/* --- Variables & Reset --- */
:root {
    --primary: #2563eb;       /* Academic Blue */
    --primary-dark: #1e40af;
    --text-main: #1f2937;
    --text-light: #6b7280;
    --bg-white: #ffffff;
    --bg-off: #f9fafb;        /* Light grey for alternate sections */
    --border: #e5e7eb;
    
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

body {
    font-family: var(--font-body);
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-white);
}

/* --- Layout Utilities --- */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

section {
    padding: 80px 0;
}

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

/* --- Typography --- */
h1, h2, h3 {
    font-family: var(--font-heading);
    font-weight: 700;
    color: #111;
}

h1.title {
    font-size: 3rem;
    line-height: 1.2;
    margin-bottom: 8px;
}

p.subtitle {
    font-size: 1.53rem;
    color: var(--text-light);
    font-weight: 300;
    margin-bottom: 16px;
}

h2 {
    font-size: 2.2rem;
    margin-bottom: 24px;
    text-align: center;
}

p {
    margin-bottom: 1.5rem;
}

/* --- Hero Section --- */
.hero {
    padding: 10px 0 30px;
    text-align: center;
    background-color: #2876F433;
}

.authors {
    max-width: 800px;
    margin: 0 auto 16px;
    font-size: 1.1rem;
}

.author {
    display: inline-block;
    margin: 0 6px;
}

.affiliations {
    max-width: 900px;
    margin: 0 auto;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 20px;
}

.affiliations p {
    margin-bottom: 4px;
}

/* --- Buttons --- */
.action-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
    gap: 8px;
}

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

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

.btn.secondary {
    background-color: white;
    color: var(--text-main);
    border: 1px solid var(--border);
}

.btn.secondary:hover {
    border-color: var(--text-main);
}

.hero-group {
    display: inline-flex;
    align-items: stretch;
    border-radius: 8px;
    overflow: hidden;
}

.hero-group-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    font-weight: 500;
    white-space: nowrap;
}

.hero-group-option {
    display: inline-flex;
    align-items: center;
    padding: 8px 14px;
    font-weight: 500;
    text-decoration: none;
    transition: background 0.2s;
}

.hero-group--paper {
    border: 1px solid var(--primary);
    background-color: var(--bg-white);
}

.hero-group--paper .hero-group-label {
    background-color: var(--primary);
    color: white;
}

.hero-group--paper .hero-group-option {
    color: var(--primary);
    border-left: 1px solid var(--border);
}

.hero-group--paper .hero-group-option:hover {
    background: rgba(37, 99, 235, 0.08);
}

.hero-group--github {
    border: 1px solid #000;
    background-color: var(--bg-white);
}

.hero-group--github .hero-group-label {
    background-color: #000;
    color: white;
}

.hero-group--github .hero-group-option {
    color: #000;
    border-left: 1px solid var(--border);
}

.hero-group--github .hero-group-option:hover {
    background: rgba(0, 0, 0, 0.06);
}

.hero-group--colab {
    border: 1px solid #d5834b;
    background-color: var(--bg-white);
}

.hero-group--colab .hero-group-label {
    background-color: #d5834b;
    color: white;
}

.hero-group--colab .hero-group-option {
    color: #d5834b;
    border-left: 1px solid var(--border);
}

.hero-group--colab .hero-group-option:hover {
    background: rgba(213, 131, 75, 0.1);
}

/* --- Teaser Section --- */
.teaser-section {
    max-width: 900px;
    margin: 0 auto;
    padding-top: 40px;
}

.video-wrapper {
    margin-bottom: 16px;
    border: none;
    border-radius: 12px;
    overflow: hidden;
    background: #000;
}

.video-wrapper video {
    width: 100%;
    display: block;
}

.box-shadow {
    box-shadow: 0 10px 40px -10px rgba(0,0,0,0.15);
}

.caption {
    font-size: 0.95rem;
    color: var(--text-light);
    text-align: justify;
    max-width: 100%;
    margin: 0 auto;
    padding-top: 10px;
}

/* --- Abstract / Two Column --- */
.two-column {
    display: grid;
    grid-template-columns: 1.3fr 1.2fr;
    gap: 60px;
    align-items: start;
}

#abstract .col-text {
    text-align: justify;
}

.col-box {
    background: white;
    padding: 32px;
    border-radius: 12px;
    border: 1px solid var(--border);
    box-shadow: 0 4px 12px rgba(0,0,0,0.03);
}

