.doc { width: min(760px, calc(100% - 48px)); margin: 0 auto; padding: 84px 0 40px; }
.doc h1 { margin: 0; color: var(--ink); font-size: 38px; font-weight: 700; line-height: 1.28; letter-spacing: -.5px; }
.doc h2 { margin: 54px 0 14px; padding-top: 30px; border-top: 1px solid var(--line); color: var(--ink); font-size: 23px; font-weight: 700; line-height: 1.35; }
.doc h3 { margin: 30px 0 8px; color: var(--ink); font-size: 16px; font-weight: 700; }
.doc p { margin: 14px 0 0; color: var(--ink-2); font-size: 15px; line-height: 1.85; }
.doc ul, .doc ol { margin: 14px 0 0; padding-left: 20px; color: var(--ink-2); font-size: 15px; line-height: 1.85; }
.doc li { margin: 7px 0; }
.doc li > strong { color: var(--ink); }
.doc a:not(.button) { color: var(--brand); font-weight: 650; text-decoration: none; transition: color 160ms ease; }
.doc a:not(.button):hover { color: var(--brand-dark); }
.doc code { border: 1px solid var(--line); border-radius: 4px; padding: 1px 5px; background: var(--canvas); color: var(--ink); font: 12.5px ui-monospace, SFMono-Regular, Menlo, monospace; }
.doc pre { overflow-x: auto; margin: 16px 0 0; border: 1px solid var(--line); border-radius: 6px; padding: 14px 16px; background: var(--canvas); }
.doc pre code { border: 0; padding: 0; background: none; line-height: 1.7; }

/*
 * 报头。必须排在上面的正文链接规则之后：面包屑链接和正文链接的选择器
 * 特异性一样，后面的规则才能保留面包屑更弱的层级。
 */
.doc-head .doc-crumb {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 20px;
  color: var(--ink-3);
  font-size: 12.5px;
  line-height: 1.5;
}
.doc-head .doc-crumb a { color: var(--ink-3); font-weight: 500; text-decoration: none; }
.doc-head .doc-crumb a:hover { color: var(--brand); }
.doc-head .doc-crumb span { color: var(--line-strong); }

/* 导语是报头里的独立编辑区，不靠「正文放大」冒充层级。 */
.doc-head .doc-lead {
  position: relative;
  margin: 24px 0 0;
  border-block: 1px solid var(--line);
  padding: 18px 0 18px 86px;
  color: var(--ink-2);
  font-size: 16.5px;
  font-weight: 500;
  line-height: 1.78;
  text-wrap: pretty;
}
.doc-head .doc-lead::before {
  position: absolute;
  top: 20px;
  left: 0;
  color: var(--brand);
  content: "导读";
  font-size: 11px;
  font-weight: 750;
  line-height: 1.4;
  letter-spacing: .12em;
}
.doc-head .doc-lead::after {
  position: absolute;
  top: 18px;
  bottom: 18px;
  left: 62px;
  width: 1px;
  background: var(--line-strong);
  content: "";
}

/* 更新时间做成一枚小胶囊，比原来那条通栏横线干净，也不会和 h2 的横线撞在一起 */
.doc-head .doc-meta {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 24px 0 0;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 5px 14px;
  background: var(--canvas);
  color: var(--ink-3);
  font-size: 12px;
  line-height: 1.7;
}
.doc-head .doc-meta span + span { display: inline-flex; align-items: center; gap: 10px; }
.doc-head .doc-meta span + span::before {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--line-strong);
  content: "";
}

.doc-scroll { overflow-x: auto; margin: 18px 0 0; }
.doc table { width: 100%; min-width: 460px; border-collapse: collapse; font-size: 14px; }
.doc th, .doc td { border-bottom: 1px solid var(--line); padding: 11px 12px; text-align: left; vertical-align: top; line-height: 1.7; }
.doc th:first-child, .doc td:first-child { white-space: nowrap; }
.doc th { border-bottom-color: var(--line-strong); background: var(--canvas); color: var(--ink); font-weight: 700; }
.doc td { color: var(--ink-2); }
.doc td strong { color: var(--ink); }

.doc-note { margin: 20px 0 0; border: 1px solid var(--line); border-left: 2px solid var(--brand); border-radius: 0 6px 6px 0; padding: 15px 18px; background: var(--brand-soft); color: var(--ink-2); font-size: 14px; line-height: 1.8; }
.doc-note.is-warn { border-left-color: var(--amber); background: var(--amber-soft); }
.doc-note > strong:first-child { display: block; margin-bottom: 4px; color: var(--ink); }
.doc-note strong { color: var(--ink); }
.doc-note :first-child { margin-top: 0; }

.doc-cta { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 20px; margin: 56px 0 0; border: 1px solid var(--line); border-radius: 8px; padding: 26px 28px; background: #fff; box-shadow: 0 18px 50px -40px rgb(15 23 42 / 30%); }
.doc-cta div { max-width: 420px; }
.doc-cta strong { display: block; color: var(--ink); font-size: 17px; }
.doc-cta p { margin: 7px 0 0; font-size: 13.5px; }

