/* =========================================================
   FB赛场 / 共享外壳样式 —— /assets/site.css
   结构：变量 → reset → 排版 → 通用组件 → 头部 → 页脚 → 响应式
   ========================================================= */

:root {
  --deep: #061826;
  --night: #0B2C47;
  --cyan: #46F2D2;
  --amber: #F2B84B;
  --stone: #8EA3AE;
  --ivory: #F3EFE4;
  --ink: #101418;
  --moss: #5C7C63;
  --clay: #B66A4E;
  --mist: #C9D6DD;

  --rail-w: clamp(190px, 16vw, 236px);
  --topbar-h: 64px;
  --gutter: clamp(18px, 4vw, 56px);
  --maxw: 1180px;

  --progress: 0;

  --font-display: "Helvetica Neue", "Arial Narrow", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: Georgia, "Times New Roman", "Songti SC", "STSong", "SimSun", serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Heiti SC", system-ui, -apple-system, sans-serif;
  --font-mono: "SFMono-Regular", Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  --line: rgba(142, 163, 174, 0.24);
  --line-strong: rgba(142, 163, 174, 0.44);
  --scan: repeating-linear-gradient(180deg, rgba(243, 239, 228, 0.032) 0 1px, transparent 1px 5px);
}

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

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dt, dd, ol, ul {
  margin: 0;
}

ol, ul { 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; }

a { color: var(--cyan); text-decoration-thickness: 1px; text-underline-offset: 3px; }

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

::selection {
  background: var(--cyan);
  color: var(--deep);
}

/* ---------- 基础排版 ---------- */
body {
  padding-left: var(--rail-w);
  overflow-x: hidden;
  background-color: var(--deep);
  background-image: radial-gradient(120% 80% at 88% -10%, rgba(70, 242, 210, 0.07), transparent 58%),
                    radial-gradient(90% 70% at 4% 100%, rgba(242, 184, 75, 0.05), transparent 60%);
  background-attachment: fixed;
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.14;
  color: var(--ivory);
}

h1 { font-size: clamp(34px, 4.6vw, 68px); }
h2 { font-size: clamp(24px, 2.8vw, 40px); }
h3 { font-size: clamp(19px, 1.9vw, 26px); letter-spacing: -0.02em; }
h4 { font-size: 17px; letter-spacing: -0.01em; }

p { max-width: 72ch; }

strong, b { color: var(--ivory); font-weight: 700; }

#main-content { scroll-margin-top: calc(var(--topbar-h) + 12px); }

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

/* ---------- 跳过链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 999;
  transform: translateY(-180%);
  background: var(--cyan);
  color: var(--deep);
  padding: 10px 18px;
  border-radius: 2px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: transform 0.18s ease;
}

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

/* ---------- 容器与区块 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(44px, 6.5vw, 92px); }
.section--tight { padding-block: clamp(26px, 3.6vw, 48px); }

.eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px 28px;
  margin-bottom: clamp(20px, 2.6vw, 34px);
}

.section-head > * { margin-bottom: 0; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--deep);
}

.btn--primary:hover {
  background: #74f7e0;
  border-color: #74f7e0;
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--mist);
}

.btn--ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  transform: translateY(-1px);
}

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

.btn--amber:hover {
  background: #ffca68;
  border-color: #ffca68;
  transform: translateY(-1px);
}

.btn--sm {
  padding: 8px 15px;
  font-size: 12.5px;
  letter-spacing: 0.08em;
}

/* ---------- 面包屑 ---------- */
.breadcrumbs {
  padding-block: 16px;
  border-bottom: 1px solid var(--line);
}

.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.09em;
  color: var(--stone);
}

.breadcrumbs__item { display: inline-flex; align-items: center; }

.breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--line-strong);
}

.breadcrumbs__link {
  color: var(--mist);
  text-decoration: none;
  transition: color 0.16s ease;
}

.breadcrumbs__link:hover { color: var(--cyan); }

.breadcrumbs__item[aria-current="page"] { color: var(--cyan); }

/* ---------- 网格与磁贴 ---------- */
.grid {
  display: grid;
  gap: var(--gap, clamp(14px, 1.8vw, 24px));
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 250px), 1fr));
}

