/* =========================================================
   天龙小蜜 · 教程中心  design system v2
   Light, airy, documentation-first.
   ========================================================= */

:root {
  /* ink & text */
  --ink: #0a1120;
  --ink-2: #16202f;
  --body: #44506a;
  --muted: #6b7891;
  --faint: #93a0b5;

  /* surface */
  --bg: #ffffff;
  --bg-soft: #f7f9fc;
  --page: #f5f8fc;
  --page-deep: #edf2f9;
  --bg-tint: #f2f7ff;

  /* lines */
  --line: #e6ebf3;
  --line-soft: #eef2f8;
  --line-strong: #d3dcea;

  /* accents */
  --brand: #2563eb;
  --brand-deep: #1d4ed8;
  --sky: #0ea5e9;
  --teal: #0d9488;
  --mint: #10b981;
  --violet: #7c3aed;
  --amber: #b45309;
  --rose: #e11d48;

  /* effects */
  --shadow-sm: 0 1px 2px rgba(10, 17, 32, .04);
  --shadow-md: 0 12px 28px -18px rgba(10, 17, 32, .28);
  --shadow-lg: 0 28px 60px -34px rgba(10, 17, 32, .35);

  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 16px;
  --r-xl: 22px;

  --max: 1200px;
  --header-h: 68px;

  --ease: cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; }

input[type="search"]::-webkit-search-cancel-button,
input[type="search"]::-webkit-search-decoration { -webkit-appearance: none; appearance: none; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--body);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "kern" 1;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--brand); text-decoration: none; transition: color .2s var(--ease); }
a:hover { color: var(--brand-deep); }
button { font-family: inherit; }
h1, h2, h3, h4 {
  color: var(--ink);
  margin: 0;
  font-weight: 700;
  letter-spacing: -.022em;
  line-height: 1.25;
}
p { margin: 0; }
::selection { background: #dbeafe; color: var(--ink); }

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 28px;
}
.wrap-docs {
  max-width: none;
  margin: 0;
  padding: 0 28px;
}

/* ---------- focus ---------- */
:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
  border-radius: 6px;
}

/* =========================================================
   Header
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(255, 255, 255, .82);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--line-soft);
}
.site-header.is-scrolled { box-shadow: 0 8px 24px -22px rgba(10, 17, 32, .5); }

.header-inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 28px;
  padding: 0 28px;
}

.brand { display: flex; align-items: center; gap: 11px; flex-shrink: 0; }
.brand img {
  height: 30px;
  width: auto;
  filter: grayscale(1) brightness(.45) contrast(1.25);
  transition: filter .3s var(--ease), opacity .2s var(--ease);
}
.brand:hover img { filter: grayscale(1) brightness(.2) contrast(1.3); }
.brand-div {
  width: 1px;
  height: 18px;
  background: var(--line-strong);
}
.brand-label {
  font-size: 13px;
  color: var(--muted);
  font-weight: 500;
  letter-spacing: .02em;
  white-space: nowrap;
}

.main-nav { display: flex; align-items: center; gap: 4px; margin-left: 8px; }
.nav-item {
  position: relative;
  padding: 8px 13px;
  border-radius: 9px;
  font-size: 15px;
  font-weight: 500;
  color: var(--body);
  white-space: nowrap;
  transition: background .22s var(--ease), color .22s var(--ease);
}
.nav-item:hover { color: var(--ink); background: var(--bg-soft); }
.nav-item.active { color: var(--ink); background: #eef4ff; font-weight: 600; }
.nav-item.active::after {
  content: "";
  position: absolute;
  left: 13px; right: 13px; bottom: -13px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--brand), var(--sky));
}

.header-actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }

.search-trigger {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 36px;
  padding: 0 10px 0 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg);
  color: var(--faint);
  font-size: 13px;
  cursor: pointer;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease), color .2s var(--ease);
}
.search-trigger:hover { border-color: var(--line-strong); color: var(--muted); box-shadow: var(--shadow-sm); }
.search-trigger kbd {
  font-family: inherit;
  font-size: 11px;
  color: var(--faint);
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 1px 5px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 40px;
  padding: 0 18px;
  border-radius: 10px;
  border: 1px solid transparent;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .01em;
  cursor: pointer;
  white-space: nowrap;
  transition: transform .2s var(--ease), box-shadow .25s var(--ease),
    background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease);
}
.btn i { font-size: 13px; }
.btn-primary {
  background: var(--ink);
  color: #fff;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .2), inset 0 1px 0 rgba(255, 255, 255, .1);
}
.btn-primary:hover { background: #1b2536; color: #fff; transform: translateY(-1px); box-shadow: 0 10px 22px -12px rgba(10, 17, 32, .55); }
.btn-ghost {
  background: #fff;
  color: var(--ink-2);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-sm);
}
.btn-ghost:hover { color: var(--ink); border-color: #bcc8da; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-soft { background: #eef4ff; color: var(--brand-deep); }
.btn-soft:hover { background: #e3edff; color: var(--brand-deep); }
.btn-sm { height: 34px; padding: 0 13px; font-size: 13px; border-radius: 9px; }
.btn-lg { height: 46px; padding: 0 24px; font-size: 15px; border-radius: 12px; }
.btn-block { width: 100%; }

.menu-toggle {
  display: none;
  width: 38px; height: 38px;
  align-items: center; justify-content: center;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
}

/* mobile nav sheet */
.mobile-nav {
  display: none;
  border-top: 1px solid var(--line-soft);
  background: #fff;
  padding: 10px 0 18px;
}
.mobile-nav.open { display: block; }
.mobile-nav a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 4px;
  font-size: 15px;
  color: var(--ink-2);
  border-bottom: 1px solid var(--line-soft);
}
.mobile-nav a:last-child { border-bottom: 0; }
.mobile-nav .btn { margin-top: 14px; }

/* =========================================================
   Hero
   ========================================================= */
.hero {
  position: relative;
  padding: 88px 0 58px;
  text-align: center;
  overflow: hidden;
  isolation: isolate;
}
.hero::before {
  content: "";
  position: absolute;
  inset: -40% -20% auto -20%;
  height: 720px;
  z-index: -1;
  background:
    radial-gradient(46% 42% at 22% 18%, rgba(37, 99, 235, .12), transparent 70%),
    radial-gradient(40% 38% at 78% 12%, rgba(14, 165, 233, .13), transparent 72%),
    radial-gradient(38% 36% at 58% 44%, rgba(16, 185, 129, .10), transparent 74%);
  filter: blur(6px);
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(10, 17, 32, .045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(10, 17, 32, .045) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(58% 52% at 50% 22%, #000 0%, transparent 78%);
  mask-image: radial-gradient(58% 52% at 50% 22%, #000 0%, transparent 78%);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 30px;
  padding: 0 13px 0 9px;
  border-radius: 999px;
  border: 1px solid rgba(37, 99, 235, .18);
  background: rgba(255, 255, 255, .72);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  font-size: 12.5px;
  font-weight: 500;
  color: var(--brand-deep);
  letter-spacing: .02em;
}
.eyebrow .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, .14);
}

