/* AI池子 V1.5 RC2 · 帮助中心（轻阅读风格，主站品牌） */
:root {
  --ink: #0f2a3f;
  --text-2: #51647a;
  --text-3: #71849a;
  --accent: #17a5cc;
  --accent-deep: #0d7fa6;
  --sea: #04263b;
  --surface: #f5f8fb;
  --line: #e3ebf2;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(13,42,63,.04), 0 6px 18px rgba(13,42,63,.05);
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--ink); background: var(--surface); line-height: 1.75; -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-deep); text-decoration: none; }
a:hover { text-decoration: underline; }

/* 顶部 */
.doc-top { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.92); border-bottom: 1px solid var(--line); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px); }
.doc-top-inner { max-width: 1180px; margin: 0 auto; padding: 0 18px; height: 60px; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.doc-brand { font-weight: 800; font-size: 18px; color: var(--ink); display: flex; align-items: baseline; gap: 8px; }
.doc-brand span { font-size: 12px; font-weight: 600; color: var(--accent-deep); background: #e7f4fb; border-radius: 999px; padding: 2px 10px; }
.doc-topnav { display: flex; gap: 18px; }
.doc-topnav a { color: #33465a; font-size: 14px; font-weight: 500; }
.doc-topnav a:hover { color: var(--accent-deep); text-decoration: none; }
.doc-topnav .nav-cta {
  display: inline-flex; align-items: center; justify-content: center;
  background: #04263b; color: #fff !important; border-radius: 999px;
  padding: 8px 16px; font-weight: 600;
}
.doc-topnav .nav-cta:hover { background: #0b3a57; color: #fff !important; text-decoration: none; }
.doc-menu-btn { display: none; background: none; border: 1px solid var(--line); border-radius: 10px; width: 40px; height: 40px; font-size: 18px; color: var(--ink); cursor: pointer; }

/* 首页 Hero */
.doc-hero { text-align: center; padding: 64px 18px 48px; }
.doc-eyebrow { font-family: ui-monospace, monospace; font-size: 12px; letter-spacing: .12em; color: var(--accent-deep); }
.doc-hero h1 { font-size: 38px; margin: 12px 0 10px; }
.doc-hero-sub { color: var(--text-2); font-size: 15px; max-width: 560px; margin: 0 auto 26px; }
.doc-search { position: relative; max-width: 560px; margin: 0 auto; }
.doc-search input { width: 100%; border: 1px solid var(--line); border-radius: 999px; padding: 14px 20px; font-size: 15px; background: #fff; box-shadow: var(--shadow); }
.doc-search input:focus { outline: 2px solid var(--accent); }
.doc-search-results { position: absolute; left: 0; right: 0; top: calc(100% + 6px); background: #fff; border: 1px solid var(--line); border-radius: 14px; box-shadow: 0 16px 40px rgba(13,42,63,.12); text-align: left; max-height: 320px; overflow: auto; display: none; z-index: 30; }
.doc-search-results.open { display: block; }
.doc-search-results a { display: block; padding: 10px 16px; border-bottom: 1px solid var(--line); }
.doc-search-results a:last-child { border-bottom: 0; }
.doc-search-results h4 { margin: 0; font-size: 14px; color: var(--ink); }
.doc-search-results p { margin: 2px 0 0; font-size: 12.5px; color: var(--text-3); }
.doc-chips { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-top: 22px; }
.doc-chip { border: 1px solid var(--line); background: #fff; border-radius: 999px; padding: 8px 16px; font-size: 13.5px; color: var(--text-2); cursor: pointer; }
.doc-chip.active { background: var(--sea); color: #fff; border-color: var(--sea); }
.doc-index-main { max-width: 1080px; margin: 0 auto; padding: 10px 18px 60px; }
.doc-group { margin-bottom: 40px; }
.doc-group h2 { font-size: 20px; margin: 0 0 16px; }
.doc-group.hidden { display: none; }
.doc-cards { display: grid; grid-template-columns: 1fr; gap: 12px; }
@media (min-width: 700px) { .doc-cards { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 980px) { .doc-cards { grid-template-columns: repeat(3, 1fr); } }
.doc-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); transition: transform 200ms ease, box-shadow 200ms ease, border-color 200ms ease; }
.doc-card:hover { transform: translateY(-2px); border-color: #c8e2ef; box-shadow: 0 12px 28px rgba(13,42,63,.1); text-decoration: none; }
.doc-card h3 { margin: 0 0 6px; font-size: 15.5px; color: var(--ink); }
.doc-card p { margin: 0 0 10px; font-size: 13px; color: var(--text-2); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.doc-card-upd { font-size: 12px; color: var(--text-3); font-family: ui-monospace, monospace; }

