:root {
  --fu-paper: #f4f6fb;
  --fu-ink: #1a2140;
  --fu-ink-2: #444c6b;
  --fu-green: #0b6b4f;
  --fu-green-2: #08553f;
  --fu-yel: #ffd84d;
  --fu-line: #d5dbea;
  --fu-face: #ffffff;
  --fu-r-big: 38px;
  --fu-r-sm: 19px;
  --fu-cjk: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
  --fu-lat: "High Tower Text", "Centaur", "Palatino Linotype", serif;
  --fu-wrap: 1180px;
  --fu-gut: 16px;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body.fu-body {
  margin: 0;
  background: var(--fu-paper);
  color: var(--fu-ink);
  font-family: var(--fu-cjk);
  font-size: 16px;
  line-height: 1.8;
  overflow-wrap: break-word;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--fu-green); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--fu-green-2); text-decoration-thickness: 2px; }

:focus-visible { outline: 3px solid var(--fu-green); outline-offset: 2px; border-radius: 4px; }

mark {
  color: inherit;
  background: linear-gradient(transparent 58%, var(--fu-yel) 58%, var(--fu-yel) 92%, transparent 92%);
  padding: 0 1px;
}

h1, h2, h3 { line-break: strict; text-wrap: balance; margin: 0; }

.fu-vh {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

.fu-skip {
  position: absolute; left: 12px; top: -60px; z-index: 10;
  background: var(--fu-ink); color: var(--fu-paper);
  padding: 10px 16px; border-radius: var(--fu-r-sm); text-decoration: none;
}
.fu-skip:focus { top: 12px; color: var(--fu-paper); }

/* ---------- 页头 ---------- */
.fu-mast { border-bottom: 1px solid var(--fu-line); background: var(--fu-paper); }
.fu-mast-in {
  max-width: var(--fu-wrap); margin: 0 auto; padding: 10px var(--fu-gut);
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
.fu-brand { display: inline-flex; align-items: center; min-height: 44px; color: var(--fu-ink); text-decoration: none; }
.fu-mark { display: block; width: 132px; height: 40px; }
.fu-menu ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 4px; flex-wrap: wrap; }
.fu-menu a {
  display: inline-flex; align-items: center; min-height: 44px; padding: 0 12px;
  color: var(--fu-ink); text-decoration: none; font-size: 15px; border-radius: var(--fu-r-sm);
}
.fu-menu a:hover { background: var(--fu-face); }
.fu-menu a[aria-current="page"] { box-shadow: inset 0 -3px 0 var(--fu-green); border-radius: 0; }

.fu-main { display: block; }

/* ---------- 首页首屏 ---------- */
.fu-hero {
  max-width: var(--fu-wrap); margin: 0 auto; padding: 28px var(--fu-gut) 36px;
  display: grid; gap: 22px 48px;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  grid-template-areas: "say art" "pick code";
  align-items: start;
}
.fu-hero-say { grid-area: say; }
.fu-hero-pick { grid-area: pick; }
.fu-hero-art { grid-area: art; }
.fu-hero-code { grid-area: code; }

.fu-hero-h {
  font-size: 88px; line-height: 1.06; font-weight: 800; letter-spacing: -0.01em;
}
.fu-hero-lead { margin: 18px 0 0; font-size: 17px; color: var(--fu-ink-2); max-width: 31em; }

.fu-pick {
  display: block; text-decoration: none; color: var(--fu-ink);
  background: var(--fu-face); border: 1px solid var(--fu-line); border-radius: var(--fu-r-big);
  padding: 22px 30px 24px;
}
.fu-pick:hover { border-color: var(--fu-green); color: var(--fu-ink); }
.fu-pick-lab { display: inline-block; font-size: 13px; color: var(--fu-green); font-weight: 700; letter-spacing: 0.02em; }
.fu-pick-t { display: block; font-size: 21px; font-weight: 700; line-height: 1.45; margin-top: 4px; }
.fu-pick-why { display: block; font-size: 15px; color: var(--fu-ink-2); margin-top: 6px; line-height: 1.7; }
.fu-pick-go { display: inline-block; margin-top: 10px; color: var(--fu-green); font-weight: 700; text-decoration: underline; text-underline-offset: 4px; }