.hero h1 {
  margin: 26px auto 0;
  max-width: 980px;
  font-size: clamp(32px, 4.3vw, 56px);
  line-height: 1.1;
  letter-spacing: -.038em;
  font-weight: 700;
}
.hero h1 .grad {
  background: linear-gradient(96deg, #2563eb 4%, #0ea5e9 46%, #10b981 96%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.hero-sub {
  margin: 22px auto 0;
  max-width: 660px;
  font-size: 17px;
  line-height: 1.8;
  color: var(--muted);
}

/* hero search */
.hero-search {
  position: relative;
  max-width: 548px;
  margin: 34px auto 0;
}
.hero-search .field {
  display: flex;
  align-items: center;
  gap: 12px;
  height: 56px;
  padding: 0 8px 0 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 15px;
  box-shadow: 0 18px 40px -26px rgba(10, 17, 32, .4), 0 1px 2px rgba(10, 17, 32, .04);
  cursor: text;
  transition: border-color .2s var(--ease), box-shadow .25s var(--ease);
}
.hero-search .field:hover { border-color: var(--line-strong); }
.hero-search .field i { color: var(--faint); font-size: 15px; }
.hero-search .field input {
  flex: 1;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  font-family: inherit;
  font-size: 15px;
  color: var(--ink);
}
.hero-search .field input::placeholder { color: var(--faint); }
.hero-search .field .key {
  font-size: 11px;
  color: var(--faint);
  border: 1px solid var(--line);
  background: var(--bg-soft);
  border-radius: 6px;
  padding: 2px 6px;
  white-space: nowrap;
}
.hero-search .submit {
  height: 42px;
  padding: 0 18px;
  border-radius: 11px;
  border: 0;
  background: var(--ink);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background .2s var(--ease), transform .2s var(--ease);
}
.hero-search .submit:hover { background: #1b2536; transform: translateY(-1px); }

.hero-quick {
  margin: 20px auto 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 13.5px;
  color: var(--faint);
}
.hero-quick a {
  color: var(--body);
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, .7);
  font-size: 12.5px;
  transition: .2s var(--ease);
}
.hero-quick a:hover { border-color: var(--brand); color: var(--brand-deep); background: #fff; }

.hero-actions { margin-top: 30px; display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }

/* stats */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  max-width: 820px;
  margin: 56px auto 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}
.stat { background: #fff; padding: 20px 12px; text-align: center; }
.stat b {
  display: block;
  font-size: 26px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
}
.stat span { font-size: 12.5px; color: var(--muted); }

/* =========================================================
   Sections
   ========================================================= */
.section { padding: 76px 0; }
.section.tight { padding: 56px 0; }
.section.soft { background: var(--page-deep); border-top: 1px solid #e7eef7; border-bottom: 1px solid #e7eef7; }

.section-head { max-width: 720px; margin: 0 auto 44px; text-align: center; }
.section-head.left { margin-left: 0; text-align: left; }
.section-kicker {
  display: block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--brand);
  margin-bottom: 12px;
}
.section-head h2 {
  font-size: clamp(24px, 2.8vw, 34px);
  letter-spacing: -.03em;
}
.section-head p { margin-top: 14px; font-size: 16.5px; color: var(--muted); line-height: 1.8; }

/* entry cards (big) */
.entry-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.entry {
  position: relative;
  display: block;
  padding: 32px 32px 28px;
  border-radius: var(--r-xl);
  border: 1px solid var(--line);
  background: #fff;
  overflow: hidden;
  transition: transform .3s var(--ease), box-shadow .35s var(--ease), border-color .3s var(--ease);
}
.entry::before {
  content: "";
  position: absolute;
  inset: 0;
  opacity: .85;
  transition: opacity .35s var(--ease);
}
.entry.blue::before { background: radial-gradient(120% 100% at 100% 0%, #eef4ff 0%, rgba(255, 255, 255, 0) 62%); }
.entry.mint::before { background: radial-gradient(120% 100% at 100% 0%, #ecfdf7 0%, rgba(255, 255, 255, 0) 62%); }
.entry > * { position: relative; }
.entry:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--line-strong); }
.entry:hover::before { opacity: 1; }
.entry-top { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; }
.entry-ico {
  width: 44px; height: 44px;
  display: grid; place-items: center;
  border-radius: 13px;
  font-size: 18px;
  color: #fff;
  box-shadow: 0 10px 20px -12px rgba(10, 17, 32, .5);
}
.entry.blue .entry-ico { background: linear-gradient(135deg, #3b82f6, #0ea5e9); }
.entry.mint .entry-ico { background: linear-gradient(135deg, #14b8a6, #10b981); }
.entry h3 { font-size: 21px; letter-spacing: -.022em; }
.entry p { margin-top: 10px; font-size: 15.5px; color: var(--muted); line-height: 1.75; }
.entry-foot {
  margin-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13.5px;
  color: var(--faint);
}
.entry-foot .go {
  display: inline-flex; align-items: center; gap: 8px;
  font-weight: 600; color: var(--brand);
}
.entry-foot .go i { transition: transform .25s var(--ease); }
.entry:hover .entry-foot .go i { transform: translateX(4px); }

/* feature grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.feature {
  padding: 26px 24px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: #fff;
  transition: transform .25s var(--ease), box-shadow .3s var(--ease), border-color .25s var(--ease);
}
.feature:hover { transform: translateY(-2px); border-color: var(--line-strong); box-shadow: var(--shadow-md); }
.feature .fi {
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border-radius: 11px;
  font-size: 16px;
  margin-bottom: 16px;
}
.fi-blue { background: #eef4ff; color: #2563eb; }
.fi-teal { background: #ecfdf7; color: #0d9488; }
.fi-violet { background: #f4f0ff; color: #7c3aed; }
.fi-amber { background: #fff7ed; color: #c2410c; }
.fi-rose { background: #fff1f4; color: #e11d48; }
.fi-sky { background: #eef9ff; color: #0284c7; }
.feature h3 { font-size: 16.5px; letter-spacing: -.01em; }
.feature p { margin-top: 8px; font-size: 14.5px; color: var(--muted); line-height: 1.7; }

