/* ============================================================
   天行体育 · 共享样式表 /assets/site.css
   高原夜空 + 经幡五色 · 粗边框硬阴影 · 数据叙事
   ============================================================ */

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

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

body { margin: 0; }

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

h1, h2, h3, h4, h5, h6, p, figure, blockquote, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }

a { color: inherit; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  margin: 0;
  padding: 0;
  cursor: pointer;
}

/* ---------- 2. 设计令牌 ---------- */
:root {
  --night: #0A1730;
  --night-deep: #06101f;
  --indigo: #12294D;
  --haze: #4C6FA8;
  --snow: #F3F6FB;
  --ice: #58D5E6;
  --fl-blue: #4C6FA8;
  --fl-white: #F3F6FB;
  --fl-red: #D9503F;
  --fl-green: #35A06A;
  --fl-yellow: #E9B33C;
  --obsidian: #1A1F2B;

  --text: #E4EBF7;
  --text-dim: #A6BAD6;
  --line: rgba(76, 111, 168, 0.55);
  --line-soft: rgba(76, 111, 168, 0.28);
  --line-strong: rgba(120, 160, 224, 0.9);

  --bw: 3px;
  --bw-thin: 2px;
  --shadow: 6px 6px 0 var(--obsidian);
  --shadow-sm: 4px 4px 0 var(--obsidian);

  --wrap-max: 1200px;
  --pad: clamp(16px, 4vw, 40px);

  --font-head: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  color: var(--text);
  background-color: var(--night);
  background-image:
    radial-gradient(1100px 520px at 78% -10%, rgba(76, 111, 168, 0.32), transparent 70%),
    radial-gradient(760px 420px at 8% 2%, rgba(88, 213, 230, 0.13), transparent 72%),
    radial-gradient(900px 620px at 52% 106%, rgba(53, 160, 106, 0.09), transparent 70%);
  background-repeat: no-repeat;
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.15;
  color: var(--snow);
}

p { max-width: 40em; }

strong { color: var(--snow); font-weight: 700; }

::selection { background: var(--fl-yellow); color: var(--obsidian); }

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

/* ---------- 4. 通用工具 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap-max);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

.stack { display: grid; gap: 16px; align-content: start; }

.hairline {
  border: 0;
  border-top: var(--bw-thin) solid var(--line);
  margin: clamp(24px, 4vw, 40px) 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--fl-yellow);
  color: var(--obsidian);
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  border: var(--bw) solid var(--obsidian);
  box-shadow: var(--shadow-sm);
  transition: top 0.16s ease;
}

.skip-link:focus { top: 10px; }

/* ---------- 5. 网格 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(12px, 2vw, 24px);
}

@media (min-width: 860px) {
  .grid-12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .span-2 { grid-column: span 2; }
  .span-3 { grid-column: span 3; }
  .span-4 { grid-column: span 4; }
  .span-5 { grid-column: span 5; }
  .span-6 { grid-column: span 6; }
  .span-7 { grid-column: span 7; }
  .span-8 { grid-column: span 8; }
  .span-9 { grid-column: span 9; }
  .span-10 { grid-column: span 10; }
  .span-12 { grid-column: span 12; }
}

/* ---------- 6. 章节与文字 ---------- */
.section {
  position: relative;
  padding-block: clamp(44px, 7vw, 96px);
}

.section--alt {
  background: var(--indigo);
  border-block: var(--bw) solid var(--obsidian);
}

.section--tight { padding-block: clamp(28px, 4vw, 56px); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--haze);
  margin-bottom: 12px;
  transition: color 0.3s ease;
}

.section-title {
  font-size: clamp(1.55rem, 3.8vw, 2.7rem);
  font-weight: 900;
  margin-bottom: 14px;
}

.section-title::after {
  content: "";
  display: block;
  width: 0;
  height: 4px;
  margin-top: 14px;
  background: var(--ice);
  transition: width 0.5s ease;
}

[data-section].is-current .section-title::after { width: 64px; }
[data-section].is-current .eyebrow { color: var(--fl-yellow); }

.lede {
  font-size: 17px;
  line-height: 1.85;
  color: var(--text);
}

.prose { max-width: 36em; }
.prose p { margin-bottom: 1.1em; max-width: 36em; }
.prose p:last-child { margin-bottom: 0; }
.prose h3 { font-size: 1.2rem; margin: 1.6em 0 0.6em; }

/* ---------- 7. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
}

.breadcrumbs a {
  color: var(--ice);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.breadcrumbs a:hover { border-bottom-color: var(--ice); }