/* 首屏图形：未勾选的大方框 + 三枚叠放页签 */
.fu-hero-art { position: relative; min-height: 312px; }
.fu-sheets { position: relative; margin-left: 96px; height: 312px; }
.fu-sheet {
  position: absolute; right: 0;
  background: var(--fu-face); border: 1.5px solid var(--fu-line); border-radius: var(--fu-r-sm);
  padding: 24px 20px 12px 40px; height: 112px;
}
.fu-sheet:nth-child(1) { top: 14px; left: 0; }
.fu-sheet:nth-child(2) { top: 112px; left: 18px; }
.fu-sheet:nth-child(3) { top: 210px; left: 36px; height: 100px; }
.fu-sheet-tab {
  position: absolute; top: -15px; left: 38px;
  background: var(--fu-face); border: 1.5px solid var(--fu-line); border-radius: 12px 12px 0 0;
  border-bottom-color: var(--fu-face);
  padding: 0 14px; font-size: 14px; font-weight: 700; line-height: 28px;
}
.fu-sheet:nth-child(3) .fu-sheet-tab { background: var(--fu-green); border-color: var(--fu-green); color: #fff; }
.fu-sheet-l { display: block; font-size: 15px; line-height: 1.65; }
.fu-sheet-l + .fu-sheet-l { color: var(--fu-ink-2); font-size: 14px; }
.fu-box {
  position: absolute; z-index: 2; left: 0; top: 150px;
  width: 124px; height: 124px; border: 9px solid var(--fu-ink); border-radius: var(--fu-r-big);
  background: var(--fu-face);
}

/* ---------- 码卡 ---------- */
.fu-code {
  background: var(--fu-face); border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm);
  padding: 16px 20px 16px;
}
.fu-code-top { display: flex; align-items: center; justify-content: space-between; gap: 10px 14px; flex-wrap: wrap; }
.fu-code-lab { font-size: 14px; color: var(--fu-ink-2); }
.fu-code-row { display: inline-flex; align-items: center; gap: 12px; }
.fu-code-val {
  font-family: var(--fu-lat); font-size: 30px; font-weight: 700; letter-spacing: 0.08em; color: var(--fu-ink);
  background: linear-gradient(transparent 62%, var(--fu-yel) 62%, var(--fu-yel) 90%, transparent 90%);
  padding: 0 2px; user-select: all;
}
.fu-copy {
  min-height: 44px; min-width: 76px; padding: 0 18px; cursor: pointer;
  font: inherit; font-size: 15px; font-weight: 700;
  color: #fff; background: var(--fu-green); border: 0; border-radius: var(--fu-r-sm);
}
.fu-copy:hover { background: var(--fu-green-2); }
.fu-copy[data-done] { background: var(--fu-ink); }
.fu-code-note { margin: 10px 0 0; font-size: 14px; line-height: 1.7; color: var(--fu-ink-2); }
.fu-code-note a { white-space: nowrap; }
.fu-go {
  display: flex; align-items: center; justify-content: center; text-align: center;
  min-height: 50px; margin-top: 14px; padding: 8px 18px;
  background: var(--fu-ink); color: var(--fu-paper); font-weight: 700; text-decoration: none;
  border-radius: var(--fu-r-sm);
}
.fu-go:hover { background: var(--fu-green); color: #fff; }
.fu-code-disc { margin: 10px 0 0; font-size: 14px; line-height: 1.7; color: var(--fu-ink-2); }
.fu-code-disc a { margin-left: 4px; }
.fu-article .fu-code { margin: 26px 0 30px; border-left: 6px solid var(--fu-green); }

/* ---------- 首页正文 ---------- */
.fu-home-body, .fu-desk {
  max-width: var(--fu-wrap); margin: 0 auto; padding: 0 var(--fu-gut);
}
.fu-home-body { border-top: 1px solid var(--fu-line); padding-top: 34px; columns: 2 30em; column-gap: 56px; }
.fu-home-body h2 { break-after: avoid; }
.fu-home-body ul, .fu-home-body ol { break-inside: avoid-column; }
.fu-desk { padding-top: 26px; padding-bottom: 56px; }
.fu-desk-h { font-size: 24px; margin-bottom: 12px; }
.fu-desk-more { margin: 14px 0 0; }
.fu-desk-more a { display: inline-flex; align-items: center; min-height: 44px; }

/* ---------- 通用正文 ---------- */
.fu-prose { max-width: 38em; }
.fu-home-body.fu-prose { max-width: var(--fu-wrap); }
.fu-prose h2, .fu-article h2.fu-h2 { font-size: 24px; line-height: 1.45; margin: 40px 0 12px; }
.fu-prose h2:first-child { margin-top: 0; }
.fu-prose h3, .fu-article h3 { font-size: 19px; line-height: 1.5; margin: 30px 0 8px; }
.fu-prose p, .fu-article p { margin: 0 0 1em; }
.fu-prose ul, .fu-prose ol, .fu-article ul, .fu-article ol { padding-left: 1.4em; margin: 0 0 1.1em; }
.fu-prose li, .fu-article li { margin: 0.3em 0; }
.fu-prose strong { font-weight: 700; }

