/* ============================================================
   6号平台移动站 · 共享样式 /assets/site.css
   深墨蓝基底 + 档案纸阅读区 + 信号橙 / 青瓷绿双点色
   ============================================================ */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; }
h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; padding: 0; }
ul, ol { list-style: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
img, svg, video { display: block; max-width: 100%; }
details summary { cursor: pointer; }
details summary::-webkit-details-marker { display: none; }
table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 令牌 ---------- */
:root {
  --ink-900: #061530;
  --ink-800: #0B1F3A;
  --ink-700: #14304F;
  --paper: #F3EDE3;
  --card: #FBF8F2;
  --signal: #FF6B2C;
  --signal-soft: #FFE3D5;
  --signal-text: #A83C10;
  --celadon: #2FA98C;
  --celadon-text: #1B6E58;
  --graphite: #4A5568;
  --rule: #C7CFD8;
  --rule-ink: rgba(199, 207, 216, 0.26);
  --on-ink: #F3EDE3;
  --on-ink-soft: rgba(243, 237, 227, 0.72);
  --font-head: "Archivo Narrow", "Roboto Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;
  --wrap: 1180px;
  --gutter: clamp(18px, 5vw, 28px);
  --r: 4px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  color: var(--graphite);
  background: var(--paper);
  font-weight: 400;
}
h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 700;
  color: var(--ink-800);
  line-height: 1.2;
  letter-spacing: 0.01em;
  font-stretch: semi-condensed;
}
h1 { font-size: clamp(32px, 7vw, 56px); }
h2 { font-size: clamp(24px, 4.6vw, 40px); }
h3 { font-size: clamp(19px, 3.2vw, 28px); }
h4 { font-size: 20px; }
strong, b { color: var(--ink-800); font-weight: 700; }
.mono, .databar__value, .copy, .sitenav__num { font-variant-numeric: tabular-nums; }
.mono { font-family: var(--font-mono); letter-spacing: 0.01em; }
.label-mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--graphite);
}
.muted { color: var(--graphite); opacity: 0.82; }
.lede { font-size: 17px; line-height: 1.85; color: var(--ink-800); max-width: 60ch; }
.text-link {
  color: var(--signal-text);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.text-link:hover { color: var(--signal); }
.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;
}
:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- 4. 布局外壳 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section { padding-block: clamp(28px, 6vw, 64px); }
.section--paper { background: var(--paper); }
.section--ink { background: var(--ink-800); color: var(--on-ink-soft); }
.section--ink h1, .section--ink h2, .section--ink h3, .section--ink h4 { color: #fff; }
.section--ink strong { color: #fff; }
.stack { display: flex; flex-direction: column; gap: 16px; }
.grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}
.grid > * { min-width: 0; }
.span-full { grid-column: 1 / -1; }
.span-focus { grid-column: 1 / -1; }
.span-half { grid-column: span 2; }

/* ---------- 5. 跳转链接与滚动进度 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -120px;
  z-index: 140;
  background: var(--signal);
  color: #26120A;
  font-weight: 700;
  font-size: 14px;
  padding: 10px 16px;
  border-radius: 2px;
  transition: top 0.18s var(--ease);
}
.skip-link:focus { top: 12px; }
.progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 3px;
  z-index: 130;
  pointer-events: none;
  background: rgba(6, 21, 48, 0.15);
}
.progress__bar {
  display: block;
  height: 100%;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: 0 50%;
}