/* 文章页 */
.doc-layout { display: flex; max-width: 1180px; margin: 0 auto; padding: 28px 18px 60px; gap: 40px; }
.doc-side { flex: 0 0 240px; position: sticky; top: 84px; align-self: flex-start; max-height: calc(100vh - 100px); overflow: auto; }
.doc-side-head { font-size: 12px; letter-spacing: .1em; color: var(--text-3); text-transform: uppercase; margin-bottom: 10px; }
.doc-cat h4 { margin: 16px 0 6px; font-size: 12.5px; color: var(--text-3); }
.doc-cat ul { margin: 0; padding: 0; list-style: none; }
.doc-cat li a { display: block; padding: 6px 10px; border-radius: 8px; font-size: 13.5px; color: #33465a; }
.doc-cat li a:hover { background: #eaf5fb; text-decoration: none; }
.doc-cat li a.on { background: #e7f4fb; color: var(--accent-deep); font-weight: 600; }
.doc-main { flex: 1; min-width: 0; max-width: 760px; }
.doc-crumb { font-size: 13px; color: var(--text-3); margin: 0 0 8px; }
.doc-main h1 { font-size: 30px; line-height: 1.3; margin: 0 0 8px; }
.doc-meta { font-size: 13px; color: var(--text-3); margin: 0 0 24px; }
.doc-body { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 30px; box-shadow: var(--shadow); font-size: 15px; }
.doc-body h2 { font-size: 20px; margin: 28px 0 10px; }
.doc-body p { margin: 0 0 14px; color: #2c4157; }
.doc-body ul, .doc-body ol { margin: 0 0 16px; padding-left: 22px; color: #2c4157; }
.doc-body li { margin-bottom: 6px; }
.doc-body a { text-decoration: underline; }
.doc-body pre { background: #0b2133; color: #cfe5f2; border-radius: 10px; padding: 14px 16px; overflow-x: auto; font-size: 13px; line-height: 1.6; }
.doc-body code { background: #eef4f9; border-radius: 5px; padding: 1px 6px; font-size: 13px; }
.doc-body pre code { background: none; padding: 0; }
.doc-cta { background: linear-gradient(135deg, #04263b, #0b3a57); border-radius: var(--radius); padding: 24px; margin-top: 24px; text-align: center; color: #fff; }
.doc-cta p { margin: 0 0 14px; color: #b8c9d8; font-size: 14px; }
.doc-cta a { color: #9fd8ef; }
.doc-btn { display: inline-block; border-radius: 999px; padding: 10px 20px; font-size: 14px; font-weight: 600; margin: 4px; }
.doc-btn.primary { background: #17a5cc; color: #04263b; }
.doc-btn { background: transparent; color: #fff !important; border: 1px solid rgba(255,255,255,.35); }
.doc-btn:hover { text-decoration: none; }
.doc-nav { display: flex; justify-content: space-between; gap: 12px; margin-top: 22px; }
.doc-nav-link { font-size: 13.5px; color: var(--text-2); }
.doc-nav-link:hover { color: var(--accent-deep); }
.doc-foot { text-align: center; font-size: 12.5px; color: var(--text-3); margin-top: 34px; }

/* 移动端 */
@media (max-width: 860px) {
  .doc-topnav { display: none; }
  .doc-menu-btn { display: inline-flex; align-items: center; justify-content: center; }
  .doc-layout { flex-direction: column; padding-top: 12px; }
  .doc-side { position: fixed; top: 60px; bottom: 0; left: 0; width: 260px; background: #fff; border-right: 1px solid var(--line); padding: 20px; transform: translateX(-100%); transition: transform 240ms ease; z-index: 60; }
  .doc-side.open { transform: none; box-shadow: 0 20px 60px rgba(13,42,63,.2); }
  .doc-main { max-width: none; }
  .doc-hero h1 { font-size: 28px; }
  .doc-body { padding: 20px 18px; }
}
@media (prefers-reduced-motion: reduce) {
  .doc-card, .doc-side { transition: none; }
}