:root {
  --ink: #102a38;
  --ink-soft: #355564;
  --paper: #f4f0e8;
  --paper-deep: #e8e0d3;
  --steel: #d9e2df;
  --line: rgba(16, 42, 56, 0.18);
  --amber: #df6b2c;
  --amber-pale: #f5c689;
  --white: #fffdf8;
  --display: "Hiragino Mincho ProN", "Yu Mincho", "YuMincho", serif;
  --body: "Hiragino Sans", "Yu Gothic", "YuGothic", sans-serif;
  --mono: "SFMono-Regular", "Cascadia Mono", "Hiragino Kaku Gothic ProN", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: var(--body); font-size: 18px; line-height: 1.7; }
a { color: inherit; }
button { font: inherit; }
.skip-link { position: fixed; top: -64px; left: 20px; z-index: 10; padding: 10px 16px; background: var(--amber); color: var(--white); }
.skip-link:focus { top: 20px; }
.site-header { min-height: 76px; display: flex; align-items: center; gap: 28px; padding: 14px clamp(24px, 4vw, 64px); border-bottom: 1px solid var(--line); background: rgba(244, 240, 232, 0.92); position: sticky; top: 0; z-index: 5; backdrop-filter: blur(12px); }
.brand { display: inline-flex; align-items: center; gap: 9px; font-family: var(--mono); font-weight: 800; letter-spacing: 0.08em; text-decoration: none; }
.brand small { align-self: end; font-family: var(--body); font-size: 16px; font-weight: 500; letter-spacing: 0; color: var(--ink-soft); }
.brand-mark { display: grid; width: 29px; height: 29px; place-items: center; background: var(--ink); color: var(--paper); font-size: 16px; }
nav { display: flex; gap: 24px; margin-left: auto; }
nav a { font-size: 16px; text-underline-offset: 5px; }
.header-action { display: inline-flex; align-items: center; min-height: 42px; padding: 7px 13px; border: 1px solid var(--ink); background: var(--ink); color: var(--white); font-size: 16px; font-weight: 800; text-decoration: none; }
.header-action:hover { background: var(--amber); color: var(--ink); }
.prototype-label { padding: 4px 11px; border: 1px solid var(--ink); font-family: var(--mono); font-size: 16px; }
.hero { min-height: 640px; display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(400px, 0.88fr); gap: 38px; align-items: center; padding: clamp(64px, 9vw, 144px) clamp(24px, 5vw, 80px); background: linear-gradient(120deg, var(--paper) 0%, var(--paper) 59%, var(--steel) 59%, var(--steel) 100%); position: relative; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0; pointer-events: none; opacity: 0.28; background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px); background-size: 42px 42px; mask-image: linear-gradient(to right, black, transparent 70%); }
.hero-copy, .hero-board { position: relative; }
.eyebrow, .section-kicker, .timeline-number { margin: 0; font-family: var(--mono); font-size: 16px; letter-spacing: 0.08em; color: var(--ink-soft); }
h1, h2, h3, p { overflow-wrap: break-word; }
h1, h2, h3 { line-height: 1.18; }
h1 { margin: 18px 0 26px; max-width: 720px; font-family: var(--display); font-size: clamp(54px, 7vw, 104px); font-weight: 500; letter-spacing: -0.05em; }
h1 em { color: var(--amber); font-style: normal; }
.hero-lead { max-width: 660px; margin: 0 0 32px; font-size: clamp(18px, 1.6vw, 22px); }
.primary-link { display: inline-flex; align-items: center; gap: 18px; padding: 13px 0; border-bottom: 3px solid var(--amber); font-weight: 700; text-decoration: none; }
.primary-link span { font-family: var(--mono); font-size: 24px; }
.hero-board { align-self: stretch; display: flex; flex-direction: column; justify-content: space-between; min-height: 420px; padding: 25px; background: var(--ink); color: var(--white); box-shadow: 16px 16px 0 var(--amber); }
.board-caption, .board-foot { margin: 0; font-family: var(--mono); font-size: 16px; letter-spacing: 0.06em; color: var(--amber-pale); }
.board-grid { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid rgba(255,255,255,.32); border-left: 1px solid rgba(255,255,255,.32); }
.board-grid div { min-height: 145px; display: grid; align-content: center; padding: 18px; border-right: 1px solid rgba(255,255,255,.32); border-bottom: 1px solid rgba(255,255,255,.32); }
.board-grid span { font-family: var(--mono); color: var(--amber-pale); font-size: 16px; }
.board-grid strong { margin-top: 4px; font-family: var(--display); font-size: 33px; font-weight: 500; }
.board-grid small { font-size: 16px; }
.start-panel { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(250px, .7fr) auto; gap: 32px; align-items: end; padding: 54px clamp(24px, 5vw, 80px); background: var(--paper-deep); }
.start-panel h2, .section-heading h2, .manager-card h2, .records-card h2, .source-title h2 { margin: 8px 0 0; font-family: var(--display); font-size: clamp(34px, 4vw, 58px); font-weight: 500; letter-spacing: -0.03em; }
.start-panel > p { max-width: 500px; margin: 0; font-size: 17px; }
.segment:focus-visible, a:focus-visible { outline: 3px solid var(--amber); outline-offset: 3px; }
.selection-note { grid-column: 1 / -1; margin: -6px 0 0; font-size: 16px; color: var(--ink-soft); }
.schedule { padding: clamp(84px, 10vw, 156px) clamp(24px, 5vw, 80px); background: var(--white); }
.section-heading { max-width: 730px; }
.section-heading > p:last-child { margin: 18px 0 0; font-size: 19px; }