/* steps (how to start) */
.howto { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; counter-reset: how; }
.howto .step {
  position: relative;
  padding: 28px 24px 24px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: #fff;
}
.howto .step::before {
  counter-increment: how;
  content: "0" counter(how);
  display: block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--brand);
  margin-bottom: 14px;
}
.howto .step h3 { font-size: 17px; }
.howto .step p { margin-top: 8px; font-size: 14.5px; color: var(--muted); line-height: 1.75; }
.howto .step a { font-size: 13px; font-weight: 600; display: inline-flex; align-items: center; gap: 6px; margin-top: 14px; }

/* faq */
.faq { max-width: 800px; margin: 0 auto; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 4px;
  font-size: 16.5px;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary .sign {
  flex-shrink: 0;
  width: 22px; height: 22px;
  display: grid; place-items: center;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  color: var(--muted);
  font-size: 10px;
  transition: transform .3s var(--ease), background .2s var(--ease), color .2s var(--ease);
}
.faq details[open] summary .sign { transform: rotate(180deg); background: var(--ink); border-color: var(--ink); color: #fff; }
.faq .answer { padding: 0 4px 22px; font-size: 15.5px; color: var(--muted); line-height: 1.85; max-width: 92%; }
.faq .answer a { font-weight: 500; }

/* support band */
.support-band {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  flex-wrap: wrap;
  padding: 34px 38px;
  border-radius: var(--r-xl);
  background: linear-gradient(115deg, #0a1120 0%, #132038 55%, #0f2a3d 100%);
  overflow: hidden;
}
.support-band::after {
  content: "";
  position: absolute;
  right: -60px; top: -80px;
  width: 320px; height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(14, 165, 233, .35), transparent 66%);
  filter: blur(10px);
}
.support-band h3 { color: #fff; font-size: 21px; letter-spacing: -.02em; }
.support-band p { color: rgba(255, 255, 255, .62); font-size: 14px; margin-top: 8px; max-width: 520px; }
.support-band .btn-primary { background: #fff; color: var(--ink); }
.support-band .btn-primary:hover { background: #eef4ff; color: var(--ink); }
.support-band .btn-ghost { background: transparent; color: #fff; border-color: rgba(255, 255, 255, .28); box-shadow: none; }
.support-band .btn-ghost:hover { background: rgba(255, 255, 255, .1); color: #fff; border-color: rgba(255, 255, 255, .5); }
.support-band > div:last-child { position: relative; display: flex; gap: 10px; flex-wrap: wrap; }

/* =========================================================
   Catalog pages (ink / lens)
   ========================================================= */
.page-head {
  padding: 52px 0 44px;
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(60% 120% at 8% -30%, rgba(37, 99, 235, .10), transparent 68%),
    radial-gradient(52% 110% at 82% -36%, rgba(13, 148, 136, .10), transparent 70%),
    transparent;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--faint);
  margin-bottom: 20px;
}
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--brand); }
.breadcrumb i { font-size: 9px; opacity: .6; }
.breadcrumb .sep { opacity: .5; }
.page-head h1 { font-size: clamp(28px, 3.4vw, 40px); letter-spacing: -.032em; }
.page-head .lede { margin-top: 14px; max-width: 620px; font-size: 16.5px; color: var(--muted); line-height: 1.8; }
.page-head-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 22px; }
.pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  height: 30px;
  padding: 0 11px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #fff;
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}
.pill i { font-size: 11px; color: var(--brand); }
.pill.mint i { color: var(--teal); }

.catalog { display: grid; grid-template-columns: 232px minmax(0, 1400px); gap: 48px; padding: 46px 0 84px; }

.cat-rail {
  position: sticky;
  top: calc(var(--header-h) + 26px);
  align-self: start;
  min-width: 0;
  max-height: calc(100vh - var(--header-h) - 40px);
  overflow-y: auto;
  scrollbar-width: thin;
  padding-right: 4px;
}
.cat-nav {
  position: static;
  top: calc(var(--header-h) + 26px);
  align-self: start;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px 12px 12px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 24px 50px -46px rgba(10, 17, 32, .5);
}
.cat-nav .label {
  padding: 0 10px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 14px;
}
.cat-nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-radius: 9px;
  font-size: 14.5px;
  color: var(--body);
  border-left: 2px solid transparent;
  transition: .2s var(--ease);
}
.cat-nav a:hover { background: #f2f6fc; color: var(--ink); }
.cat-nav a.active {
  background: #eef4ff;
  color: var(--brand-deep);
  font-weight: 600;
  border-left-color: var(--brand);
  box-shadow: 0 1px 2px rgba(10, 17, 32, .05), 0 8px 20px -16px rgba(10, 17, 32, .5);
}
.cat-nav a .count { margin-left: auto; font-size: 11.5px; color: var(--faint); font-variant-numeric: tabular-nums; }
.cat-nav-foot {
  display: block;
  margin: 10px 10px 2px;
  padding-top: 11px;
  border-top: 1px solid var(--line-soft);
  font-size: 11.5px;
  color: var(--faint);
}

.cat-section { margin-bottom: 46px; scroll-margin-top: 90px; }
.cat-section-head { display: flex; align-items: baseline; gap: 12px; margin-bottom: 18px; }
.cat-section-head h2 { font-size: 18px; letter-spacing: -.02em; }
.cat-section-head .n { font-size: 12px; color: var(--faint); }

.cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.cards-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.cards-cat { grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); }
.card-link {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: #fff;
  transition: transform .22s var(--ease), border-color .22s var(--ease), box-shadow .3s var(--ease), background .22s var(--ease);
}
.card-link:hover {
  transform: translateY(-2px);
  border-color: #c8d7ee;
  box-shadow: var(--shadow-md);
  background: #fff;
}
.card-link .ci {
  flex-shrink: 0;
  width: 34px; height: 34px;
  display: grid; place-items: center;
  border-radius: 10px;
  background: var(--bg-soft);
  color: var(--muted);
  font-size: 13px;
  transition: .22s var(--ease);
}
.card-link:hover .ci { background: #eef4ff; color: var(--brand); }
.card-link.vid .ci { background: #f0fdf9; color: var(--teal); }
.card-link.vid:hover .ci { background: #dcfce7; color: #047857; }
.card-link .ct { min-width: 0; }
.card-link strong {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -.01em;
  line-height: 1.5;
}
.card-link small { display: block; font-size: 13.5px; color: var(--faint); margin-top: 3px; line-height: 1.5; }
.card-link .arrow { margin-left: auto; align-self: center; color: var(--line-strong); font-size: 11px; transition: .22s var(--ease); }
.card-link:hover .arrow { color: var(--brand); transform: translateX(3px); }