/* ---------- 6. 头部：双层信息导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--ink-800);
  color: var(--on-ink);
  border-bottom: 1px solid var(--ink-900);
}
.site-header__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.brandbar {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 60px;
  padding-block: 10px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  flex: 0 1 auto;
}
.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 38px;
  height: 38px;
  border-radius: 2px;
  background: var(--signal);
  color: #26120A;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.brand__text { display: flex; flex-direction: column; line-height: 1.25; }
.brand__name {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.02em;
}
.brand__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--celadon);
}
.brandbar__note {
  display: none;
  flex: 1 1 auto;
  font-size: 13px;
  line-height: 1.6;
  color: var(--on-ink-soft);
  border-left: 1px solid var(--rule-ink);
  padding-left: 14px;
  margin-left: 6px;
  max-width: 46ch;
}
.brandbar__cta { margin-left: auto; flex: none; }
.nav-toggle {
  position: relative;
  z-index: 80;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-width: 44px;
  min-height: 44px;
  padding: 8px 12px;
  border: 1px solid var(--rule-ink);
  border-radius: 2px;
  color: var(--on-ink);
  background: transparent;
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}
.nav-toggle:hover { background: rgba(243, 237, 227, 0.08); border-color: var(--on-ink); }
.nav-toggle__bars { display: flex; flex-direction: column; gap: 4px; width: 18px; }
.nav-toggle__bars i {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}
.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
}
.site-header[data-open] .nav-toggle__bars i:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle__bars i:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.sitenav {
  position: relative;
  margin-inline: calc(var(--gutter) * -1);
  border-top: 1px solid var(--rule-ink);
}
.sitenav__list {
  display: flex;
  align-items: stretch;
  gap: 2px;
  padding-inline: var(--gutter);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}
.sitenav__list::-webkit-scrollbar { display: none; }
.sitenav__item { flex: none; }
.sitenav__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  min-height: 46px;
  padding: 12px 14px;
  font-size: 15px;
  font-weight: 500;
  color: var(--on-ink-soft);
  white-space: nowrap;
  border-bottom: 3px solid transparent;
  transition: color 0.2s var(--ease), background 0.2s var(--ease), border-color 0.2s var(--ease);
}
.sitenav__link:hover { color: #fff; background: rgba(243, 237, 227, 0.06); }
.sitenav__link[aria-current="page"] { color: #fff; border-bottom-color: var(--signal); }
.sitenav__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--celadon);
  opacity: 0.85;
}
.sitenav__link[aria-current="page"] .sitenav__num { color: var(--signal); opacity: 1; }
.sitenav__cta { display: none; padding: 20px var(--gutter) 8px; }
.sitenav::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 44px;
  pointer-events: none;
  background: linear-gradient(90deg, rgba(11, 31, 58, 0), var(--ink-800));
}
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 65;
  background: rgba(6, 21, 48, 0.64);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.28s var(--ease);
}
.site-header[data-open] .nav-scrim { opacity: 1; pointer-events: auto; }
body.nav-open { overflow: hidden; }

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 18px;
  border-radius: 2px;
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.btn--signal { background: var(--signal); border-color: var(--signal); color: #26120A; }
.btn--signal:hover { background: #FF8347; border-color: #FF8347; }
.btn--ink { background: var(--ink-800); border-color: var(--ink-800); color: var(--on-ink); }
.btn--ink:hover { background: var(--ink-700); border-color: var(--ink-700); }
.btn--ghost { background: transparent; border-color: var(--rule-ink); color: var(--on-ink); }
.btn--ghost:hover { background: rgba(243, 237, 227, 0.1); border-color: var(--on-ink); }
.btn--block { width: 100%; }

/* ---------- 8. 章节头 / 卡片 / 数据条 ---------- */
.sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 10px 24px;
  padding-bottom: 12px;
  margin-bottom: 22px;
  border-bottom: 2px solid var(--ink-800);
}
.sec-head__text { display: flex; flex-direction: column; gap: 6px; flex: 1 1 auto; }
.sec-head__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--signal-text);
}
.sec-head__title { margin: 0; }
.sec-head__note { flex: 0 1 auto; font-size: 14px; line-height: 1.75; max-width: 44ch; }
.sec-head--dark { border-bottom-color: var(--rule-ink); }
.sec-head--dark .sec-head__num { color: var(--signal); }
.sec-head--dark .sec-head__note { color: var(--on-ink-soft); }

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(16px, 2.6vw, 24px);
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--r);
}
.card > :last-child { margin-bottom: 0; }
.card--focus { border-width: 2px; border-color: var(--ink-800); }
.card--dark { background: var(--ink-800); border-color: var(--ink-700); color: var(--on-ink-soft); }
.card--dark .card__title, .card--dark h3, .card--dark h4 { color: #fff; }
.card__label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--graphite);
}
.card__label--signal { color: var(--signal-text); }
.card__label--celadon { color: var(--celadon-text); }
.card--dark .card__label--celadon { color: var(--celadon); }
.card__title { font-size: clamp(19px, 3vw, 26px); }
.card__body { font-size: 15px; line-height: 1.8; }
.card__foot {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}
.card--dark .card__foot { border-top-color: var(--rule-ink); }

