/* ============================================================
   9393 主站 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 刊头 / 页脚 / 基础组件
   ============================================================ */

/* ---------- 0. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body,
h1, h2, h3, h4, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }

ul, ol { padding: 0; list-style: none; }

img, svg, video { display: block; max-width: 100%; }

button, input, select, textarea { font: inherit; color: inherit; }

button { background: none; border: 0; cursor: pointer; }

a { color: inherit; }

table { border-collapse: collapse; width: 100%; }

[hidden] { display: none !important; }

/* ---------- 1. 变量 ---------- */
:root {
  --paper: #F3EDE2;
  --ink: #101A24;
  --deep: #0E3A5C;
  --signal: #F2622A;
  --turq: #2BA79E;
  --sand: #D9C39B;
  --lime: #C6E85C;
  --paper-white: #FFFDF8;
  --slate: #6B7C8C;
  --ember: #C8451B;

  --ink-70: rgba(16, 26, 36, 0.72);
  --ink-45: rgba(16, 26, 36, 0.45);
  --ink-14: rgba(16, 26, 36, 0.14);
  --ink-08: rgba(16, 26, 36, 0.08);

  --font-display: "Songti SC", "STSong", "Noto Serif SC", Georgia, "Times New Roman", serif;
  --font-heavy: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas, "Courier New", monospace;

  --step-caption: 0.8125rem;
  --step-body: 1.125rem;
  --step-h3: 1.5rem;
  --step-h2: clamp(1.5rem, 3.2vw, 2.6rem);
  --step-h1: clamp(1.9rem, 4.4vw, 3.4rem);
  --step-display: clamp(2.4rem, 8vw, 7rem);

  --r-sm: 12px;
  --r-md: 20px;
  --r-lg: 32px;
  --r-pill: 999px;

  --sheet: 1240px;
  --pad-x: clamp(20px, 5vw, 72px);
  --gap: clamp(24px, 4vw, 64px);
  --section-gap: clamp(72px, 9vw, 148px);
  --stagger: 70ms;
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

:focus-visible {
  outline: 3px solid var(--signal);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 2. 排版阶梯 ---------- */
.display {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--step-display);
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.h1 {
  font-family: var(--font-heavy);
  font-weight: 800;
  font-size: var(--step-h1);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.h2 {
  font-family: var(--font-heavy);
  font-weight: 800;
  font-size: var(--step-h2);
  line-height: 1.18;
  letter-spacing: -0.005em;
  color: var(--ink);
}

.h3 {
  font-family: var(--font-heavy);
  font-weight: 700;
  font-size: var(--step-h3);
  line-height: 1.32;
  color: var(--deep);
}

.lede {
  font-size: var(--step-body);
  line-height: 1.8;
  color: var(--ink-70);
  max-width: 38em;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.9em;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.16em;
  color: var(--deep);
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--signal);
  flex: none;
}

.prose { max-width: 68ch; }

.prose p {
  margin-bottom: 1.15em;
  color: var(--ink-70);
  max-width: 38em;
}

.prose strong { color: var(--ink); }

/* ---------- 3. 容器与网格 ---------- */
.shell {
  width: 100%;
  max-width: var(--sheet);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

.shell--narrow { max-width: 880px; }

.section { padding-block: var(--section-gap); }
.section--tight { padding-block: clamp(48px, 6vw, 88px); }

.grid { display: grid; gap: var(--gap); }
.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 3fr); }
.grid--halves { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--thirds { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--quarters { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.rule {
  height: 6px;
  border: 0;
  margin: 0;
  background-image: repeating-linear-gradient(90deg, var(--ink-14) 0 1px, transparent 1px 16px);
}

/* ---------- 4. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: var(--r-pill);
  border: 1px solid transparent;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.07em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.22s ease, color 0.22s ease, border-color 0.22s ease, transform 0.22s ease;
}

.btn:active { transform: translateY(1px); }

.btn--signal { background: var(--signal); color: #fff; }
.btn--signal:hover { background: var(--ember); }

.btn--deep { background: var(--deep); color: var(--paper); }
.btn--deep:hover { background: var(--ink); }

.btn--ghost { background: transparent; color: var(--ink); border-color: var(--ink); }
.btn--ghost:hover { background: var(--ink); color: var(--paper); }

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

/* ---------- 5. 标签与数据高亮 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  border-radius: var(--r-pill);
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.06em;
  background: var(--sand);
  color: var(--ink);
  white-space: nowrap;
}

.tag--sand { background: var(--sand); color: var(--ink); }
.tag--turq { background: var(--turq); color: #fff; }
.tag--deep { background: var(--deep); color: var(--paper); }