.catalog-note {
  display: flex;
  gap: 12px;
  padding: 16px 18px;
  border-radius: var(--r-md);
  background: var(--bg-tint);
  border: 1px solid #dbe8ff;
  font-size: 13.5px;
  color: #33456b;
  line-height: 1.7;
  margin-top: 8px;
}
.catalog-note i { color: var(--brand); margin-top: 3px; }


/* ---------- 目录页：页头分栏 + 筛选 ---------- */
.ph-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 48px; }
.ph-main { min-width: 0; }
.ph-side { width: 316px; flex-shrink: 0; padding-bottom: 4px; }
.filter-box {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 46px;
  padding: 0 12px 0 14px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 10px 24px -24px rgba(10, 17, 32, .5);
  cursor: text;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.filter-box:focus-within { border-color: #b9cdf0; box-shadow: 0 0 0 3px rgba(37, 99, 235, .1), 0 1px 2px rgba(10, 17, 32, .04); }
.filter-box > i { font-size: 13px; color: var(--faint); }
.filter-box input {
  flex: 1;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  font-family: inherit;
  font-size: 14px;
  color: var(--ink);
}
.filter-box input::placeholder { color: #a6b2c5; }
.filter-box kbd {
  font-family: inherit;
  font-size: 11px;
  color: var(--faint);
  border: 1px solid var(--line);
  background: var(--bg-soft);
  border-radius: 5px;
  padding: 1px 6px;
}
.filter-hint { display: block; margin-top: 9px; font-size: 12.5px; color: var(--faint); text-align: right; }

/* ---------- 目录页：分类区块 ---------- */
.cat-body { min-width: 0; }
.cat-section { margin-bottom: 36px; scroll-margin-top: 92px; }
.cat-section-head { display: flex; align-items: center; gap: 11px; margin-bottom: 14px; }
.cat-section-head h2 { font-size: 19px; letter-spacing: -.02em; white-space: nowrap; }
.csh-ico {
  width: 30px; height: 30px;
  display: grid; place-items: center;
  border-radius: 9px;
  font-size: 12.5px;
  flex-shrink: 0;
}
.csh-count {
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 1px 9px;
  font-variant-numeric: tabular-nums;
}
.cat-section-head::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--line) 0%, rgba(230, 235, 243, 0) 92%);
}

/* ---------- 目录卡片 ---------- */
.tgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(326px, 1fr)); gap: 14px; }
.tcard {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 18px 19px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  transition: transform .22s var(--ease), box-shadow .28s var(--ease), border-color .22s var(--ease);
}
.tcard:hover {
  transform: translateY(-2px);
  border-color: #c8d7ee;
  box-shadow: 0 16px 34px -26px rgba(10, 17, 32, .55);
  color: inherit;
}
.tcard-ico {
  width: 42px; height: 42px;
  display: grid; place-items: center;
  border-radius: 12px;
  font-size: 16px;
  flex-shrink: 0;
  transition: transform .22s var(--ease);
}
.tcard:hover .tcard-ico { transform: scale(1.04); }
.tcard-main { min-width: 0; padding-top: 2px; }
.tcard-main strong {
  display: block;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.45;
  letter-spacing: -.01em;
}
.tcard-main em {
  display: block;
  font-style: normal;
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.6;
  margin-top: 5px;
}
.tcard-arrow {
  margin-left: auto;
  align-self: center;
  font-size: 11px;
  color: #ccd6e4;
  transition: color .2s var(--ease), transform .2s var(--ease);
}
.tcard:hover .tcard-arrow { color: var(--brand); transform: translateX(3px); }

/* 色调 */
.t-blue { background: #eaf1ff; color: #2563eb; }
.t-violet { background: #f3edff; color: #7c3aed; }
.t-teal { background: #e4fbf4; color: #0d9488; }
.t-amber { background: #fff4e5; color: #d97706; }
.t-rose { background: #ffeef3; color: #e11d48; }
.t-sky { background: #e7f6ff; color: #0284c7; }

.filter-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 64px 0 72px;
  color: var(--muted);
}
.filter-empty i { font-size: 22px; color: var(--faint); margin-bottom: 10px; }
.filter-empty strong { font-size: 16px; color: var(--ink); font-weight: 600; }
.filter-empty span { font-size: 13.5px; color: var(--faint); }

/* 右栏：购买悬浮卡（无目录时） */
.buy-rail {
  position: sticky;
  top: calc(var(--header-h) + 26px);
  align-self: start;
}
.buy-card {
  padding: 20px 18px 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 24px 50px -46px rgba(10, 17, 32, .5);
}
.bc-ico {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  border-radius: 10px;
  background: linear-gradient(140deg, #3b82f6, #06b6d4);
  color: #fff;
  font-size: 14px;
  box-shadow: 0 8px 18px -8px rgba(37, 99, 235, .55);
  margin-bottom: 12px;
}
.buy-card .bc-t { display: block; font-size: 15.5px; color: var(--ink); letter-spacing: -.01em; }
.buy-card > p { margin-top: 5px; font-size: 12.5px; line-height: 1.65; color: var(--muted); }
.buy-btn {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: 12px;
  transition: transform .2s var(--ease), box-shadow .25s var(--ease), filter .2s var(--ease);
}
.buy-btn > i:first-child { font-size: 15px; }
.buy-btn .bb-t { flex: 1; min-width: 0; line-height: 1.25; }
.buy-btn .bb-t strong { display: block; font-size: 14.5px; }
.buy-btn .bb-t em { display: block; font-style: normal; font-size: 11.5px; opacity: .78; margin-top: 2px; }
.buy-btn .bb-go { font-size: 11px; opacity: .65; transition: transform .2s var(--ease), opacity .2s var(--ease); }
.buy-btn:hover .bb-go { transform: translateX(3px); opacity: 1; }
.buy-btn.primary {
  background: linear-gradient(135deg, #2563eb, #0891b2);
  color: #fff;
  box-shadow: 0 10px 22px -10px rgba(37, 99, 235, .6);
}
.buy-btn.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 28px -10px rgba(37, 99, 235, .68);
  filter: saturate(1.08);
}
.buy-btn.mint {
  background: #f0fbf6;
  border: 1px solid #b7e6d0;
  color: #047857;
}
.buy-btn.mint:hover {
  transform: translateY(-2px);
  background: #e9f8f1;
  box-shadow: 0 10px 22px -14px rgba(5, 150, 105, .5);
}

