/* ==========================================================================
   ThrottleStop 中文站 · 设计系统
  品牌色取自官方 logo：crimson #AF1E2D
  风格：扁平 / 现代 / 专业，无渐变堆叠、无 emoji
   ========================================================================== */

/* ---------- 1. 变量与基础 ---------- */
:root {
  --brand: #af1e2d;
  --brand-600: #981928;
  --brand-700: #7e1420;
  --brand-050: #fdf1f2;
  --brand-100: #f8dfe2;

  --ink: #14161a;
  --ink-2: #24282f;
  --body: #454b55;
  --muted: #6d7480;
  --faint: #9aa0aa;

  --line: #e3e5e9;
  --line-strong: #cfd3d9;
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --bg-deep: #131519;

  --radius: 10px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(20, 22, 26, .05);
  --shadow-md: 0 10px 30px -12px rgba(20, 22, 26, .18);

  --wrap: 1200px;
  --gut: 28px;
  --sans: "Inter", "Segoe UI", -apple-system, BlinkMacSystemFont, "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Cascadia Mono", Consolas, "Liberation Mono", monospace;
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--body);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  margin: 0;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -.015em;
}

h1 { font-size: clamp(32px, 4.2vw, 52px); line-height: 1.14; letter-spacing: -.025em; }
h2 { font-size: clamp(25px, 2.6vw, 34px); }
h3 { font-size: 19px; }
h4 { font-size: 16px; letter-spacing: 0; }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--brand); text-decoration: none; transition: color .16s ease; }
a:hover { color: var(--brand-700); }

ul, ol { margin: 0; padding-left: 1.15em; }
li { margin: .3em 0; }

img, svg { max-width: 100%; }
img { height: auto; }

strong { color: var(--ink); font-weight: 600; }
code, .mono { font-family: var(--mono); font-size: .92em; letter-spacing: -.01em; }

::selection { background: var(--brand-100); color: var(--ink); }

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

.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 200;
  padding: 10px 16px; background: var(--ink); color: #fff;
  border-radius: 0 0 8px 8px; font-size: 14px;
}
.skip-link:focus { top: 0; color: #fff; }

/* ---------- 2. 布局 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--gut);
}

.section { padding: 84px 0; border-top: 1px solid var(--line); }
.section--soft { background: var(--bg-soft); }
.section--tight { padding: 62px 0; }

.section-head { max-width: 760px; margin-bottom: 44px; }
.section-head--center { margin-left: auto; margin-right: auto; text-align: center; }

.section-title { margin: 14px 0 14px; }
.section-desc { color: var(--muted); font-size: 16.5px; line-height: 1.8; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 12.5px; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase; color: var(--brand);
}
.eyebrow::before {
  content: ""; width: 22px; height: 2px; background: var(--brand); display: block;
}
.section-head--center .eyebrow::after {
  content: ""; width: 22px; height: 2px; background: var(--brand); display: block;
}

.lede { font-size: 17.5px; line-height: 1.85; color: var(--body); }

.grid { display: grid; gap: 20px; }
.g-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.g-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.g-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* ---------- 3. 头部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, .94);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; align-items: center; gap: 26px;
  height: 70px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--ink); flex-shrink: 0;
}
.brand:hover { color: var(--ink); }
.brand-mark { width: 30px; height: 30px; display: block; }
.brand-name {
  font-size: 18.5px; font-weight: 700; letter-spacing: -.02em; line-height: 1;
}
.brand-sub {
  display: block; font-family: var(--mono); font-size: 9.5px; font-weight: 500;
  letter-spacing: .16em; color: var(--faint); margin-top: 3px; text-transform: uppercase;
}

.nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav a {
  position: relative; padding: 8px 13px; border-radius: 6px;
  color: var(--ink-2); font-size: 14.5px; font-weight: 500;
}
.nav a:hover { color: var(--brand); background: var(--brand-050); }
.nav a[aria-current="page"] { color: var(--brand); font-weight: 600; }
.nav a[aria-current="page"]::after {
  content: ""; position: absolute; left: 13px; right: 13px; bottom: 1px;
  height: 2px; background: var(--brand);
}

