:root {
  --color-navy-950: #101b2d;
  --color-navy-900: #16243a;
  --color-navy-800: #203653;
  --color-ink: #202938;
  --color-muted: #647084;
  --color-white: #ffffff;
  --color-gray-50: #f7f8fa;
  --color-gray-100: #eef1f5;
  --color-gray-200: #dce2e9;
  --color-accent: #d88a16;
  --color-accent-soft: #fff5df;
  --color-warning: #9b3b24;
  --color-warning-soft: #fff0eb;
  --color-note: #235f78;
  --color-note-soft: #edf8fb;
  --shadow-card: 0 12px 34px rgba(16, 27, 45, 0.08);
  --radius: 14px;
  --content-width: 1120px;
  --reading-width: 780px;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--color-ink);
  background: var(--color-white);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.85;
  text-rendering: optimizeLegibility;
}
a { color: var(--color-navy-800); text-underline-offset: 0.18em; }
a:hover { color: var(--color-accent); }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 100; padding: .6rem 1rem; background: #fff; }
.skip-link:focus { top: 1rem; }
.site-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid var(--color-gray-200); background: rgba(255,255,255,.96); backdrop-filter: blur(10px); }
.header-inner, .footer-inner, .section-inner { width: min(calc(100% - 2rem), var(--content-width)); margin-inline: auto; }
.header-inner { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 2rem; }
.site-brand { display: flex; align-items: center; gap: .75rem; color: var(--color-navy-950); text-decoration: none; line-height: 1.3; }
.site-brand strong { display: block; font-family: Georgia, "Yu Mincho", serif; font-size: 1.2rem; letter-spacing: .04em; }
.site-brand small { display: block; margin-top: .15rem; color: var(--color-muted); font-size: .72rem; font-weight: 500; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 11px; color: #fff; background: var(--color-navy-900); font-family: Georgia, serif; font-size: 1.25rem; }
.global-nav { display: flex; flex-wrap: wrap; gap: .35rem 1.25rem; font-size: .91rem; font-weight: 700; }
.global-nav a { color: var(--color-navy-900); text-decoration: none; }
.hero { overflow: hidden; position: relative; color: #fff; background: linear-gradient(135deg, var(--color-navy-950), var(--color-navy-800)); }
.hero::after { content: ""; position: absolute; right: -120px; bottom: -180px; width: 420px; height: 420px; border: 80px solid rgba(255,255,255,.04); border-radius: 50%; }
.hero-inner { position: relative; z-index: 1; width: min(calc(100% - 2rem), var(--content-width)); margin-inline: auto; padding: clamp(4.5rem, 10vw, 7.5rem) 0; }
.eyebrow { margin: 0 0 1rem; color: #f3bd65; font-size: .8rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.hero h1 { max-width: 780px; margin: 0; font-family: Georgia, "Yu Mincho", serif; font-size: clamp(2.2rem, 6vw, 4.4rem); line-height: 1.25; letter-spacing: .03em; }
.hero-lead { max-width: 700px; margin: 1.5rem 0 0; color: #dce5f0; font-size: clamp(1rem, 2vw, 1.18rem); }
.hero-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 2rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: .7rem 1.2rem; border: 1px solid transparent; border-radius: 999px; font-weight: 800; text-decoration: none; }
.button-primary { color: var(--color-navy-950); background: #f5b850; }
.button-primary:hover { color: var(--color-navy-950); background: #ffd27d; }
.button-ghost { color: #fff; border-color: rgba(255,255,255,.45); }
.button-ghost:hover { color: #fff; border-color: #fff; }
.content-section { padding: clamp(3.5rem, 7vw, 6rem) 0; }
.content-section.alt { background: var(--color-gray-50); }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 1rem; margin-bottom: 1.7rem; }
.section-heading h2 { margin: 0; color: var(--color-navy-950); font-family: Georgia, "Yu Mincho", serif; font-size: clamp(1.55rem, 3vw, 2.15rem); line-height: 1.35; }
.section-heading p { max-width: 680px; margin: .45rem 0 0; color: var(--color-muted); }
.text-link { white-space: nowrap; font-weight: 800; }
.principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.principle { padding: 1.45rem; border: 1px solid var(--color-gray-200); border-radius: var(--radius); background: #fff; }
.principle-number { color: var(--color-accent); font: 700 1rem/1 Georgia, serif; }
.principle h2, .principle h3 { margin: .7rem 0 .45rem; color: var(--color-navy-900); font-size: 1.08rem; }
.principle p { margin: 0; color: var(--color-muted); font-size: .93rem; }
.category-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.category-card, .article-card, .related-site-card { border: 1px solid var(--color-gray-200); border-radius: var(--radius); background: #fff; box-shadow: 0 1px 0 rgba(16,27,45,.02); transition: transform .2s ease, box-shadow .2s ease; }
