover {
    background: #1d4ed8;
    color: #fff;
}
.btn-secondary {
    background: #f3f4f6;
    color: #1f2937;
    border-color: #e5e7eb;
}
.btn-secondary:hover {
    background: #e0e7ef;
    color: #2563eb;
}

.authors-row {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: nowrap;
    margin-bottom: 0.5rem;
    overflow-x: auto;
}

.authors {
    gap: 0.4rem;
    font-size: 1.5rem;
    margin-bottom: 0;
    line-height: 1.6;
    color: #4b5563;
}
.authors sup {
  vertical-align: top; 
  font-size: 0.75em; 
  top: 0.75em; 
  position: relative; 
}
.authors a {
    color: #6D28D9; 
    text-decoration: none;
}

.authors a:visited {
    color: #5B21B6; 
}

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

.institutions {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    color: #6b7280;
}

.hero-description {
    text-align: left;
    max-width: 800px;
    margin: 0 auto;
}

.hero-description p {
    font-size: 1.75rem;
    margin-bottom: 4rem;
    line-height: 1.7;
    color: #4b5563;
}

.hero-video {
    margin-top: 3rem;
}

/* Hero Video Section */
.hero-video .video-wrapper {
    max-width: 900px;
    margin: 0 auto;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
}

.video-wrapper {
    max-width: 900px;
    margin: 0 auto;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
}

.video-wrapper video {
    width: 100%;
    height: auto;
    display: block;
    min-height: 400px;
}

/* Gallery Section */
.gallery {
    padding: 100px 0;
    background: #e2e8f0;
}

.gallery h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.gallery-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

.gallery-item {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
}

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

/* Examples Section */
.examples {
    padding: 80px 0;
    background: #f8fafc;
}

.examples h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.examples-content {
    max-width: 1200px;
    margin: 0 auto;
}

.examples-video-container {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 15px 35px -5px rgba(0, 0, 0, 0.1);
    background: #000;
}

.examples-video-container video {
    width: 100%;
    height: auto;
    display: block;
    min-height: 400px;
}

.examples-thumbnails {
    display: flex;
    flex-direction: row;
    gap: 0.5rem;
    padding: 1rem;
    background: #1a1a1a;
    overflow-x: auto;
    justify-content: flex-start;
    flex-wrap: nowrap;
    align-items: center;
}

.thumbnail {
    position: relative;
    border-radius: 6px;
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.3s ease;
    box-shadow: 0 3px 10px -2px rgba(0, 0, 0, 0.3);
    width: 120px;
    height: 67px;
    flex-shrink: 0;
    flex-grow: 0;
    flex-basis: auto;
}

.thumbnail:hover {
    transform: scale(1.05);
}

.thumbnail img {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
}

.thumbnail-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.thumbnail:hover .thumbnail-overlay {
    opacity: 1;
}

.thumbnail.active {
    transform: scale(1.05);
    box-shadow: 0 10px 25px -5px rgba(37, 99, 235, 0.3);
    border: 2px solid #2563eb;
}

.thumbnail.active .thumbnail-overlay {
    opacity: 1;
    background: rgba(37, 99, 235, 0.7);
}

.thumbnail-overlay i {
    color: white;
    font-size: 2rem;
}

/* Pipeline Section */
.pipeline {
    padding: 100px 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.pipeline h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.pipeline-embed {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
    overflow: hidden;
    padding: 1rem;
}

.pipeline-pdf {
    width: 100%;
    height: 900px;
    border: none;
    display: block;
}

.pipeline-img {
    max-width: 100%;
    height: auto;
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-top: 12px;
    margin-bottom: 12px;
}

/* Pipeline Description Section */
.pipeline-desc {
    background: #f1f5f9;
    padding: 28px 0 18px 0;
}
.pipeline-desc-text {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.13rem;
    line-height: 1.65;
    color: #374151;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 1px 8px rgba(0,0,0,0.03);
    padding: 1.3rem 1.6rem;
}