.header-actions { display: flex; align-items: center; gap: 10px; margin-left: 10px; }
.header-ver {
  font-family: var(--mono); font-size: 11.5px; color: var(--muted);
  border: 1px solid var(--line); border-radius: 5px; padding: 3px 7px;
  letter-spacing: .02em; white-space: nowrap;
}

.nav-toggle {
  display: none; margin-left: auto; width: 40px; height: 40px;
  align-items: center; justify-content: center;
  background: #fff; border: 1px solid var(--line); border-radius: 7px; cursor: pointer;
}
.nav-toggle svg { width: 18px; height: 18px; }

/* ---------- 4. 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 44px; padding: 0 20px; border: 1px solid transparent; border-radius: 7px;
  font-family: inherit; font-size: 15px; font-weight: 600; line-height: 1;
  cursor: pointer; white-space: nowrap;
  transition: background-color .16s ease, border-color .16s ease, color .16s ease;
}
.btn svg { width: 16px; height: 16px; flex-shrink: 0; }

.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-600); color: #fff; }
.btn-primary:active { background: var(--brand-700); }

.btn-ghost { background: #fff; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--ink); color: var(--ink); background: #fff; }

.btn-dark { background: var(--ink); color: #fff; }
.btn-dark:hover { background: #000; color: #fff; }

.btn-sm { height: 38px; padding: 0 15px; font-size: 14px; border-radius: 6px; }
.btn-block { width: 100%; }
.btn-lg { height: 50px; padding: 0 26px; font-size: 16px; }

.btn-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

.inline-link {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 14.5px; font-weight: 600;
}
.inline-link svg { width: 14px; height: 14px; transition: transform .16s ease; }
.inline-link:hover svg { transform: translateX(2px); }

/* ---------- 5. 首页 Hero ---------- */
.hero { padding: 74px 0 0; position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: 0 0 auto auto;
  width: 46%; height: 100%;
  background:
    linear-gradient(90deg, transparent, rgba(175, 30, 45, .035)),
    repeating-linear-gradient(90deg, transparent 0 39px, rgba(20, 22, 26, .028) 39px 40px);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  display: grid; grid-template-columns: 1.06fr .94fr;
  gap: 56px; align-items: center; padding-bottom: 68px;
}

.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 5px 11px 5px 6px; border: 1px solid var(--brand-100);
  background: var(--brand-050); border-radius: 100px;
  font-size: 12.5px; color: var(--brand-700); font-weight: 600; letter-spacing: .01em;
}
.hero-badge b {
  font-family: var(--mono); font-size: 11px; font-weight: 700;
  background: var(--brand); color: #fff; padding: 2px 7px; border-radius: 100px;
  letter-spacing: .04em;
}
.hero h1 { margin: 20px 0 18px; }
.hero h1 em {
  font-style: normal; color: var(--brand);
  box-shadow: inset 0 -.12em 0 var(--brand-100);
}
.hero-lead { font-size: 17px; line-height: 1.82; color: var(--body); max-width: 34em; }
.hero-lead strong { font-weight: 600; }
.hero .btn-row { margin-top: 30px; }
.hero-note {
  margin-top: 16px; font-size: 13px; color: var(--muted);
  display: flex; align-items: center; gap: 7px;
}
.hero-note svg { width: 14px; height: 14px; color: var(--brand); flex-shrink: 0; }

/* 规格条 */
.spec-strip {
  position: relative;
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid var(--line); background: #fff;
}
.spec {
  padding: 22px 24px; border-right: 1px solid var(--line);
}
.spec:last-child { border-right: 0; }
.spec dt {
  font-family: var(--mono); font-size: 11px; letter-spacing: .12em;
  text-transform: uppercase; color: var(--faint); margin-bottom: 6px;
}
.spec dd {
  margin: 0; font-size: 17px; font-weight: 600; color: var(--ink);
  font-variant-numeric: tabular-nums; letter-spacing: -.01em;
}
.spec dd span { font-size: 12.5px; font-weight: 500; color: var(--muted); margin-left: 5px; }

