:root {
  --sky: #48a9dc;
  --sky-dark: #1677a8;
  --sky-pale: #eaf7fd;
  --ink: #17324d;
  --muted: #5f7485;
  --cream: #fffaf0;
  --paper: #ffffff;
  --line: #bedceb;
  --orange: #f3a91b;
  --shadow: 0 14px 36px rgba(30, 99, 135, .12);
  --radius: 17px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 3%, rgba(255,255,255,.95) 0 70px, transparent 72px),
    linear-gradient(180deg, #dff4ff 0 330px, #f8fcfe 330px 100%);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  line-height: 1.72;
}
a { color: #0b6f9f; text-underline-offset: .2em; }
a:hover { color: #064e72; }
img { max-width: 100%; height: auto; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 20; background: #fff; padding: .7rem 1rem; border: 2px solid var(--sky-dark); }
.skip-link:focus { top: 1rem; }
.site-header { border-bottom: 1px solid rgba(30,101,138,.18); background: rgba(247,252,255,.93); backdrop-filter: blur(12px); }
.header-inner { width: min(1120px, calc(100% - 32px)); margin: auto; min-height: 92px; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.wordmark { text-decoration: none; display: flex; align-items: baseline; gap: 10px; color: var(--ink); white-space: nowrap; }
.wordmark-main { font-weight: 850; letter-spacing: -.05em; font-size: 1.45rem; }
.wordmark-sub { color: var(--sky-dark); font: 700 .66rem/1 ui-monospace, monospace; letter-spacing: .12em; text-transform: uppercase; }
nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 5px; }
nav a { padding: .42rem .58rem; border-radius: 7px; color: #31556b; font-size: .88rem; font-weight: 700; text-decoration: none; }
nav a:hover, nav a[aria-current="page"] { background: #dff3fd; color: #075d89; }
main { width: min(1120px, calc(100% - 32px)); margin: 0 auto; padding: 54px 0 90px; }
.hero { position: relative; overflow: hidden; display: grid; grid-template-columns: 1.25fr .75fr; gap: 50px; align-items: center; min-height: 470px; padding: 58px; background: rgba(255,255,255,.92); border: 1px solid var(--line); border-radius: 28px; box-shadow: var(--shadow); }
.hero::after { content: ""; position: absolute; width: 360px; height: 360px; right: -105px; top: -150px; border: 54px solid #d6f2ff; border-radius: 50%; opacity: .85; }
.eyebrow { margin: 0 0 12px; color: var(--sky-dark); font-size: .82rem; font-weight: 850; letter-spacing: .13em; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.28; letter-spacing: -.035em; }
h1 { max-width: 12ch; margin: 0 0 22px; font-size: clamp(2.6rem, 7vw, 5.2rem); }
h2 { margin: 0 0 18px; font-size: clamp(1.65rem, 3vw, 2.5rem); }
h3 { margin: 0 0 9px; font-size: 1.14rem; }
.lead { max-width: 60ch; margin: 0; color: #405e70; font-size: 1.12rem; }
.hero-note { position: relative; z-index: 1; padding: 28px; background: var(--cream); border: 1px solid #f1d89e; border-radius: var(--radius); transform: rotate(1.2deg); }
.hero-note strong { display: block; margin-bottom: 6px; font-size: 1.22rem; }
.status-pill { display: inline-block; margin-bottom: 13px; padding: .25rem .65rem; color: #8a4a00; background: #ffedbd; border-radius: 999px; font-size: .78rem; font-weight: 850; }
.section { margin-top: 78px; }
.section-intro { max-width: 68ch; color: var(--muted); }
.metric-grid, .card-grid, .fun-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-top: 25px; }
.metric, .card, .fun-card, .chart-card, .notice, .download-card { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: 0 8px 24px rgba(31,99,133,.07); }
.metric { padding: 24px; }
.metric strong { display: block; color: var(--sky-dark); font-size: clamp(1.55rem, 3vw, 2.35rem); line-height: 1.1; letter-spacing: -.04em; }
.metric span { display: block; margin-top: 9px; color: var(--muted); font-size: .9rem; }
.card { padding: 24px; }
.card p, .fun-card p { margin-bottom: 0; color: var(--muted); }
.card a.stretched { font-weight: 800; }
.fun-grid { grid-template-columns: repeat(3, 1fr); }
.fun-card { padding: 22px; border-top: 5px solid var(--sky); }
.fun-card strong { display: block; font-size: 1.55rem; color: var(--sky-dark); }
.chart-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 28px; }
.chart-card { padding: 24px; overflow: hidden; }
.chart-card.full { grid-column: 1 / -1; }
.chart-card svg { display: block; width: 100%; height: auto; margin-top: 12px; }
.chart-card details { margin-top: 14px; }
.chart-card summary { cursor: pointer; font-weight: 750; color: var(--sky-dark); }
.table-wrap { overflow-x: auto; margin-top: 12px; }
table { width: 100%; border-collapse: collapse; font-size: .88rem; }
