:root {
  --primary: #0f8f83;
  --primary-dark: #087268;
  --blue: #2563eb;
  --ink: #0f172a;
  --muted: #5f6f82;
  --line: #e2e8f0;
  --soft: #f5f8fb;
  --card: #ffffff;
  --warning-bg: #fff8e7;
  --warning-line: #f4b740;
  --success-bg: #ecfdf5;
  --success-line: #10b981;
  --max: 920px;
  --radius: 18px;
  --shadow: 0 12px 32px rgba(15, 23, 42, .08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(15, 143, 131, .09), transparent 28rem),
    var(--soft);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.75;
}
a { color: var(--blue); }
img { max-width: 100%; height: auto; }
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 1000;
  transform: translateY(-150%);
  padding: 8px 12px;
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  box-shadow: var(--shadow);
}
.skip-link:focus { transform: translateY(0); }
.container { width: min(calc(100% - 28px), var(--max)); margin: 0 auto; }
.site-header {
  background: rgba(255, 255, 255, .9);
  border-bottom: 1px solid rgba(226, 232, 240, .9);
  backdrop-filter: blur(14px);
}
.header-inner {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 900;
}
.brand-mark {
  width: 38px;
  height: 38px;
  display: block;
  flex: 0 0 38px;
  border-radius: 12px;
  object-fit: contain;
}
.top-nav { display: flex; flex-wrap: wrap; gap: 14px; }
.top-nav a { color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 700; }
.top-nav a:hover { color: var(--primary-dark); }
.breadcrumb { margin: 18px 0 12px; font-size: 13px; color: var(--muted); }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: 7px; padding: 0; margin: 0; list-style: none; }
.breadcrumb li + li::before { content: "/"; margin-right: 7px; color: #94a3b8; }
.breadcrumb a { color: var(--muted); }
.article-shell { margin-bottom: 32px; }
.guide-hero,
.content-card {
  background: var(--card);
  border: 1px solid rgba(226, 232, 240, .9);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.guide-hero { padding: clamp(24px, 5vw, 46px); }
.eyebrow {
  margin: 0 0 8px;
  color: var(--primary-dark);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .08em;
  text-transform: uppercase;
}
h1 { margin: 0; font-size: clamp(30px, 6vw, 48px); line-height: 1.18; letter-spacing: -.03em; }
.lead { max-width: 760px; margin: 16px 0 0; color: var(--muted); font-size: 17px; }
.meta { margin-top: 14px; color: #748397; font-size: 13px; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border-radius: 13px;
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  font-weight: 900;
  box-shadow: 0 8px 20px rgba(15, 143, 131, .16);
}
.button:hover { background: var(--primary-dark); }
.button.secondary { background: #eaf1ff; color: #1d4ed8; box-shadow: none; }
.button.neutral { background: #eef2f7; color: #334155; box-shadow: none; }
.toc { margin: 16px 0; padding: 18px 20px; background: #eef8f7; border: 1px solid #d4efec; border-radius: 16px; }
.toc strong { display: block; margin-bottom: 7px; }
.toc-links { display: flex; flex-wrap: wrap; gap: 8px 16px; }
.toc a { font-size: 14px; font-weight: 700; color: var(--primary-dark); }
.content-card { margin-top: 16px; padding: clamp(22px, 5vw, 40px); }
h2 { margin: 0 0 14px; font-size: clamp(23px, 4vw, 30px); line-height: 1.3; }
h3 { margin: 24px 0 8px; font-size: 19px; line-height: 1.4; }
p { margin: 10px 0; }
.steps { padding-left: 22px; }
.steps > li { padding-left: 4px; margin-bottom: 20px; }
.steps > li::marker { color: var(--primary); font-weight: 900; }
.callout { margin: 18px 0; padding: 14px 16px; border-left: 4px solid var(--warning-line); border-radius: 10px; background: var(--warning-bg); }
.callout.success { border-left-color: var(--success-line); background: var(--success-bg); }
.download-options { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin: 18px 0; }
.download-box { padding: 16px; border: 1px solid var(--line); border-radius: 15px; background: #fbfdff; }
.download-box strong { display: block; margin-bottom: 5px; }
.download-box p { margin: 0 0 12px; color: var(--muted); font-size: 14px; }
.download-box .button { width: 100%; }
figure { margin: 22px 0; }
figure img { display: block; width: 100%; border-radius: 14px; background: #eef2f7; box-shadow: 0 7px 22px rgba(15, 23, 42, .1); }
figcaption { margin-top: 8px; text-align: center; color: var(--muted); font-size: 13px; }
.compact-image img { max-width: 520px; margin-inline: auto; }
.faq details { border-top: 1px solid var(--line); }
.faq details:first-of-type { border-top: 0; }
.faq summary { cursor: pointer; padding: 16px 0; font-weight: 900; }
.faq details p { margin: -4px 0 16px; color: var(--muted); }
.related-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.related-card { display: block; padding: 16px; border: 1px solid var(--line); border-radius: 14px; color: var(--ink); text-decoration: none; }
.related-card:hover { border-color: #99ddd6; background: #f5fffd; }
.related-card span { display: block; margin-top: 3px; color: var(--muted); font-size: 13px; }
.site-footer { padding: 8px 0 28px; text-align: center; color: var(--muted); font-size: 13px; }
a:focus-visible, summary:focus-visible { outline: 3px solid rgba(37, 99, 235, .4); outline-offset: 3px; }
@media (max-width: 720px) {
  .header-inner { align-items: flex-start; flex-direction: column; padding: 12px 0; }
  .top-nav { gap: 8px 14px; }
  .download-options, .related-grid { grid-template-columns: 1fr; }
  .guide-hero, .content-card { border-radius: 16px; }
}
@media (max-width: 440px) {
  .actions { display: grid; }
  .button { width: 100%; }
  .top-nav { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}