/* 界面截图外壳（.shot 主体样式见第 21 节） */
.panel-dots { display: flex; gap: 5px; }
.panel-dots i { width: 8px; height: 8px; border-radius: 50%; background: #d6d9df; display: block; }
.panel-tag {
  margin-left: auto; font-family: var(--mono); font-size: 10px; letter-spacing: .08em;
  text-transform: uppercase; color: var(--brand); border: 1px solid var(--brand-100);
  background: var(--brand-050); padding: 2px 6px; border-radius: 4px;
}
.panel-caption {
  margin-top: 12px; font-size: 12px; color: var(--faint); text-align: right;
}

/* ---------- 6. 卡片 ---------- */
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 24px; transition: border-color .18s ease, box-shadow .18s ease;
}
.card:hover { border-color: var(--line-strong); box-shadow: var(--shadow-sm); }
.card h3 { margin-bottom: 9px; }
.card p { font-size: 14.8px; color: var(--muted); line-height: 1.78; }

.icon-box {
  width: 40px; height: 40px; border-radius: 9px;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
  background: var(--brand-050); color: var(--brand); margin-bottom: 16px;
  border: 1px solid var(--brand-100);
}
.icon-box svg { width: 20px; height: 20px; }

.card-num {
  font-family: var(--mono); font-size: 12px; font-weight: 700; color: var(--brand);
  letter-spacing: .08em; margin-bottom: 14px; display: block;
}

.card--plain { background: var(--bg-soft); border-color: transparent; }
.card--plain:hover { background: #fff; border-color: var(--line); }

/* 场景卡 */
.scene {
  display: flex; flex-direction: column; gap: 10px;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; position: relative;
}
.scene-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.scene-tag {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--faint);
}
.scene h3 { font-size: 17px; margin: 0; }
.scene p { font-size: 14.4px; color: var(--muted); line-height: 1.75; margin: 0; }
.scene-fix {
  border-top: 1px dashed var(--line); padding-top: 11px; margin-top: 2px;
  font-size: 13.2px; color: var(--ink-2); display: flex; gap: 7px;
}
.scene-fix b {
  font-family: var(--mono); font-size: 10px; letter-spacing: .08em; text-transform: uppercase;
  color: var(--brand); flex-shrink: 0; padding-top: 3px; font-weight: 700;
}

/* ---------- 7. 三种节流 / 编号列表 ---------- */
.throttle { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.throttle-item { padding: 30px 26px; border-right: 1px solid var(--line); background: #fff; }
.throttle-item:last-child { border-right: 0; }
.throttle-item h3 { font-size: 17px; margin: 14px 0 8px; }
.throttle-item .en { display: block; margin-top: -4px; font-family: var(--mono); font-size: 11px; letter-spacing: .08em; color: var(--faint); text-transform: uppercase; }
.throttle-item p { font-size: 14.4px; color: var(--muted); line-height: 1.78; }
.throttle-item .fix {
  margin-top: 14px; padding-top: 13px; border-top: 1px solid var(--line);
  font-size: 13.4px; color: var(--ink-2);
}

/* ---------- 8. 功能矩阵 ---------- */
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.feat {
  background: #fff; padding: 26px 24px 24px;
  display: flex; flex-direction: column; gap: 8px;
}
.feat h3 { font-size: 16.5px; display: flex; align-items: center; gap: 9px; }
.feat h3 svg { width: 17px; height: 17px; color: var(--brand); flex-shrink: 0; }
.feat p { font-size: 14.2px; color: var(--muted); line-height: 1.76; margin: 0; }
.feat-kbd {
  align-self: flex-start; margin-top: 4px;
  font-family: var(--mono); font-size: 10.5px; color: var(--muted);
  border: 1px solid var(--line); border-radius: 4px; padding: 2px 6px;
}