.tile {
  position: relative;
  padding: clamp(18px, 2.4vw, 30px);
  background: linear-gradient(160deg, rgba(11, 44, 71, 0.96), rgba(6, 24, 38, 0.96));
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.tile:hover { border-color: var(--line-strong); }

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1.6;
  color: var(--mist);
  white-space: nowrap;
}

.tag--cyan { color: var(--cyan); border-color: rgba(70, 242, 210, 0.52); }
.tag--amber { color: var(--amber); border-color: rgba(242, 184, 75, 0.52); }
.tag--moss { color: #AFC9B4; border-color: rgba(92, 124, 99, 0.78); }

/* ---------- 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  background:
    var(--scan),
    linear-gradient(150deg, #0B2C47, #061826 70%);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 20px 100%, 0 calc(100% - 20px));
}

.media-frame > img,
.media-frame > picture,
.media-frame > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.94) contrast(1.04);
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__caption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 26px 16px 12px;
  background: linear-gradient(180deg, transparent, rgba(6, 24, 38, 0.88));
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
}

/* ---------- 呼吸条 ---------- */
.breathing-strip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  padding-block: 14px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.breathing-strip__title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--ivory);
}

.breathing-strip__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

/* ---------- 等宽数据 ---------- */
.data-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

/* ---------- 长文 ---------- */
.prose { max-width: 70ch; }
.prose > * + * { margin-top: 1.05em; }
.prose h2 { margin-top: 1.9em; font-size: clamp(22px, 2.2vw, 30px); }
.prose h3 { margin-top: 1.6em; color: var(--ivory); }
.prose ul, .prose ol { padding-left: 1.3em; list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 0.4em; }
.prose a { color: var(--cyan); }

/* =========================================================
   头部 —— 左侧赛场索引轨道
   ========================================================= */
.site-header {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 80;
  display: flex;
  flex-direction: column;
  width: var(--rail-w);
  padding: 30px 22px 24px;
  background-image: var(--scan), linear-gradient(180deg, var(--night) 0%, var(--deep) 64%);
  border-right: 1px solid var(--line);
}

.site-header::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 120px;
  background: linear-gradient(180deg, transparent, rgba(70, 242, 210, 0.06));
  pointer-events: none;
}

/* 品牌 */
.brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 12px;
  text-decoration: none;
  color: var(--ivory);
}

.brand__mark {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -0.05em;
  line-height: 1;
  color: var(--ivory);
}

.brand__rule {
  display: block;
  width: 24px;
  height: 1px;
  background: var(--cyan);
}

.brand__name {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.34em;
  line-height: 1;
  color: var(--mist);
}

.brand__tagline {
  margin: 0 0 26px;
  max-width: 15em;
  font-family: var(--font-serif);
  font-size: 12.5px;
  line-height: 1.65;
  letter-spacing: 0.07em;
  color: var(--stone);
}

/* 汉堡按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 13px;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  color: var(--ivory);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  cursor: pointer;
  position: relative;
  z-index: 130;
}

.nav-toggle__lines {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 18px;
}

.nav-toggle__lines span {
  display: block;
  height: 2px;
  width: 100%;
  background: currentColor;
  transition: transform 0.24s ease, opacity 0.24s ease;
}

.site-header[data-open="true"] .nav-toggle__lines span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle__lines span:nth-child(2) { opacity: 0; }
.site-header[data-open="true"] .nav-toggle__lines span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 导航 */
.site-nav {
  display: flex;
  flex-direction: column;
  gap: 16px;
  flex: 1 1 auto;
  min-height: 0;
  padding-top: 6px;
}

.site-nav__close { display: none; }

.site-nav__eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.24em;
  color: var(--stone);
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-left: -12px;
}

.site-nav__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 10px 9px 12px;
  border-left: 2px solid transparent;
  color: var(--mist);
  font-size: 14px;
  letter-spacing: 0.05em;
  line-height: 1.4;
  text-decoration: none;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--stone);
  transition: color 0.18s ease;
}

