/* ============================================================
   星空赛场 XINGKONG — 共享样式 /assets/site.css
   深空蓝黑底 · 矿物色强调 · 粗边框硬阴影 · 框架式导航
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; }

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

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

a { color: inherit; text-decoration: none; }

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

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

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

/* ---------- 2. 变量 ---------- */
:root {
  /* 矿物色体系 */
  --ink: #0B1020;
  --ink-deep: #05070F;
  --panel: #2A2F3A;
  --paper: #F2EFE6;
  --violet: #6B4CE6;
  --signal: #2FD8C6;
  --orange: #FF7A2F;
  --gold: #E8B44A;
  --moss: #4F7A54;
  --clay: #B5623C;

  --line-soft: rgba(242, 239, 230, 0.16);
  --line-strong: rgba(242, 239, 230, 0.88);
  --paper-72: rgba(242, 239, 230, 0.72);
  --paper-58: rgba(242, 239, 230, 0.58);

  /* 栅格与节奏 */
  --rail-w: 236px;
  --gutter: clamp(20px, 3.4vw, 56px);
  --gap: clamp(16px, 2vw, 28px);
  --section-y: clamp(48px, 7vw, 96px);

  /* 字体栈 */
  --font-display: "Archivo Narrow", "Arial Narrow", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  /* 字级 */
  --fs-88: clamp(52px, 7.4vw, 88px);
  --fs-64: clamp(40px, 5.2vw, 64px);
  --fs-40: clamp(28px, 3.4vw, 40px);
  --fs-28: clamp(22px, 2.2vw, 28px);
  --fs-20: 20px;
  --fs-17: 17px;
  --fs-14: 14px;

  /* 材质 */
  --stroke: 2px;
  --shadow-hard: 8px 8px 0 var(--ink-deep);
  --shadow-hard-lift: 12px 12px 0 var(--ink-deep);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  padding-left: var(--rail-w);
  font-family: var(--font-body);
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--paper);
  background-color: var(--ink);
  background-image:
    radial-gradient(760px 520px at 88% -8%, rgba(107, 76, 230, 0.30), transparent 70%),
    radial-gradient(560px 460px at 10% 108%, rgba(47, 216, 198, 0.13), transparent 72%),
    radial-gradient(920px 620px at 62% 38%, rgba(255, 122, 47, 0.06), transparent 76%);
  background-attachment: fixed, fixed, fixed;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: 0.06em;
}

p { max-width: 100%; }

strong { font-weight: 700; }

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

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

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 10px 16px;
  border: 2px solid var(--ink-deep);
  background: var(--signal);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.08em;
  transform: translateY(-220%);
  transition: transform 180ms ease;
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 4. 字级工具 ---------- */
.type-display {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-88);
  line-height: 1.02;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.type-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-64);
  line-height: 1.06;
  letter-spacing: 0.06em;
}

.type-head {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-40);
  line-height: 1.12;
  letter-spacing: 0.06em;
}

.type-sub {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-28);
  line-height: 1.2;
  letter-spacing: 0.06em;
}

.type-lead {
  font-size: var(--fs-20);
  line-height: 1.7;
}

.type-body {
  font-size: var(--fs-17);
  line-height: 1.75;
}

.type-meta {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.08em;
}

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

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--signal);
}

.measure { max-width: 34em; }
.measure--wide { max-width: 38em; }

/* ---------- 5. 颜色工具 ---------- */
.c-violet { color: var(--violet); }
.c-signal { color: var(--signal); }
.c-orange { color: var(--orange); }
.c-gold { color: var(--gold); }
.c-clay { color: var(--clay); }
.c-moss { color: #7FB287; }
.c-muted { color: var(--paper-72); }

/* ---------- 6. 布局骨架 ---------- */
.wrap {
  width: 100%;
  max-width: 1600px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 14px;
  margin-bottom: clamp(20px, 3vw, 32px);
  border-bottom: 1px solid var(--clay);
}