/* ---------- 9. 步骤 ---------- */
.steps { display: grid; gap: 0; border-top: 1px solid var(--line); }
.step {
  display: grid; grid-template-columns: 78px 1fr; gap: 24px;
  padding: 26px 0; border-bottom: 1px solid var(--line); align-items: start;
}
.step-n {
  font-family: var(--mono); font-size: 13px; font-weight: 700; color: var(--brand);
  letter-spacing: .06em; padding-top: 3px;
}
.step h3 { font-size: 17.5px; margin-bottom: 7px; }
.step p { font-size: 14.8px; color: var(--muted); line-height: 1.8; }
.step .meta {
  margin-top: 10px; font-family: var(--mono); font-size: 11.5px; color: var(--faint);
  letter-spacing: .02em;
}

/* 横向步骤 */
.flow { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; counter-reset: flow; }
.flow-item { position: relative; padding: 24px 22px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
.flow-item::before {
  counter-increment: flow; content: "0" counter(flow);
  font-family: var(--mono); font-size: 11px; font-weight: 700; color: var(--brand);
  letter-spacing: .1em; display: block; margin-bottom: 12px;
}
.flow-item h3 { font-size: 16.5px; margin-bottom: 7px; }
.flow-item p { font-size: 14.2px; color: var(--muted); margin: 0; line-height: 1.76; }

/* ---------- 10. 表格 ---------- */
.table-wrap {
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  background: #fff;
}
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
table.data {
  width: 100%; border-collapse: collapse; font-size: 14.4px; min-width: 620px;
}
table.data caption {
  caption-side: top; text-align: left; padding: 15px 18px;
  font-size: 13px; color: var(--muted); border-bottom: 1px solid var(--line);
  background: #fcfcfd;
}
table.data th, table.data td {
  text-align: left; padding: 13px 18px; border-bottom: 1px solid var(--line);
  vertical-align: top;
}
table.data thead th {
  background: var(--bg-soft); font-size: 12px; letter-spacing: .06em;
  text-transform: uppercase; color: var(--muted); font-weight: 600;
  font-family: var(--mono); white-space: nowrap;
}
table.data tbody tr:last-child td { border-bottom: 0; }
table.data tbody tr:hover { background: #fcfcfd; }
table.data td.num { font-family: var(--mono); font-variant-numeric: tabular-nums; white-space: nowrap; }
table.data td.name { color: var(--ink); font-weight: 600; }

.badge {
  display: inline-block; font-family: var(--mono); font-size: 10.5px; letter-spacing: .05em;
  padding: 2px 7px; border-radius: 4px; border: 1px solid var(--line);
  color: var(--muted); white-space: nowrap;
}
.badge--on { background: var(--brand-050); border-color: var(--brand-100); color: var(--brand-700); font-weight: 600; }

/* ---------- 11. 提示条 / 警示 ---------- */
.notice {
  display: flex; gap: 14px; padding: 18px 20px; border-radius: var(--radius);
  border: 1px solid var(--line); background: var(--bg-soft); font-size: 14.4px;
  color: var(--ink-2); line-height: 1.75;
}
.notice svg { width: 18px; height: 18px; flex-shrink: 0; margin-top: 2px; color: var(--brand); }
.notice b { color: var(--ink); }
.notice--warn { background: var(--brand-050); border-color: var(--brand-100); }
.notice--warn svg { color: var(--brand); }
.notice-title { display: block; font-weight: 700; color: var(--ink); margin-bottom: 3px; }

/* ---------- 12. 数据来源 / 定义列表 ---------- */
.meta-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  background: var(--line); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden;
}
.meta-cell { background: #fff; padding: 20px 18px; }
.meta-cell dt {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 7px;
}
.meta-cell dd { margin: 0; font-size: 15px; font-weight: 600; color: var(--ink); }
.meta-cell dd small { display: block; font-weight: 400; font-size: 12.5px; color: var(--muted); margin-top: 3px; }