.site-nav__label { display: inline; }

.site-nav__link:hover {
  color: var(--ivory);
  background: rgba(70, 242, 210, 0.06);
  border-left-color: rgba(70, 242, 210, 0.45);
}

.site-nav__link[aria-current="page"] {
  color: var(--cyan);
  background: rgba(70, 242, 210, 0.1);
  border-left-color: var(--cyan);
}

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

.site-nav__cta {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

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

.site-nav__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 10.5px;
  line-height: 1.6;
  letter-spacing: 0.06em;
  color: var(--stone);
}

/* 轨道状态 */
.site-header__status {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.site-header__pulse {
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 0 rgba(70, 242, 210, 0.55);
  animation: fb-pulse 2.6s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

@keyframes fb-pulse {
  0% { box-shadow: 0 0 0 0 rgba(70, 242, 210, 0.5); }
  70% { box-shadow: 0 0 0 8px rgba(70, 242, 210, 0); }
  100% { box-shadow: 0 0 0 0 rgba(70, 242, 210, 0); }
}

/* 遮罩与滚动进度 */
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 110;
  background: rgba(6, 24, 38, 0.74);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.28s ease, visibility 0.28s ease;
}

.site-header[data-open="true"] .nav-scrim {
  opacity: 1;
  visibility: visible;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: calc(var(--rail-w) - 2px);
  z-index: 96;
  width: 2px;
  height: 100vh;
  background: linear-gradient(180deg, var(--cyan), var(--amber));
  transform: scaleY(var(--progress, 0));
  transform-origin: top center;
  pointer-events: none;
}

.has-nav-open,
.has-nav-open body { overflow: hidden; }

/* =========================================================
   页脚 —— 计分牌底座
   ========================================================= */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 110px);
  background-image: var(--scan), linear-gradient(180deg, rgba(11, 44, 71, 0.55), var(--deep) 42%);
  border-top: 1px solid var(--line);
  color: var(--mist);
  overflow: hidden;
}

.footer__scan {
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), var(--amber) 52%, rgba(6, 24, 38, 0) 100%);
  opacity: 0.6;
}

.footer__inner {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 76px) var(--gutter) 0;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1.3fr) minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
}

.footer__brand { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; }

.footer__mark {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
}

.footer__mark-a {
  font-family: var(--font-display);
  font-size: 38px;
  font-weight: 800;
  letter-spacing: -0.06em;
  line-height: 1;
  color: var(--ivory);
}

.footer__mark-b {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.32em;
  color: var(--cyan);
}

.footer__tagline {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.footer__summary {
  margin: 0;
  max-width: 30ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

.footer__cols {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.footer__col { min-width: 0; }

.footer__col-title {
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer__list { display: flex; flex-direction: column; gap: 9px; }

.footer__link {
  display: inline-block;
  color: var(--mist);
  font-size: 14px;
  letter-spacing: 0.03em;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}

.footer__link:hover {
  color: var(--cyan);
  border-bottom-color: rgba(70, 242, 210, 0.55);
}

.footer__contact { min-width: 0; }

.footer__contact-list { display: flex; flex-direction: column; gap: 12px; }

.footer__contact-item {
  display: grid;
  grid-template-columns: 4.6em minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
}

.footer__contact-item dt {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.footer__contact-item dd {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--ivory);
  word-break: break-word;
}

.footer__note {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-size: 12px;
  line-height: 1.75;
  color: var(--stone);
}

.footer__base {
  width: 100%;
  max-width: var(--maxw);
  margin: clamp(32px, 5vw, 60px) auto 0;
  padding: 20px var(--gutter) 28px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.footer__legal { margin: 0; }
.footer__route { margin: 0; color: rgba(142, 163, 174, 0.85); }

/* 滚动显现 */
.js-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.55s cubic-bezier(0.22, 0.75, 0.24, 1);
}

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

/* =========================================================
   响应式
   ========================================================= */

/* 桌面紧凑轨道 */
@media (min-width: 960px) and (max-width: 1199px) {
  :root { --rail-w: 184px; }
  .site-header { padding: 24px 16px 20px; }
  .site-nav__link { font-size: 13px; padding: 8px 8px 8px 10px; }
  .brand__mark { font-size: 26px; }
  .footer__inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr); }
  .footer__contact { grid-column: 1 / -1; }
}