.doc-related { margin: 44px 0 0; border-top: 1px solid var(--line); padding-top: 26px; }
.doc-related h2 { margin: 0 0 4px; padding: 0; border: 0; font-size: 13px; }
.doc-related ul { margin: 10px 0 0; padding: 0; list-style: none; }
.doc-related li { margin: 0; border-top: 1px solid var(--line); }
.doc-related li:first-child { border-top: 0; }
.doc .doc-related a { display: flex; align-items: baseline; gap: 10px; padding: 13px 0; color: var(--ink); font-size: 14.5px; font-weight: 650; text-decoration: none; }
.doc .doc-related a:hover { color: var(--brand); }
.doc-related small { color: var(--ink-3); font-size: 12px; font-weight: 400; }

/* 目录页先分“阅读路径”，再分路径里的资料组，不和普通文章共用扁平的 h2 层级。 */
.doc-hub { counter-reset: guide-group; }
.doc-hub > h2 { font-size: 25px; }
.doc-hub > h3 {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 34px 0 0;
  color: var(--brand-dark);
  counter-increment: guide-group;
  font-size: 16px;
  line-height: 1.45;
}
.doc-hub > h3::before {
  display: grid;
  width: 30px;
  height: 24px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 5px;
  background: var(--brand-soft);
  color: var(--brand);
  content: "0" counter(guide-group);
  font: 750 10px ui-monospace, SFMono-Regular, Menlo, monospace;
}
.doc-hub > h3 + p { margin-top: 12px; }
.doc-hub > .doc-related {
  margin: 16px 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 18px;
  background: #fff;
}
.doc-hub .doc-related a {
  margin: 0 -18px;
  padding: 15px 18px;
  transition: color 160ms ease, background-color 160ms ease;
}
.doc-hub .doc-related a:hover { background: var(--canvas); }

@media (max-width: 740px) {
  /* 窄屏下标题和说明并排会把标题挤成一栏，改成上下堆叠 */
  .doc .doc-related a { flex-direction: column; gap: 3px; }
  .doc { padding: 60px 0 32px; }
  .doc h1 { font-size: 29px; }
  .doc h2 { margin-top: 40px; padding-top: 24px; font-size: 20px; }
  .doc-head .doc-lead { margin-top: 20px; padding: 16px 0; font-size: 16px; }
  .doc-head .doc-lead::before { position: static; display: block; margin-bottom: 7px; }
  .doc-head .doc-lead::after { display: none; }

  /* 指南首页在移动端是一张阅读地图：导读、路径和资料组需要各自成层。 */
  .doc-hub {
    width: min(760px, calc(100% - 32px));
    padding-top: 68px;
  }
  .doc-hub .doc-head .doc-lead {
    margin-top: 18px;
    border-block: 1px solid var(--line);
    border-radius: 0;
    padding: 17px 0 17px 58px;
    background: transparent;
    font-size: 15px;
    line-height: 1.72;
  }
  .doc-hub .doc-head .doc-lead::before {
    position: absolute;
    top: 20px;
    left: 0;
    display: block;
    margin: 0;
    font-size: 10.5px;
    letter-spacing: .1em;
  }
  .doc-hub .doc-head .doc-lead::after {
    display: block;
    top: 17px;
    bottom: 17px;
    left: 42px;
  }
  .doc-hub .doc-head .doc-meta {
    display: inline-flex;
    width: auto;
    justify-content: flex-start;
    gap: 9px;
    box-sizing: border-box;
    margin-top: 18px;
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 4px 12px;
    background: var(--canvas);
  }
  .doc-hub > h2 {
    margin-top: 36px;
    border: 0;
    padding-top: 0;
    font-size: 21px;
  }
  .doc-hub > h3 {
    align-items: flex-start;
    gap: 11px;
    margin-top: 26px;
    color: var(--ink);
    font-size: 17px;
  }
  .doc-hub > .doc-related + h3 {
    margin-top: 34px;
    border-top: 1px solid var(--line);
    padding-top: 28px;
  }
  .doc-hub > h3 + p {
    margin-top: 10px;
    font-size: 14px;
    line-height: 1.72;
  }
  .doc-hub > .doc-related {
    margin-top: 14px;
    border-radius: 10px;
    padding: 0;
  }
  .doc-hub .doc-related a {
    min-height: 64px;
    align-items: flex-start;
    justify-content: center;
    gap: 4px;
    box-sizing: border-box;
    margin: 0;
    padding: 14px 15px;
    line-height: 1.45;
    overflow-wrap: anywhere;
    text-wrap: pretty;
  }
  .doc-hub .doc-related small {
    font-size: 12.5px;
    line-height: 1.55;
  }
  .doc-hub > .doc-cta {
    align-items: stretch;
    gap: 18px;
    margin-top: 40px;
    padding: 22px 18px;
  }
  .doc-hub > .doc-cta div { max-width: none; }
  .doc-hub > .doc-cta .button { width: 100%; justify-content: center; }
}

@media (max-width: 360px) {
  .doc-hub { width: min(760px, calc(100% - 28px)); }
  .doc-hub .doc-head .doc-lead { padding-left: 54px; }
  .doc-hub .doc-head .doc-lead::after { left: 39px; }
  .doc-hub .doc-head .doc-meta { font-size: 11.5px; }
}