.section-head__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-28);
  letter-spacing: 0.06em;
  line-height: 1.2;
}

.section-head__meta {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.08em;
  color: var(--paper-58);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gap);
}

.col-1 { grid-column: span 1; }
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-11 { grid-column: span 11; }
.col-12 { grid-column: span 12; }

/* ---------- 7. 装饰元素 ---------- */
.rule {
  height: 0;
  border: 0;
  border-top: 1px solid var(--clay);
  opacity: 0.8;
}

.tick {
  display: block;
  width: 2px;
  height: 12px;
  background: var(--clay);
}

.diag { position: relative; }

.diag::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    15deg,
    rgba(242, 239, 230, 0.055) 0 1px,
    transparent 1px 16px
  );
}

.pulse {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  animation: xk-pulse 3.2s ease-in-out infinite;
}

.pulse--signal { background: var(--signal); }

@keyframes xk-pulse {
  0%, 100% { opacity: 0.4; transform: scale(0.85); }
  50% { opacity: 1; transform: scale(1); }
}

/* ---------- 8. 链接 ---------- */
.link {
  position: relative;
  display: inline-block;
  color: var(--signal);
  transition: color 180ms ease;
}

.link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

.link:hover::after,
.link:focus-visible::after { transform: scaleX(1); }

/* ---------- 9. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 20px;
  border: 2px solid var(--paper);
  background: transparent;
  color: var(--paper);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-17);
  letter-spacing: 0.06em;
  line-height: 1.2;
  text-align: center;
  box-shadow: 6px 6px 0 var(--ink-deep);
  transition: background-color 160ms ease, color 160ms ease,
              border-color 160ms ease, box-shadow 160ms ease;
}

.btn:hover {
  background: var(--paper);
  color: var(--ink);
  box-shadow: 10px 10px 0 var(--ink-deep);
}

.btn--gold {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

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

.btn--signal {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--ink);
}

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

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

/* ---------- 10. 卡片 / 标签 / 数据 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2vw, 26px);
  border: 2px solid var(--line-strong);
  background: var(--panel);
  box-shadow: var(--shadow-hard);
  transition: box-shadow 200ms ease, border-color 200ms ease;
}

.card:hover {
  border-color: var(--paper);
  outline: 1px solid var(--paper);
  outline-offset: -1px;
  box-shadow: var(--shadow-hard-lift);
}

.card__label {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.18em;
  color: var(--clay);
  text-transform: uppercase;
}

.card__title {
  margin-top: 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-28);
  line-height: 1.2;
  letter-spacing: 0.06em;
}

.card__text {
  margin-top: 10px;
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--paper-72);
  max-width: 34em;
}

.card__meta {
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.06em;
  color: var(--paper-58);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.06em;
  line-height: 1.6;
  color: var(--paper);
}

.tag--signal { color: var(--signal); }
.tag--orange { color: var(--orange); }
.tag--violet { color: var(--violet); }
.tag--paper { color: var(--paper); }

.tag--moss {
  color: #7FB287;
  background: rgba(79, 122, 84, 0.22);
}

/* ---------- 11. 图片容器（供页面阶段放置图片） ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 2px solid var(--line-strong);
  background: linear-gradient(152deg, var(--panel) 0%, var(--ink-deep) 78%);
  box-shadow: var(--shadow-hard);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    15deg,
    rgba(47, 216, 198, 0.09) 0 1px,
    transparent 1px 18px
  );
  mix-blend-mode: screen;
}

.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  padding: 10px 14px;
  background: linear-gradient(180deg, rgba(5, 7, 15, 0) 0%, rgba(5, 7, 15, 0.9) 100%);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.06em;
  color: var(--paper);
}

.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--wide { aspect-ratio: 21 / 9; }

/* ---------- 12. 面包屑 ---------- */
.crumbs {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.04em;
  color: var(--paper-58);
}

.crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.crumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

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

.crumbs__link {
  color: var(--paper-58);
  transition: color 180ms ease;
}

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

.crumbs__current { color: var(--paper); }

/* ---------- 13. 页头：框架式侧栏导航 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 80;
  display: flex;
  flex-direction: column;
  gap: 22px;
  width: var(--rail-w);
  padding: 24px 18px 20px;
  overflow-y: auto;
  background-color: var(--panel);
  background-image: linear-gradient(15deg, rgba(107, 76, 230, 0.22) 0%, rgba(42, 47, 58, 0) 44%);
  border-right: 2px solid var(--ink-deep);
}

.site-header__frame {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  color: var(--paper);
}

.brand__mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  background: var(--violet);
  color: var(--paper);
  border: 2px solid var(--ink-deep);
  box-shadow: 4px 4px 0 var(--ink-deep);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 24px;
  line-height: 1;
}

.brand__text { display: block; }

.brand__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-20);
  line-height: 1.2;
  letter-spacing: 0.06em;
}

.brand__line {
  display: block;
  margin-top: 4px;
  font-size: var(--fs-14);
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--paper-72);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 2px solid var(--paper);
  color: var(--paper);
  box-shadow: 4px 4px 0 var(--ink-deep);
  transition: background-color 160ms ease, color 160ms ease,
              border-color 160ms ease, box-shadow 160ms ease;
}

.nav-toggle:hover {
  background: var(--paper);
  color: var(--ink);
}

.nav-toggle[aria-expanded="true"] {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--ink);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 180ms ease;
}

.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

.nav-toggle__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-14);
  letter-spacing: 0.14em;
}

.site-nav {
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  gap: 14px;
}

.site-nav__caption {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--paper-58);
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--line-soft);
}

.site-nav__item { border-bottom: 1px solid var(--line-soft); }

.site-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 11px 8px 11px 12px;
  color: rgba(242, 239, 230, 0.78);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-17);
  letter-spacing: 0.06em;
  transition: color 180ms ease, background-color 180ms ease;
}

.site-nav__link::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 4px;
  background: var(--signal);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 180ms ease;
}

.site-nav__link:hover {
  color: var(--paper);
  background: rgba(242, 239, 230, 0.055);
}

.site-nav__link:hover::before { transform: scaleY(1); }

.site-nav__link[aria-current="page"] {
  color: var(--paper);
  background: rgba(47, 216, 198, 0.10);
}

.site-nav__link[aria-current="page"]::before {
  transform: scaleY(1);
  background: var(--signal);
}

.site-nav__link[aria-current="page"] .site-nav__index { color: var(--signal); }

.site-nav__index {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0;
  color: var(--clay);
}

.site-nav__text { display: inline-block; }

.site-header__cta {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: flex-start;
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
}

.rail-note {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--paper-58);
}

/* ---------- 14. 页脚 ---------- */
.site-footer {
  margin-top: var(--section-y);
  border-top: 2px solid var(--ink-deep);
  background-color: var(--panel);
  background-image: linear-gradient(15deg, rgba(107, 76, 230, 0.16) 0%, rgba(42, 47, 58, 0) 42%);
  color: var(--paper);
}

.site-footer__inner {
  width: 100%;
  max-width: 1600px;
  margin-inline: auto;
  padding: clamp(32px, 5vw, 64px) var(--gutter) 28px;
}

.footer__brand { max-width: 38em; }

.footer__slogan {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-28);
  line-height: 1.25;
  letter-spacing: 0.06em;
}

.footer__brandname {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--signal);
}

.footer__note {
  margin-top: 12px;
  max-width: 34em;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--paper-72);
}

.footer__grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
  margin-top: clamp(28px, 4vw, 48px);
  padding-top: clamp(24px, 3vw, 36px);
  border-top: 1px solid var(--clay);
}