.chip {
  display: inline-block;
  padding: 2px 10px;
  border-radius: var(--r-sm);
  font-family: var(--font-mono);
  font-size: 0.9em;
  letter-spacing: 0.02em;
  background: var(--lime);
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.chip--lime { background: var(--lime); color: var(--ink); }

/* ---------- 6. 结论板 ---------- */
.conclusion {
  position: relative;
  overflow: hidden;
  background: var(--paper-white);
  border: 1px solid var(--ink-08);
  border-radius: var(--r-lg);
  padding: clamp(22px, 3vw, 36px) clamp(22px, 3vw, 36px) clamp(20px, 2.6vw, 30px) clamp(30px, 4vw, 48px);
  max-width: 46ch;
  box-shadow: 0 22px 44px -30px rgba(16, 26, 36, 0.5);
}

.conclusion::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 8px;
  background: var(--signal);
}

.conclusion__label {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.16em;
  color: var(--slate);
}

.conclusion__text {
  margin-top: 10px;
  font-size: 1.25rem;
  line-height: 1.62;
  font-weight: 700;
  color: var(--ink);
}

.conclusion__meta {
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.02em;
  color: var(--slate);
}

/* ---------- 7. 证据折叠区 ---------- */
.evidence { border-top: 1px solid var(--ink-14); }
.evidence:last-of-type { border-bottom: 1px solid var(--ink-14); }

.evidence__summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}

.evidence__summary::-webkit-details-marker { display: none; }

.evidence__summary::before {
  content: "+";
  flex: none;
  width: 1em;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  line-height: 1;
  color: var(--signal);
}

.evidence[open] .evidence__summary::before { content: "\2013"; }

.evidence__body {
  padding: 0 0 22px 1.9em;
  color: var(--ink-70);
  font-size: 1rem;
}

/* ---------- 8. 对照表 ---------- */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--r-md);
  -webkit-overflow-scrolling: touch;
}

.table {
  width: 100%;
  min-width: 580px;
  font-size: 0.9375rem;
}

.table th,
.table td {
  text-align: left;
  padding: 14px 16px;
  border-bottom: 1px solid var(--ink-14);
  vertical-align: top;
}

.table thead th {
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.12em;
  color: var(--deep);
  border-bottom: 2px solid var(--deep);
  background: rgba(217, 195, 155, 0.28);
}

.table tbody tr { transition: background-color 0.2s ease; }
.table tbody tr:hover { background: rgba(217, 195, 155, 0.32); }
.table tbody td:first-child { font-weight: 700; color: var(--ink); }

.table__caption {
  caption-side: bottom;
  text-align: left;
  padding-top: 12px;
  font-size: var(--step-caption);
  line-height: 1.7;
  color: var(--slate);
}

/* ---------- 9. 面包屑 ---------- */
.crumbs {
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.06em;
  color: var(--slate);
}

.crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.crumbs__item { display: inline-flex; align-items: center; gap: 8px; }

.crumbs__item + .crumbs__item::before {
  content: "/";
  color: var(--ink-45);
}

.crumbs__link {
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.crumbs__link:hover { color: var(--ink); border-bottom-color: var(--signal); }

.crumbs__current { color: var(--ink); font-weight: 700; }

/* ---------- 10. 图片容器 ---------- */
.figure { margin: 0; }

.figure__frame {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--sand);
  border: 1px solid var(--ink-08);
}

.figure__media,
.figure__frame img,
.figure__frame picture {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__frame--paper { background: var(--paper-white); }

.figure--square .figure__frame { aspect-ratio: 1 / 1; }
.figure--wide .figure__frame { aspect-ratio: 16 / 9; }
.figure--tall .figure__frame { aspect-ratio: 3 / 4; }

.figure__caption {
  position: relative;
  margin-top: 12px;
  padding-left: 22px;
  font-size: var(--step-caption);
  line-height: 1.7;
  color: var(--slate);
}

.figure__caption::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 14px;
  height: 1px;
  background: var(--slate);
}

/* ---------- 11. 城市标签页 ---------- */
.tabs__bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--ink-14);
}

.tabs__tab {
  padding: 9px 20px;
  border-radius: var(--r-pill);
  border: 1px solid var(--ink-14);
  background: transparent;
  color: var(--ink);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.tabs__tab:hover { border-color: var(--turq); color: var(--deep); }

.tabs__tab[aria-selected="true"] {
  background: var(--deep);
  border-color: var(--deep);
  color: var(--paper);
}

