/* ==========================================================================
   88体育看台 · 共享站点样式 /assets/site.css
   高原看台命令栏 / 台阶式导航 / 经幡五色信号 / 锐利直角与精密网格
   ========================================================================== */

/* ---------- 1. 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, dd, ul, ol { margin: 0; }

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

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

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

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

[hidden] { display: none !important; }

/* ---------- 2. Tokens ---------- */
:root {
  /* 高原夜空 */
  --navy: #0B1B33;
  --navy-deep: #08152A;
  --navy-2: #12294A;
  --navy-3: #1B3348;

  /* 浅区与文字 */
  --snow: #F4F7FB;
  --white: #FFFFFF;

  /* 功能色 */
  --orange: #FF7A1A;
  --orange-soft: #FF9147;
  --orange-ink: #1A0D00;
  --link: #8CC4FF;
  --red: #D64545;
  --green: #2E9B6B;
  --yellow: #F2C14E;

  /* 中性辅助 */
  --mist: #A9BDC9;
  --line: #7F97A8;
  --line-soft: rgba(127, 151, 168, 0.28);
  --line-faint: rgba(169, 189, 201, 0.16);
  --ink-link-light: #0F5FA8;

  /* 字体 */
  --font-display: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-body: var(--font-display);
  --font-mono: 'IBM Plex Mono', 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 空间 */
  --sp-1: 8px;
  --sp-2: 16px;
  --sp-3: 24px;
  --sp-4: 32px;
  --sp-5: 48px;
  --sp-6: 72px;
  --sp-7: 104px;

  --gutter: clamp(16px, 4vw, 40px);
  --maxw: 1320px;
  --header-h: 76px;

  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

/* ---------- 3. Base / 中文排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--navy);
  background-image:
    linear-gradient(to right, rgba(169, 189, 201, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(169, 189, 201, 0.045) 1px, transparent 1px);
  background-size: 88px 88px;
  color: var(--snow);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

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

code, kbd, samp, time, .mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.06em;
}

hr {
  border: 0;
  height: 1px;
  background: var(--line-soft);
}

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

#main-content { scroll-margin-top: calc(var(--header-h) + 48px); }

.container {
  width: calc(100% - var(--gutter) * 2);
  max-width: var(--maxw);
  margin-inline: auto;
}

/* 键盘焦点统一环 */
:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 3px;
  border-radius: 0;
}

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

/* ---------- 4. Skip link ---------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 300;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 20px;
  background: var(--yellow);
  color: var(--navy);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transform: translateY(-260%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--navy);
  outline-offset: -6px;
}

/* ---------- 5. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 44px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 0;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  transition: background 0.18s var(--ease), color 0.18s var(--ease),
              border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

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

.btn-primary:hover {
  background: var(--orange-soft);
  border-color: var(--orange-soft);
  color: var(--orange-ink);
}

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

.btn-ghost:hover {
  background: rgba(140, 196, 255, 0.08);
  border-color: var(--link);
  color: var(--link);
}

.btn-block { width: 100%; }

/* ---------- 6. Header：命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: var(--navy-2);
  border-bottom: 1px solid var(--line-soft);
}

.site-header[data-scrolled] {
  box-shadow: 0 18px 40px rgba(3, 10, 20, 0.45);
}

/* 6.1 状态轨 */
.header-rail {
  background: var(--navy-deep);
  border-bottom: 1px solid rgba(127, 151, 168, 0.18);
}

.header-rail-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-2);
  min-height: 34px;
}

.rail-status {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  font-size: 12.5px;
  line-height: 1.4;
  color: var(--mist);
}

.rail-dot {
  flex: none;
  width: 7px;
  height: 7px;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(46, 155, 107, 0.18);
}

.rail-label {
  flex: none;
  padding-right: 10px;
  border-right: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--link);
}

.rail-text {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.rail-meta {
  display: flex;
  flex: none;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.rail-meta-sep {
  width: 1px;
  height: 11px;
  background: var(--line-soft);
}

/* 6.2 主导航条 */
.header-bar { position: relative; background: var(--navy-2); }

.header-bar-inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  min-height: var(--header-h);
}

.brand {
  display: flex;
  flex: none;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  padding-block: 8px;
}

.brand-mark {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 26px;
}

.brand-rung {
  width: 4px;
  background: var(--line);
  transition: background 0.2s var(--ease), height 0.2s var(--ease);
}

.brand-rung:nth-child(1) { height: 24%; background: var(--link); }
.brand-rung:nth-child(2) { height: 44%; background: var(--snow); }
.brand-rung:nth-child(3) { height: 64%; background: var(--red); }
.brand-rung:nth-child(4) { height: 82%; background: var(--green); }
.brand-rung:nth-child(5) { height: 100%; background: var(--yellow); }

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 3px;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 900;
  letter-spacing: 0.04em;
  color: var(--white);
  transition: color 0.18s var(--ease);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--mist);
}

