/* ==========================================================================
   CloudAura Fine-Tune — Scientific Paper / Academic Poster Aesthetic
   Light theme with serif headings, clean data presentation
   ========================================================================== */

:root {
    /* Colors — warm academic palette */
    --bg-primary: #faf8f5;
    --bg-secondary: #f3f0eb;
    --bg-card: #ffffff;
    --bg-card-hover: #f7f5f2;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a5a;
    --text-muted: #7a7a8a;
    --accent: #e63946;
    --accent-light: rgba(230, 57, 70, 0.08);
    --accent-hover: #c62f3b;
    --success: #2d8a4e;
    --warning: #b8860b;
    --danger: #c0392b;
    --border: #e0ddd8;
    --border-light: #eae7e2;
    --base-color: #7a7a8a;
    --sft-color: #5b4a9e;
    --dpo-color: #1a6b8a;

    /* Typography */
    --font-serif: 'Playfair Display', 'Georgia', 'Times New Roman', serif;
    --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */

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

body {
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ==========================================================================
   Header — slim, understated navigation
   ========================================================================== */

header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
    background: rgba(250, 248, 245, 0.92);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.logo span {
    color: var(--accent);
    font-weight: 400;
    font-style: italic;
}

nav {
    display: flex;
    gap: 2rem;
}

nav a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.8125rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    transition: color 0.25s ease;
    position: relative;
}

nav a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.25s ease;
}

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

nav a:hover::after {
    width: 100%;
}

/* ==========================================================================
   Hero — title page of a research paper
   ========================================================================== */

.hero {
    padding: 5rem 0 4rem;
    text-align: center;
    border-bottom: 2px solid var(--text-primary);
}

.hero-label {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1.5rem;
}

.hero h1 {
    font-family: var(--font-serif);
    font-size: 2.75rem;
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 400;
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.hero-rule {
    width: 60px;
    height: 2px;
    background: var(--accent);
    margin: 0 auto 2rem;
}

.hero-abstract {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    max-width: 680px;
    margin: 0 auto;
    line-height: 1.8;
    text-align: justify;
}

.hero-abstract strong {
    font-family: var(--font-serif);
    font-weight: 700;
    font-style: italic;
    color: var(--text-primary);
}

.hero-timestamp {
    margin-top: 1.5rem;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.hero-status {
    margin-top: 0.75rem;
    font-size: 0.875rem;
    color: var(--warning);
}

/* ==========================================================================
   Tags — keyword badges
   ========================================================================== */

.tags {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.tag {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 0.3rem 0.75rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-weight: 500;
}

/* ==========================================================================
   Section Structure — academic paper sections
   ========================================================================== */

section {
    padding: 3.5rem 0;
}

.section-number {
    font-family: var(--font-sans);
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.25rem;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    letter-spacing: -0.01em;
}

.section-subtitle {
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ==========================================================================
   Metric Cards — key findings, top of page
   ========================================================================== */

.metric-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.25rem;
    margin-bottom: 1rem;
}

.metric-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.75rem 1.25rem;
    text-align: center;
    transition: box-shadow 0.3s ease, transform 0.3s ease;
}

.metric-card:hover {
    box-shadow: 0 4px 20px rgba(26, 26, 46, 0.06);
    transform: translateY(-2px);
}

.metric-label {
    font-size: 0.6875rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    font-weight: 600;
}

.metric-value {
    font-family: var(--font-mono);
    font-size: 2rem;
    font-weight: 700;
    line-height: 1;
}

.metric-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
    font-style: italic;
}

/* Color utility classes for metric values */
.accent-color { color: var(--accent); }
.sft-color { color: var(--sft-color); }
.dpo-color { color: var(--dpo-color); }
.success-color { color: var(--success); }
.warning-color { color: var(--warning); }

/* ==========================================================================
   Pipeline — research paper figure style
   ========================================================================== */

.pipeline {
    display: flex;
    align-items: stretch;
    gap: 0;
    margin-bottom: 3rem;
    position: relative;
}

.pipeline-step {
    flex: 1;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.5rem 1.25rem;
    position: relative;
    transition: box-shadow 0.3s ease;
}

.pipeline-step:hover {
    box-shadow: 0 2px 12px rgba(26, 26, 46, 0.06);
}

.pipeline-arrow {
    display: flex;
    align-items: center;
    padding: 0 0.5rem;
    color: var(--text-muted);
    font-size: 1.25rem;
    flex-shrink: 0;
}

.pipeline-arrow::after {
    content: '';
    display: block;
    width: 24px;
    height: 1px;
    background: var(--text-muted);
    position: relative;
}