.crumb-sep { color: var(--haze); }

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border: var(--bw) solid var(--obsidian);
  border-radius: 2px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition: transform 0.14s ease, box-shadow 0.14s ease, background 0.16s ease, color 0.16s ease, border-color 0.16s ease;
}

.btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: 6px 6px 0 var(--obsidian);
}

.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--obsidian);
}

.btn-primary { background: var(--fl-yellow); color: var(--obsidian); }
.btn-primary:hover { background: #f2c45c; }

.btn-ghost {
  background: transparent;
  color: var(--snow);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-sm);
}

.btn-ghost:hover { color: var(--ice); border-color: var(--ice); }

.btn-ice { background: var(--ice); color: var(--night); }
.btn-ice:hover { background: #79e1ef; }

/* ---------- 9. 容器组件 ---------- */
.panel {
  background: var(--indigo);
  border: var(--bw) solid var(--obsidian);
  box-shadow: var(--shadow);
  padding: clamp(16px, 2.6vw, 28px);
}

.panel--flat { box-shadow: none; }

.panel--outline {
  background: transparent;
  border-color: var(--line-strong);
  box-shadow: none;
}

/* ---------- 10. 数据卡 ---------- */
.data-card {
  position: relative;
  display: grid;
  gap: 10px;
  align-content: start;
  padding: clamp(16px, 2.4vw, 24px);
  background: var(--indigo);
  border: var(--bw) solid var(--obsidian);
  box-shadow: var(--shadow);
  overflow: visible;
}

.data-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--haze);
  text-transform: uppercase;
}

.data-card-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(1.8rem, 4.6vw, 3.2rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--snow);
}

.data-card-label { font-size: 14px; color: var(--text-dim); }

.data-card-foot {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--haze);
  border-top: var(--bw-thin) solid var(--line);
  padding-top: 10px;
}

.stat { display: grid; gap: 6px; align-content: start; }

.stat-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(2rem, 6.4vw, 4rem);
  line-height: 0.95;
  letter-spacing: -0.035em;
  color: var(--snow);
}

.stat-value--overflow {
  font-size: clamp(2.6rem, 9vw, 6rem);
  margin-left: -0.06em;
}

.stat-label {
  font-size: 13px;
  color: var(--text-dim);
  letter-spacing: 0.02em;
}

/* ---------- 11. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  border: var(--bw-thin) solid var(--line-strong);
  border-radius: 2px;
  color: var(--text-dim);
  background: rgba(10, 23, 48, 0.6);
}

.tag--blue { border-color: var(--fl-blue); color: #a4c3f2; }
.tag--yellow { border-color: var(--fl-yellow); color: var(--fl-yellow); }
.tag--red { border-color: var(--fl-red); color: #f0a094; }
.tag--green { border-color: var(--fl-green); color: #82d8ac; }
.tag--ice { border-color: var(--ice); color: var(--ice); }

/* ---------- 12. 步骤阶梯 ---------- */
.steps { display: grid; gap: 14px; counter-reset: step; }

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 14px;
  padding: clamp(14px, 2vw, 20px);
  background: var(--indigo);
  border: var(--bw-thin) solid var(--line);
  border-left: 4px solid var(--haze);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.step:hover { border-left-color: var(--ice); }

.step-index {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 20px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--fl-yellow);
}

.step-body { display: grid; gap: 6px; }

.step-title {
  font-weight: 700;
  font-size: 16px;
  color: var(--snow);
  line-height: 1.5;
}

.step-text { font-size: 15px; color: var(--text-dim); max-width: 40em; }

/* ---------- 13. 图像容器基础 ---------- */
.img-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  background-color: var(--indigo);
  background-image:
    radial-gradient(1.6px 1.6px at 14% 22%, rgba(243, 246, 251, 0.55), transparent),
    radial-gradient(1.3px 1.3px at 72% 12%, rgba(88, 213, 230, 0.6), transparent),
    radial-gradient(1.5px 1.5px at 38% 68%, rgba(243, 246, 251, 0.35), transparent),
    radial-gradient(2px 2px at 86% 78%, rgba(233, 179, 60, 0.45), transparent),
    linear-gradient(160deg, rgba(76, 111, 168, 0.28), rgba(10, 23, 48, 0.9));
  border: var(--bw) solid var(--obsidian);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.img-frame img,
.img-frame svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame--wide { aspect-ratio: 21 / 9; }
.img-frame--tall { aspect-ratio: 3 / 4; }
.img-frame--square { aspect-ratio: 1 / 1; }
.img-frame--bare { box-shadow: none; border-color: var(--line); }