/* Applications Section */
.applications {
    padding: 100px 0;
    background: #f8fafc;
}

.applications h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.application-caption {
    text-align: center;
    font-size: 1.08rem;
    font-weight: 500;
    color: #2563eb;
    margin-top: 4px;
    letter-spacing: 0.01em;
}

.application-img {
    max-width: 60%;
    height: auto;
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-top: 24px;
    margin-bottom: 24px;
}

/* Repainting Section */
.repainting {
    padding: 80px 0;
    background: white;
}

.repainting h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.repainting-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

.repainting-item {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.repainting-item:hover {
    transform: translateY(-5px);
}

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

/* Limitations Section */
.limitations {
    padding: 80px 0;
    background: #f8fafc;
}

.limitations h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

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

.limitation-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    box-shadow: 0 5px 15px -5px rgba(0, 0, 0, 0.1);
    border-left: 4px solid #ef4444;
}

.limitation-item h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #1f2937;
    font-weight: 600;
}

.limitation-item p {
    font-size: 1.1rem;
    color: #4b5563;
    line-height: 1.6;
}

/* Citation Section */
.citation {
    padding: 20px 0;
    background: white;
}

.citation h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.citation-box {
    max-width: 800px;
    margin: 0 auto;
    background: #f8fafc;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.citation-box:hover {
    transform: translateY(-5px);
}

.citation-box pre {
    margin: 0;
    white-space: pre-wrap;
    font-family: 'Courier New', monospace;
    font-size: 1.25rem;
    line-height: 1.5;
}

.citation-box code {
    color: #1f2937;
    background: none;
    padding: 0;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

.footer p {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.8;
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .authors {
        font-size: 0.85rem;
        gap: 0.25rem;
    }
    
    .hero-description p {
        font-size: 1.75rem;
    }
    
    .gallery h2,
    .video h2,
    .examples h2,
    .pipeline h2,
    .applications h2,
    .citation h2 {
        font-size: 2rem;
    }
    
    .limitation-item {
        padding: 1.5rem;
    }
    
    .limitation-item h3 {
        font-size: 1.1rem;
    }
    
    .limitation-item p {
        font-size: 1rem;
    }
}

@media (max-width: 900px) {
    .authors-row, .authors {
        flex-wrap: wrap;
        gap: 0.3rem;
        font-size: 0.9rem;
    }
    .hero-links {
        flex-direction: column;
        gap: 0.7rem;
    }
}

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

.hero, .gallery, .video, .examples, .pipeline, .applications, .repainting, .limitations, .citation {
    animation: fadeInUp 0.8s ease-out;
}

/* Interactive 3D Section */
.interactive-3d {
    padding: 80px 0;
    background: #f8fafc;
}

.interactive-3d h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.interactive-description {
    text-align: center;
    margin-bottom: 2rem;
}

.interactive-description p {
    font-size: 1rem;
    color: #4b5563;
    max-width: 600px;
    margin: 0 auto;
}

.viewer-container {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
}

#threejs-container {
    width: 100%;
    height: 500px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 15px 35px -5px rgba(0, 0, 0, 0.1);
    background: #000;
    position: relative;
}

.controls-info {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 1rem;
    border-radius: 8px;
    font-size: 0.85rem;
    backdrop-filter: blur(10px);
}

.control-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.control-item:last-child {
    margin-bottom: 0;
}

.key {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-weight: 600;
    min-width: 30px;
    text-align: center;
    font-family: monospace;
}

/* Lightbox Modal for Gallery */
#lightbox-modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100vw;
    height: 100vh;
    overflow: auto;
    background: rgba(0,0,0,0.85);
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

#lightbox-modal.active {
    display: flex;
}

#lightbox-img {
    max-width: 90vw;
    max-height: 80vh;
    margin: auto;
    display: block;
    box-shadow: 0 4px 32px rgba(0,0,0,0.5);
    border-radius: 8px;
    background: #fff;
}