/* 桌面矮屏压缩 */
@media (min-width: 960px) and (max-height: 780px) {
  .brand__tagline { display: none; }
  .site-nav { gap: 10px; }
  .site-nav__link { padding-block: 6px; font-size: 13px; }
  .site-nav__cta { padding-top: 12px; }
  .site-header__status { margin-top: 10px; padding-top: 10px; }
}

/* 手机与平板：抽屉模式 */
@media (max-width: 959px) {
  body { padding-left: 0; padding-top: var(--topbar-h); }

  .site-header {
    inset: 0 0 auto 0;
    width: auto;
    height: var(--topbar-h);
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 0 14px;
    border-right: 0;
    border-bottom: 1px solid var(--line-strong);
  }

  .site-header::after { display: none; }

  .brand {
    flex-direction: row;
    align-items: center;
    gap: 9px;
    margin-bottom: 0;
  }

  .brand__mark { font-size: 22px; }
  .brand__rule { width: 1px; height: 15px; }
  .brand__name {
    writing-mode: horizontal-tb;
    font-size: 12px;
    letter-spacing: 0.22em;
    color: var(--mist);
  }

  .brand__tagline { display: none; }

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

  .site-header__status { display: none; }

  .site-nav {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 120;
    width: min(88vw, 380px);
    max-width: 100%;
    padding: calc(var(--topbar-h) + 22px) 22px 28px;
    gap: 20px;
    background-image: var(--scan), linear-gradient(180deg, var(--night) 0%, var(--deep) 72%);
    border-right: 1px solid var(--line-strong);
    overflow-y: auto;
    overscroll-behavior: contain;
    transform: translateX(-104%);
    transition: transform 0.34s cubic-bezier(0.22, 0.75, 0.24, 1);
  }

  .site-header[data-open="true"] .site-nav { transform: translateX(0); }

  .site-nav__close {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    align-self: flex-start;
    padding: 8px 13px;
    border: 1px solid var(--line-strong);
    border-radius: 2px;
    color: var(--mist);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.12em;
    cursor: pointer;
  }

  .site-nav__close:hover { color: var(--cyan); border-color: var(--cyan); }

  .site-nav__close-icon {
    position: relative;
    width: 12px;
    height: 12px;
  }

  .site-nav__close-icon::before,
  .site-nav__close-icon::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 0;
    width: 12px;
    height: 1.5px;
    background: currentColor;
  }

  .site-nav__close-icon::before { transform: rotate(45deg); }
  .site-nav__close-icon::after { transform: rotate(-45deg); }

  .site-nav__list { margin-left: 0; gap: 4px; }

  .site-nav__link {
    padding: 13px 12px;
    font-size: 16px;
    letter-spacing: 0.06em;
    border-left-width: 2px;
  }

  .site-nav__num { font-size: 11px; }

  .site-nav__cta { margin-top: 8px; }

  .site-nav__note { font-size: 11px; }

  .scroll-progress {
    left: 0;
    top: var(--topbar-h);
    width: 100%;
    height: 2px;
    transform: scaleX(var(--progress, 0));
    transform-origin: left center;
    background: linear-gradient(90deg, var(--cyan), var(--amber));
  }

  .footer__inner { grid-template-columns: minmax(0, 1fr); gap: 32px; }
  .footer__summary { max-width: 46ch; }
  .footer__contact { grid-column: auto; }
  .footer__base { flex-direction: column; align-items: flex-start; }
}

/* 手机细节 */
@media (max-width: 619px) {
  :root { --topbar-h: 58px; }

  body { font-size: 15.5px; }

  .footer__cols { grid-template-columns: minmax(0, 1fr); gap: 26px; }

  .footer__contact-item { grid-template-columns: minmax(0, 1fr); gap: 2px; }

  .footer__mark-a { font-size: 32px; }

  .breathing-strip { gap: 6px 16px; }
}

/* 动效偏好 */
@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;
    scroll-behavior: auto !important;
  }

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

  .site-nav { transition: none !important; }
}