:root {
  color-scheme: light;
  --ink: #1a292c;
  --muted: #526569;
  --teal: #087c77;
  --teal-dark: #05635f;
  --teal-light: #eff9f7;
  --border: #dce5e4;
  --paper: #ffffff;
  --canvas: #f7f9f8;
  --header: #10272b;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { scroll-padding-top: 2rem; }
body { margin: 0; background: var(--paper); color: var(--ink); line-height: 1.8; overflow-wrap: anywhere; }
a { color: var(--teal); text-decoration-thickness: 1px; text-underline-offset: .22em; }
a:hover { color: var(--teal-dark); text-decoration-thickness: 2px; }
a:focus-visible, [tabindex="0"]:focus-visible { outline: 3px solid #148b84; outline-offset: 5px; border-radius: 2px; }
main:focus { outline: none; }
button, input, textarea, select { font: inherit; }
::selection { background: #c2ebe5; color: #10272b; }

.skip-link { position: absolute; top: .6rem; left: 1rem; z-index: 10; padding: .55rem 1rem; background: white; transform: translateY(-180%); }
.skip-link:focus { transform: translateY(0); }
.site-header { background: var(--header); color: #fff; }
.header-inner, .footer-inner { max-width: 1120px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; padding: 1.05rem 2rem; }
.brand { color: #fff; font-size: 1.65rem; font-weight: 760; line-height: 1.4; letter-spacing: -.055em; text-decoration: none; white-space: nowrap; }
.brand:hover { color: #fff; }
.brand > span:first-child { color: #8ed8cb; }
.brand-dot { color: #55cbb8; }
.site-header nav a { color: #dcebea; font-size: .875rem; font-weight: 600; text-decoration: none; padding: .5rem 0; }
.site-header nav a:hover { color: #fff; text-decoration: underline; }
.preview-banner { display: flex; align-items: baseline; justify-content: center; flex-wrap: wrap; gap: .35rem 1rem; padding: .8rem 1.5rem; background: #fff6da; border-bottom: 1px solid #ebdaa0; color: #624d12; font-size: .875rem; }

.article-shell { max-width: 960px; margin: 0 auto; padding: 1.6rem 2rem 4rem; }
.breadcrumbs { display: flex; flex-wrap: wrap; gap: .3rem .75rem; color: var(--muted); font-size: .75rem; line-height: 1.7; margin-bottom: 2.6rem; }
.breadcrumbs a { color: var(--muted); white-space: nowrap; }
.breadcrumbs > span:last-child { max-width: 100%; }
.article { max-width: 760px; margin: 0 auto; }
.article-header { padding-bottom: 2.15rem; border-bottom: 1px solid var(--border); margin-bottom: 2.2rem; }
.eyebrow { margin: 0 0 1rem; color: var(--teal); font-size: .7rem; font-weight: 750; line-height: 1.5; letter-spacing: .16em; }
h1 { margin: 0; font-size: clamp(1.8rem, 4vw, 2.55rem); font-weight: 750; line-height: 1.55; letter-spacing: .015em; }
.article-summary { margin: 1.5rem 0 0; color: var(--muted); font-size: 1rem; line-height: 2; }
.table-of-contents { padding: 1.4rem 1.6rem; margin-bottom: 2.8rem; border: 1px solid #cfe6df; border-radius: 8px; background: var(--teal-light); }
.table-of-contents h2 { margin: 0 0 .75rem; font-size: .875rem; line-height: 1.7; font-weight: 750; }
.table-of-contents ol { margin: 0; padding-left: 1.5rem; font-size: .875rem; line-height: 1.9; }
.table-of-contents li { padding: .14rem 0 .14rem .15rem; }
.table-of-contents li.toc-level-3 { margin-left: 1rem; }
.table-of-contents li.toc-level-4, .table-of-contents li.toc-level-5, .table-of-contents li.toc-level-6 { margin-left: 2rem; }
.table-of-contents a { text-decoration: none; }
.table-of-contents a:hover { text-decoration: underline; }

