:root {
  --ink: #17211b;
  --muted: #58625c;
  --paper: #f7f8f5;
  --surface: #ffffff;
  --line: #d9ded9;
  --green: #176b45;
  --green-dark: #0d4f32;
  --blue: #2458a6;
  --amber-bg: #fff8e8;
  --amber-line: #c68722;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.75;
}
a { color: var(--blue); }
.article-container { width: min(780px, calc(100% - 40px)); margin: 0 auto; }

.article-header {
  border-bottom: 1px solid var(--line);
  background: rgba(247, 248, 245, 0.96);
}
.header-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 20px;
  font-weight: 750;
  text-decoration: none;
}
.brand img { width: 36px; height: 36px; border-radius: 7px; }
.home-link { color: var(--muted); font-size: 14px; }

main { padding: 48px 0 72px; }
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 13px;
}
h1 {
  margin: 0;
  font-size: 38px;
  line-height: 1.25;
  letter-spacing: 0;
}
.lead { margin: 18px 0 0; color: var(--muted); font-size: 18px; }
.notice {
  margin: 28px 0 8px;
  border: 1px solid var(--line);
  border-left: 4px solid var(--green);
  border-radius: 6px;
  background: var(--surface);
  padding: 18px 20px;
}
code {
  border-radius: 4px;
  background: #eef1ed;
  padding: 2px 5px;
  font-size: 0.92em;
}

.article-section { margin-top: 44px; }
.article-section h2, .usage-note h2 {
  margin: 0 0 12px;
  font-size: 25px;
  line-height: 1.4;
  letter-spacing: 0;
}
.article-section p { margin: 12px 0; }
.article-section ul, .article-section ol { margin: 14px 0; padding-left: 24px; }
.article-section li { margin: 8px 0; }
.faq details { border-top: 1px solid var(--line); padding: 16px 0; }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; font-weight: 700; }
.faq details p { margin: 10px 0 0; color: var(--muted); }

.usage-note {
  margin-top: 46px;
  border: 1px solid #ead7aa;
  border-left: 4px solid var(--amber-line);
  border-radius: 6px;
  background: var(--amber-bg);
  padding: 20px;
}
.usage-note h2 { font-size: 20px; }
.usage-note p { margin: 9px 0 0; font-size: 14px; }

.cta {
  margin-top: 42px;
  border-radius: 8px;
  background: #17211b;
  color: #fff;
  padding: 26px;
}
.cta p { margin: 0 0 12px; }
.cta a { color: #fff; font-weight: 750; }
.related {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  margin-top: 32px;
  border-top: 1px solid var(--line);
  padding-top: 22px;
}
.related strong { flex-basis: 100%; }

.article-footer {
  border-top: 1px solid var(--line);
  background: var(--surface);
  padding: 28px 0 38px;
  color: var(--muted);
  font-size: 13px;
}
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px 24px; }
.footer-inner nav { display: flex; flex-wrap: wrap; gap: 14px; }

@media (max-width: 640px) {
  .article-container { width: min(100% - 28px, 780px); }
  main { padding: 36px 0 54px; }
  h1 { font-size: 31px; }
  .lead { font-size: 16px; }
  .article-section { margin-top: 38px; }
  .article-section h2 { font-size: 22px; }
  .home-link { max-width: 120px; text-align: right; }
}