.databar { display: flex; flex-direction: column; border-top: 1px solid var(--rule); }
.databar__row {
  display: grid;
  grid-template-columns: auto minmax(24px, 1fr) auto;
  align-items: center;
  gap: 10px;
  padding: 13px 0;
  border-bottom: 1px solid var(--rule);
}
.databar__label { font-size: 14px; line-height: 1.6; min-width: 0; }
.databar__lead {
  height: 1px;
  background-image: repeating-linear-gradient(90deg, var(--rule) 0 4px, transparent 4px 9px);
}
.databar__value {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 500;
  color: var(--ink-800);
  text-align: right;
  white-space: nowrap;
}
.databar__value--signal { color: var(--signal-text); }
.databar__unit { font-size: 12px; color: var(--graphite); margin-left: 4px; }
.databar--dark { border-top-color: var(--rule-ink); }
.databar--dark .databar__row { border-bottom-color: var(--rule-ink); }
.databar--dark .databar__label { color: var(--on-ink-soft); }
.databar--dark .databar__lead {
  background-image: repeating-linear-gradient(90deg, var(--rule-ink) 0 4px, transparent 4px 9px);
}
.databar--dark .databar__value { color: #fff; }
.databar--dark .databar__value--signal { color: var(--signal); }
.databar--dark .databar__unit { color: var(--on-ink-soft); }

/* ---------- 9. 框景与刻度尺 ---------- */
.frame {
  position: relative;
  padding: clamp(20px, 4.5vw, 40px);
  border: 1px solid var(--rule-ink);
  border-radius: 2px;
}
.frame::before {
  content: "";
  position: absolute;
  inset: -1px;
  pointer-events: none;
  background-image:
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon)),
    linear-gradient(var(--celadon), var(--celadon));
  background-repeat: no-repeat;
  background-position: left top, left top, right top, right top, left bottom, left bottom, right bottom, right bottom;
  background-size: 14px 2px, 2px 14px, 14px 2px, 2px 14px, 14px 2px, 2px 14px, 14px 2px, 2px 14px;
}
.frame--dark { background: var(--ink-800); border-color: var(--ink-900); color: var(--on-ink-soft); }
.frame--dark h1, .frame--dark h2, .frame--dark h3 { color: #fff; }
.frame__scale {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 10px;
  pointer-events: none;
  transform-origin: 0 50%;
  background-image: repeating-linear-gradient(90deg, var(--rule-ink) 0 1px, transparent 1px 16px);
  background-size: 100% 6px;
  background-repeat: no-repeat;
}
.frame--dark .frame__scale {
  background-image: repeating-linear-gradient(90deg, rgba(243, 237, 227, 0.32) 0 1px, transparent 1px 16px);
}
.scale-rule {
  height: 12px;
  color: var(--rule);
  background-image:
    repeating-linear-gradient(90deg, currentColor 0 1px, transparent 1px 70px),
    repeating-linear-gradient(90deg, currentColor 0 1px, transparent 1px 14px);
  background-size: 100% 12px, 100% 6px;
  background-repeat: repeat-x, repeat-x;
  background-position: 0 0, 0 0;
}
.site-footer .scale-rule { color: var(--rule-ink); }

/* ---------- 10. 折叠问答 / 标签筛选 / 编号复制 / 阶梯档位 ---------- */
.acc {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  overflow: hidden;
}
.acc + .acc { margin-top: 10px; }
.acc__q {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 54px;
  padding: 14px 16px;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink-800);
  list-style: none;
  transition: background 0.2s var(--ease);
}
.acc__q::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: transparent;
  transition: background 0.2s var(--ease);
}
.acc[open] > .acc__q::before { background: var(--signal); }
.acc__q:hover { background: rgba(11, 31, 58, 0.045); }
.acc__t { flex: 1 1 auto; }
.acc__mark { position: relative; flex: none; width: 18px; height: 18px; }
.acc__mark::before, .acc__mark::after {
  content: "";
  position: absolute;
  background: var(--ink-800);
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}
.acc__mark::before { left: 0; right: 0; top: 8px; height: 2px; }
.acc__mark::after { top: 0; bottom: 0; left: 8px; width: 2px; }
.acc[open] .acc__mark::after { transform: scaleY(0); }
.acc__a {
  padding: 0 18px 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--graphite);
  animation: accIn 0.22s var(--ease) both;
}
@keyframes accIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }

.tagbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 38px;
  padding: 7px 14px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--card);
  color: var(--ink-800);
  font-size: 14px;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.tag:hover { border-color: var(--ink-800); }
.tag[aria-pressed="true"] { background: var(--ink-800); border-color: var(--ink-800); color: var(--on-ink); }
.tag__count { font-family: var(--font-mono); font-size: 12px; opacity: 0.72; }
.tagbar__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--graphite);
}