.col-box h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    font-family: var(--font-body);
}

.simple-list {
    list-style: none;
}

.simple-list li {
    display: flex;
    gap: 16px;
    margin-bottom: 20px;
}

.simple-list .icon {
    font-size: 1.5rem;
}

.simple-list li:last-child {
    margin-bottom: 0;
}

/* --- Method Grid --- */
.section-intro {
    text-align: center;
    max-width: 1000px;
    margin: 0 auto 48px;
    font-size: 1.1rem;
    color: var(--text-light);
}

.method-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 60px;
}

.method-card {
    text-align: center;
    padding: 24px;
}

.card-icon {
    width: 40px;
    height: 40px;
    background: var(--text-main);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-weight: 700;
}

.method-card h3 {
    font-family: var(--font-body);
    font-size: 1.2rem;
    margin-bottom: 12px;
}

.method-card p {
    text-align: justify;
}

.figure-container {
    text-align: center;
}

.main-figure {
    max-width: min(850px, 100%);
    width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 16px;
    border: 1px solid var(--border);
}

/* --- Results --- */
#results {
    padding-bottom: 48px;
}

.results-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.table-card, .chart-card {
    background: white;
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border);
}

.table-card h3 {
    text-align: center;
    font-family: var(--font-body);
    font-size: 1.2rem;
    margin-bottom: 20px;
}

.clean-table {
    width: 100%;
}

.table-header, .table-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
    text-align: center;
}

.table-header {
    font-weight: 700;
    color: var(--primary);
    border-bottom: 2px solid var(--border);
}

.table-row.highlight {
    background-color: #f0fdf4;
    color: #15803d;
    font-weight: 600;
}

.table-note {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 16px;
    text-align: center;
}

.result-img {
    width: 100%;
    border-radius: 8px;
    margin-bottom: 12px;
}

/* --- Resources --- */
.resources {
    background: var(--bg-white);
}

.resources-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.resource-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 24px;
    box-shadow: 0 2px 14px rgba(0, 0, 0, 0.03);
}

.resource-card.highlight {
    border-color: var(--primary);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.1);
}

.resource-title {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 8px;
    color: var(--text-main);
}

.resource-desc {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 16px;
}

.resource-actions.inline {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.btn-outline {
    display: inline-block;
    padding: 10px 20px;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-light);
    font-size: 0.9rem;
    text-decoration: none;
}

.colab-ad {
    margin-top: 12px;
}

.colab-ad-inner {
    background: #0b1220;
    border: 1px solid rgba(148, 163, 184, 0.25);
    border-radius: 12px;
    overflow: hidden;
    max-width: 90%;
    margin: 0 auto;
}

.colab-ad-title {
    padding: 10px 12px;
    color: #cbd5e1;
    font-weight: 600;
    border-bottom: 1px solid rgba(148, 163, 184, 0.18);
    background: rgba(15, 23, 42, 0.6);
    font-size: 0.85rem;
}

.colab-placeholder {
    width: 100%;
    height: auto;
    display: block;
}


/* --- BibTeX --- */
.bibtex-box {
    position: relative;
    background: #1f2937;
    padding: 24px;
    border-radius: 12px;
}

.bibtex-scroll {
    overflow-x: auto;
}

.btn-copy {
    position: absolute;
    top: 12px;
    right: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    border: none;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.1);
    color: #9ca3af;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}

.btn-copy:hover {
    background: rgba(255, 255, 255, 0.15);
    color: #e5e7eb;
}

.btn-copy.copied {
    background: rgba(34, 197, 94, 0.2);
    color: #6ee7b7;
}

.btn-copy .hidden {
    display: none;
}

.bibtex-box pre {
    margin: 0;
    padding-right: 48px;
}

pre code {
    font-family: var(--font-mono);
    color: #e5e7eb;
    font-size: 0.9rem;
}

/* --- Footer --- */
footer {
    padding: 40px 0;
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
    border-top: 1px solid var(--border);
}

/* --- Mobile Responsiveness --- */
@media (max-width: 768px) {
    h1.title {
        font-size: 2.2rem;
    }

    .two-column {
        grid-template-columns: 1fr;
        gap: 40px;
    }

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

    .results-wrapper {
        grid-template-columns: 1fr;
    }
    
    .resources-grid {
        grid-template-columns: 1fr;
    }
}