.article-body { font-size: 1rem; line-height: 2.05; letter-spacing: .025em; }
.article-body > :first-child { margin-top: 0; }
.article-body p { margin: 1.2rem 0 1.6rem; }
.article-body h2 { margin: 3.5rem 0 1.4rem; padding-bottom: .7rem; border-bottom: 2px solid var(--border); font-size: 1.5rem; font-weight: 740; line-height: 1.65; }
.article-body h3 { margin: 2.4rem 0 1rem; font-size: 1.22rem; line-height: 1.7; font-weight: 730; }
.article-body h4, .article-body h5, .article-body h6 { margin: 2rem 0 .8rem; font-size: 1.05rem; font-weight: 750; line-height: 1.75; }
.article-body :is(h2,h3,h4,h5,h6) { scroll-margin-top: 2rem; }
.article-body ul, .article-body ol { margin: 1.2rem 0 1.8rem; padding-left: 1.65rem; }
.article-body li { margin: .45rem 0; padding-left: .15rem; }
.article-body li::marker { color: var(--teal); }
.article-body strong { font-weight: 750; }
.article-body blockquote { margin: 1.8rem 0; padding: .8rem 1.5rem; background: var(--canvas); border-left: 3px solid #78b8ad; color: #465c5e; }
.article-body blockquote > :first-child { margin-top: 0; }
.article-body blockquote > :last-child { margin-bottom: 0; }
.article-body code { background: #eef3f2; border: 1px solid #e1e9e7; padding: .12em .35em; border-radius: 4px; font-size: .88em; font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; letter-spacing: 0; overflow-wrap: anywhere; }
.article-body pre { padding: 1.2rem 1.4rem; margin: 1.8rem 0; border-radius: 6px; background: #172d31; color: #e4f0ed; line-height: 1.7; overflow-x: auto; }
.article-body pre code { padding: 0; border: 0; background: none; color: inherit; white-space: pre; overflow-wrap: normal; font-size: .85rem; }
.table-scroll { width: 100%; overflow-x: auto; overscroll-behavior-x: contain; margin: 1.8rem 0; border: 1px solid var(--border); border-radius: 6px; }
.article-body table { width: 100%; border-collapse: collapse; font-size: .875rem; line-height: 1.8; letter-spacing: 0; }
.article-body th, .article-body td { min-width: 7rem; padding: .85rem 1rem; vertical-align: top; border-right: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.article-body th { background: #f0f6f4; font-weight: 730; }
.article-body tr:last-child td { border-bottom: 0; }
.article-body th:last-child, .article-body td:last-child { border-right: 0; }
.article-body .align-left { text-align: left; }
.article-body .align-center { text-align: center; }
.article-body .align-right { text-align: right; }
.article-sources { margin-top: 3.5rem; border-top: 1px solid var(--border); padding-top: 1.75rem; font-size: .875rem; }
.article-sources h2 { margin: 0 0 1rem; font-size: 1rem; }
.article-sources ul { margin: 0; padding-left: 1.3rem; }
.article-sources li { margin: .75rem 0; }
.source-date { display: block; color: var(--muted); font-size: .75rem; line-height: 1.8; }
.external-mark { font-size: .8em; }
.article-back { max-width: 760px; margin: 3rem auto 0; border-top: 1px solid var(--border); padding-top: 1.5rem; font-size: .875rem; }
.article-back a { text-decoration: none; }
.article-back a:hover { text-decoration: underline; }

