:root {
    --bg-eggshell: #FAF9F6;
    --text-primary: #1A1A1A;
    --text-body: #2D2D2D;
    --text-muted: #6B6B6B;
    --border-subtle: #E5E4E0;
    --font-heading: 'JetBrains Mono', monospace;
    --font-body: 'Inter', sans-serif;
    --font-editorial: 'Playfair Display', serif;
    --accent-blue: #3B82F6;
    --accent-red: #EF4444;
    --accent-green: #10B981;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-body);
    background: var(--bg-eggshell);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-eggshell);
    border-bottom: 1px solid var(--text-primary);
    z-index: 100;
}

.header-container {
    display: flex;
    align-items: center;
    padding: 0.75rem 2rem;
    gap: 1.5rem;
}

.header-back {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: 0.05em;
}

.header-back:hover { opacity: 0.6; }

.header-title {
    font-family: var(--font-heading);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
}

/* Main */
.main {
    max-width: 960px;
    margin: 0 auto;
    padding: 5rem 2rem 3rem;
}

/* Intro */
.intro {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-subtle);
}

.intro-title {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
    margin-bottom: 0.5rem;
}

.intro-subtitle {
    font-family: var(--font-editorial);
    font-style: italic;
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.intro-description {
    font-size: 0.9375rem;
    line-height: 1.75;
    color: var(--text-body);
    max-width: 720px;
}

.intro-description code {
    font-family: var(--font-heading);
    font-size: 0.8125rem;
    background: #f0efec;
    padding: 0.125rem 0.375rem;
    border-radius: 3px;
}

.hackathon-badge {
    display: inline-block;
    font-family: var(--font-heading);
    font-size: 0.625rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.2rem 0.5rem;
    border: 1px solid var(--accent-blue);
    color: var(--accent-blue);
    vertical-align: middle;
    margin-left: 0.5rem;
}

/* Section headers */
.section-header {
    margin-bottom: 1.5rem;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-primary);
    margin-bottom: 0.375rem;
}

.section-desc {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Content sections */
.content-section {
    margin-bottom: 3rem;
}

.content-text {
    font-size: 0.9375rem;
    line-height: 1.75;
    color: var(--text-body);
    max-width: 720px;
    margin-bottom: 1.5rem;
}

/* Architecture Diagram */
.arch-diagram-container {
    border: 1px solid var(--text-primary);
    background: #fff;
    padding: 2rem;
    margin-bottom: 1.5rem;
    overflow-x: auto;
}

.arch-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0;
    min-width: 700px;
}

.arch-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    padding: 1rem 1.25rem;
    border: 2px solid var(--text-primary);
    background: var(--bg-eggshell);
    min-width: 120px;
    text-align: center;
}

.arch-node-accent {
    border-color: var(--accent-blue);
    background: #eff6ff;
}

.arch-node-label {
    font-family: var(--font-heading);
    font-size: 0.6875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-primary);
}

.arch-node-accent .arch-node-label {
    color: var(--accent-blue);
}

.arch-node-desc {
    font-size: 0.6875rem;
    color: var(--text-muted);
    line-height: 1.4;
}

.arch-arrow-right {
    display: flex;
    align-items: center;
    padding: 0 0.25rem;
    color: var(--text-muted);
    flex-shrink: 0;
}

/* VLM detail box */
.vlm-detail {
    border: 1px solid var(--text-primary);
    background: #fff;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.vlm-detail-title {
    font-family: var(--font-heading);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.vlm-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

.vlm-input-card {
    border: 1px solid var(--border-subtle);
    padding: 1rem;
}

.vlm-input-label {
    font-family: var(--font-heading);
    font-size: 0.625rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.vlm-input-desc {
    font-size: 0.8125rem;
    color: var(--text-body);
    line-height: 1.5;
}

.vlm-output-label {
    font-family: var(--font-heading);
    font-size: 0.625rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.vlm-outputs {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.vlm-output-tag {
    font-family: var(--font-heading);
    font-size: 0.6875rem;
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--text-primary);
    background: var(--bg-eggshell);
}

/* Decision flow diagram */
.flow-diagram {
    border: 1px solid var(--text-primary);
    background: #fff;
    padding: 2rem;
    margin-bottom: 1.5rem;
}

.flow-rows {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
}

.flow-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--text-primary);
    text-align: center;
    min-width: 200px;
}

.flow-node-decision {
    transform: none;
    border-color: var(--accent-blue);
    background: #eff6ff;
    border-style: dashed;
}

.flow-node-action-retry {
    border-color: var(--accent-green);
    background: #ecfdf5;
}

.flow-node-action-stop {
    border-color: var(--accent-red);
    background: #fef2f2;
}

.flow-node-label {
    font-family: var(--font-heading);
    font-size: 0.6875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.flow-node-decision .flow-node-label { color: var(--accent-blue); }
.flow-node-action-retry .flow-node-label { color: var(--accent-green); }
.flow-node-action-stop .flow-node-label { color: var(--accent-red); }

.flow-node-desc {
    font-size: 0.6875rem;
    color: var(--text-muted);
}

.flow-arrow-down {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-muted);
    padding: 0.25rem 0;
}

.flow-arrow-label {
    font-family: var(--font-heading);
    font-size: 0.5625rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-top: 0.125rem;
}

.flow-branch {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    justify-content: center;
}

.flow-branch-path {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
}

/* Video section */
.video-section {
    margin-bottom: 3rem;
}

.video-container {
    border: 1px solid var(--text-primary);
    background: #000;
    overflow: hidden;
}

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

/* Footer */
.footer {
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--border-subtle);
}

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

/* Responsive */
@media (max-width: 768px) {
    .main { padding: 4.5rem 1rem 2rem; }
    .intro-title { font-size: 1.5rem; }
    .vlm-inputs { grid-template-columns: 1fr; }
    .flow-branch { flex-direction: column; align-items: center; gap: 1.5rem; }
}