.img-frame-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--haze);
}

/* ---------- 14. 头部 ---------- */
.site-header {
  position: relative;
  z-index: 70;
  background: var(--night);
  border-bottom: var(--bw) solid var(--obsidian);
}

.site-header[data-rail-fixed] { border-bottom-color: transparent; }

.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 120;
  background: rgba(88, 213, 230, 0.12);
  pointer-events: none;
}

.progress-value {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--ice), var(--fl-yellow));
}

/* 辅助条 */
.utility-bar {
  background: var(--night-deep);
  border-bottom: var(--bw-thin) solid var(--line);
}

.utility-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  min-height: 40px;
  padding-block: 5px;
}

.utility-brand {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--haze);
}

.utility-links { display: flex; gap: clamp(12px, 2vw, 24px); flex-wrap: wrap; }

.utility-link {
  font-size: 13px;
  color: var(--text-dim);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: var(--bw-thin) solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}

.utility-link:hover { color: var(--snow); border-bottom-color: var(--ice); }
.utility-link--accent { color: var(--fl-yellow); }

/* 刊头 */
.masthead { padding-top: clamp(20px, 3.6vw, 36px); }

.masthead-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
}

.brand-mark { line-height: 1; }

.brand-name {
  display: inline-block;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2rem, 6.2vw, 3.6rem);
  letter-spacing: 0.14em;
  text-indent: 0.14em;
  color: var(--snow);
  text-decoration: none;
  transition: color 0.18s ease;
}

.brand-name:hover { color: var(--ice); }

.brand-line {
  max-width: none;
  font-family: var(--font-mono);
  font-size: clamp(11px, 1.5vw, 13px);
  letter-spacing: 0.16em;
  color: var(--haze);
}

/* 导航 */
.nav-bar {
  width: 100%;
  margin-top: clamp(14px, 2.4vw, 22px);
  border-top: var(--bw-thin) solid var(--line);
}

.site-nav { width: 100%; }

.nav-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  width: 100%;
}

.nav-item { position: relative; }

.nav-item + .nav-item { border-left: var(--bw-thin) solid var(--line-soft); }

.nav-link {
  display: block;
  padding: 15px clamp(12px, 2vw, 24px);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--text);
  text-decoration: none;
  border-bottom: 3px solid transparent;
  transition: color 0.16s ease, background 0.16s ease, border-color 0.16s ease;
}

.nav-link:hover {
  color: var(--snow);
  background: rgba(88, 213, 230, 0.08);
  border-bottom-color: var(--ice);
}

.nav-link[aria-current="page"] {
  color: var(--fl-yellow);
  border-bottom-color: var(--fl-yellow);
}

/* 移动按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin: 12px auto;
  padding: 10px 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--snow);
  border: var(--bw-thin) solid var(--line-strong);
  border-radius: 2px;
  background: rgba(18, 41, 77, 0.7);
}

.nav-toggle:hover { border-color: var(--ice); color: var(--ice); }

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

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
}

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

/* 轮次轴 */
.rail {
  background: var(--indigo);
  border-top: var(--bw-thin) solid var(--line);
  border-bottom: var(--bw) solid var(--obsidian);
}

.rail--fixed {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  box-shadow: 0 5px 0 var(--obsidian);
}

.rail-holder { height: 0; overflow: hidden; }

.rail-inner {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.6vw, 18px);
  min-height: 56px;
  padding-block: 7px;
}

.rail-label {
  flex: none;
  padding-left: 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--haze);
  border-left: 3px solid var(--ice);
}

.round-strip {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 3px 2px;
  scrollbar-width: thin;
  scrollbar-color: var(--haze) transparent;
}

.round-tab {
  flex: none;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 11px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--text-dim);
  background: rgba(10, 23, 48, 0.5);
  border: var(--bw-thin) solid var(--line);
  border-radius: 2px;
  transition: color 0.16s ease, border-color 0.16s ease, background 0.16s ease, box-shadow 0.16s ease;
}

.round-tab:hover { color: var(--snow); border-color: var(--ice); }

.round-tab[aria-pressed="true"] {
  color: var(--obsidian);
  background: var(--fl-yellow);
  border-color: var(--fl-yellow);
  box-shadow: 3px 3px 0 var(--obsidian);
}

.round-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--haze);
}

.round-dot--blue { background: var(--fl-blue); }
.round-dot--white { background: var(--fl-white); }
.round-dot--red { background: var(--fl-red); }
.round-dot--green { background: var(--fl-green); }
.round-dot--yellow { background: var(--fl-yellow); }

