/* Modern Reset & Variables */
:root {
    --bg-color: #0a0a0a;
    --surface-color: #1a1a1a;
    --surface-color-hover: #252525;
    --text-primary: #f0f0f0;
    --text-secondary: #a0a0a0;
    --accent-primary: #FF4500;
    --accent-secondary: #0071BC;
    --accent-gradient: linear-gradient(135deg, #FF4500 0%, #FF8C00 100%);
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --max-width: 1200px;
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

a {
    color: var(--accent-secondary);
    text-decoration: none;
    transition: var(--transition);
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    background: linear-gradient(to right, #fff, #aaa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    color: var(--text-primary);
}

h3 {
    font-size: clamp(1.2rem, 2.5vw, 1.6rem);
    color: var(--text-primary);
}

p {
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* Layout Utilities */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 6rem 0;
}

/* Hero Section */
.hero {
    min-height: 95vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    background: radial-gradient(circle at center, rgba(255, 69, 0, 0.1) 0%, transparent 70%);
}

.hero-content {
    max-width: 900px;
    z-index: 0;
}

.hero-tag {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(255, 69, 0, 0.1);
    color: var(--accent-primary);
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: 2rem;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(255, 69, 0, 0.2);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2.5rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    transition: var(--transition);
    font-size: 1rem;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(255, 69, 0, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(255, 69, 0, 0.4);
    color: white;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
    color: white;
}

/* Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.card {
    background: var(--surface-color);
    padding: 2rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
}

.card:hover {
    background: var(--surface-color-hover);
    transform: translateY(-5px);
    border-color: rgba(255, 255, 255, 0.1);
}

/* Abstract */
#abstract .container {
    max-width: 750px;
    text-align: justify;
}

#abstract h2 {
    text-align: center;
    margin-bottom: 2rem;
}

/* Narrative Sections */
.narrative-section {
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.narrative-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.narrative-text h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

/* Stats */
.stat-card {
    text-align: center;
    padding: 2rem;
    background: rgba(255, 69, 0, 0.05);
    border: 1px solid rgba(255, 69, 0, 0.1);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 69, 0, 0.25);
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--accent-primary);
    line-height: 1;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.stat-sub {
    font-size: 0.85rem;
    color: rgba(160,160,160,0.6);
    margin: 0;
}

/* Authors */
.authors-container {
    margin-top: 3rem;
    text-align: center;
}

.authors-list {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin-bottom: 0.75rem;
}

.author-item a {
    color: var(--text-primary);
    font-weight: 500;
    font-size: 1rem;
}

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

.author-item sup {
    font-size: 0.65rem;
    color: var(--accent-primary);
    margin-left: 1px;
}

.institutions {
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.25rem 2rem;
}

.institutions span strong {
    color: var(--accent-primary);
}

.venue {
    margin-top: 0.75rem;
    color: rgba(160,160,160,0.5);
    font-size: 0.85rem;
}

/* Section header helper */
.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header p {
    max-width: 600px;
    margin: 0.5rem auto 0;
    font-size: 1rem;
}

/* Challenge cards */
.challenges-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.challenge-card {
    display: flex;
    gap: 1.2rem;
    align-items: flex-start;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255,255,255,0.06);
    background: var(--surface-color);
    transition: var(--transition);
}

.challenge-card:hover {
    background: var(--surface-color-hover);
}

.challenge-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
    margin-top: 2px;
}

.challenge-card h3 {
    font-size: 1rem;
    margin-bottom: 0.4rem;
    color: var(--text-primary);
}

.challenge-card p {
    font-size: 0.9rem;
    margin: 0;
    line-height: 1.65;
}

/* Module cards */
.modules-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.module-card {
    padding: 2rem 1.75rem;
    border-radius: var(--border-radius);
    background: var(--surface-color);
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
}

.module-card:hover { transform: translateY(-4px); }

.module-num {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--accent-primary);
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-bottom: 0.75rem;
    opacity: 0.8;
}

.module-icon { font-size: 1.6rem; margin-bottom: 0.85rem; }

.module-card h3 { font-size: 1rem; margin-bottom: 0.5rem; }

.module-card p {
    font-size: 0.88rem;
    margin: 0;
    line-height: 1.7;
}

/* Method tags row */
.method-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    justify-content: center;
    padding: 1.25rem 1.5rem;
    background: var(--surface-color);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: var(--border-radius);
}

.method-tag {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 5px 14px;
    border-radius: 50px;
    background: rgba(255,69,0,0.07);
    border: 1px solid rgba(255,69,0,0.15);
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.method-tag strong {
    color: var(--accent-primary);
    font-family: var(--font-mono);
    font-size: 0.72rem;
}

/* Tables */
.table-section { margin-bottom: 1rem; }

.table-title-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 0.7rem;
}

.table-title-bar {
    width: 3px;
    height: 20px;
    border-radius: 2px;
    background: var(--accent-gradient);
    flex-shrink: 0;
}

.table-title-row span {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
}

.table-caption {
    font-size: 0.82rem;
    color: rgba(160,160,160,0.55);
    font-style: italic;
    margin-bottom: 0.5rem;
}

.table-wrap {
    overflow-x: auto;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255,255,255,0.06);
    background: var(--surface-color);
    margin-bottom: 2rem;
}

/* Data Table */
.data-table-container {
    overflow-x: auto;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--surface-color);
    text-align: left;
    min-width: 480px;
}

.data-table th,
.data-table td {
    padding: 0.75rem 0.7rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.85rem;
}