#lightbox-close {
    position: absolute;
    top: 24px;
    right: 40px;
    color: #fff;
    font-size: 2.5rem;
    cursor: pointer;
    z-index: 1100;
}

@media (max-width: 600px) {
    .lightbox-content {
        max-width: 98vw;
        max-height: 70vh;
    }
    .lightbox-close {
        top: 12px;
        right: 18px;
        font-size: 2rem;
    }
}

@media (max-width: 1100px) {
    .applications-grid {
        gap: 18px;
    }
    .application-item {
        max-width: 260px;
        padding: 12px 8px 8px 8px;
        min-height: 320px;
    }
    .application-item video {
        max-width: 220px;
    }
    .application-video {
        max-width: 400px;
    }
}

@media (max-width: 800px) {
    .applications-grid {
        flex-direction: column;
        align-items: center;
    }
    .application-item {
        max-width: 95vw;
        width: 100%;
        min-height: 220px;
    }
    .application-item video {
        max-width: 95vw;
    }
    .application-video {
        max-width: 95vw;
    }
}

/* Hero Title Row Inline Logo */
.hero-title-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
    margin-bottom: 0.5rem;
}
.hero-logo {
    height: 56px;
    width: 56px;
    object-fit: contain;
    display: block;
}
.hero-title-main {
    font-size: 5rem;
    font-weight: 900;
    color: #1f2937;
    letter-spacing: -0.01em;
}
.hero-title-sub {
    font-size: 2.5rem;
    font-weight: 600;
    color: #1f2937;
    margin-top: 0.5em;
    margin-bottom: 2rem;
    line-height: 1.2;
}
@media (max-width: 600px) {
    .hero-title-row {
        flex-direction: row;
        gap: 10px;
    }
    .hero-logo {
        height: 38px;
        width: 38px;
    }
    .hero-title-main {
        font-size: 1.4rem;
    }
    .hero-title-sub {
        font-size: 1.1rem;
    }
}

/* Abstract Section */
.abstract {
    background: #f8fafc;
    padding: 60px 0 72px 0;
    margin-bottom: 0;
}
.abstract h2 {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5em;
}
.abstract .section-desc {
    text-align: center;
    color: #e2e8f0;
    margin-bottom: 1.2em;
}
.abstract-text {
    max-width: 900px;
    margin: 0 auto;
    font-size: 1.5rem;
    line-height: 1.7;
    color: #374151;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 2px 16px rgba(0,0,0,0.04);
    padding: 2rem 2.2rem;
}

.pipeline-caption {
    font-size: 1.5rem;
    color: #64748b;
    margin: 18px auto 0 auto;
    max-width: 100%;
    text-align: center;
    line-height: 1.6;
}

/* Center the Want to Dive Deeper section */
.learn-more-text {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}
.learn-more-btn {
    display: inline-block;
    margin: 0 auto;
}
.learn-more {
    text-align: center;
    padding: 120px 0;
} 

/* motivation */

.motivation {
    padding: 100px 0;
    background: #ffffff;
}

.motivation h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

/* 
  最外层的 embed 容器
  - 使用 Flexbox 让内部的 block 垂直排列
  - align-items: center 使得 block 水平居中
*/
.motivation-embed {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3rem;  
}

.motivation-block {
    max-width: 800px;
    width: 100%;
}

.motivation-block p {
    margin-bottom: 1.5em;
}

.motivation-img,
.motivation-chat {
    display: block;          
    margin: 1.5rem auto;    
    
    max-width: 100%;      
    height: auto;     

    border-radius: 8px;
}


.video-sec h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
    font-weight: 700;
}

.video-sec {
    padding: 100px 0;
    background: #f8fafc;
}

.teaser-img {
    max-width: 90%;
    height: auto;
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-top: 24px;
    margin-bottom: 24px;
}

.fa-brands {
    font-family: "Font Awesome 6 Brands" !important; 
    font-weight: 400 !important; 
}