.footer__title {
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--paper-72);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 14px;
}

.footer__link {
  position: relative;
  display: inline-block;
  font-size: var(--fs-17);
  color: rgba(242, 239, 230, 0.82);
  transition: color 180ms ease;
}

.footer__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 100%;
  height: 1px;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

.footer__link:hover { color: var(--paper); }
.footer__link:hover::after { transform: scaleX(1); }

.footer__contact {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 36px;
  margin-top: clamp(28px, 4vw, 40px);
  padding-top: clamp(22px, 3vw, 32px);
  border-top: 1px solid var(--clay);
}

.footer__contact-item {
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--paper-72);
  overflow-wrap: anywhere;
}

.footer__contact-item .mono { color: var(--paper); }

.footer__contact-note {
  flex: 1 1 100%;
  max-width: 52em;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--paper-58);
}

.footer__legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 24px;
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  color: var(--paper-58);
}

.footer__icp { letter-spacing: 0.08em; }

.footer__copyright { letter-spacing: 0.06em; }

/* ---------- 15. 脚本生成的界面件 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  height: 3px;
  pointer-events: none;
  background: rgba(242, 239, 230, 0.08);
}

.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--signal) 0%, var(--violet) 100%);
  transform: scaleX(0);
  transform-origin: left;
}

.to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 120;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: 2px solid var(--paper);
  background: var(--panel);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.08em;
  box-shadow: 6px 6px 0 var(--ink-deep);
  opacity: 0;
  visibility: hidden;
  transition: opacity 180ms ease, visibility 180ms ease,
              background-color 160ms ease, color 160ms ease;
}

.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
}

.to-top:hover {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--ink);
}

/* 显现协议：仅在脚本可用时隐藏 */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 320ms ease, transform 320ms ease;
}

.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 16. 平板 ---------- */
@media (max-width: 1023px) {
  body { padding-left: 0; }

  .site-header {
    position: sticky;
    top: 0;
    right: auto;
    bottom: auto;
    left: auto;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0;
    width: 100%;
    overflow: visible;
    padding: 12px var(--gutter);
    border-right: 0;
    border-bottom: 2px solid var(--ink-deep);
  }

  .site-header[data-open] {
    background-color: var(--panel);
    box-shadow: 0 8px 0 rgba(5, 7, 15, 0.55);
  }

  .site-header__frame {
    align-items: center;
    width: 100%;
  }

  .brand__mark {
    width: 36px;
    height: 36px;
    font-size: 20px;
  }

  .brand__name { font-size: var(--fs-17); }
  .brand__line { display: none; }

  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    flex: 0 0 auto;
    width: 100%;
    max-height: calc(100vh - 140px);
    margin-top: 14px;
    overflow-y: auto;
  }

  .site-header[data-open] .site-nav { display: flex; }

  .site-nav__link {
    padding: 14px 8px 14px 12px;
    font-size: var(--fs-20);
  }

  .site-header__cta { margin-top: 16px; }

  .grid { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-1, .col-2, .col-3 { grid-column: span 3; }
  .col-4, .col-5, .col-6, .col-7,
  .col-8, .col-9, .col-10, .col-11, .col-12 { grid-column: span 6; }

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

/* ---------- 17. 手机 ---------- */
@media (max-width: 640px) {
  body { font-size: var(--fs-17); }

  :root {
    --fs-88: clamp(38px, 12vw, 52px);
    --fs-64: clamp(32px, 9.4vw, 42px);
    --fs-40: clamp(26px, 7.6vw, 32px);
  }

  .grid { grid-template-columns: minmax(0, 1fr); }
  [class*="col-"] { grid-column: span 1; }

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

  .site-header__cta .btn { width: 100%; }

  .to-top { right: 12px; bottom: 12px; }
}

/* ---------- 18. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .js [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

@media (min-width: 1024px) {
  .scroll-progress { left: var(--rail-w); }
}