.source-note { font-size: 13px; color: var(--faint); line-height: 1.8; }
.source-note a { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }

/* ---------- 13. 页面头部（内页） ---------- */
.page-hero {
  padding: 56px 0 48px; border-bottom: 1px solid var(--line);
  background:
    radial-gradient(900px 260px at 88% -40%, var(--brand-050), transparent 70%),
    #fff;
}
.page-hero h1 { margin: 16px 0 16px; max-width: 20em; }
.page-hero .lede { max-width: 46em; }

.breadcrumb {
  display: flex; flex-wrap: wrap; align-items: center; gap: 7px;
  font-size: 12.5px; color: var(--faint); margin-bottom: 18px;
  font-family: var(--mono); letter-spacing: .01em;
}
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--brand); }
.breadcrumb span[aria-hidden] { color: var(--line-strong); }

/* ---------- 14. 下载页 ---------- */
.dl-card {
  display: grid; grid-template-columns: 1fr 240px; gap: 0;
  border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden;
  background: #fff; box-shadow: var(--shadow-sm);
}
.dl-main { padding: 34px 34px 30px; }
.dl-aside {
  background: var(--bg-soft); border-left: 1px solid var(--line);
  padding: 30px 26px; display: flex; flex-direction: column; gap: 14px;
}
.dl-aside h3 { font-size: 14px; }
.dl-aside ul { list-style: none; padding: 0; margin: 0; }
.dl-aside li {
  position: relative;
  font-size: 13.2px; color: var(--muted); padding: 7px 0 7px 22px;
  border-bottom: 1px dashed var(--line); line-height: 1.65;
}
.dl-aside li:last-child { border-bottom: 0; }
.dl-aside li svg {
  position: absolute; left: 0; top: 11px;
  width: 14px; height: 14px; color: var(--brand);
}

.dl-headline { display: flex; flex-wrap: wrap; align-items: baseline; gap: 12px; margin-bottom: 8px; }
.dl-headline h2 { font-size: clamp(26px, 3vw, 34px); }
.dl-ver {
  font-family: var(--mono); font-size: 13px; font-weight: 700; color: #fff;
  background: var(--brand); padding: 3px 9px; border-radius: 5px; letter-spacing: .02em;
}
.dl-sub { color: var(--muted); font-size: 15px; margin-bottom: 22px; }
.dl-facts {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px;
  background: var(--line); border: 1px solid var(--line); border-radius: 8px;
  overflow: hidden; margin-bottom: 24px;
}
.dl-fact { background: #fff; padding: 12px 15px; }
.dl-fact dt {
  font-family: var(--mono); font-size: 10px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 3px;
}
.dl-fact dd { margin: 0; font-size: 14px; font-weight: 600; color: var(--ink); word-break: break-all; }

/* ---------- 15. 弹窗 ---------- */
.modal[hidden] { display: none; }
.modal {
  position: fixed; inset: 0; z-index: 300;
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
}
.modal-backdrop {
  position: absolute; inset: 0; background: rgba(16, 18, 22, .55);
  border: 0; padding: 0; cursor: pointer;
}
.modal-box {
  position: relative; width: min(560px, 100%);
  background: #fff; border-radius: 14px; border: 1px solid var(--line);
  box-shadow: 0 30px 80px -20px rgba(0, 0, 0, .45);
  padding: 28px 30px 26px; max-height: calc(100dvh - 40px); overflow-y: auto;
  animation: modal-in .18s ease-out;
}
@keyframes modal-in {
  from { opacity: 0; transform: translateY(10px) scale(.99); }
  to { opacity: 1; transform: none; }
}
.modal-head { display: flex; align-items: flex-start; gap: 12px; }
.modal-head h2 { font-size: 20px; margin: 0 0 5px; }
.modal-head p { font-size: 13.6px; color: var(--muted); margin: 0; line-height: 1.7; }
.modal-close {
  margin-left: auto; width: 32px; height: 32px; flex-shrink: 0;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--line); background: #fff; border-radius: 7px;
  cursor: pointer; color: var(--muted);
}
.modal-close:hover { border-color: var(--line-strong); color: var(--ink); }
.modal-close svg { width: 15px; height: 15px; }

.qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 22px 0 18px; }
.qr-item {
  border: 1px solid var(--line); border-radius: 10px; padding: 16px 14px 14px;
  text-align: center; background: #fff;
}
.qr-img {
  display: block; width: 100%; max-width: 176px; height: auto;
  margin: 0 auto 12px; border: 1px solid var(--line); border-radius: 8px;
  background: #fff;
}
.qr-label { font-size: 13.2px; font-weight: 600; color: var(--ink); line-height: 1.5; }
.qr-label small { display: block; font-weight: 400; font-size: 11.5px; color: var(--faint); margin-top: 2px; font-family: var(--mono); letter-spacing: .02em; }

.modal-foot {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 10px; border-top: 1px solid var(--line); padding-top: 16px;
  font-size: 12.4px; color: var(--muted);
}
.modal-foot a { font-weight: 600; }

/* ---------- 16. FAQ ---------- */
.faq { border-top: 1px solid var(--line); max-width: 880px; }
.faq details {
  border-bottom: 1px solid var(--line); background: #fff;
}
.faq summary {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 20px 4px; cursor: pointer; list-style: none;
  font-size: 16px; font-weight: 600; color: var(--ink); line-height: 1.6;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary:hover { color: var(--brand); }
.faq summary::after {
  content: "+"; margin-left: auto; font-family: var(--mono); font-size: 20px;
  font-weight: 400; color: var(--brand); line-height: 1.35;
  transition: transform .2s ease;
}
.faq details[open] summary::after { content: "−"; }
.faq .faq-n {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
  padding-top: 4px; flex-shrink: 0; width: 26px;
}
.faq-a { padding: 0 4px 22px 44px; max-width: 720px; font-size: 14.8px; color: var(--muted); line-height: 1.85; }
.faq-a p { margin-bottom: .7em; }
.faq-a strong { color: var(--ink-2); }

/* ---------- 17. CTA 区 ---------- */
.cta {
  border: 1px solid var(--line); border-radius: var(--radius-lg);
  background: #fff; padding: 44px 44px;
  display: flex; align-items: center; justify-content: space-between; gap: 32px;
  position: relative; overflow: hidden;
}
.cta::after {
  content: ""; position: absolute; right: -40px; top: -40px; width: 200px; height: 200px;
  border: 22px solid var(--brand-050); border-radius: 50%; opacity: .8; pointer-events: none;
  z-index: 0;
}
.cta-text { position: relative; z-index: 1; }
.cta h2 { font-size: clamp(23px, 2.4vw, 30px); margin-bottom: 10px; }
.cta p { color: var(--muted); font-size: 15px; margin: 0; max-width: 40em; }
.cta .btn-row { position: relative; z-index: 1; flex-shrink: 0; }

/* ---------- 18. 页脚 ---------- */
.site-footer { background: var(--bg-deep); color: #b9bec7; margin-top: 0; padding: 58px 0 0; }
.footer-top {
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.2fr; gap: 40px;
  padding-bottom: 44px;
}
.footer-brand .brand { color: #fff; }
.footer-brand .brand:hover { color: #fff; }
.footer-brand p { font-size: 13.6px; line-height: 1.85; color: #9298a2; margin: 16px 0 0; max-width: 26em; }
.footer-col h4 {
  color: #fff; font-size: 12.5px; letter-spacing: .1em; text-transform: uppercase;
  font-family: var(--mono); font-weight: 600; margin: 0 0 14px;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin: 0 0 9px; }
.footer-col a { color: #b9bec7; font-size: 14px; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .1);
  padding: 20px 0 26px; display: flex; flex-wrap: wrap; gap: 10px 22px;
  align-items: center; justify-content: space-between;
  font-size: 12.4px; color: #7d838d;
}
.footer-bottom p { margin: 0; }
.footer-bottom a { color: #9aa0aa; }
.footer-bottom a:hover { color: #fff; }