.category-card:hover, .article-card:hover, .related-site-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-card); }
.category-card { display: block; padding: 1.35rem; color: inherit; text-decoration: none; }
.category-card .category-index { color: var(--color-accent); font: 700 .78rem/1 Georgia, serif; }
.category-card h3 { margin: .75rem 0 .45rem; color: var(--color-navy-900); font-size: 1.08rem; }
.category-card p { margin: 0; color: var(--color-muted); font-size: .9rem; }
.article-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.1rem; }
.article-card { display: flex; flex-direction: column; padding: 1.4rem; }
.article-card .tag { align-self: flex-start; }
.article-card h3 { margin: .8rem 0 .55rem; color: var(--color-navy-950); font-size: 1.16rem; line-height: 1.5; }
.article-card h3 a { color: inherit; text-decoration: none; }
.article-card p { margin: 0 0 1rem; color: var(--color-muted); font-size: .92rem; }
.article-card .card-meta { margin-top: auto; color: var(--color-muted); font-size: .78rem; }
.tag { display: inline-flex; padding: .25rem .65rem; border-radius: 999px; color: var(--color-navy-800); background: var(--color-accent-soft); font-size: .75rem; font-weight: 800; text-decoration: none; }
.route-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
.route-card { padding: 1.5rem; border-left: 4px solid var(--color-accent); border-radius: 0 var(--radius) var(--radius) 0; background: #fff; box-shadow: var(--shadow-card); }
.route-card h3 { margin: 0 0 .4rem; color: var(--color-navy-900); }
.route-card p { margin: 0 0 .6rem; color: var(--color-muted); }
.related-sites { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
.related-site-card { padding: 1.3rem; }
.related-site-card h3 { margin: 0 0 .35rem; font-size: 1.05rem; }
.related-site-card p { margin: 0; color: var(--color-muted); font-size: .9rem; }
.disclaimer-band { padding: 2rem 0; border-block: 1px solid #ead7ad; background: var(--color-accent-soft); }
.disclaimer-band p { margin: 0; font-size: .91rem; }
.page-hero { padding: 3.5rem 0 2.5rem; border-bottom: 1px solid var(--color-gray-200); background: var(--color-gray-50); }
.page-hero h1 { margin: .6rem 0 .8rem; color: var(--color-navy-950); font-family: Georgia, "Yu Mincho", serif; font-size: clamp(2rem, 5vw, 3.3rem); line-height: 1.35; }
.page-hero p { max-width: 760px; margin: 0; color: var(--color-muted); font-size: 1.03rem; }
.breadcrumbs ol { display: flex; flex-wrap: wrap; gap: .35rem; margin: 0; padding: 0; color: var(--color-muted); list-style: none; font-size: .78rem; }
.breadcrumbs li:not(:last-child)::after { content: "/"; margin-left: .35rem; color: #a2aab6; }
.article-shell { width: min(calc(100% - 2rem), var(--reading-width)); margin-inline: auto; padding: 3rem 0 5rem; }
.article-header { margin-bottom: 2rem; }
.article-header h1 { margin: .7rem 0 1rem; color: var(--color-navy-950); font-family: Georgia, "Yu Mincho", serif; font-size: clamp(2rem, 5vw, 3.25rem); line-height: 1.35; letter-spacing: .02em; }
.article-description { color: var(--color-muted); font-size: 1.08rem; }
.article-meta { display: flex; flex-wrap: wrap; gap: .5rem 1.3rem; margin-top: 1rem; color: var(--color-muted); font-size: .82rem; }
.toc { margin: 2rem 0 2.5rem; padding: 1.4rem 1.5rem; border: 1px solid var(--color-gray-200); border-radius: var(--radius); background: var(--color-gray-50); }
.toc h2 { margin: 0 0 .7rem; font-size: 1rem; }
.toc ol { margin: 0; padding-left: 1.25rem; }
.toc li { margin: .25rem 0; }
.toc .toc-level-3 { margin-left: 1rem; font-size: .9rem; }
.article-body { font-size: 1.02rem; }
.article-body h2 { margin: 3.2rem 0 1rem; padding-bottom: .55rem; border-bottom: 2px solid var(--color-gray-200); color: var(--color-navy-950); font-family: Georgia, "Yu Mincho", serif; font-size: 1.7rem; line-height: 1.45; }
.article-body h3 { margin: 2.2rem 0 .8rem; color: var(--color-navy-900); font-size: 1.25rem; }
.article-body p { margin: 1rem 0; }
.article-body ul, .article-body ol { padding-left: 1.4rem; }
.article-body li { margin: .45rem 0; }
.article-body blockquote { margin: 1.5rem 0; padding: .6rem 1.2rem; border-left: 4px solid var(--color-gray-200); color: var(--color-muted); }
.article-body code { padding: .12em .35em; border-radius: 4px; background: var(--color-gray-100); font-family: Consolas, monospace; font-size: .9em; }
.article-body pre { overflow-x: auto; padding: 1rem; border-radius: 10px; color: #eaf0f7; background: var(--color-navy-950); }