.pipeline-arrow::before {
    content: '';
    display: block;
    width: 6px;
    height: 6px;
    border-top: 1px solid var(--text-muted);
    border-right: 1px solid var(--text-muted);
    transform: rotate(45deg);
    position: absolute;
    right: 0.5rem;
}

.step-num {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--accent);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    margin-bottom: 0.5rem;
}

.pipeline-step h3 {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.pipeline-step p {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ==========================================================================
   Config Block — monospace technical specification
   ========================================================================== */

.config-section {
    margin-top: 2.5rem;
}

.config-title {
    font-family: var(--font-serif);
    font-size: 0.9375rem;
    font-weight: 600;
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.config-block {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-left: 3px solid var(--accent);
    border-radius: 0 4px 4px 0;
    padding: 1.5rem 1.75rem;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    overflow-x: auto;
    white-space: pre;
    color: var(--text-secondary);
    line-height: 1.9;
}

.config-key {
    color: var(--text-primary);
    font-weight: 600;
}

/* ==========================================================================
   Results Section
   ========================================================================== */

.results-section {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}

.comparison-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.5rem;
    transition: box-shadow 0.3s ease;
}

.comparison-card:hover {
    box-shadow: 0 2px 12px rgba(26, 26, 46, 0.06);
}

.comparison-card h3 {
    font-family: var(--font-serif);
    font-size: 0.9375rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-light);
}

/* Bar chart rows */
.bar-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.875rem;
}

.bar-label {
    width: 70px;
    font-size: 0.7rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    text-align: right;
    flex-shrink: 0;
    font-weight: 500;
    letter-spacing: 0.02em;
}

.bar-track {
    flex: 1;
    height: 24px;
    background: var(--bg-secondary);
    border-radius: 2px;
    position: relative;
    overflow: hidden;
    border: 1px solid var(--border-light);
}

.bar-fill {
    height: 100%;
    border-radius: 2px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 0.5rem;
    transition: width 0s;
}

.bar-fill.animated {
    transition: width 1.2s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.bar-fill.base {
    background: var(--base-color);
}

.bar-fill.sft {
    background: var(--sft-color);
}

.bar-fill.dpo {
    background: var(--dpo-color);
}

.bar-fill span {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
    color: #ffffff;
    white-space: nowrap;
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

/* ==========================================================================
   Detail Panels (tables, losses)
   ========================================================================== */

.detail-panel {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.75rem;
    margin-top: 1.5rem;
}

.panel-title {
    font-family: var(--font-serif);
    font-size: 0.9375rem;
    font-weight: 600;
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-light);
}

/* Training losses */
.training-losses {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
    margin-top: 1.5rem;
}

.loss-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.5rem;
}

.loss-title {
    font-family: var(--font-serif);
    font-size: 0.9375rem;
    font-weight: 600;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-light);
}

.loss-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.loss-value {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-top: 0.25rem;
}

/* ==========================================================================
   Results Table — clean academic table
   ========================================================================== */

.results-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8125rem;
    margin-top: 0.5rem;
}

.results-table thead th {
    text-align: left;
    padding: 0.625rem 1rem;
    color: var(--text-muted);
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    border-bottom: 2px solid var(--text-primary);
    background: transparent;
}

.results-table tbody td {
    padding: 0.625rem 1rem;
    border-bottom: 1px solid var(--border-light);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-primary);
}

.results-table tbody tr:last-child td {
    border-bottom: 2px solid var(--text-primary);
}

.results-table tbody tr:hover td {
    background: var(--accent-light);
}

.highlight-row td {
    background: var(--accent-light);
}

/* Improvement badges */
.improvement {
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    padding: 0.15rem 0.5rem;
    border-radius: 2px;
    font-weight: 600;
}

.improvement.positive {
    background: rgba(45, 138, 78, 0.1);
    color: var(--success);
}

.improvement.neutral {
    background: rgba(122, 122, 138, 0.1);
    color: var(--text-secondary);
}

/* ==========================================================================
   Dataset Cards
   ========================================================================== */

.dataset-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
}

.dataset-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.5rem;
    transition: box-shadow 0.3s ease;
}

.dataset-card:hover {
    box-shadow: 0 2px 12px rgba(26, 26, 46, 0.06);
}

.dataset-card h3 {
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-weight: 600;
}

.dataset-card .dataset-type {
    font-size: 0.625rem;
    padding: 0.2rem 0.6rem;
    border-radius: 2px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    display: inline-block;
    margin-bottom: 0.75rem;
}

.dataset-type.sft {
    background: rgba(91, 74, 158, 0.1);
    color: var(--sft-color);
}

.dataset-type.dpo {
    background: rgba(26, 107, 138, 0.1);
    color: var(--dpo-color);
}