.copy {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 34px;
  padding: 5px 10px;
  border: 1px dashed var(--celadon-text);
  border-radius: 2px;
  background: rgba(47, 169, 140, 0.07);
  color: var(--celadon-text);
  font-family: var(--font-mono);
  font-size: 13px;
}
.copy:hover { background: rgba(47, 169, 140, 0.16); }
.copy[data-state]::after {
  content: attr(data-state);
  position: absolute;
  left: 0;
  top: calc(100% + 6px);
  z-index: 5;
  padding: 4px 9px;
  border-radius: 2px;
  background: var(--ink-800);
  color: var(--on-ink);
  font-family: var(--font-body);
  font-size: 12px;
  white-space: nowrap;
}
.copy--dark {
  border-color: var(--celadon);
  color: var(--celadon);
  background: rgba(47, 169, 140, 0.14);
}

.stair { display: flex; flex-direction: column; gap: 8px; }
.stair__step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  min-height: 56px;
  padding: 12px 16px;
  text-align: left;
  background: var(--card);
  border: 1px solid var(--rule);
  border-left: 4px solid var(--rule);
  border-radius: 2px;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}
.stair__step:hover { border-color: var(--ink-800); }
.stair__step[aria-expanded="true"], .stair__step.is-on {
  border-left-color: var(--signal);
  background: var(--signal-soft);
}
.stair__qty {
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--ink-800);
  white-space: nowrap;
}
.stair__desc { font-size: 14px; line-height: 1.7; color: var(--graphite); }
.stair__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--celadon-text);
  border: 1px solid currentColor;
  border-radius: 2px;
  padding: 2px 7px;
  white-space: nowrap;
}

/* ---------- 11. 提示块 / 图片容器 / 面包屑 ---------- */
.callout {
  padding: 14px 16px;
  border-left: 3px solid var(--celadon);
  border-radius: 0 var(--r) var(--r) 0;
  background: rgba(47, 169, 140, 0.08);
  color: var(--ink-800);
  font-size: 14px;
  line-height: 1.8;
}
.callout--signal { border-left-color: var(--signal); background: var(--signal-soft); color: #5B2410; }
.section--ink .callout { background: rgba(47, 169, 140, 0.16); color: var(--on-ink); }

.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--rule);
  border-radius: var(--r);
  background: var(--card);
}
.media-frame__img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}
.media-frame--wide .media-frame__img { aspect-ratio: 16 / 9; }
.media-frame--tall .media-frame__img { aspect-ratio: 3 / 4; }
.media-frame__ph {
  display: grid;
  place-items: center;
  aspect-ratio: 4 / 3;
  padding: 16px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--graphite);
  background-color: var(--card);
  background-image: repeating-linear-gradient(135deg, rgba(11, 31, 58, 0.07) 0 1px, transparent 1px 10px);
}
.media-frame--wide .media-frame__ph { aspect-ratio: 16 / 9; }
.media-frame--tall .media-frame__ph { aspect-ratio: 3 / 4; }
.media-frame__cap {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 14px;
  border-top: 1px solid var(--rule);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--graphite);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--graphite);
}
.breadcrumb a { color: var(--ink-800); }
.breadcrumb a:hover { color: var(--signal-text); }
.breadcrumb__sep { color: var(--rule); }

/* ---------- 12. 页脚 ---------- */
.site-footer {
  padding-block: clamp(32px, 6vw, 56px) 24px;
  background: var(--ink-900);
  color: var(--on-ink-soft);
  border-top: 1px solid var(--ink-700);
}
.site-footer__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.foot-top { display: grid; gap: 24px; }
.foot-brand { display: flex; flex-direction: column; gap: 6px; }
.foot-brand__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  margin-bottom: 6px;
  border-radius: 2px;
  background: var(--signal);
  color: #26120A;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
}
.foot-brand__name {
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 700;
  color: #fff;
  line-height: 1.3;
}
.foot-brand__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--celadon);
}
.foot-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.foot-col__title {
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule-ink);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--on-ink);
}
.foot-links { display: flex; flex-direction: column; }
.foot-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  color: var(--on-ink-soft);
  transition: color 0.2s var(--ease);
}
.foot-links a::before {
  content: "";
  width: 8px;
  height: 1px;
  margin-right: 10px;
  background: var(--celadon);
  transition: width 0.2s var(--ease), background 0.2s var(--ease);
}
.foot-links a:hover { color: #fff; }
.foot-links a:hover::before { width: 18px; background: var(--signal); }
.foot-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  font-size: 14px;
  line-height: 1.8;
}
.foot-contact__item { display: inline-flex; align-items: baseline; gap: 8px; min-width: 0; }
.foot-contact__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--celadon);
}
.foot-contact__val {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--on-ink);
  word-break: break-word;
}
.foot-promise { margin-top: 12px; font-size: 13px; line-height: 1.8; max-width: 62ch; }
.foot-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 18px;
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px solid var(--rule-ink);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: rgba(243, 237, 227, 0.6);
}
.foot-icp { color: var(--on-ink); }