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

/* 6.3 导航链接 */
.site-nav { margin-left: auto; }

.nav-list {
  display: flex;
  align-items: stretch;
}

.nav-item { display: flex; }

.nav-link {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 2px;
  min-height: 44px;
  padding: 12px clamp(9px, 1.3vw, 17px);
  color: var(--snow);
  transition: background 0.18s var(--ease), color 0.18s var(--ease);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 10px;
  line-height: 1;
  letter-spacing: 0.14em;
  color: rgba(169, 189, 201, 0.78);
  transition: color 0.18s var(--ease);
}

.nav-label {
  font-size: 15px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: clamp(9px, 1.3vw, 17px);
  right: clamp(9px, 1.3vw, 17px);
  bottom: 7px;
  height: 1px;
  background: var(--link);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s var(--ease), background 0.18s var(--ease);
}

.nav-link:hover { background: rgba(140, 196, 255, 0.08); }
.nav-link:hover .nav-index,
.nav-link:hover .nav-label { color: var(--link); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] {
  background: rgba(140, 196, 255, 0.12);
  color: var(--white);
}

.nav-link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--link);
}

.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--orange);
}

.nav-link[aria-current="page"] .nav-index { color: var(--link); }
.nav-link[aria-current="page"] .nav-label { font-weight: 700; }

/* 6.4 右侧动作区 & 开关 */
.header-actions {
  display: flex;
  flex: none;
  align-items: center;
  gap: 10px;
  margin-left: clamp(6px, 1.2vw, 18px);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid var(--line-soft);
  background: transparent;
  color: var(--snow);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

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

.nav-toggle-icon {
  display: block;
  width: 18px;
  height: 12px;
  background:
    linear-gradient(currentColor, currentColor) top / 100% 2px no-repeat,
    linear-gradient(currentColor, currentColor) center / 100% 2px no-repeat,
    linear-gradient(currentColor, currentColor) bottom / 100% 2px no-repeat;
}

.site-header[data-open] .nav-toggle {
  border-color: var(--orange);
  color: var(--orange);
}

/* 6.5 滚动进度 */
.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(127, 151, 168, 0.18);
  pointer-events: none;
}

.scroll-meter-fill {
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--link) 0%, var(--orange) 100%);
  transform: scaleX(0);
  transform-origin: left center;
}

/* 6.6 移动面板底部块（桌面隐藏） */
.nav-foot { display: none; }

/* ---------- 7. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: var(--sp-7);
  background: var(--navy-deep);
  border-top: 1px solid var(--line-soft);
  color: var(--snow);
}

.footer-flag {
  display: flex;
  height: 6px;
}

.footer-flag span { display: block; height: 100%; }
.footer-flag span:nth-child(1) { flex: 5 1 0; background: var(--link); }
.footer-flag span:nth-child(2) { flex: 3 1 0; background: var(--snow); }
.footer-flag span:nth-child(3) { flex: 4 1 0; background: var(--red); }
.footer-flag span:nth-child(4) { flex: 3 1 0; background: var(--green); }
.footer-flag span:nth-child(5) { flex: 2 1 0; background: var(--yellow); }

.footer-inner {
  padding-block: var(--sp-6) var(--sp-3);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.7fr) minmax(0, 0.7fr) minmax(0, 1.25fr);
  gap: var(--sp-5) var(--sp-4);
  padding-bottom: var(--sp-5);
  border-bottom: 1px solid var(--line-faint);
}

.footer-brand-line {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 900;
  line-height: 1.3;
  letter-spacing: 0.02em;
  color: var(--white);
}

.footer-brand-note {
  margin-top: 12px;
  font-size: 13.5px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  margin-top: 14px;
  padding-bottom: 2px;
  border-bottom: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--snow);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-brand-link:hover {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

.footer-group-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--link);
}

.footer-group-title::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--link);
}

.footer-list { display: grid; }

.footer-list a {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding-left: 0;
  font-size: 15px;
  color: var(--snow);
  transition: color 0.18s var(--ease), padding-left 0.18s var(--ease);
}

.footer-list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 1px;
  background: var(--orange);
  transition: width 0.18s var(--ease);
}

.footer-list a:hover {
  padding-left: 18px;
  color: var(--orange);
}

.footer-list a:hover::before { width: 12px; }

.contact-list { display: grid; gap: 14px; }

.contact-item { display: block; }

.contact-key {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mist);
}

.contact-val {
  display: block;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--snow);
  overflow-wrap: anywhere;
}

.contact-note {
  margin-top: 18px;
  padding-left: 12px;
  border-left: 2px solid var(--yellow);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 28px;
  padding-top: var(--sp-3);
}

.footer-legal {
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.footer-legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0 22px;
}

.footer-legal-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  border-bottom: 1px solid transparent;
  font-size: 13.5px;
  color: var(--snow);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