.tabs__panel { padding-top: 26px; }
.tabs__panel[hidden] { display: none; }

/* ---------- 12. 动效基础 ---------- */
html[data-js="on"] [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s ease, transform 0.55s cubic-bezier(0.22, 0.61, 0.36, 1);
  transition-delay: calc(var(--i, 0) * var(--stagger));
}

html[data-js="on"] [data-reveal="in"] {
  opacity: 1;
  transform: none;
}

/* ---------- 13. Skip link ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: -120px;
  transform: translateX(-50%);
  z-index: 300;
  padding: 13px 24px;
  background: var(--ink);
  color: var(--paper-white);
  font-size: 0.9375rem;
  text-decoration: none;
  border-radius: 0 0 var(--r-md) var(--r-md);
  transition: top 0.24s ease;
}

.skip-link:focus { top: 0; }

/* ---------- 14. 刊头 ---------- */
.masthead {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--paper);
  border-bottom: 1px solid var(--ink-14);
  transition: box-shadow 0.3s ease;
}

.masthead::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--deep) 0 36%,
    var(--signal) 36% 50%,
    var(--turq) 50% 72%,
    var(--sand) 72% 100%
  );
}

.masthead[data-condensed="true"] { box-shadow: 0 14px 30px -26px rgba(16, 26, 36, 0.6); }

.masthead__bar {
  position: relative;
  display: flex;
  justify-content: center;
  padding: clamp(20px, 2.8vw, 32px) max(var(--pad-x), calc((100% - var(--sheet)) / 2)) clamp(10px, 1.4vw, 16px);
  transition: padding 0.3s ease;
}

.masthead__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-decoration: none;
  color: var(--ink);
}

.masthead__mark {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 5.2vw, 3rem);
  line-height: 1;
  letter-spacing: -0.03em;
  transition: font-size 0.3s ease;
}

.masthead__tagline {
  display: block;
  margin-top: 8px;
  max-height: 2em;
  overflow: hidden;
  font-size: var(--step-caption);
  letter-spacing: 0.36em;
  text-indent: 0.36em;
  color: var(--slate);
  transition: opacity 0.25s ease, max-height 0.3s ease, margin-top 0.3s ease;
}

.masthead__issue {
  position: absolute;
  right: max(var(--pad-x), calc((100% - var(--sheet)) / 2));
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.1em;
  color: var(--slate);
  transition: opacity 0.25s ease;
}

.masthead__sep {
  width: 14px;
  height: 1px;
  background: var(--sand);
}

.masthead[data-condensed="true"] .masthead__bar {
  padding-top: 10px;
  padding-bottom: 6px;
}

.masthead[data-condensed="true"] .masthead__mark { font-size: clamp(1.4rem, 3.4vw, 2rem); }

.masthead[data-condensed="true"] .masthead__tagline {
  opacity: 0;
  max-height: 0;
  margin-top: 0;
}

.masthead[data-condensed="true"] .masthead__issue { opacity: 0; }

/* 栏目条 */
.nav {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 max(var(--pad-x), calc((100% - var(--sheet)) / 2)) 16px;
}

.nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(14px, 2.4vw, 34px);
}

.nav__link {
  position: relative;
  display: inline-block;
  padding: 6px 2px;
  color: var(--ink);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-decoration: none;
  transition: color 0.2s ease;
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.24s ease;
}

.nav__link:hover { color: var(--deep); }
.nav__link:hover::after { transform: scaleX(1); }

.nav__link[aria-current="page"] { color: var(--deep); }
.nav__link[aria-current="page"]::after { transform: scaleX(1); }

.nav__cta {
  position: absolute;
  right: max(var(--pad-x), calc((100% - var(--sheet)) / 2));
  top: 50%;
  transform: translateY(-50%);
  padding: 11px 22px;
  font-size: 0.875rem;
}

/* 移动开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  position: absolute;
  right: max(var(--pad-x), calc((100% - var(--sheet)) / 2));
  top: clamp(24px, 4vw, 34px);
  padding: 9px 16px 9px 14px;
  border: 1px solid var(--ink-14);
  border-radius: var(--r-pill);
  background: var(--paper-white);
  color: var(--ink);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.12em;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: var(--signal);
  transition: transform 0.25s ease, top 0.25s ease;
}

.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { top: 8px; }

.masthead[data-open="true"] .nav-toggle__bars::before { top: 4px; transform: rotate(45deg); }
.masthead[data-open="true"] .nav-toggle__bars::after { top: 4px; transform: rotate(-45deg); }

.nav-toggle__text { line-height: 1; }

/* 滚动刻度 */
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 3px;
  background: var(--ink-08);
  overflow: hidden;
}