/* ---------- 19. 响应式 ---------- */
@media (max-width: 1080px) {
  .hero-inner { gap: 36px; }
  .footer-top { grid-template-columns: 1.4fr 1fr 1fr; }
  .footer-col:last-child { grid-column: 1 / -1; }
}

@media (max-width: 920px) {
  :root { --gut: 22px; }
  .nav, .header-ver { display: none; }
  .nav-toggle { display: inline-flex; margin-left: 4px; }
  .header-actions { margin-left: auto; }
  .header-actions .btn { height: 38px; padding: 0 15px; font-size: 14px; }

  .site-header.is-open .nav {
    display: flex; position: absolute; left: 0; right: 0; top: 70px;
    flex-direction: column; align-items: stretch; gap: 2px;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 10px var(--gut) 18px; margin: 0;
    box-shadow: 0 18px 30px -20px rgba(0, 0, 0, .25);
  }
  .site-header.is-open .nav a { padding: 11px 12px; font-size: 15px; border-radius: 7px; }
  .site-header.is-open .nav a[aria-current="page"] { background: var(--brand-050); }
  .site-header.is-open .nav a[aria-current="page"]::after { display: none; }

  .hero { padding-top: 46px; }
  .hero-inner { grid-template-columns: 1fr; gap: 38px; padding-bottom: 52px; }
  .hero::before { display: none; }
  .spec-strip { grid-template-columns: repeat(2, 1fr); }
  .spec { border-bottom: 1px solid var(--line); }
  .spec:nth-child(2n) { border-right: 0; }
  .spec:nth-last-child(-n+2) { border-bottom: 0; }

  .g-3, .g-4, .feat-grid, .flow, .throttle { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .throttle-item:nth-child(3) { border-right: 0; border-top: 1px solid var(--line); grid-column: 1 / -1; }
  .throttle-item:nth-child(2) { border-right: 0; }
  .throttle-item:first-child { border-right: 1px solid var(--line); }
  .meta-grid { grid-template-columns: repeat(2, 1fr); }
  .dl-card { grid-template-columns: 1fr; }
  .dl-aside { border-left: 0; border-top: 1px solid var(--line); }
  .cta { flex-direction: column; align-items: flex-start; padding: 34px 28px; }
  .cta::after { display: none; }
}

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .section { padding: 56px 0; }
  .g-2, .g-3, .g-4, .feat-grid, .flow, .throttle { grid-template-columns: 1fr; }
  .throttle-item { border-right: 0; border-bottom: 1px solid var(--line); }
  .throttle-item:last-child { border-bottom: 0; }
  .throttle-item:first-child { border-right: 0; }
  .meta-grid { grid-template-columns: 1fr 1fr; }
  .step { grid-template-columns: 44px 1fr; gap: 14px; padding: 22px 0; }
  .step-n { font-size: 12px; }
  .hero-note { font-size: 12.4px; }
  .dl-main { padding: 24px 22px; }
  .dl-facts { grid-template-columns: 1fr; }
  .qr-grid { grid-template-columns: 1fr; gap: 12px; }
  .modal-box { padding: 22px 20px 20px; }
  .qr-img { max-width: 168px; }
  .qr-label { font-size: 13px; }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 28px; }
  .faq summary { font-size: 15px; }
  .faq-a { padding-left: 0; }
  .cta { padding: 28px 22px; }
  .btn-lg { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

@media print {
  .site-header, .site-footer, .modal, .cta { display: none !important; }
  body { color: #000; }
}

/* ---------- 20. 文档页（使用指南） ---------- */
.doc-layout {
  display: grid; grid-template-columns: 216px minmax(0, 1fr);
  gap: 54px; align-items: start;
}
.doc-layout > * { min-width: 0; }
.toc { position: sticky; top: 94px; border-left: 2px solid var(--line); padding-left: 18px; }
.toc h2 {
  font-family: var(--mono); font-size: 11px; letter-spacing: .12em; text-transform: uppercase;
  color: var(--faint); font-weight: 600; margin: 0 0 10px;
}
.toc ol { list-style: none; margin: 0; padding: 0; }
.toc li { margin: 0; }
.toc a {
  display: block; padding: 6px 0; font-size: 13.6px; color: var(--muted);
  line-height: 1.5; border-left: 2px solid transparent; margin-left: -20px; padding-left: 18px;
}
.toc a:hover { color: var(--brand); border-left-color: var(--brand-100); }

.doc { min-width: 0; }
.doc section { margin-bottom: 52px; scroll-margin-top: 96px; }
.doc section:last-child { margin-bottom: 0; }
.doc h2 { font-size: 25px; margin: 10px 0 14px; }
.doc h3 { font-size: 17px; margin: 26px 0 8px; }
.doc p { font-size: 15.4px; line-height: 1.88; color: var(--body); margin-bottom: 12px; }
.doc p:last-child { margin-bottom: 0; }
.doc ul, .doc ol { font-size: 15px; color: var(--body); line-height: 1.85; margin-bottom: 14px; }
.doc li { margin: 6px 0; }
.doc .notice { margin: 18px 0; }
.doc code {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 4px;
  padding: 1px 5px; font-size: 12.8px; color: var(--ink-2);
}

.checklist { list-style: none; padding: 0; margin: 18px 0 0; display: grid; gap: 10px; }
.checklist li {
  position: relative; font-size: 14.8px; line-height: 1.7;
  color: var(--body); border: 1px solid var(--line); border-radius: 8px;
  padding: 12px 15px 12px 40px; background: #fff; margin: 0;
}
.checklist li::before {
  content: ""; position: absolute; left: 15px; top: 16px;
  width: 16px; height: 16px;
  background: var(--brand);
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m4 12 5 5L20 6'/%3E%3C/svg%3E") center/contain no-repeat;
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m4 12 5 5L20 6'/%3E%3C/svg%3E") center/contain no-repeat;
}

@media (max-width: 920px) {
  .doc-layout { grid-template-columns: 1fr; gap: 30px; }
  .toc {
    position: static; border-left: 0; border-top: 1px solid var(--line);
    padding: 16px 0 0; display: flex; flex-wrap: wrap; gap: 4px 18px;
  }
  .toc h2 { width: 100%; }
  .toc ol { display: flex; flex-wrap: wrap; gap: 2px 18px; }
  .toc a { margin-left: 0; padding: 4px 0; border-left: 0; }
}

/* 超小屏（≤360px）压缩头部，避免横向溢出 */
@media (max-width: 360px) {
  .header-inner { gap: 10px; }
  .brand-name { font-size: 16px; }
  .brand-sub { display: none; }
  .brand-mark { width: 26px; height: 26px; }
  .header-actions .btn { padding: 0 12px; font-size: 13px; }
  .nav-toggle { width: 36px; height: 36px; }
}

/* ---------- 21. 英雄区界面截图 ---------- */
.shot {
  margin: 0; background: #fff; border: 1px solid var(--line-strong);
  border-radius: 12px; overflow: hidden; box-shadow: var(--shadow-md);
}
.shot-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 11px 14px; background: var(--bg-soft); border-bottom: 1px solid var(--line);
}
.shot-title {
  font-family: var(--mono); font-size: 11.5px; color: var(--muted); letter-spacing: .02em;
}
.shot-img {
  display: block; width: 100%; height: auto; background: #1f1f20;
}

/* 桌面端让界面截图更大 */
@media (min-width: 1025px) {
  .hero-inner { grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr); }
}
/* 单列时限制截图放大倍数，避免糊 */
@media (max-width: 920px) {
  .shot { max-width: 543px; margin-left: auto; margin-right: auto; }
}