th, td { padding: .6rem .7rem; border-bottom: 1px solid #dceaf1; text-align: left; white-space: nowrap; }
th { color: #31556b; background: #f1f9fd; }
.page-header { max-width: 780px; padding: 34px 0 18px; }
.page-header h1 { max-width: 15ch; font-size: clamp(2.35rem, 6vw, 4.2rem); }
.timeline { position: relative; margin-top: 40px; }
.timeline::before { content: ""; position: absolute; left: 83px; top: 10px; bottom: 10px; width: 2px; background: #9ed2e9; }
.timeline-item { position: relative; display: grid; grid-template-columns: 70px 1fr; gap: 42px; margin-bottom: 24px; }
.timeline-year { font: 850 1.1rem/1 ui-monospace, monospace; color: var(--sky-dark); }
.timeline-card { padding: 20px 22px; background: white; border: 1px solid var(--line); border-radius: 13px; }
.timeline-card::before { content: ""; position: absolute; left: 77px; top: 7px; width: 12px; height: 12px; background: var(--sky); border: 3px solid white; border-radius: 50%; box-shadow: 0 0 0 1px var(--sky); }
.timeline-card p { margin: .4rem 0 0; color: var(--muted); }
.evidence { display: inline-block; padding: .13rem .44rem; border-radius: 5px; background: #eaf7fd; color: #11678f; font-size: .72rem; font-weight: 800; }
.feature-list { display: grid; gap: 18px; margin-top: 34px; }
.feature { scroll-margin-top: 20px; display: grid; grid-template-columns: 180px 1fr; gap: 28px; padding: 26px; background: white; border: 1px solid var(--line); border-radius: var(--radius); }
.feature-tag { color: var(--sky-dark); font: 800 .84rem/1.4 ui-monospace, monospace; }
.feature p { margin: 0; color: var(--muted); }
.flow { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; padding: 0; list-style: none; counter-reset: flow; }
.flow li { position: relative; min-height: 140px; padding: 20px; background: white; border: 1px solid var(--line); border-radius: 14px; }
.flow li::before { counter-increment: flow; content: counter(flow); display: grid; place-items: center; width: 28px; height: 28px; margin-bottom: 14px; color: white; background: var(--sky); border-radius: 50%; font-weight: 850; }
.notice { padding: 24px 27px; border-left: 6px solid var(--orange); }
.gallery-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 30px; }
.gallery-item { margin: 0; padding: 18px; background: white; border: 1px solid var(--line); border-radius: 14px; }
.gallery-item .image-stage { display: grid; place-items: center; min-height: 170px; padding: 16px; background: #f7fbfd; border-radius: 9px; }
.gallery-item figcaption { margin-top: 13px; color: var(--muted); font-size: .87rem; }
.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.download-card { padding: 20px; }
.download-card code { color: var(--sky-dark); font-weight: 800; }
.source-list li { margin-bottom: .75rem; }
.site-footer { display: flex; justify-content: space-between; gap: 30px; width: min(1120px, calc(100% - 32px)); margin: auto; padding: 38px 0 54px; border-top: 1px solid var(--line); color: var(--muted); font-size: .88rem; }
.site-footer p { max-width: 60ch; margin: 5px 0 0; }
.footer-links { display: flex; gap: 16px; flex-wrap: wrap; align-content: flex-start; }

@media (max-width: 900px) {
  .header-inner { align-items: flex-start; flex-direction: column; padding: 20px 0; gap: 12px; }
  nav { justify-content: flex-start; }
  .hero { grid-template-columns: 1fr; padding: 40px; }
  .hero-note { max-width: 520px; }
  .metric-grid, .card-grid { grid-template-columns: repeat(2, 1fr); }
  .fun-grid, .gallery-grid, .download-grid { grid-template-columns: repeat(2, 1fr); }
  .flow { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 620px) {
  main { width: min(100% - 22px, 1120px); padding-top: 28px; }
  .wordmark { white-space: normal; flex-wrap: wrap; }
  .wordmark-sub { font-size: .58rem; }
  nav { width: 100%; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); }
  nav a { padding: .5rem .2rem; text-align: center; }
  .hero { padding: 29px 23px; border-radius: 20px; }
  .hero h1 { font-size: clamp(2.25rem, 12vw, 3rem); word-break: keep-all; }
  .metric-grid, .card-grid, .fun-grid, .chart-grid, .gallery-grid, .download-grid { grid-template-columns: 1fr; }
  .chart-card.full { grid-column: auto; }
  .timeline::before { left: 24px; }
  .timeline-item { grid-template-columns: 1fr; gap: 8px; padding-left: 48px; }
  .timeline-card::before { left: 18px; top: 3px; }
  .feature { grid-template-columns: 1fr; gap: 8px; }
  .flow { grid-template-columns: 1fr; }
  .site-footer { flex-direction: column; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }