/* =========================================================
   独学ロードマップ — Design tokens
   Base: blueprint navy · Ink: paper white · Route lines: 3 colors
   Fonts: system stacks only (zero network requests → fast LCP/CLS)
   ========================================================= */
:root{
  --navy: #101E33;
  --navy-deep: #0B1728;
  --grid: rgba(159,176,196,0.09);
  --ink: #EEF2F6;
  --ink-muted: #9FB0C4;
  --ink-faint: #6C8099;
  --route-lang: #E7A33E;
  --route-tool: #4FB3A6;
  --route-career: #D97B93;
  --paper: #F6F4EF;
  --paper-line: #DAD6CB;
  --ink-on-paper: #17202B;
  --ink-on-paper-muted: #55606E;
  --radius: 3px;
  --font-display: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", "Noto Sans JP", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;
  --max: 1120px;
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{ animation-duration:0.001ms !important; animation-iteration-count:1 !important; transition-duration:0.001ms !important; scroll-behavior:auto !important; }
}

body{
  margin:0;
  background:
    linear-gradient(var(--grid) 1px, transparent 1px) 0 0/40px 40px,
    linear-gradient(90deg, var(--grid) 1px, transparent 1px) 0 0/40px 40px,
    var(--navy);
  color:var(--ink);
  font-family:var(--font-display);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

img{ max-width:100%; height:auto; display:block; }
a{ color:inherit; text-decoration-color:rgba(238,242,246,0.35); text-underline-offset:3px; }
a:hover{ text-decoration-color:currentColor; }
a:focus-visible, button:focus-visible, summary:focus-visible{
  outline:2px solid var(--route-lang);
  outline-offset:3px;
  border-radius:2px;
}

.wrap{ max-width:var(--max); margin:0 auto; padding:0 24px; }

.skip-link{
  position:absolute; left:-999px; top:auto;
  background:var(--ink); color:var(--navy-deep); padding:10px 16px;
  z-index:100; font-family:var(--font-mono); font-size:14px; border-radius:0 0 4px 0;
}
.skip-link:focus{ left:0; top:0; }

.site-header{
  position:sticky; top:0; z-index:20;
  background:rgba(16,30,51,0.86);
  backdrop-filter:saturate(140%) blur(8px);
  border-bottom:1px solid rgba(159,176,196,0.18);
}
.site-header .wrap{ display:flex; align-items:center; justify-content:space-between; height:64px; gap:16px; }
.brand{ display:flex; align-items:baseline; gap:10px; font-family:var(--font-mono); font-weight:700; font-size:15px; letter-spacing:0.02em; white-space:nowrap; }
.brand .dot{ color:var(--route-lang); }
.brand small{ display:block; font-family:var(--font-display); font-weight:400; color:var(--ink-muted); font-size:11px; letter-spacing:0.06em; }
.main-nav{ display:flex; gap:4px; flex-wrap:wrap; }
.main-nav a{
  font-size:14px; padding:8px 12px; border-radius:2px; color:var(--ink-muted);
  text-decoration:none; border:1px solid transparent;
}
.main-nav a:hover{ color:var(--ink); border-color:rgba(159,176,196,0.25); }
.main-nav a[aria-current="page"]{ color:var(--ink); border-color:rgba(159,176,196,0.4); background:rgba(159,176,196,0.06); }

.crumbs{ font-family:var(--font-mono); font-size:12.5px; color:var(--ink-faint); padding:18px 0 0; }
.crumbs ol{ list-style:none; display:flex; flex-wrap:wrap; gap:6px; margin:0; padding:0; }
.crumbs a{ color:var(--ink-faint); text-decoration:none; }
.crumbs a:hover{ color:var(--ink-muted); text-decoration:underline; }
.crumbs li:not(:last-child)::after{ content:"/"; margin-left:6px; color:rgba(159,176,196,0.35); }

.hero{ padding:56px 0 40px; }
.eyebrow{
  display:inline-flex; align-items:center; gap:8px;
  font-family:var(--font-mono); font-size:12.5px; letter-spacing:0.08em;
  color:var(--accent, var(--route-lang)); text-transform:uppercase; margin:0 0 18px;
}
.eyebrow::before{ content:""; width:22px; height:2px; background:var(--accent, var(--route-lang)); }
h1{
  font-size:clamp(30px, 4.6vw, 52px); line-height:1.22; font-weight:800;
  letter-spacing:-0.01em; margin:0 0 20px; max-width:18ch;
}
.lede{ font-size:clamp(16px, 2vw, 19px); color:var(--ink-muted); max-width:56ch; margin:0 0 8px; }
.meta-line{ font-family:var(--font-mono); font-size:12.5px; color:var(--ink-faint); margin-top:20px; display:flex; gap:16px; flex-wrap:wrap; }

.route-map{ margin:36px 0 8px; }
.route-map svg{ width:100%; height:auto; display:block; }
.route-map .stop-label{ font-family:var(--font-mono); font-size:11px; fill:var(--ink-muted); }
.route-map .stop-label.current{ fill:var(--ink); font-weight:700; }
.route-map figcaption{ font-family:var(--font-mono); font-size:11.5px; color:var(--ink-faint); margin-top:10px; }

section{ padding:44px 0; }
section.divider-top{ border-top:1px solid rgba(159,176,196,0.14); }
h2{ font-size:clamp(22px, 3vw, 30px); font-weight:800; letter-spacing:-0.005em; margin:0 0 6px; }
h2 .num{ font-family:var(--font-mono); color:var(--ink-faint); font-weight:500; font-size:0.6em; margin-right:10px; }
.section-intro{ color:var(--ink-muted); max-width:64ch; margin:0 0 28px; }
h3{ font-size:19px; font-weight:700; margin:0 0 8px; }
p{ margin:0 0 14px; }
.prose p, .prose li{ color:var(--ink-muted); max-width:70ch; }
.prose h3{ color:var(--ink); }
.prose ul, .prose ol{ padding-left:1.3em; max-width:70ch; }
.prose li{ margin-bottom:8px; }
.prose strong{ color:var(--ink); }
.prose a{ color:var(--ink); }
.prose table{ width:100%; border-collapse:collapse; margin:18px 0; font-size:14.5px; }
.prose caption{ text-align:left; font-family:var(--font-mono); font-size:12px; color:var(--ink-faint); margin-bottom:8px; }
.prose th, .prose td{ text-align:left; padding:10px 12px; border-bottom:1px solid rgba(159,176,196,0.18); color:var(--ink-muted); vertical-align:top; }
.prose th{ color:var(--ink); font-family:var(--font-mono); font-weight:600; font-size:12.5px; letter-spacing:0.02em; }

.stations{ display:grid; gap:14px; grid-template-columns:repeat(auto-fit, minmax(280px,1fr)); list-style:none; margin:0; padding:0; }
.station{
  border:1px solid rgba(159,176,196,0.2); border-left:3px solid var(--accent, var(--route-lang));
  border-radius:var(--radius); padding:20px 22px; background:rgba(238,242,246,0.03);
}
.station .code{ font-family:var(--font-mono); font-size:12px; color:var(--accent, var(--route-lang)); letter-spacing:0.05em; margin-bottom:8px; display:block; }
.station h3{ margin-bottom:8px; }
.station p{ color:var(--ink-muted); font-size:14.5px; margin-bottom:10px; }
.station a.more{ font-family:var(--font-mono); font-size:13px; color:var(--ink); }
.station a.more::after{ content:" →"; }

.route-grid{ display:grid; gap:16px; grid-template-columns:repeat(auto-fit, minmax(260px,1fr)); }
.route-card{
  display:block; padding:24px; border-radius:var(--radius); text-decoration:none;
  border:1px solid rgba(159,176,196,0.2); position:relative; overflow:hidden;
  background:rgba(238,242,246,0.025);
}
.route-card::before{ content:""; position:absolute; left:0; top:0; bottom:0; width:4px; background:var(--line); }
.route-card .line-name{ font-family:var(--font-mono); font-size:12px; color:var(--line); letter-spacing:0.05em; margin-bottom:10px; }
.route-card h3{ margin-bottom:8px; }
.route-card p{ color:var(--ink-muted); font-size:14.5px; margin-bottom:0; }

.table-scroll{ overflow-x:auto; -webkit-overflow-scrolling:touch; }

.faq-list{ max-width:74ch; }
.faq-item{ border-bottom:1px solid rgba(159,176,196,0.16); padding:6px 0; }
.faq-item summary{
  cursor:pointer; list-style:none; font-weight:700; font-size:16px; padding:14px 28px 14px 0;
  position:relative;
}
.faq-item summary::-webkit-details-marker{ display:none; }
.faq-item summary::after{
  content:"+"; position:absolute; right:0; top:12px; font-family:var(--font-mono);
  font-size:20px; color:var(--ink-faint); transition:transform .15s ease;
}
.faq-item[open] summary::after{ content:"–"; }
.faq-item .a{ color:var(--ink-muted); padding:0 0 18px; max-width:66ch; }

.callout{
  border:1px solid rgba(159,176,196,0.22); border-radius:var(--radius);
  padding:28px 28px; background:rgba(238,242,246,0.03);
  display:flex; flex-wrap:wrap; gap:20px; align-items:center; justify-content:space-between;
}
.callout p{ margin:0; color:var(--ink-muted); max-width:56ch; }
.btn{
  display:inline-flex; align-items:center; gap:8px; font-family:var(--font-mono); font-size:13.5px;
  padding:11px 18px; border-radius:2px; border:1px solid var(--ink); color:var(--ink); text-decoration:none;
  white-space:nowrap;
}
.btn:hover{ background:var(--ink); color:var(--navy-deep); }

.site-footer{ border-top:1px solid rgba(159,176,196,0.16); padding:48px 0 40px; margin-top:40px; }
.footer-grid{ display:grid; gap:32px; grid-template-columns:1.4fr repeat(3, 1fr); margin-bottom:32px; }
.footer-grid h4{ font-family:var(--font-mono); font-size:12px; color:var(--ink-faint); letter-spacing:0.06em; margin:0 0 14px; text-transform:uppercase; }
.footer-grid ul{ list-style:none; margin:0; padding:0; }
.footer-grid li{ margin-bottom:9px; }
.footer-grid a{ color:var(--ink-muted); text-decoration:none; font-size:14px; }
.footer-grid a:hover{ color:var(--ink); text-decoration:underline; }
.footer-note{ color:var(--ink-faint); font-size:13px; max-width:60ch; }
.footer-bottom{ display:flex; justify-content:space-between; flex-wrap:wrap; gap:10px; font-family:var(--font-mono); font-size:12px; color:var(--ink-faint); padding-top:20px; border-top:1px solid rgba(159,176,196,0.12); }

@media (max-width:720px){
  .footer-grid{ grid-template-columns:1fr 1fr; }
  .site-header .wrap{ height:auto; padding-top:12px; padding-bottom:12px; flex-direction:column; align-items:flex-start; }
  .main-nav{ width:100%; }
}

.paper{
  background:var(--paper); color:var(--ink-on-paper); border-radius:var(--radius);
  padding:26px 28px;
}
.paper h3{ color:var(--ink-on-paper); }
.paper p, .paper li{ color:var(--ink-on-paper-muted); }
.paper a{ color:var(--ink-on-paper); }