.data-table th {
    background: rgba(255, 255, 255, 0.04);
    font-weight: 700;
    color: var(--text-secondary);
    font-size: 0.72rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    text-align: center;
    white-space: nowrap;
}

.data-table th:first-child { text-align: left; }
.data-table td:first-child { text-align: left; }
.data-table td { text-align: center; color: rgba(160,160,160,0.65); }

.data-table tr:last-child td { border-bottom: none; }

.data-table tr:hover:not(.row-ours):not(.row-oracle) td {
    background: rgba(255, 255, 255, 0.02);
}

.sf-yes { color: #4ade80 !important; }
.sf-no  { color: rgba(160,160,160,0.3) !important; }

.row-ours td {
    background: rgba(255, 69, 0, 0.05);
    color: rgba(255,140,0,0.8);
}

.row-ours td:first-child {
    color: var(--text-primary);
    font-weight: 600;
}

.row-oracle td { color: rgba(160,160,160,0.35); font-style: italic; }

.map-ours {
    color: var(--accent-primary) !important;
    font-weight: 700 !important;
}

.ours-badge {
    background: rgba(255,69,0,0.15);
    color: var(--accent-primary);
    font-size: 0.6rem;
    padding: 2px 7px;
    border-radius: 50px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-right: 6px;
}

/* Ablation */
.ablation-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 1.25rem;
}

.ablation-legend {
    font-size: 0.8rem;
    color: rgba(160,160,160,0.4);
    font-style: italic;
    text-align: center;
}

/* Citation */
.citation-block {
    position: relative;
    background: #111;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    overflow-x: auto;
    border: 1px solid rgba(255, 255, 255, 0.1);
    max-width: 800px;
    margin: 1.5rem auto 0;
}

.copy-btn {
    position: absolute;
    top: 1rem; right: 1rem;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    color: var(--text-secondary);
    border-radius: 8px;
    padding: 6px 14px;
    cursor: pointer;
    font-size: 0.78rem;
    font-weight: 500;
    transition: var(--transition);
    font-family: var(--font-sans);
}

.copy-btn:hover {
    background: rgba(255,255,255,0.09);
    color: var(--text-primary);
}

.copy-btn.copied {
    background: rgba(74,222,128,0.1);
    border-color: rgba(74,222,128,0.3);
    color: #4ade80;
}

pre {
    font-family: var(--font-mono);
    color: #e6e6e6;
    font-size: 0.9rem;
    line-height: 1.7;
    white-space: pre-wrap;
}

/* Footer */
footer {
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding: 4rem 0;
    margin-top: 4rem;
    text-align: center;
}

footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    font-size: 0.8rem;
    color: rgba(160,160,160,0.45);
    display: flex;
    align-items: center;
    gap: 4px;
}

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

/* Animations */
.fade-in-up {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Mobile Responsive */
@media (max-width: 900px) {
    .challenges-grid { grid-template-columns: 1fr; }
    .modules-grid { grid-template-columns: 1fr; }
    .ablation-grid { grid-template-columns: 1fr; }
    .narrative-content { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    #abstract .container { text-align: left; }
    .hero-buttons { flex-direction: column; width: 100%; }
    .btn { width: 100%; justify-content: center; }
    h1 { font-size: 2.5rem; }
    .stat-number { font-size: 2.5rem; }
    .grid { grid-template-columns: 1fr; }
}

/* ── Narrative layout (architecture + ablation sections) ── */
.narrative-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 3rem;
    align-items: center;
}

.narrative-text h3 {
    font-size: clamp(1.2rem, 2vw, 1.6rem);
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.narrative-visual {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    border: 1px solid rgba(255,255,255,0.05);
    overflow: hidden;
}

.narrative-visual img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 8px;
}

/* ── Carousel ── */
.carousel-container {
    position: relative;
    width: 100%;
    overflow: hidden;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255,255,255,0.1);
    background: var(--surface-color);
}

.carousel-slides-wrapper {
    position: relative;
    width: 100%;
}

.carousel-slide {
    display: none;
    width: 100%;
}

.carousel-slide.active {
    display: block;
    animation: fadeEffect 0.5s;
}

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

.carousel-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(0,0,0,0.75);
    padding: 0.5rem;
    border-top: 1px solid rgba(255,255,255,0.08);
}

.carousel-center-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex-grow: 1;
    gap: 0.4rem;
}

.carousel-caption-text {
    text-align: center;
    color: var(--text-primary);
    font-size: 0.85rem;
    padding: 0.25rem 1rem;
    line-height: 1.4;
}

.carousel-nav {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    padding-bottom: 0.25rem;
}

.carousel-dot {
    height: 9px;
    width: 9px;
    background: #444;
    border-radius: 50%;
    display: inline-block;
    cursor: pointer;
    transition: background 0.3s;
}

.carousel-dot.active,
.carousel-dot:hover {
    background: var(--accent-primary);
}

.carousel-btn {
    background: transparent;
    color: var(--text-secondary);
    border: none;
    padding: 0.5rem 1rem;
    cursor: pointer;
    font-size: 1.1rem;
    transition: color 0.3s;
    flex-shrink: 0;
}

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

@keyframes fadeEffect {
    from { opacity: 0.3; }
    to   { opacity: 1; }
}

@media (max-width: 768px) {
    .narrative-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

pre {
    font-family: var(--font-mono);
    color: #e6e6e6;
    font-size: 0.9rem;
    line-height: 1.7;
    white-space: pre-wrap;
    text-align: left;  /* add this */
}