/* ---------- 文章页 ---------- */
.fu-doc, .fu-leaf, .fu-shelf { max-width: var(--fu-wrap); margin: 0 auto; padding: 22px var(--fu-gut) 56px; }
.fu-crumb { list-style: none; margin: 0 0 10px; padding: 0; display: flex; flex-wrap: wrap; font-size: 14px; color: var(--fu-ink-2); }
.fu-crumb li { display: inline-flex; align-items: center; }
.fu-crumb li + li::before { content: "/"; margin: 0 8px; color: var(--fu-line); }
.fu-crumb a { display: inline-flex; align-items: center; min-height: 44px; color: var(--fu-ink-2); }
.fu-h1 { font-size: 52px; line-height: 1.2; font-weight: 800; max-width: 20em; }
.fu-h1-s { font-size: 44px; }
.fu-pgno { display: inline-block; margin-left: 12px; font-size: 0.45em; color: var(--fu-ink-2); font-weight: 400; }
.fu-byline { display: flex; flex-wrap: wrap; gap: 4px 18px; margin-top: 12px; font-size: 14px; color: var(--fu-ink-2); }
.fu-byline time { font-family: var(--fu-lat); font-size: 15px; }

.fu-cover { margin: 26px 0 0; }
.fu-cover img { border-radius: var(--fu-r-big); border: 1px solid var(--fu-line); width: 100%; }
.fu-cover figcaption { font-size: 14px; color: var(--fu-ink-2); margin-top: 8px; }

.fu-docgrid { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 48px; margin-top: 34px; align-items: start; }
.fu-toc { position: sticky; top: 16px; }
.fu-toc-box { background: var(--fu-face); border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm); padding: 6px 14px 10px; }
.fu-toc-box summary { min-height: 44px; display: flex; align-items: center; font-weight: 700; cursor: pointer; font-size: 15px; }
.fu-toc-ol { margin: 0; padding-left: 1.3em; font-size: 14px; line-height: 1.5; }
.fu-toc-ol li { margin: 0; }
.fu-toc-ol a { display: flex; align-items: center; min-height: 44px; color: var(--fu-ink); text-decoration: none; }
.fu-toc-ol a:hover { color: var(--fu-green); text-decoration: underline; }

.fu-article { max-width: 38em; font-size: 17px; }
.fu-article h2.fu-h2 {
  position: relative; margin-top: 64px; padding-top: 22px; border-top: 2px solid var(--fu-ink);
}
.fu-article > h2.fu-h2:first-of-type { margin-top: 64px; }
.fu-tab {
  position: absolute; top: -32px; left: 0;
  display: inline-block; padding: 0 14px; line-height: 30px; font-size: 14px; font-weight: 700;
  font-family: var(--fu-lat), var(--fu-cjk);
  color: #fff; background: var(--fu-ink); border-radius: 12px 12px 0 0;
}
.fu-h2-wrap { position: relative; margin-top: 64px; }
.fu-article .fu-h2-wrap > h2.fu-h2 { margin-top: 0; }

.fu-fig { margin: 26px 0 28px; }
.fu-fig img { border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm); background: var(--fu-face); }
.fu-fig-narrow img { max-width: 340px; width: 100%; }
.fu-fig figcaption { font-size: 14px; line-height: 1.7; color: var(--fu-ink-2); margin-top: 8px; max-width: 34em; }

.fu-tbl { overflow-x: auto; margin: 22px 0 26px; border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm); background: var(--fu-face); }
.fu-tbl-t { border-collapse: collapse; width: 100%; font-size: 15px; line-height: 1.65; }
.fu-tbl-t th, .fu-tbl-t td { text-align: left; vertical-align: top; padding: 11px 14px; border-bottom: 1px solid var(--fu-line); }
.fu-tbl-t th { background: var(--fu-ink); color: var(--fu-paper); font-weight: 700; white-space: nowrap; }
.fu-tbl-t tr:last-child td { border-bottom: 0; }
.fu-tbl-t td:first-child { font-weight: 700; }

.fu-faq { max-width: calc(250px + 48px + 38em); margin: 56px 0 0; padding-left: calc(250px + 48px); }
.fu-faq-h { font-size: 26px; margin-bottom: 14px; }
.fu-faq-list { margin: 0; }
.fu-faq-item { border-top: 1px solid var(--fu-line); padding: 16px 0; }
.fu-faq-item dt { font-weight: 700; font-size: 17px; }
.fu-faq-item dd { margin: 6px 0 0; color: var(--fu-ink); }

