@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  --ink: #0F172A;
  --ink2: #16203a;
  --hot: #FF4D2D;
  --paper: #F2F2EE;
  --mute: #9FABC2;
  --line: rgba(242, 242, 238, 0.16);
  --dark-line: rgba(15, 23, 42, 0.22);
  --mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: 'IBM Plex Sans', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
  --r: 10px;
  --barH: 65px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font: 400 17px/1.7 var(--sans);
  overflow-x: hidden;
}

a { color: inherit; }
img { max-width: 100%; }

:focus-visible {
  outline: 2px solid var(--hot);
  outline-offset: 2px;
}

.skip {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 80;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 18px;
  background: var(--hot);
  color: var(--ink);
  border-radius: 3px;
  font: 700 16px var(--mono);
  text-decoration: none;
  transition: top 0.15s ease;
}
.skip:focus { top: 8px; }

/* 顶栏 */
.topbar {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--ink);
  border-bottom: 1px solid var(--line);
}

.bar {
  display: flex;
  align-items: center;
  gap: 14px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 10px 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 6px 2px;
  color: var(--paper);
  text-decoration: none;
  font: 700 17px/1.2 var(--mono);
  letter-spacing: 0.01em;
}

.mark {
  display: block;
  width: 24px;
  height: 24px;
  background: var(--hot);
  border-radius: 3px;
}

.logo {
  display: block;
  width: 26px;
  height: 26px;
  border-radius: 3px;
}

.brand-t { white-space: nowrap; }

.burger {
  margin-left: auto;
  min-height: 44px;
  padding: 10px 18px;
  border: 0;
  border-radius: 3px;
  background: var(--hot);
  color: var(--ink);
  font: 700 16px var(--mono);
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: background 0.18s ease;
}
.burger:hover { background: var(--paper); }

.menu {
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  display: none;
  background: var(--ink2);
  border-bottom: 2px solid var(--hot);
}
.menu.open { display: block; }

.top-list,
.anchor-list,
.side-list,
.f-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.top-list { padding: 6px 20px 14px; }

.top-list a {
  display: block;
  min-height: 44px;
  padding: 11px 4px;
  color: var(--paper);
  text-decoration: none;
  font-size: 16px;
  border-bottom: 1px solid var(--line);
  transition: color 0.18s ease;
}
.top-list a:hover { color: var(--hot); }

/* 首屏 */
.hero {
  background-color: var(--ink);
  background-image: radial-gradient(rgba(242, 242, 238, 0.16) 1px, transparent 1px);
  background-size: 16px 16px;
  border-bottom: 1px solid var(--line);
  padding: 34px 20px 40px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
}

.hero-copy {
  order: -1;
  text-align: right;
}

.hero-copy h1 {
  margin: 0 0 14px;
  font: 700 clamp(28px, 7.4vw, 50px)/1.16 var(--mono);
  letter-spacing: -0.015em;
}

.hero-desc {
  margin: 0 0 22px auto;
  max-width: 44ch;
  color: var(--mute);
  font-size: 17px;
}

.hero-cta { margin: 0; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 26px;
  background: var(--hot);
  color: var(--ink);
  border-radius: 3px;
  font: 700 16px var(--mono);
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: background 0.18s ease, color 0.18s ease;
}
.btn:hover { background: var(--paper); }

.hero-img {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--hot);
  border-radius: var(--r);
}

.hero-ph {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: 6px;
  aspect-ratio: 16 / 10;
  padding: 6px;
  border: 2px solid var(--hot);
  border-radius: var(--r);
}
.hero-ph i { display: block; background: rgba(255, 77, 45, 0.22); }
.hero-ph i:nth-child(2) { background: rgba(242, 242, 238, 0.08); }
.hero-ph i:nth-child(3) { background: rgba(242, 242, 238, 0.14); }
.hero-ph i:nth-child(4) { background: rgba(255, 77, 45, 0.4); }

/* 粘性锚点条 */
.anchors {
  position: sticky;
  top: calc(var(--barH) + 1px);
  z-index: 50;
  background: var(--ink2);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.anchor-list {
  display: flex;
  gap: 4px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 6px 14px;
}

.anchor-list a {
  display: flex;
  align-items: center;
  min-height: 42px;
  padding: 8px 12px;
  color: var(--paper);
  text-decoration: none;
  font: 500 15px/1.3 var(--mono);
  white-space: nowrap;
  border-radius: 3px;
  transition: background 0.18s ease, color 0.18s ease;
}
.anchor-list a:hover { background: var(--hot); color: var(--ink); }

/* 正文骨架 */
.wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 20px 56px;
}

.side {
  min-width: 0;
  padding: 14px;
  background: var(--ink2);
  border: 1px solid var(--line);
  border-radius: var(--r);
}

.side-t {
  margin: 0 0 8px;
  font: 700 14px var(--mono);
  letter-spacing: 0.2em;
  color: var(--hot);
}

.side hr {
  width: 34px;
  margin: 0 0 12px;
  border: 0;
  border-top: 2px solid var(--hot);
}

.side-list {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 2px;
  -webkit-overflow-scrolling: touch;
}
.side-list li { flex: 0 0 auto; }
.side-list a {
  display: flex;
  align-items: center;
  min-height: 42px;
  padding: 9px 12px;
  color: var(--paper);
  text-decoration: none;
  font-size: 16px;
  white-space: nowrap;
  border: 1px solid var(--line);
  border-radius: 3px;
  transition: border-color 0.18s ease, color 0.18s ease;
}
.side-list a:hover { border-color: var(--hot); color: var(--hot); }