.article-body pre code { padding: 0; color: inherit; background: transparent; }
.table-wrap { width: 100%; overflow-x: auto; margin: 1.5rem 0; border: 1px solid var(--color-gray-200); border-radius: 10px; -webkit-overflow-scrolling: touch; }
table { width: 100%; min-width: 600px; border-collapse: collapse; font-size: .92rem; }
th, td { padding: .75rem .85rem; border-bottom: 1px solid var(--color-gray-200); text-align: left; vertical-align: top; }
th { color: var(--color-navy-950); background: var(--color-gray-100); }
tr:last-child td { border-bottom: 0; }
.note-box, .warning-box { margin: 1.6rem 0; padding: 1.1rem 1.2rem; border-left: 5px solid; border-radius: 0 10px 10px 0; }
.note-box { border-color: var(--color-note); background: var(--color-note-soft); }
.warning-box { border-color: var(--color-warning); background: var(--color-warning-soft); }
.reference-section, .related-section, .article-disclaimer { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--color-gray-200); }
.reference-section h2, .related-section h2, .article-disclaimer h2 { margin: 0 0 .8rem; color: var(--color-navy-900); font-size: 1.18rem; }
.reference-section ul { padding-left: 1.2rem; }
.reference-section small { display: block; color: var(--color-muted); }
.related-card-section { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--color-gray-200); }
.related-card-section h2 { margin: 0 0 1rem; color: var(--color-navy-900); font-size: 1.18rem; }
.related-card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .85rem; }
.related-card { display: grid; gap: .45rem; padding: 1rem; border: 1px solid var(--color-gray-200); border-radius: 10px; color: inherit; background: #fff; text-decoration: none; }
.related-card:hover { border-color: #b08a39; box-shadow: var(--shadow-card); }
.related-card.is-cross-site { background: var(--color-accent-soft); }
.related-card-meta { color: #8a6d2d; font-size: .76rem; font-weight: 800; }
.related-card h3 { margin: 0; color: var(--color-navy-950); font-size: 1.02rem; line-height: 1.55; }
.related-card p { margin: 0; color: var(--color-muted); font-size: .9rem; line-height: 1.7; }
.related-card-cta { color: var(--color-navy-900); font-size: .8rem; font-weight: 800; }
.related-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: .75rem; }
.related-list a { display: block; padding: .9rem 1rem; border: 1px solid var(--color-gray-200); border-radius: 9px; font-weight: 700; text-decoration: none; }
.article-disclaimer { color: var(--color-muted); font-size: .88rem; }
.back-home { margin-top: 2rem; }
.empty-state { padding: 2rem; border: 1px dashed var(--color-gray-200); border-radius: var(--radius); color: var(--color-muted); background: var(--color-gray-50); }
.prose { width: min(calc(100% - 2rem), var(--reading-width)); margin-inline: auto; padding: 3rem 0 5rem; }
.prose h2 { margin-top: 2.5rem; color: var(--color-navy-900); }
.prose h3 { margin-top: 2rem; color: var(--color-navy-900); }
.site-footer { color: #ced7e3; background: var(--color-navy-950); }
.footer-inner { padding: 3rem 0; }
.footer-title { margin: 0; color: #fff; font-family: Georgia, "Yu Mincho", serif; font-size: 1.2rem; font-weight: 800; }
.footer-inner > div > p:last-child { margin: .25rem 0 0; font-size: .85rem; }
.footer-nav { display: flex; flex-wrap: wrap; gap: .5rem 1.2rem; margin-top: 1.4rem; }
.footer-nav a { color: #fff; font-size: .86rem; }
.footer-note { max-width: 800px; margin: 1.4rem 0 0; padding-top: 1.2rem; border-top: 1px solid rgba(255,255,255,.15); font-size: .8rem; }
.copyright { margin: 1.2rem 0 0; color: #8f9daf; font-size: .75rem; }

@media (max-width: 860px) {
  .header-inner { align-items: flex-start; flex-direction: column; gap: .75rem; padding: .75rem 0; }
  .global-nav { width: 100%; overflow-x: auto; flex-wrap: nowrap; padding-bottom: .2rem; }
  .global-nav a { white-space: nowrap; }
  .principles, .category-grid, .article-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 580px) {
  body { font-size: 15px; }
  .site-header { position: static; }
  .site-brand small { display: none; }
  .hero-inner { padding: 4rem 0; }
  .principles, .category-grid, .article-grid, .route-grid, .related-sites, .related-list, .related-card-grid { grid-template-columns: 1fr; }
  .section-heading { align-items: flex-start; flex-direction: column; }
  .page-hero { padding-top: 2.5rem; }
  .article-shell { padding-top: 2rem; }
  .article-body h2 { font-size: 1.45rem; }
  .toc { padding: 1.1rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}