.fu-after { margin: 40px 0 0; padding: 22px 0 0 calc(250px + 48px); border-top: 1px solid var(--fu-line); }
.fu-after-lab { font-size: 14px; color: var(--fu-ink-2); }
.fu-chips { list-style: none; margin: 8px 0 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.fu-chips li > * { display: inline-flex; align-items: center; min-height: 36px; padding: 0 14px; border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm); background: var(--fu-face); font-size: 14px; }
.fu-after-go { display: flex; flex-wrap: wrap; gap: 4px 22px; margin-top: 18px; }
.fu-after-go a { display: inline-flex; align-items: center; min-height: 44px; }

/* ---------- 站务页、列表页 ---------- */
.fu-leafhead, .fu-shelfhead { margin-bottom: 24px; }
.fu-leafbody { margin-top: 8px; }
.fu-leafbody .fu-tbl-t td:first-child { font-weight: 400; color: var(--fu-ink-2); }
.fu-leafnav { list-style: none; margin: 44px 0 0; padding: 18px 0 0; border-top: 1px solid var(--fu-line); display: flex; flex-wrap: wrap; gap: 4px 20px; }
.fu-leafnav a { display: inline-flex; align-items: center; min-height: 44px; }

.fu-shelf-intro { margin-top: 14px; color: var(--fu-ink); }
.fu-shelf-count, .fu-shelf-alias { font-size: 14px; color: var(--fu-ink-2); }
.fu-post-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.fu-post-a {
  display: grid; grid-template-columns: 120px minmax(0, 1fr); gap: 2px 22px;
  text-decoration: none; color: var(--fu-ink);
  background: var(--fu-face); border: 1px solid var(--fu-line); border-radius: var(--fu-r-big);
  padding: 22px 30px;
}
.fu-post-a:hover { border-color: var(--fu-green); color: var(--fu-ink); }
.fu-post-tab { grid-row: 1 / span 3; align-self: start; font-family: var(--fu-lat), var(--fu-cjk); font-size: 14px; font-weight: 700; color: var(--fu-green); border-top: 3px solid var(--fu-green); padding-top: 6px; }
.fu-post-t { font-size: 20px; font-weight: 700; line-height: 1.5; }
.fu-post-d { font-size: 15px; color: var(--fu-ink-2); line-height: 1.7; }
.fu-post-m { font-size: 13px; color: var(--fu-ink-2); }
.fu-pages { display: flex; gap: 16px; align-items: center; margin-top: 24px; }
.fu-pages-a { display: inline-flex; align-items: center; min-height: 44px; }
.fu-term-list { list-style: none; padding: 0; }
.fu-term-list a { display: inline-flex; align-items: center; min-height: 44px; margin-right: 8px; }

/* ---------- 站内查找、404 ---------- */
.fu-find-form { margin: 18px 0 10px; max-width: 38em; }
.fu-find-lab { display: block; font-size: 15px; margin-bottom: 8px; color: var(--fu-ink-2); }
.fu-find-row { display: flex; gap: 10px; }
.fu-find-in {
  flex: 1; min-width: 0; min-height: 48px; padding: 0 16px; font: inherit; font-size: 16px;
  color: var(--fu-ink); background: var(--fu-face); border: 1.5px solid var(--fu-line); border-radius: var(--fu-r-sm);
}
.fu-find-btn {
  min-height: 48px; padding: 0 20px; font: inherit; font-weight: 700; cursor: pointer;
  color: #fff; background: var(--fu-green); border: 0; border-radius: var(--fu-r-sm);
}
.fu-find-state { font-size: 15px; color: var(--fu-ink-2); }
.fu-find-out { list-style: none; padding: 0; margin: 0; max-width: 38em; display: grid; gap: 12px; }
.fu-find-out a { display: block; padding: 14px 18px; background: var(--fu-face); border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm); text-decoration: none; color: var(--fu-ink); }
.fu-find-out a:hover { border-color: var(--fu-green); }
.fu-find-out b { display: block; font-size: 17px; }
.fu-find-out span { display: block; font-size: 14px; color: var(--fu-ink-2); line-height: 1.7; }
.fu-lost-go li { margin: 0.4em 0; }