/* 售后页页头：快速通道卡 */
.quick-card {
  padding: 14px 12px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 24px 50px -46px rgba(10, 17, 32, .5);
}
.ph-quick { margin-top: 18px; }}
.qc-title {
  display: block;
  padding: 2px 10px 9px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .07em;
  color: #7d8ba1;
}
.qc-row {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 11px 10px;
  border-radius: 10px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink);
  transition: background .18s var(--ease);
}
.qc-row + .qc-row { margin-top: 2px; }
.qc-row > i:first-child {
  width: 28px; height: 28px;
  display: grid; place-items: center;
  border-radius: 8px;
  background: #eef4ff;
  color: var(--brand);
  font-size: 12px;
}
.qc-row span { flex: 1; min-width: 0; }
.qc-row > i:last-child { font-size: 10.5px; color: #ccd6e4; transition: transform .2s var(--ease), color .2s var(--ease); }
.qc-row:hover { background: #f2f6fc; }
.qc-row:hover > i:last-child { color: var(--brand); transform: translateX(3px); }

.rail-help {
  margin-top: 14px;
  padding: 18px 17px 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 24px 50px -46px rgba(10, 17, 32, .5);
}
.rail-help .rh-ico {
  width: 32px; height: 32px;
  display: grid; place-items: center;
  border-radius: 9px;
  background: #eef4ff;
  color: var(--brand);
  font-size: 13px;
  margin-bottom: 12px;
}
.rail-help strong { display: block; font-size: 14px; color: var(--ink); letter-spacing: -.01em; }
.rail-help p { margin-top: 6px; font-size: 12.5px; line-height: 1.75; color: var(--muted); }
.rail-help a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 12px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--brand);
}

/* =========================================================
   Doc / article pages
   ========================================================= */
.docs { display: grid; grid-template-columns: 272px minmax(0, 1fr) 208px; gap: 40px; padding: 28px 0 80px; }
.docs-body {
  max-width: none;
  min-width: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 34px 40px 46px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 30px 70px -60px rgba(10, 17, 32, .55);
}

/* 右栏：本页目录 */
.toc {
  position: sticky;
  top: calc(var(--header-h) + 26px);
  align-self: start;
  max-height: calc(100vh - var(--header-h) - 48px);
  overflow-y: auto;
  padding-left: 4px;
  scrollbar-width: thin;
}
.toc-title {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .06em;
  color: #8b98ad;
  margin-bottom: 10px;
}
.toc-list { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--line); }
.toc-list a {
  display: block;
  padding: 6px 0 6px 12px;
  margin-left: -1px;
  border-left: 2px solid transparent;
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--muted);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.toc-list a:hover { color: var(--ink); }
.toc-list a.active { color: var(--brand-deep); border-left-color: var(--brand); font-weight: 600; }

.docs-nav {
  position: sticky;
  top: calc(var(--header-h) + 22px);
  align-self: start;
  max-height: calc(100vh - var(--header-h) - 48px);
  overflow-y: auto;
  padding: 16px 12px 14px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .04), 0 24px 50px -46px rgba(10, 17, 32, .5);
  scrollbar-width: thin;
}
.docs-nav::-webkit-scrollbar { width: 5px; }
.docs-nav::-webkit-scrollbar-thumb { background: var(--line-strong); border-radius: 3px; }
.docs-nav::-webkit-scrollbar-track { background: transparent; }

.docs-nav .back {
  display: inline-flex;
  margin-left: 2px;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 18px;
}
.docs-nav .back:hover { color: var(--brand); }
.nav-search {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 38px;
  padding: 0 11px;
  border: 1px solid var(--line);
  border-radius: 9px;
  margin-bottom: 18px;
  background: var(--bg-soft);
}
.nav-search i { font-size: 11px; color: var(--faint); }
.nav-search input {
  flex: 1; min-width: 0; border: 0; outline: 0; background: transparent;
  font-family: inherit; font-size: 13.5px; color: var(--ink);
}
.nav-groups { display: block; }
.nav-toggle { display: none; }
.nav-group { margin-bottom: 26px; }
.nav-group-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .05em;
  color: #7d8ba1;
  padding: 0 12px;
  margin-bottom: 10px;
}
.nav-group-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line-soft);
}
.nav-list { list-style: none; margin: 0; padding: 0; }
.nav-list a {
  display: block;
  padding: 9px 12px;
  border-radius: 9px;
  font-size: 15px;
  color: var(--body);
  line-height: 1.55;
  border-left: 2px solid transparent;
  transition: .18s var(--ease);
}
.nav-list a:hover { background: #f2f6fc; color: var(--ink); }
.nav-list a.active {
  background: #eef4ff;
  color: var(--brand-deep);
  font-weight: 600;
  border-left-color: var(--brand);
}
.nav-list li.hidden { display: none; }

.docs-body { min-width: 0; }
.docs-crumb {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  font-size: 13px; color: var(--faint); margin-bottom: 16px;
}
.docs-crumb a { color: var(--muted); }
.docs-crumb a:hover { color: var(--brand); }
.docs-crumb i { font-size: 9px; opacity: .55; }

.article-head { margin-bottom: 30px; padding-bottom: 26px; border-bottom: 1px solid var(--line); }
.article-head h1 { font-size: clamp(26px, 3vw, 34px); letter-spacing: -.03em; line-height: 1.25; }
.article-desc { margin-top: 14px; font-size: 16.5px; color: var(--muted); line-height: 1.8; max-width: 76ch; }
.article-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }

/* prose */
.prose { font-size: 16.5px; line-height: 1.9; color: #3c4a63; }
.prose > * + * { margin-top: 18px; }
.prose h3 {
  font-size: 17px;
  letter-spacing: -.02em;
  margin-top: 40px;
  padding-left: 14px;
  position: relative;
  line-height: 1.5;
}
.prose h3::before {
  content: "";
  position: absolute;
  left: 0; top: .42em;
  width: 3px; height: .95em;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--brand), var(--sky));
}
.prose h3:first-child { margin-top: 0; }
.prose p { margin-top: 14px; }
.prose strong { color: var(--ink-2); font-weight: 600; }
.prose a { font-weight: 500; text-decoration: underline; text-decoration-color: rgba(37, 99, 235, .28); text-underline-offset: 3px; }
.prose a:hover { text-decoration-color: var(--brand); }
code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: .87em;
  padding: 1px 5px;
  border-radius: 5px;
  background: #eef2f8;
  color: #17253c;
}
.prose code, .faq .answer code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: .86em;
  padding: 2px 6px;
  border-radius: 5px;
  background: #eef2f8;
  color: #17253c;
  white-space: nowrap;
}
.prose kbd {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: .84em;
  padding: 2px 6px;
  margin: 0 2px;
  border-radius: 6px;
  border: 1px solid var(--line-strong);
  border-bottom-width: 2px;
  background: var(--bg-soft);
  color: var(--ink-2);
  white-space: nowrap;
}

/* steps list */
ol.steps { list-style: none; margin: 20px 0 0; padding: 0; counter-reset: st; }
ol.steps > li {
  position: relative;
  counter-increment: st;
  padding: 0 0 20px 44px;
  margin: 0;
}
ol.steps > li::before {
  content: counter(st);
  position: absolute;
  left: 0; top: 1px;
  width: 27px; height: 27px;
  display: grid; place-items: center;
  border-radius: 50%;
  background: #eef4ff;
  border: 1px solid #d8e5ff;
  color: var(--brand-deep);
  font-size: 12.5px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
ol.steps > li::after {
  content: "";
  position: absolute;
  left: 13px; top: 32px; bottom: 2px;
  width: 1px;
  background: linear-gradient(180deg, var(--line) 0%, var(--line-soft) 100%);
}
ol.steps > li:last-child { padding-bottom: 0; }
ol.steps > li:last-child::after { display: none; }
ol.steps > li > figure { margin-top: 14px; }
ol.steps > li > p + p { margin-top: 10px; }

/* plain paragraph groups */
.pgroup { margin-top: 18px; }
.pgroup p { margin-top: 10px; padding-left: 20px; position: relative; }
.pgroup p::before {
  content: "";
  position: absolute;
  left: 4px; top: .78em;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--line-strong);
}
.pgroup.plain p { padding-left: 0; }
.pgroup.plain p::before { display: none; }

/* figures */
figure.shot {
  margin: 22px auto 0;
  max-width: 780px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: #fff;
  box-shadow: 0 1px 2px rgba(10, 17, 32, .03);
}
figure.shot img {
  width: 100%;
  border-radius: 7px;
  cursor: zoom-in;
  transition: opacity .2s var(--ease);
  background: #fff;
}
figure.shot img:hover { opacity: .94; }
figure.shot figcaption {
  font-size: 12.5px;
  color: var(--faint);
  text-align: center;
  padding: 9px 6px 2px;
}

/* callout */
.callout {
  display: flex;
  gap: 14px;
  margin-top: 22px;
  padding: 16px 18px;
  border-radius: var(--r-md);
  border: 1px solid #dbe8ff;
  background: #f5f9ff;
  font-size: 14.5px;
  line-height: 1.8;
  color: #2f405c;
}
.callout .ci { flex-shrink: 0; margin-top: 2px; color: var(--brand); }
.callout.warn { border-color: #fde3c4; background: #fffaf2; color: #6b4a1d; }
.callout.warn .ci { color: #c2410c; }
.callout.danger { border-color: #fbd5dd; background: #fff7f9; color: #7a2437; }
.callout.danger .ci { color: var(--rose); }
.callout.success { border-color: #cdeee1; background: #f5fdfa; color: #14554a; }
.callout.success .ci { color: var(--teal); }
.callout strong { color: inherit; font-weight: 700; }
.callout .ct-title { display: block; font-weight: 700; margin-bottom: 3px; color: inherit; }

/* item list / code */
.code-block {
  position: relative;
  margin-top: 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: #fff;
  overflow: hidden;
}
.code-block .cb-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 9px 12px 9px 14px;
  border-bottom: 1px solid var(--line-soft);
  background: var(--bg-soft);
}
.code-block .cb-head span { font-size: 11.5px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--faint); }
.code-block .cb-copy {
  display: inline-flex; align-items: center; gap: 6px;
  height: 26px; padding: 0 9px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff;
  color: var(--muted);
  font-size: 11.5px;
  cursor: pointer;
  transition: .2s var(--ease);
}
.code-block .cb-copy:hover { color: var(--brand-deep); border-color: var(--brand); }
.code-block .cb-body {
  padding: 14px;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 12.5px;
  line-height: 2;
  color: #334155;
  word-break: break-word;
  max-height: 280px;
  overflow: auto;
}

/* video player */
.player {
  position: relative;
  margin: 26px 0 6px;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: #0a1120;
  border: 1px solid var(--line);
  aspect-ratio: 16 / 9;
  box-shadow: var(--shadow-md);
}
.player video { width: 100%; height: 100%; display: block; background: #000; }
.player-cover {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  cursor: pointer;
  background:
    radial-gradient(60% 60% at 50% 42%, rgba(37, 99, 235, .32), transparent 70%),
    radial-gradient(50% 50% at 82% 84%, rgba(13, 148, 136, .3), transparent 72%),
    linear-gradient(150deg, #0b1424 0%, #101c31 50%, #0a1620 100%);
  overflow: hidden;
}
.player-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, .05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, .05) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: radial-gradient(60% 60% at 50% 50%, #000, transparent 78%);
  mask-image: radial-gradient(60% 60% at 50% 50%, #000, transparent 78%);
}
.player-cover .pv-badge {
  position: absolute;
  top: 16px; left: 16px;
  display: inline-flex; align-items: center; gap: 7px;
  height: 26px; padding: 0 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, .1);
  border: 1px solid rgba(255, 255, 255, .16);
  color: rgba(255, 255, 255, .82);
  font-size: 11.5px;
  letter-spacing: .04em;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.player-cover .play {
  position: relative;
  width: 68px; height: 68px;
  display: grid; place-items: center;
  border-radius: 50%;
  border: 0;
  background: #fff;
  color: var(--ink);
  font-size: 20px;
  padding-left: 4px;
  cursor: pointer;
  box-shadow: 0 18px 40px -14px rgba(0, 0, 0, .65);
  transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.player-cover .play::after {
  content: "";
  position: absolute;
  inset: -12px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, .22);
  transition: transform .35s var(--ease), opacity .3s var(--ease);
}
.player-cover:hover .play { transform: scale(1.05); box-shadow: 0 24px 50px -16px rgba(0, 0, 0, .75); }
.player-cover:hover .play::after { transform: scale(1.1); opacity: .6; }
.player-cover .pv-title { position: relative; color: #fff; font-size: 15px; font-weight: 600; letter-spacing: .01em; text-align: center; padding: 0 24px; }
.player-cover .pv-hint { position: relative; color: rgba(255, 255, 255, .48); font-size: 12px; letter-spacing: .02em; }