/* ---------- 13. 返回顶部 ---------- */
.totop {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 55;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid var(--rule-ink);
  border-radius: 2px;
  background: var(--ink-800);
  color: var(--on-ink);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease);
}
.totop[data-visible] { opacity: 1; transform: none; pointer-events: auto; }

/* ---------- 14. 滚动显现 ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity 0.5s var(--ease), transform 0.5s var(--ease); }
.reveal--in { opacity: 1; transform: none; }
.reveal .frame__scale,
.reveal .scale-rule { transform: scaleX(0); transform-origin: 0 50%; transition: transform 0.8s var(--ease) 0.08s; }
.reveal--in .frame__scale,
.reveal--in .scale-rule { transform: none; }
.reveal .databar__row { opacity: 0; transform: translateY(6px); transition: opacity 0.4s var(--ease), transform 0.4s var(--ease); }
.reveal--in .databar__row { opacity: 1; transform: none; }
.reveal--in .databar__row:nth-child(2) { transition-delay: 0.06s; }
.reveal--in .databar__row:nth-child(3) { transition-delay: 0.12s; }
.reveal--in .databar__row:nth-child(4) { transition-delay: 0.18s; }
.reveal--in .databar__row:nth-child(5) { transition-delay: 0.24s; }
.reveal--in .databar__row:nth-child(6) { transition-delay: 0.3s; }

/* ---------- 15. 响应式 ---------- */
@media (min-width: 480px) {
  .brandbar__cta { display: inline-flex; }
}
@media (max-width: 479px) {
  .brandbar__cta { display: none; }
  .brand { gap: 8px; }
  .brand__mark { width: 34px; height: 34px; font-size: 13px; }
  .brand__name { font-size: 16px; }
}
@media (min-width: 760px) {
  .grid { grid-template-columns: repeat(8, minmax(0, 1fr)); gap: 18px; }
  .span-focus { grid-column: span 8; }
  .span-half { grid-column: span 4; }
  .foot-top { grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); gap: 32px; }
}
@media (min-width: 900px) {
  .nav-toggle { display: none; }
  .nav-scrim { display: none; }
  .sitenav__cta { display: none; }
  .sitenav::after { display: none; }
  .sitenav__link { font-size: 15px; padding: 13px 15px; }
}
@media (min-width: 1000px) {
  .brandbar__note { display: block; }
}
@media (min-width: 1080px) {
  .grid { grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 20px; }
  .span-focus { grid-column: span 8; }
  .span-half { grid-column: span 4; }
  .foot-grid { gap: 32px; }
}

/* 移动端抽屉 */
@media (max-width: 899px) {
  .sitenav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: auto;
    z-index: 70;
    width: min(88vw, 360px);
    margin-inline: 0;
    padding: 76px 20px 28px;
    overflow-y: auto;
    background: var(--ink-900);
    border-top: 0;
    border-left: 1px solid var(--rule-ink);
    transform: translateX(100%);
    visibility: hidden;
    transition: transform 0.28s var(--ease), visibility 0.28s var(--ease);
  }
  .site-header[data-open] .sitenav { transform: translateX(0); visibility: visible; }
  .sitenav__list { flex-direction: column; gap: 0; padding-inline: 0; overflow: visible; }
  .sitenav__item { border-bottom: 1px solid var(--rule-ink); }
  .sitenav__link {
    align-items: center;
    min-height: 52px;
    padding: 14px 10px;
    font-size: 17px;
    border-bottom: 0;
    border-left: 3px solid transparent;
  }
  .sitenav__link[aria-current="page"] {
    color: #fff;
    background: var(--ink-700);
    border-bottom-color: transparent;
    border-left-color: var(--signal);
  }
  .sitenav__cta { display: block; padding: 22px 0 0; }
}

/* ---------- 16. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .reveal, .reveal--in { opacity: 1 !important; transform: none !important; }
  .reveal .frame__scale, .reveal .scale-rule,
  .reveal--in .frame__scale, .reveal--in .scale-rule { transform: none !important; }
  .reveal .databar__row, .reveal--in .databar__row { opacity: 1 !important; transform: none !important; }
  .totop { transform: none; }
}