.schedule-scope { max-width: 760px; margin: 18px 0 0; padding-left: 16px; border-left: 3px solid var(--amber); font-size: 16px; line-height: 1.8; color: var(--ink-soft); }
.timeline { margin: 64px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.timeline-item { display: grid; grid-template-columns: minmax(190px, 0.45fr) 1fr; min-height: 210px; border-bottom: 1px solid var(--line); }
.timeline-date { margin: 0; padding: 30px 20px 30px 0; font-family: var(--mono); font-size: 17px; color: var(--ink-soft); }
.timeline-item > div { padding: 26px 0 30px 32px; border-left: 1px solid var(--line); position: relative; }
.timeline-item > div::before { content: ""; position: absolute; top: 30px; left: -7px; width: 13px; height: 13px; background: var(--ink); transform: rotate(45deg); }
.timeline-item.is-priority > div::before { background: var(--amber); }
.timeline-item h3 { margin: 5px 0 9px; font-family: var(--display); font-size: clamp(28px, 3vw, 42px); font-weight: 500; }
.timeline-item p:not(.timeline-date):not(.timeline-number) { max-width: 700px; margin: 0; }
.timeline-item a, .text-link { display: inline-block; margin-top: 13px; font-weight: 700; text-decoration-color: var(--amber); text-underline-offset: 4px; }
.detail-grid { display: grid; grid-template-columns: 1.03fr .97fr; }
.manager-card, .records-card { min-height: 650px; padding: clamp(45px, 6vw, 92px); }
.manager-card { background: var(--ink); color: var(--white); }
.manager-card .section-kicker { color: var(--amber-pale); }
.manager-card h2 { max-width: 650px; }
.step-list { display: grid; gap: 0; margin: 52px 0 28px; border-top: 1px solid rgba(255,255,255,.32); }
.step-list div { display: grid; grid-template-columns: 42px 1fr; gap: 15px; padding: 21px 0; border-bottom: 1px solid rgba(255,255,255,.32); }
.step-list span { display: grid; width: 30px; height: 30px; place-items: center; background: var(--amber); color: var(--ink); font-family: var(--mono); font-size: 16px; font-weight: 700; }
.step-list p { margin: 0; font-size: 17px; }
.records-card { background: var(--steel); }
.records-card dl { margin: 51px 0 0; }
.records-card dl div { display: grid; grid-template-columns: 132px 1fr; gap: 18px; padding: 20px 0; border-top: 1px solid var(--line); }
.records-card dt { font-family: var(--mono); font-size: 17px; font-weight: 700; }
.records-card dd { margin: 0; font-size: 17px; }
.records-card dd strong { color: var(--amber); font-weight: 800; }
.caution { margin: 34px 0 0; padding-top: 20px; border-top: 1px solid var(--line); font-size: 16px; }
.sources { display: grid; grid-template-columns: .8fr 1.2fr; gap: 50px; padding: clamp(80px, 10vw, 150px) clamp(24px, 5vw, 80px) 48px; background: var(--paper); }
.source-list { border-top: 2px solid var(--ink); }
.source-list a { display: grid; grid-template-columns: 42px 1fr auto; gap: 14px; align-items: center; padding: 23px 0; border-bottom: 1px solid var(--line); text-decoration: none; }
.source-list a:hover strong { color: var(--amber); }
.source-list span, .source-list b { font-family: var(--mono); font-size: 16px; }
.source-list strong { display: block; font-family: var(--display); font-size: 24px; font-weight: 600; transition: color .2s ease; }
.source-list small { display: block; margin-top: 3px; font-size: 16px; color: var(--ink-soft); }
.source-meta { grid-column: 1 / -1; margin: 0; padding-top: 16px; border-top: 1px solid var(--line); font-size: 16px; color: var(--ink-soft); }
.source-meta a { margin-left: 12px; color: var(--ink); font-weight: 800; text-underline-offset: 4px; }
footer { display: grid; grid-template-columns: auto 1fr 1.5fr; gap: 30px; align-items: center; padding: 32px clamp(24px, 5vw, 80px); color: var(--paper); background: var(--ink); }
footer p { margin: 0; font-size: 16px; }
.footer-brand { color: var(--white); }
.footer-brand .brand-mark { background: var(--amber); color: var(--ink); }
@media (max-width: 760px) {
  body { font-size: 17px; }
  .site-header { min-height: 64px; gap: 12px; padding: 10px 20px; }
  .brand small, nav, .prototype-label { display: none; }
  .header-action { order: 2; min-height: 40px; padding: 6px 11px; margin-left: auto; }
  .hero { min-height: auto; grid-template-columns: 1fr; padding: 72px 24px 56px; background: linear-gradient(165deg, var(--paper) 0%, var(--paper) 58%, var(--steel) 58%, var(--steel) 100%); }
  .hero-board { min-height: 360px; box-shadow: 9px 9px 0 var(--amber); }
  .start-panel, .sources { grid-template-columns: 1fr; padding: 50px 24px; }
  .schedule { padding: 80px 24px; }
  .timeline { margin-top: 46px; }
  .timeline-item { grid-template-columns: 1fr; padding: 18px 0 26px; }
  .timeline-date { padding: 0 0 10px; }
  .timeline-item > div { padding: 16px 0 0 22px; }
  .timeline-item > div::before { top: 21px; left: -6px; }
  .detail-grid { grid-template-columns: 1fr; }
  .manager-card, .records-card { min-height: 0; padding: 62px 24px; }
  .records-card dl div { grid-template-columns: 1fr; gap: 6px; }
  .sources { gap: 34px; }
  footer { grid-template-columns: 1fr; gap: 12px; padding: 30px 24px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .source-list strong { transition: none; } }