.doc { min-width: 0; }

.prose {
  padding: 26px 18px;
  background: var(--paper);
  color: var(--ink);
  border-radius: var(--r);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.28);
  overflow-wrap: break-word;
}

.prose article { scroll-margin-top: calc(var(--barH) + 70px); }
.prose article + article {
  margin-top: 44px;
  padding-top: 34px;
  border-top: 1px dashed var(--dark-line);
}

.prose h2 {
  margin: 0 0 10px;
  font: 700 clamp(21px, 6vw, 30px)/1.28 var(--mono);
  letter-spacing: -0.01em;
}
.prose h2::before {
  content: '';
  display: inline-block;
  width: 11px;
  height: 11px;
  margin-right: 10px;
  background: var(--hot);
  vertical-align: 2px;
}
.prose h2 + hr {
  width: 64px;
  margin: 0 0 18px;
  border: 0;
  border-top: 2px solid var(--hot);
}

.prose h3 {
  margin: 26px 0 8px;
  font: 700 19px/1.4 var(--mono);
}

.prose p { margin: 0 0 16px; }

.prose a {
  color: #A82F12;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.prose ul,
.prose ol { margin: 0 0 18px; padding-left: 22px; }
.prose li { margin: 0 0 8px; }

.prose blockquote {
  margin: 0 0 18px;
  padding: 12px 16px;
  border-left: 4px solid var(--hot);
  background: rgba(255, 77, 45, 0.09);
}

.prose hr {
  width: 64px;
  margin: 26px 0;
  border: 0;
  border-top: 2px solid var(--hot);
}

.prose img { height: auto; border-radius: 6px; }

.prose pre {
  margin: 0 0 18px;
  padding: 14px;
  overflow-x: auto;
  background: var(--ink);
  color: var(--paper);
  border-radius: 6px;
  font: 400 15px/1.6 var(--mono);
}
.prose code { font-family: var(--mono); font-size: 0.95em; }
.prose pre code { font-size: 15px; }

.prose table {
  display: block;
  width: 100%;
  margin: 0 0 18px;
  overflow-x: auto;
  border-collapse: collapse;
  font-size: 16px;
}
.prose th,
.prose td {
  padding: 8px 10px;
  border: 1px solid var(--dark-line);
  text-align: left;
}

/* 页脚 */
.foot {
  margin-top: 20px;
  background: var(--ink2);
  border-top: 2px solid var(--hot);
}

.f-row {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 26px;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 30px 20px 22px;
}

.f-brand { flex: 0 0 auto; }

.f-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  color: var(--paper);
  text-decoration: none;
  font: 700 16px var(--mono);
}

.f-list {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
}

.f-list a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 8px;
  color: var(--paper);
  text-decoration: none;
  font-size: 16px;
  transition: color 0.18s ease;
}
.f-list a:hover { color: var(--hot); }

.f-form { flex: 1 1 240px; min-width: 0; }

.sub { display: flex; flex-wrap: wrap; gap: 8px; }

.sub input {
  flex: 1 1 150px;
  min-width: 0;
  min-height: 44px;
  padding: 10px 12px;
  background: var(--ink);
  color: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  font: 400 16px var(--sans);
}
.sub input::placeholder { color: var(--mute); }

.sub button {
  min-height: 44px;
  padding: 10px 20px;
  border: 0;
  border-radius: 3px;
  background: var(--hot);
  color: var(--ink);
  font: 700 16px var(--mono);
  cursor: pointer;
  transition: background 0.18s ease;
}
.sub button:hover { background: var(--paper); }

.f-copy {
  flex: 1 1 100%;
  margin-top: 4px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--mute);
  font-size: 15px;
}
.f-copy a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 6px 4px;
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid var(--hot);
}

/* 滚动揭示 */
.rv {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.rv.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .rv { opacity: 1; transform: none; transition: none; }
  * { transition: none !important; }
}

@media (min-width: 900px) {
  .burger { display: none; }
  .menu {
    position: static;
    display: block;
    flex: 1;
    background: none;
    border: 0;
  }
  .top-list {
    display: flex;
    justify-content: flex-end;
    flex-wrap: wrap;
    gap: 2px;
    padding: 0;
  }
  .top-list a {
    border: 0;
    padding: 10px 11px;
    font: 500 15px/1.4 var(--mono);
  }
  .top-list a:hover { color: var(--hot); }

  .hero {
    min-height: 70vh;
    display: flex;
    align-items: center;
    padding: 56px 20px;
  }
  .hero-grid { grid-template-columns: 0.85fr 1.15fr; gap: 48px; }
  .hero-copy { order: 0; }

  .anchor-list { padding: 6px 20px; }

  .wrap {
    grid-template-columns: 224px minmax(0, 1fr);
    gap: 40px;
    align-items: start;
    padding: 40px 20px 64px;
  }
  .side { position: sticky; top: calc(var(--barH) + 62px); }

  .side-list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }
  .side-list li { flex: none; }
  .side-list a {
    border: 0;
    border-bottom: 1px dashed var(--line);
    border-radius: 0;
    padding: 10px 2px;
  }

  .prose { padding: 44px 48px; }
}

@media (min-width: 1100px) {
  .prose { padding: 52px 60px; }
}

button[aria-expanded]{min-width:44px;min-height:44px}