.round-tab[aria-pressed="true"] .round-dot { background: var(--obsidian); }

.rail-clock {
  flex: none;
  display: flex;
  align-items: baseline;
  gap: 8px;
  max-width: none;
  font-family: var(--font-mono);
}

.clock-label {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--haze);
}

.clock-value {
  font-size: 20px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  color: var(--ice);
}

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 100px);
  background: var(--night-deep);
  border-top: var(--bw) solid var(--obsidian);
  color: var(--text);
}

.footer-flags { display: flex; height: 8px; }

.flag-seg { flex: 1; height: 100%; }
.flag-seg--blue { background: var(--fl-blue); }
.flag-seg--white { background: var(--fl-white); }
.flag-seg--red { background: var(--fl-red); }
.flag-seg--green { background: var(--fl-green); }
.flag-seg--yellow { background: var(--fl-yellow); }

.footer-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 44px);
  padding-block: clamp(34px, 5vw, 62px);
}

.footer-brand {
  display: grid;
  gap: 14px;
  align-content: start;
}

.footer-brand-name {
  max-width: none;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  letter-spacing: 0.1em;
  line-height: 1;
  color: var(--snow);
}

.footer-brand-line {
  font-size: 14px;
  line-height: 1.85;
  color: var(--text-dim);
  max-width: 28em;
}

.footer-cta { justify-self: start; }

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: clamp(20px, 3vw, 36px);
}

.footer-col-title {
  max-width: none;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ice);
}

.footer-list { display: grid; gap: 10px; }

.footer-link {
  font-size: 15px;
  color: var(--text-dim);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: var(--bw-thin) solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}

.footer-link:hover { color: var(--snow); border-bottom-color: var(--fl-yellow); }

.footer-contact {
  display: grid;
  gap: 10px;
  border-top: var(--bw-thin) solid var(--line);
  padding-top: 20px;
}

.footer-contact-line {
  max-width: 62em;
  font-size: 14px;
  line-height: 1.95;
  color: var(--text-dim);
}

.footer-contact-line strong { color: var(--snow); font-family: var(--font-mono); }

.footer-note {
  max-width: 62em;
  font-size: 13px;
  line-height: 1.9;
  color: var(--haze);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  border-top: var(--bw-thin) solid var(--line);
  padding-top: 18px;
  font-size: 13px;
  color: var(--text-dim);
}

.footer-legal {
  font-family: var(--font-mono);
  letter-spacing: 0.06em;
  color: var(--haze);
}

.footer-year { font-family: var(--font-mono); letter-spacing: 0.04em; }

.footer-inline-links { display: flex; flex-wrap: wrap; gap: 16px; }

.footer-inline-links a {
  color: var(--text-dim);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.footer-inline-links a:hover { color: var(--ice); border-bottom-color: var(--ice); }

/* ---------- 16. 滚动揭示 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.42s ease, transform 0.42s ease;
}

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

/* ---------- 17. 响应式 ---------- */
@media (min-width: 860px) {
  .footer-inner { grid-template-columns: minmax(240px, 1.05fr) 2fr; }
  .footer-brand { grid-column: 1; }
  .footer-grid { grid-column: 2; }
  .footer-contact,
  .footer-bottom { grid-column: 1 / -1; }
}

@media (max-width: 860px) {
  body { font-size: 16.5px; }

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

  .site-nav {
    display: none;
    border-top: var(--bw-thin) solid var(--line-soft);
  }

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

  .nav-list {
    flex-wrap: nowrap;
    justify-content: flex-start;
    overflow-x: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--haze) transparent;
  }

  .nav-item + .nav-item { border-left: 0; }

  .nav-link {
    white-space: nowrap;
    padding: 13px 16px;
    border-bottom: 0;
    border-left: 3px solid transparent;
  }

  .nav-link:hover,
  .nav-link[aria-current="page"] { border-bottom-color: transparent; }

  .nav-link[aria-current="page"] { border-left-color: var(--fl-yellow); }

  .rail-label { display: none; }
  .clock-label { display: none; }
  .rail-inner { min-height: 52px; }
}

@media (max-width: 600px) {
  .utility-inner { justify-content: center; }
  .utility-brand { display: none; }
  .brand-name { letter-spacing: 0.1em; text-indent: 0.1em; }
  .brand-line { letter-spacing: 0.08em; }
  .footer-bottom { justify-content: flex-start; }
}

/* ---------- 18. 降低动效 ---------- */
@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;
  }

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

  .section-title::after { transition: none; }
}