:root {
  --bg: #ffffff;
  --surface: #fafaf9;
  --surface-2: #f5f5f4;
  --line: #e7e5e4;
  --line-strong: #d6d3d1;
  --text: #111111;
  --muted: #6b7280;
  --mono-bg: #f8f8f7;
  --shadow: 0 1px 2px rgba(17, 17, 17, 0.03);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.72;
  letter-spacing: -0.01em;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
button, input, textarea, select { font: inherit; }
::selection { background: #e5e7eb; }

.progress-bar {
  position: fixed;
  inset: 0 auto auto 0;
  height: 2px;
  width: 0;
  background: #111111;
  z-index: 100;
}

.container {
  width: min(100% - 32px, 940px);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(231, 229, 228, 0.9);
}
.nav-shell {
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  font-weight: 650;
  font-size: 0.97rem;
  white-space: nowrap;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
  white-space: nowrap;
}
.site-nav::-webkit-scrollbar { display: none; }
.site-nav a,
.lang-link {
  color: var(--muted);
  padding: 8px 10px;
  border-radius: 999px;
  font-size: 0.93rem;
}
.site-nav a:hover,
.site-nav a.is-active,
.lang-link:hover {
  color: var(--text);
  background: var(--surface);
}
.lang-link {
  border: 1px solid var(--line);
  flex-shrink: 0;
}

main { padding-bottom: 72px; }
.section {
  padding-top: 74px;
}
.hero {
  padding-top: 42px;
}
.eyebrow {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.55rem);
  line-height: 1.08;
  letter-spacing: -0.04em;
}
.lead {
  margin: 18px 0 0;
  font-size: 1.08rem;
  color: #222222;
  max-width: 44rem;
}
.caption-lead {
  margin-top: 14px;
  max-width: 43rem;
  color: var(--muted);
  font-size: 0.98rem;
}

.meta-grid,
.summary-grid,
.scope-grid,
.architecture-grid,
.impl-grid,
.gallery-grid,
.notes-grid,
.metrics-grid,
.pipeline-grid,
.result-grid,
.decision-grid {
  display: grid;
  gap: 16px;
}
.meta-grid {
  margin-top: 26px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.summary-grid,
.scope-grid,
.impl-grid,
.notes-grid,
.result-grid,
.decision-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.architecture-grid,
.gallery-grid,
.pipeline-grid,
.metrics-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.meta-item,
.block,
.figure-frame,
.data-table-wrap,
.diagram,
.pipeline-card,
.decision-card,
.metric-card,
.gallery-card,
.note-card,
.result-card,
.callout,
.scope-card {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 18px;
  box-shadow: var(--shadow);
}
.meta-item,
.block,
.pipeline-card,
.decision-card,
.metric-card,
.note-card,
.result-card,
.callout,
.scope-card {
  padding: 18px 18px 16px;
}
.meta-item strong,
.metric-card strong {
  display: block;
  font-size: 0.94rem;
  margin-bottom: 6px;
}
.meta-item span,
.metric-card span,
.block p:last-child,
.note-card p:last-child,
.result-card p:last-child,
.decision-card p:last-child,
.scope-card p:last-child { margin-bottom: 0; }

.hero-figure,
.figure-frame,
.gallery-card {
  margin-top: 26px;
  overflow: hidden;
}
.figure-frame img,
.gallery-card img,
.hero-figure img {
  width: 100%;
  height: auto;
  object-fit: contain;
  background: #ffffff;
}
.hero-figure,
.figure-frame,
.gallery-card {
  border-radius: 20px;
  border: 1px solid var(--line);
  background: #ffffff;
}
.hero-figure figcaption,
.figure-frame figcaption,
.gallery-card figcaption {
  padding: 12px 14px 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.92rem;
  background: var(--surface);
}
.figure-frame.is-clickable,
.gallery-card.is-clickable,
.hero-figure.is-clickable { cursor: zoom-in; }

.section-heading {
  margin-bottom: 20px;
}
.section-index {
  display: inline-block;
  min-width: 2.8rem;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.section-heading h2 {
  margin: 6px 0 0;
  font-size: clamp(1.55rem, 3vw, 2.15rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
}
.section-heading p {
  margin: 10px 0 0;
  color: var(--muted);
}