.index-shell { max-width: 1120px; min-height: 65vh; margin: 0 auto; padding: 4rem 2rem 5rem; }
.index-header { margin-bottom: 2.7rem; }
.index-header p:last-child { margin: .9rem 0 0; color: var(--muted); font-size: .9375rem; }
.article-grid { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.5rem; }
.article-card { border: 1px solid var(--border); border-radius: 8px; background: var(--paper); }
.article-card article { display: flex; flex-direction: column; align-items: flex-start; height: 100%; padding: 1.8rem; }
.article-card h2 { margin: 0 0 .8rem; font-size: 1.25rem; line-height: 1.7; }
.article-card h2 a { color: var(--ink); text-decoration: none; }
.article-card h2 a:hover { color: var(--teal); text-decoration: underline; }
.article-card p { margin: 0 0 1.4rem; color: var(--muted); font-size: .875rem; line-height: 1.95; }
.read-link { margin-top: auto; font-size: .8125rem; font-weight: 700; text-decoration: none; }
.read-link:hover { text-decoration: underline; }
.empty-state { border: 1px dashed var(--border); border-radius: 8px; padding: 3.5rem 1.5rem; background: var(--canvas); text-align: center; color: var(--muted); }
.empty-state p { margin: 0; }
.not-found { max-width: 800px; margin: 0 auto; min-height: 70vh; padding: 5rem 2rem; text-align: center; }
.error-code { margin: 0 0 .7rem; color: var(--teal); font-size: 3.5rem; font-weight: 750; letter-spacing: .07em; line-height: 1.3; }
.not-found h1 { font-size: 1.65rem; }
.not-found > p:not(.error-code) { margin: 1.2rem 0 2rem; color: var(--muted); }
.button-link { display: inline-block; padding: .7rem 1.6rem; border-radius: 5px; background: var(--teal); color: #fff; font-weight: 650; text-decoration: none; }
.button-link:hover { background: var(--teal-dark); color: #fff; }
.site-footer { border-top: 1px solid var(--border); background: var(--canvas); color: var(--muted); }
.footer-inner { padding-top: 1.65rem; padding-bottom: 1.65rem; font-size: .75rem; }
.footer-brand { color: #294a4d; font-size: 1rem; font-weight: 750; letter-spacing: -.04em; }
.footer-inner a { color: var(--muted); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

@media (max-width: 640px) {
  .header-inner, .footer-inner { padding-right: 1.25rem; padding-left: 1.25rem; }
  .header-inner { padding-top: .9rem; padding-bottom: .9rem; }
  .brand { font-size: 1.45rem; }
  .site-header nav a { font-size: .8125rem; }
  .article-shell { padding: 1.2rem 1.25rem 3rem; }
  .breadcrumbs { margin-bottom: 2rem; }
  .article-header { padding-bottom: 1.75rem; margin-bottom: 1.75rem; }
  h1 { font-size: 1.75rem; line-height: 1.6; }
  .article-summary { margin-top: 1.1rem; font-size: .9375rem; }
  .table-of-contents { padding: 1.1rem 1.2rem; margin-bottom: 2.25rem; }
  .article-body { font-size: .9375rem; }
  .article-body h2 { margin-top: 2.75rem; font-size: 1.3rem; }
  .article-body h3 { font-size: 1.125rem; }
  .article-body blockquote { padding: .8rem 1.1rem; }
  .article-body pre { padding: 1rem; }
  .index-shell { padding: 2.75rem 1.25rem 3.5rem; }
  .article-grid { grid-template-columns: 1fr; gap: 1rem; }
  .article-card article { padding: 1.4rem; }
  .article-card h2 { font-size: 1.15rem; }
  .not-found { padding: 4rem 1.25rem; }
  .not-found h1 { font-size: 1.4rem; }
}

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
  a { transition: color .12s ease; }
}

@media print {
  .site-header, .site-footer, .skip-link, .preview-banner, .article-back, .table-of-contents { display: none; }
  .article-shell { max-width: none; padding: 0; }
  .article { max-width: none; }
  .article-body pre { white-space: pre-wrap; color: #000; background: #f5f5f5; }
  a { color: #000; }
  .table-scroll { overflow: visible; }
  .article-body h2, .article-body h3 { break-after: avoid; }
}