.scroll-progress span {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--signal);
  transform: scaleX(var(--progress, 0));
  transform-origin: left center;
}

/* ---------- 15. 页脚 ---------- */
.footer {
  position: relative;
  margin-top: var(--section-gap);
  padding: clamp(52px, 6vw, 92px) var(--pad-x) clamp(30px, 3.4vw, 48px);
  background: var(--deep);
  color: var(--paper);
  border-radius: var(--r-lg) var(--r-lg) 0 0;
  overflow: hidden;
}

.footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 8px;
  background-image: repeating-linear-gradient(90deg, rgba(243, 237, 226, 0.38) 0 2px, transparent 2px 20px);
}

.footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 2.4fr);
  gap: clamp(32px, 5vw, 80px);
  max-width: var(--sheet);
  margin-inline: auto;
}

.footer__brand { max-width: 34ch; }

.footer__mark {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.2rem, 4.6vw, 3.2rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper-white);
}

.footer__tagline {
  margin-top: 10px;
  font-size: var(--step-caption);
  letter-spacing: 0.3em;
  color: var(--salty, var(--sand));
}

.footer__note {
  margin-top: 16px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(243, 237, 226, 0.72);
}

.footer__cols {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
}

.footer__title {
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--sand);
}

.footer__list {
  margin-top: 14px;
  display: grid;
  gap: 10px;
}

.footer__link {
  display: inline-block;
  color: rgba(243, 237, 226, 0.84);
  font-size: 0.9375rem;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.footer__link:hover,
.footer__link:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.footer__contact {
  max-width: var(--sheet);
  margin: clamp(38px, 5vw, 66px) auto 0;
  padding-top: clamp(22px, 3vw, 34px);
  border-top: 1px solid rgba(243, 237, 226, 0.18);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px 40px;
}

.footer__contact-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer__key {
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.16em;
  color: var(--turq);
}

.footer__value {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--paper-white);
}

.footer__fine {
  grid-column: 1 / -1;
  margin-top: 6px;
  max-width: 62ch;
  font-size: var(--step-caption);
  line-height: 1.8;
  color: rgba(243, 237, 226, 0.6);
}

.footer__legal {
  max-width: var(--sheet);
  margin: clamp(30px, 4vw, 52px) auto 0;
  padding-top: 18px;
  border-top: 1px solid rgba(243, 237, 226, 0.18);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
  font-family: var(--font-mono);
  font-size: var(--step-caption);
  letter-spacing: 0.06em;
  color: rgba(243, 237, 226, 0.62);
}

.footer__dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--signal);
  flex: none;
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1024px) {
  .grid--split,
  .grid--thirds,
  .grid--quarters { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .footer__grid { grid-template-columns: 1fr; }
  .footer__cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  .masthead__bar {
    justify-content: flex-start;
    padding: 16px var(--pad-x) 14px;
  }

  .masthead__brand { align-items: flex-start; }

  .masthead__tagline {
    letter-spacing: 0.24em;
    text-indent: 0.24em;
  }

  .masthead__issue { display: none; }

  .nav-toggle {
    display: inline-flex;
    top: 50%;
    transform: translateY(-50%);
  }

  .nav {
    display: none;
    padding: 6px var(--pad-x) 22px;
    border-top: 1px dashed var(--ink-14);
  }

  .masthead[data-open="true"] .nav { display: block; }

  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav__item { border-bottom: 1px solid var(--ink-08); }

  .nav__link {
    display: block;
    padding: 15px 2px;
    font-size: 1.0625rem;
  }

  .nav__link::after { display: none; }

  .nav__link[aria-current="page"] {
    color: var(--signal);
    padding-left: 12px;
    border-left: 3px solid var(--signal);
  }

  .nav__cta {
    position: static;
    transform: none;
    width: 100%;
    margin-top: 18px;
    padding: 15px 22px;
  }

  .masthead[data-condensed="true"] .masthead__tagline {
    opacity: 1;
    max-height: 2em;
    margin-top: 8px;
  }
}

@media (max-width: 680px) {
  body { font-size: 16px; }

  .grid--split,
  .grid--halves,
  .grid--thirds,
  .grid--quarters { grid-template-columns: 1fr; }

  .footer__cols { grid-template-columns: 1fr; }
  .footer__contact { grid-template-columns: 1fr; }
  .footer__legal { gap: 10px 14px; }
  .conclusion { max-width: none; }
}

/* ---------- 17. 降级动效 ---------- */
@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;
  }

  html[data-js="on"] [data-reveal] {
    opacity: 1;
    transform: none;
  }
}