/* ---------- 页脚 ---------- */
.fu-colo { background: var(--fu-ink); color: #e6e9f4; margin-top: 24px; }
.fu-colo-in {
  max-width: var(--fu-wrap); margin: 0 auto; padding: 36px var(--fu-gut) 28px;
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); gap: 18px 48px;
}
.fu-brand-foot { color: #f4f6fb; }
.fu-colo-say { margin: 8px 0 0; font-size: 14px; line-height: 1.7; }
.fu-colo-say a { display: inline-block; min-height: 44px; padding: 10px 0; box-sizing: border-box; }
.fu-colo a { color: #f4f6fb; }
.fu-colo a:hover { color: var(--fu-yel); }
.fu-colo-links { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 20px; align-content: start; }
.fu-colo-links a { display: flex; align-items: center; min-height: 44px; font-size: 15px; }
.fu-colo-year { grid-column: 1 / -1; margin: 6px 0 0; font-size: 13px; color: #b9bfd6; font-family: var(--fu-lat), var(--fu-cjk); }

/* ---------- 窄屏 ---------- */
@media (max-width: 960px) {
  .fu-hero { grid-template-columns: minmax(0, 1fr); grid-template-areas: "say" "code" "pick" "art"; gap: 16px; padding-top: 16px; }
  .fu-hero-h { font-size: 64px; }
  .fu-hero-art { max-width: 520px; }
  .fu-docgrid { grid-template-columns: minmax(0, 1fr); gap: 20px; margin-top: 22px; }
  .fu-toc { position: static; }
  .fu-faq, .fu-after { padding-left: 0; }
  .fu-colo-in { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 640px) {
  .fu-mast-in { padding-top: 6px; padding-bottom: 4px; gap: 0; }
  .fu-mark { width: 112px; height: 34px; }
  .fu-menu { width: 100%; }
  .fu-menu ul { gap: 0; margin-left: -10px; }
  .fu-menu a { padding: 0 10px; }
  .fu-hero { padding-top: 12px; padding-bottom: 24px; gap: 12px; }
  .fu-hero-h { font-size: 44px; line-height: 1.12; }
  .fu-hero-lead { font-size: 15px; margin-top: 10px; line-height: 1.7; }
  .fu-code { padding: 12px 14px; }
  .fu-code-val { font-size: 26px; }
  .fu-code-note { font-size: 13px; margin-top: 6px; }
  .fu-pick { padding: 14px 18px 16px; border-radius: var(--fu-r-sm); }
  .fu-pick-t { font-size: 17px; }
  .fu-pick-why { font-size: 14px; }
  .fu-pick-go { margin-top: 6px; }
  .fu-hero-art { min-height: 0; }
  .fu-sheets { margin-left: 52px; height: 300px; }
  .fu-sheet { padding: 22px 12px 10px 30px; height: 108px; }
  .fu-sheet:nth-child(2) { top: 108px; left: 10px; }
  .fu-sheet:nth-child(3) { top: 202px; left: 20px; height: 96px; }
  .fu-sheet-tab { left: 24px; }
  .fu-sheet-l { font-size: 14px; }
  .fu-sheet-l + .fu-sheet-l { font-size: 13px; }
  .fu-box { width: 72px; height: 72px; border-width: 7px; border-radius: var(--fu-r-sm); top: 160px; left: 0; }
  .fu-home-body { columns: auto; }
  .fu-h1 { font-size: 30px; line-height: 1.3; }
  .fu-h1-s { font-size: 32px; }
  .fu-article { font-size: 16px; }
  .fu-prose h2, .fu-article h2.fu-h2 { font-size: 21px; }
  .fu-cover img { border-radius: var(--fu-r-sm); }
  .fu-post-a { grid-template-columns: minmax(0, 1fr); padding: 16px 18px; border-radius: var(--fu-r-sm); }
  .fu-post-tab { grid-row: auto; }

  .fu-tbl { border: 0; background: transparent; overflow: visible; }
  .fu-tbl-t, .fu-tbl-t tbody, .fu-tbl-t tr, .fu-tbl-t td { display: block; width: 100%; }
  .fu-tbl-t thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .fu-tbl-t tr { background: var(--fu-face); border: 1px solid var(--fu-line); border-radius: var(--fu-r-sm); margin-bottom: 12px; padding: 4px 0; }
  .fu-tbl-t td { border-bottom: 0; padding: 6px 14px; }
  .fu-tbl-t td::before { content: attr(data-fu-col); display: block; font-size: 13px; font-weight: 700; color: var(--fu-green); }
  .fu-colo-links { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}

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

@media print {
  .fu-mast, .fu-colo, .fu-toc, .fu-skip { display: none; }
}