.dataset-type.eval {
    background: rgba(45, 138, 78, 0.1);
    color: var(--success);
}

.dataset-card p {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0.75rem;
}

.dataset-card a {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.75rem;
    font-family: var(--font-mono);
    font-weight: 500;
    transition: color 0.2s ease;
}

.dataset-card a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* ==========================================================================
   Discussion / Tradeoffs
   ========================================================================== */

.discussion-section {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
}

.tradeoff-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
}

.tradeoff-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.5rem;
    transition: box-shadow 0.3s ease;
}

.tradeoff-card:hover {
    box-shadow: 0 2px 12px rgba(26, 26, 46, 0.06);
}

.tradeoff-card h3 {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.tradeoff-card p {
    color: var(--text-secondary);
    font-size: 0.8125rem;
    line-height: 1.7;
}

.highlight {
    color: var(--accent);
    font-weight: 600;
}

/* ==========================================================================
   Footer — minimal, like a paper's final line
   ========================================================================== */

footer {
    padding: 3rem 0 2.5rem;
    text-align: center;
}

.footer-rule {
    width: 40px;
    height: 1px;
    background: var(--text-muted);
    margin: 0 auto 1.5rem;
}

.footer-title {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.footer-sub {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.footer-links {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.footer-links a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* ==========================================================================
   Animations — fade-in on scroll
   ========================================================================== */

.fade-in {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* Stagger animation delay for grid children */
.metric-grid .fade-in:nth-child(1) { transition-delay: 0s; }
.metric-grid .fade-in:nth-child(2) { transition-delay: 0.1s; }
.metric-grid .fade-in:nth-child(3) { transition-delay: 0.2s; }
.metric-grid .fade-in:nth-child(4) { transition-delay: 0.3s; }

.pipeline .fade-in:nth-child(1) { transition-delay: 0s; }
.pipeline .fade-in:nth-child(3) { transition-delay: 0.15s; }
.pipeline .fade-in:nth-child(5) { transition-delay: 0.3s; }
.pipeline .fade-in:nth-child(7) { transition-delay: 0.45s; }

.comparison-grid .fade-in:nth-child(1) { transition-delay: 0s; }
.comparison-grid .fade-in:nth-child(2) { transition-delay: 0.1s; }
.comparison-grid .fade-in:nth-child(3) { transition-delay: 0.2s; }
.comparison-grid .fade-in:nth-child(4) { transition-delay: 0.3s; }

.dataset-grid .fade-in:nth-child(1) { transition-delay: 0s; }
.dataset-grid .fade-in:nth-child(2) { transition-delay: 0.1s; }
.dataset-grid .fade-in:nth-child(3) { transition-delay: 0.2s; }
.dataset-grid .fade-in:nth-child(4) { transition-delay: 0.3s; }

.tradeoff-grid .fade-in:nth-child(1) { transition-delay: 0s; }
.tradeoff-grid .fade-in:nth-child(2) { transition-delay: 0.1s; }
.tradeoff-grid .fade-in:nth-child(3) { transition-delay: 0.2s; }
.tradeoff-grid .fade-in:nth-child(4) { transition-delay: 0.3s; }

/* Bar fill animation — start at 0 width, animate to target */
@keyframes barGrow {
    from { width: 0; }
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media (max-width: 900px) {
    .metric-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .training-losses {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.25rem;
    }

    .hero {
        padding: 3rem 0 2.5rem;
    }

    .hero h1 {
        font-size: 1.875rem;
    }

    .hero-subtitle {
        font-size: 1.0625rem;
    }

    .hero-abstract {
        text-align: left;
        font-size: 0.875rem;
    }

    .pipeline {
        flex-direction: column;
        gap: 0;
    }

    .pipeline-arrow {
        transform: rotate(90deg);
        padding: 0.25rem 0;
        justify-content: center;
    }

    .section-title {
        font-size: 1.5rem;
    }

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

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

    .results-table {
        font-size: 0.75rem;
    }

    .results-table thead th,
    .results-table tbody td {
        padding: 0.5rem 0.5rem;
    }
}

@media (max-width: 480px) {
    .metric-grid {
        grid-template-columns: 1fr;
    }

    header .container {
        flex-direction: column;
        gap: 0.75rem;
    }

    nav {
        gap: 1rem;
    }

    .hero h1 {
        font-size: 1.5rem;
    }

    .metric-value {
        font-size: 1.5rem;
    }
}

/* ==========================================================================
   Print styles — readable when printed
   ========================================================================== */

@media print {
    header {
        position: static;
    }

    .fade-in {
        opacity: 1;
        transform: none;
    }

    body {
        font-size: 11pt;
    }

    .container {
        max-width: 100%;
    }
}