.list-tight {
  margin: 0;
  padding-left: 1.1rem;
}
.list-tight li { margin: 0.25rem 0; }

.callout {
  background: #fcfcfb;
  margin-top: 18px;
}
.callout p { margin: 0; }

.diagram {
  padding: 18px;
  background: #fcfcfb;
}
.diagram-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 42px minmax(0, 1fr) 42px minmax(0, 1fr);
  gap: 10px;
  align-items: stretch;
}
.diagram-node {
  border: 1px solid var(--line);
  background: white;
  border-radius: 14px;
  padding: 14px;
}
.diagram-node h3 {
  margin: 0 0 8px;
  font-size: 1rem;
}
.diagram-node ul {
  margin: 0;
  padding-left: 1rem;
  color: #2b2b2b;
}
.diagram-arrow {
  display: grid;
  place-items: center;
  color: var(--muted);
  font-size: 1.25rem;
}
.diagram-note {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.92rem;
}

.pipeline-card h3,
.decision-card h3,
.note-card h3,
.result-card h3,
.scope-card h3,
.block h3 {
  margin: 0 0 10px;
  font-size: 1.03rem;
}
.pipeline-code {
  margin: 12px 0 0;
  padding: 14px;
  background: var(--mono-bg);
  border: 1px solid var(--line);
  border-radius: 14px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.91rem;
  line-height: 1.7;
  white-space: pre-wrap;
}
.decision-no {
  display: inline-block;
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.data-table-wrap {
  overflow-x: auto;
  background: white;
}
.table {
  width: 100%;
  border-collapse: collapse;
  min-width: 560px;
}
.table th,
.table td {
  padding: 13px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}
.table th {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  background: var(--surface);
}
.table tr:last-child td { border-bottom: 0; }
.table td strong { display: inline; font-size: inherit; }

.subtle {
  color: var(--muted);
}
.mono {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
.metric-card small,
.small {
  color: var(--muted);
  font-size: 0.92rem;
}

.gallery-card img { background: white; }
.gallery-grid { align-items: start; }

.footer {
  border-top: 1px solid var(--line);
  padding: 18px 0 28px;
  color: var(--muted);
  font-size: 0.94rem;
}
.footer-shell {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}
.footer a:hover { color: var(--text); }

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.lightbox {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 32px;
  background: rgba(17, 17, 17, 0.88);
  z-index: 90;
}
.lightbox.is-open { display: flex; }
.lightbox-inner {
  width: min(100%, 1200px);
  max-height: 100%;
}
.lightbox img {
  width: 100%;
  max-height: calc(100vh - 120px);
  object-fit: contain;
  border-radius: 16px;
  background: white;
}
.lightbox-caption {
  color: rgba(255, 255, 255, 0.82);
  margin-top: 12px;
  font-size: 0.95rem;
}
.lightbox-close {
  position: absolute;
  top: 18px;
  right: 22px;
  width: 42px;
  height: 42px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.06);
  color: white;
  font-size: 1.15rem;
  cursor: pointer;
}

@media (max-width: 880px) {
  .summary-grid,
  .scope-grid,
  .architecture-grid,
  .impl-grid,
  .gallery-grid,
  .notes-grid,
  .metrics-grid,
  .pipeline-grid,
  .result-grid,
  .decision-grid,
  .meta-grid {
    grid-template-columns: 1fr;
  }
  .diagram-row {
    grid-template-columns: 1fr;
  }
  .diagram-arrow {
    transform: rotate(90deg);
    min-height: 24px;
  }
  .site-nav { flex: 1 1 auto; }
}

@media (max-width: 680px) {
  .nav-shell {
    display: grid;
    grid-template-columns: 1fr auto;
    align-items: center;
    padding-block: 8px;
  }
  .brand { grid-column: 1 / 2; }
  .lang-link { grid-column: 2 / 3; justify-self: end; }
  .site-nav { grid-column: 1 / -1; }
  .section { padding-top: 64px; }
  .lightbox { padding: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}