/* prev / next */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 46px; }
.pager a {
  display: block;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: #f8fafd;
  transition: .22s var(--ease);
}
.pager a:hover { background: #fff; border-color: #c8d7ee; box-shadow: var(--shadow-md); transform: translateY(-2px); }
.pager small { display: block; font-size: 11.5px; color: var(--faint); letter-spacing: .06em; margin-bottom: 5px; }
.pager strong { font-size: 14px; font-weight: 600; color: var(--ink); display: flex; align-items: center; gap: 8px; }
.pager .next { text-align: right; }
.pager .next strong { justify-content: flex-end; }
.pager a:hover strong { color: var(--brand-deep); }

/* article footer help */
.help-box {
  margin-top: 40px;
  padding: 24px 26px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fbfdff, #f6f9fe);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.help-box h4 { font-size: 15px; }
.help-box p { margin-top: 6px; font-size: 14px; color: var(--muted); }
.help-box .acts { display: flex; gap: 10px; flex-wrap: wrap; }

/* lightbox */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 5vh 4vw;
  background: rgba(6, 12, 24, .82);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  cursor: zoom-out;
}
.lightbox.open { display: flex; }
.lightbox img {
  max-width: 100%;
  max-height: 90vh;
  border-radius: 10px;
  box-shadow: 0 40px 90px -30px rgba(0, 0, 0, .8);
  background: #fff;
}

/* search modal */
.searchModal {
  position: fixed;
  inset: 0;
  z-index: 210;
  display: none;
  padding: 12vh 20px 20px;
  background: rgba(10, 17, 32, .42);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.searchModal.open { display: block; }
.sm-panel {
  width: 100%;
  max-width: 620px;
  margin: 0 auto;
  background: #fff;
  border-radius: var(--r-lg);
  box-shadow: 0 40px 100px -30px rgba(10, 17, 32, .6);
  overflow: hidden;
  animation: smIn .24s var(--ease);
}
@keyframes smIn { from { opacity: 0; transform: translateY(-8px) scale(.99); } to { opacity: 1; transform: none; } }
.sm-field { display: flex; align-items: center; gap: 12px; padding: 16px 18px; border-bottom: 1px solid var(--line-soft); }
.sm-field i { color: var(--faint); }
.sm-field input { flex: 1; border: 0; outline: 0; font-family: inherit; font-size: 16px; color: var(--ink); background: transparent; }
.sm-field .esc { font-size: 11px; color: var(--faint); border: 1px solid var(--line); border-radius: 5px; padding: 2px 6px; }
.sm-results { max-height: 56vh; overflow-y: auto; padding: 8px; }
.sm-group { font-size: 10.5px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--faint); padding: 10px 10px 6px; }
.sm-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 9px;
  color: var(--ink-2);
}
.sm-item:hover, .sm-item.sel { background: #f3f7ff; }
.sm-item i { width: 16px; text-align: center; font-size: 12px; color: var(--faint); }
.sm-item.sel i { color: var(--brand); }
.sm-item strong { font-size: 15px; font-weight: 500; color: var(--ink); }
.sm-item .cat { margin-left: auto; font-size: 11.5px; color: var(--faint); }
.sm-empty { padding: 34px 16px; text-align: center; color: var(--faint); font-size: 13.5px; }
.sm-foot { display: flex; gap: 16px; padding: 10px 16px; border-top: 1px solid var(--line-soft); background: var(--bg-soft); font-size: 11.5px; color: var(--faint); }
.sm-foot kbd { font-family: inherit; border: 1px solid var(--line); background: #fff; border-radius: 4px; padding: 0 4px; }

/* =========================================================
   Support page
   ========================================================= */
.support-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 28px; }
.support-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: #fff;
  transition: .25s var(--ease);
}
.support-card:hover { border-color: var(--line-strong); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.support-card .si {
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border-radius: 11px;
  font-size: 16px;
  margin-bottom: 16px;
}
.support-card h3 { font-size: 15.5px; }
.support-card p { margin-top: 8px; font-size: 14.5px; color: var(--muted); line-height: 1.7; }
.support-card .btn { margin-top: 18px; }

.qq-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 24px; }
.qq-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: #fff;
  transition: .22s var(--ease);
}
.qq-card:hover { border-color: #c8d7ee; box-shadow: var(--shadow-md); transform: translateY(-2px); }
.qq-card .qi {
  width: 38px; height: 38px;
  display: grid; place-items: center;
  border-radius: 11px;
  background: #eef9ff;
  color: #0284c7;
  font-size: 17px;
}
.qq-card strong { display: block; font-size: 15px; color: var(--ink); }
.qq-card small { font-size: 12px; color: var(--faint); }
.qq-card .arrow { margin-left: auto; color: var(--line-strong); font-size: 11px; }
.qq-card:hover .arrow { color: var(--sky); }

.verify-panel {
  margin-top: 28px;
  padding: 26px 28px;
  border-radius: var(--r-lg);
  background: #fffaf2;
  border: 1px solid #fde3c4;
}
.verify-panel h3 { font-size: 16px; color: #7a4a12; display: flex; align-items: center; gap: 10px; }
.verify-panel h3 i { color: #c2410c; }
.verify-panel ol { margin: 16px 0 0; padding-left: 20px; color: #7a4a12; font-size: 14px; line-height: 2; }
.verify-panel li::marker { color: #d97706; font-weight: 700; }
.verify-panel .fine { margin-top: 14px; font-size: 12.5px; color: #98724a; }

