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

:root {
    /* Colors */
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --background: #ffffff;
    --background-alt: #f9fafb;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --highlight-color: #fbbf24;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Layout */
    --max-width: 1200px;
    --border-radius: 0.5rem;
    --border-radius-lg: 1rem;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s ease;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
}

/* Utility Classes */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

@media (min-width: 768px) {
    .container {
        padding: 0 var(--spacing-lg);
    }
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--text-primary);
}

.bg-light {
    background-color: var(--background-alt);
}

.highlight {
    color: var(--primary-color);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition-normal);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

@media (min-width: 768px) {
    .nav-container {
        padding: 0 var(--spacing-lg);
    }
}

.nav-brand a {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition-fast);
}

.nav-brand a:hover {
    opacity: 0.8;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition-fast);
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: var(--spacing-lg);
}

.nav-menu a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
    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: var(--transition-fast);
}

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

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        flex-direction: column;
        background: var(--background);
        padding: var(--spacing-lg);
        transition: var(--transition-normal);
        box-shadow: var(--shadow-lg);
        gap: var(--spacing-sm);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(-45deg) translate(-9px, 6px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(45deg) translate(-8px, -8px);
    }
}

/* Hero Section */
.hero {
    padding: calc(70px + var(--spacing-3xl)) 0 var(--spacing-3xl);
    background: linear-gradient(135deg, var(--background) 0%, var(--background-alt) 100%);
}

.hero-content {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 768px) {
    .hero-title {
        font-size: var(--font-size-5xl);
    }
}

.authors {
    margin-bottom: var(--spacing-lg);
}

.author-group {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.author {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
}

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

.affiliations {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-2xl);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Hero Visual */
.hero-visual {
    max-width: 800px;
    margin: 0 auto;
}

.teaser-image {
    position: relative;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

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

.image-caption {
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: var(--spacing-sm);
    font-size: var(--font-size-sm);
    text-align: left;
}

/* Abstract Section */
.abstract-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: var(--font-size-lg);
    line-height: 1.8;
}

.abstract-content p {
    margin-bottom: var(--spacing-md);
}

.abstract-content em {
    color: var(--primary-color);
    font-style: italic;
}

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



/* Method Section */
.method-overview {
    margin-bottom: var(--spacing-2xl);
}

.method-text {
    max-width: 800px;
    margin: 0 auto;
}

.method-text h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

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

.method-list li {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--border-color);
}

.method-list li:last-child {
    border-bottom: none;
}

.architecture-section,
.sensitivity-robustness,
.self-consistency {
    margin-bottom: var(--spacing-2xl);
}

.architecture-section h3,
.sensitivity-robustness h3,
.self-consistency h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    text-align: center;
    color: var(--text-primary);
}

.architecture-content,
.tradeoff-content,
.consistency-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

@media (min-width: 768px) {
    .architecture-content,
    .tradeoff-content,
    .consistency-content {
        grid-template-columns: 1fr 1fr;
    }
}

.architecture-image,
.tradeoff-image,
.consistency-image {
    position: relative;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.architecture-image img,
.tradeoff-image img,
.consistency-image img {
    width: 100%;
    height: auto;
    display: block;
}

.architecture-description h4 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.architecture-description ul,
.tradeoff-description ul,
.consistency-description ul {
    list-style: none;
    padding: 0;
}

.architecture-description li,
.tradeoff-description li,
.consistency-description li {
    padding: var(--spacing-xs) 0;
    position: relative;
    padding-left: var(--spacing-md);
}

.architecture-description li::before,
.tradeoff-description li::before,
.consistency-description li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Results Section */
.results-overview {
    margin-bottom: var(--spacing-2xl);
}

.results-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    max-width: 600px;
    margin: 0 auto;
}

.summary-item {
    text-align: center;
    background: var(--background);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
}

.summary-number {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    color: var(--success-color);
    margin-bottom: var(--spacing-xs);
}

.summary-text {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.results-section {
    margin-bottom: var(--spacing-2xl);
}

.results-section h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    text-align: center;
    color: var(--text-primary);
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

@media (min-width: 768px) {
    .results-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.results-image {
    position: relative;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

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

.results-description h4 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

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

.results-description li {
    padding: var(--spacing-xs) 0;
    position: relative;
    padding-left: var(--spacing-md);
}

.results-description li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

/* Video Section */
.video-container {
    max-width: 1400px;
    margin: 0 auto;
}

.main-video {
    margin-bottom: var(--spacing-2xl);
    text-align: center;
}

.research-video {
    width: 100%;
    max-width: 1200px;
    height: auto;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    background: var(--background-alt);
    margin-bottom: var(--spacing-lg);
}

.research-video:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
    transition: var(--transition-normal);
}

.video-caption {
    max-width: 800px;
    margin: 0 auto;
}

.video-caption h3 {
    font-size: var(--font-size-3xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.video-caption p {
    color: var(--text-secondary);
    font-size: var(--font-size-lg);
    line-height: 1.6;
}

.video-download {
    text-align: center;
}

.video-download .btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--font-size-base);
    padding: 1rem 1.5rem;
}

/* Video responsive behavior */
@media (max-width: 768px) {
    .research-video {
        border-radius: var(--border-radius);
        max-width: 100%;
    }
    
    .video-caption h3 {
        font-size: var(--font-size-2xl);
    }
    
    .video-caption {
        max-width: 100%;
        padding: 0 var(--spacing-sm);
    }
}

/* Resources Section */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.resource-item {
    background: var(--background);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition-normal);
}

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

.resource-icon {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.resource-item h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.resource-item p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
}

.resource-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
}

.resource-link:hover {
    text-decoration: underline;
}

/* Citation Section */
.citation-section {
    max-width: 800px;
    margin: 0 auto;
}

.citation-section h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    text-align: center;
    color: var(--text-primary);
}

.citation-box {
    position: relative;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.citation-box pre {
    padding: var(--spacing-lg);
    margin: 0;
    background: #f8f9fa;
    font-family: 'Courier New', monospace;
    font-size: var(--font-size-sm);
    line-height: 1.4;
    overflow-x: auto;
}

.copy-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: var(--font-size-sm);
    transition: var(--transition-fast);
}

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

.copy-btn.copied {
    background: var(--success-color);
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-lg);
        text-align: center;
    }
}

.footer-info h4 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--primary-color);
}

.footer-info p {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
}

.footer-links a {
    color: white;
    text-decoration: none;
    transition: var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid #374151;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

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

/* Loading States */
img {
    transition: var(--transition-normal);
}

img:not([src]) {
    background: var(--background-alt);
    min-height: 200px;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    html {
        scroll-behavior: auto;
    }
}

/* Focus Styles */
a:focus,
button:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .navbar,
    .hero-buttons,
    .copy-btn,
    .footer {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
    
    .hero {
        padding-top: var(--spacing-lg);
    }
}