/* =========================================================
   Footer
   ========================================================= */
.site-footer {
  background: #080e19;
  color: rgba(255, 255, 255, .58);
  font-size: 14px;
  margin-top: 0;
}
.footer-main {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
  padding: 56px 0 44px;
}
.footer-lock { display: flex; align-items: center; gap: 11px; }
.fl-mark {
  width: 34px; height: 34px;
  display: grid; place-items: center;
  border-radius: 9px;
  background: linear-gradient(140deg, #3b82f6, #06b6d4 55%, #10b981);
  color: #fff;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0;
  box-shadow: 0 8px 20px -10px rgba(6, 182, 212, .8);
}
.fl-text { display: flex; flex-direction: column; line-height: 1.25; }
.fl-text strong { color: #fff; font-size: 15px; font-weight: 700; letter-spacing: .01em; }
.fl-text em { font-style: normal; font-size: 11px; color: rgba(255, 255, 255, .4); letter-spacing: .04em; }
.footer-brand p { margin-top: 14px; max-width: 280px; line-height: 1.8; color: rgba(255, 255, 255, .42); font-size: 13px; }
.footer-qr { display: flex; align-items: center; gap: 12px; margin-top: 20px; }
.footer-qr img {
  width: 64px; height: 64px;
  padding: 4px;
  border-radius: 9px;
  background: #fff;
  flex-shrink: 0;
}
.footer-qr span { font-size: 12px; color: rgba(255, 255, 255, .55); line-height: 1.5; }
.footer-qr em { display: block; font-style: normal; font-size: 11px; color: rgba(255, 255, 255, .3); }

.footer-col h4 {
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.footer-col a {
  display: block;
  padding: 5px 0;
  color: rgba(255, 255, 255, .55);
  font-size: 13.5px;
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .08);
  padding: 22px 0 28px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 12px;
  color: rgba(255, 255, 255, .48);
}
.footer-bottom .legal { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 16px; }
.footer-bottom a { color: rgba(255, 255, 255, .45); }
.footer-bottom a:hover { color: #fff; }
.footer-health {
  padding: 12px 0 0;
  font-size: 11.5px;
  color: rgba(255, 255, 255, .36);
  line-height: 1.7;
}

/* =========================================================
   Motion
   ========================================================= */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 1480px) {
  .docs { grid-template-columns: 272px minmax(0, 1fr); }
  .toc, .buy-rail { display: none; }
}

@media (max-width: 1080px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-main { grid-template-columns: 1.4fr 1fr 1fr; row-gap: 32px; }
  .catalog { grid-template-columns: 200px minmax(0, 1fr); gap: 32px; }
  .docs { grid-template-columns: 252px minmax(0, 1fr); gap: 30px; }
  .catalog { grid-template-columns: 200px minmax(0, 1fr); }
}

@media (max-width: 900px) {
  .main-nav { display: none; }
  .search-trigger span { display: none; }
  .search-trigger kbd { display: none; }
  .search-trigger { width: 36px; padding: 0; justify-content: center; }
  .menu-toggle { display: inline-flex; }
  .header-actions .btn-download { display: none; }
  .header-inner { gap: 12px; }
  .brand { margin-right: auto; }

  .hero { padding: 62px 0 54px; }
  .hero::before { height: 560px; }
  .stats { grid-template-columns: repeat(2, 1fr); margin-top: 40px; }

  .entry-grid { grid-template-columns: 1fr; }
  .howto { grid-template-columns: 1fr; }
  .support-grid, .qq-grid { grid-template-columns: 1fr; }

  .cards-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .catalog { grid-template-columns: 1fr; padding: 26px 0 60px; gap: 24px; }
  .ph-row { flex-direction: column; align-items: stretch; gap: 22px; }
  .ph-side { width: 100%; }
  .filter-hint { text-align: left; }
  .cat-rail { position: static; max-height: none; overflow: visible; padding-right: 0; }
  .rail-help { display: none; }
  .cat-nav {
    position: static;
    display: flex;
    align-items: center;
    gap: 8px;
    overflow-x: auto;
    padding: 0 0 4px;
    background: transparent;
    border: 0;
    border-radius: 0;
    box-shadow: none;
  }
  .cat-nav .label, .cat-nav-foot { display: none; }
  .cat-nav a {
    flex: 0 0 auto;
    white-space: nowrap;
    height: 36px;
    padding: 0 14px;
    border: 1px solid var(--line);
    border-left: 1px solid var(--line);
    background: #fff;
    border-radius: 999px;
    font-size: 14px;
    box-shadow: none;
  }
  .cat-nav a .count { display: none; }
  .cat-nav a.active { background: #eef4ff; border-color: #b9cdf0; box-shadow: none; }

  .docs { grid-template-columns: 1fr; padding: 14px 0 56px; gap: 16px; }
  .docs-body { padding: 22px 20px 30px; border-radius: 16px; }
  .docs-nav {
    position: static;
    max-height: none;
    padding: 14px 16px;
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    background: #fff;
    box-shadow: none;
  }
  .docs-nav .back, .nav-search { display: none; }
  .docs-nav .nav-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 4px 2px;
    border: 0;
    background: transparent;
    font-family: inherit;
    font-size: 14px;
    font-weight: 600;
    color: var(--ink);
    cursor: pointer;
  }
  .docs-nav .nav-toggle span { display: inline-flex; align-items: center; gap: 9px; }
  .docs-nav .nav-toggle span i { color: var(--brand); font-size: 12px; }
  .docs-nav .nav-toggle em { font-style: normal; font-size: 11.5px; font-weight: 500; color: var(--faint); }
  .docs-nav .nav-toggle > i { font-size: 11px; color: var(--muted); transition: transform .25s var(--ease); }
  .docs-nav.open .nav-toggle > i { transform: rotate(180deg); }
  .docs-nav .nav-groups { display: none; margin-top: 14px; border-top: 1px solid var(--line); padding-top: 14px; }
  .docs-nav.open .nav-groups { display: block; }
  .nav-group { margin-bottom: 10px; }
  .nav-list a { padding: 6px 8px; }

  .footer-main { grid-template-columns: 1fr 1fr; gap: 28px; padding: 42px 0 32px; }
  .footer-brand { grid-column: 1 / -1; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { text-align: left; }
  .pager .next strong { justify-content: flex-start; }
}

@media (max-width: 620px) {
  .wrap, .wrap-docs, .header-inner { padding: 0 18px; }
  .hero h1 { font-size: 31px; }
  .hero-sub { font-size: 15px; }
  .hero-search .field { height: 52px; padding-left: 14px; }
  .hero-search .field .key { display: none; }
  .hero-search .submit { padding: 0 14px; }
  .section { padding: 52px 0; }
  .cards, .cards-3 { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .support-band { padding: 26px 22px; }
  .article-head h1 { font-size: 25px; }
  .prose { font-size: 15.5px; }
  .player-cover .play { width: 56px; height: 56px; font-size: 17px; }
  .footer-main { grid-template-columns: 1fr; }
}