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

.footer-copy {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  margin-left: auto;
  padding: 10px 18px;
  border: 1px solid var(--line-soft);
  background: transparent;
  color: var(--snow);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  transition: background 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.to-top::after {
  content: "↑";
  font-size: 14px;
  line-height: 1;
}

.to-top:hover {
  background: var(--yellow);
  border-color: var(--yellow);
  color: var(--navy);
}

/* ---------- 8. 版面骨架 ---------- */
.section { padding-block: clamp(48px, 7vw, 96px); }
.section--tight { padding-block: clamp(32px, 4vw, 56px); }

.section--stage {
  background: var(--navy-2);
  border-block: 1px solid var(--line-soft);
}

.section--deep {
  background: var(--navy-deep);
  border-block: 1px solid var(--line-faint);
}

.section--light {
  background: var(--snow);
  color: var(--navy);
}

.section--light h2,
.section--light h3,
.section--light h4 { color: var(--navy); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px 32px;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.section-title {
  font-size: clamp(26px, 3.4vw, 42px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.015em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--link);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}

.section--light .eyebrow { color: var(--ink-link-light); }

/* ---------- 9. 网格 ---------- */
.grid-split {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 48px);
}

.grid-split > .col-narrow { grid-column: span 4; }
.grid-split > .col-wide { grid-column: span 8; }

.grid-split-rev > .col-narrow { grid-column: span 5; }
.grid-split-rev > .col-wide { grid-column: span 7; }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 28px);
}

/* ---------- 10. 文本容器 ---------- */
.prose { max-width: 68ch; }

.prose > * + * { margin-top: 1.05em; }

.prose h2 { margin-top: 1.8em; font-size: clamp(22px, 2.4vw, 30px); }
.prose h3 { margin-top: 1.5em; font-size: clamp(18px, 1.8vw, 22px); }

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

.prose a:hover { color: var(--orange); }

.section--light .prose a { color: var(--ink-link-light); }
.section--light .prose a:hover { color: #B8480E; }

.prose ul,
.prose ol {
  padding-left: 1.2em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

.prose li + li { margin-top: 0.45em; }

.prose blockquote {
  padding-left: 16px;
  border-left: 2px solid var(--orange);
  color: var(--mist);
}

.section--light .prose blockquote { color: var(--navy-2); }

/* ---------- 11. 面包屑 ---------- */
.breadcrumb { padding-block: var(--sp-3) 0; }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mist);
}

.breadcrumb-list li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb-list li + li::before {
  content: "/";
  color: var(--line);
}

.breadcrumb-list a {
  color: var(--snow);
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: var(--line-soft);
}

.breadcrumb-list a:hover {
  color: var(--link);
  text-decoration-color: var(--link);
}

.breadcrumb-list [aria-current="page"] { color: var(--yellow); }

/* ---------- 12. 基础组件 ---------- */
.metric {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(40px, 6vw, 76px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.metric--sm { font-size: clamp(28px, 3.4vw, 44px); }

.metric-label {
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 2px 9px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 10.5px;
  line-height: 1.7;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.tag--blue { color: var(--link); }
.tag--red { color: var(--red); }
.tag--green { color: var(--green); }
.tag--yellow { color: var(--yellow); }
.tag--orange { color: var(--orange); }

.rule {
  display: block;
  height: 1px;
  border: 0;
  background: var(--line-soft);
}

.rule--flag {
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--link) 0 22%,
    var(--snow) 22% 38%,
    var(--red) 38% 58%,
    var(--green) 58% 78%,
    var(--yellow) 78% 100%
  );
}

.stack > * + * { margin-top: var(--sp-2); }
.stack-lg > * + * { margin-top: var(--sp-3); }

/* ---------- 13. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  background-color: var(--navy-3);
  background-image: repeating-linear-gradient(
    135deg,
    rgba(140, 196, 255, 0.09) 0 1px,
    transparent 1px 14px
  );
  border: 1px solid var(--line-soft);
  aspect-ratio: 16 / 10;
}

.media-frame > img,
.media-frame > video,
.media-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame--flush { border-color: transparent; }

.media-frame figcaption,
.media-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 10px 14px;
  background: linear-gradient(180deg, rgba(8, 21, 42, 0) 0%, rgba(8, 21, 42, 0.88) 100%);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--snow);
}

/* ---------- 14. 平板 ---------- */
@media (max-width: 1100px) {
  .nav-toggle { display: inline-flex; }
  .header-cta { display: none; }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    max-height: calc(100dvh - 120px);
    overflow-y: auto;
    background: var(--navy);
    border-top: 1px solid var(--line-soft);
    border-bottom: 1px solid var(--line-soft);
    box-shadow: 0 26px 52px rgba(3, 10, 20, 0.6);
    padding-bottom: var(--sp-1);
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
  }

  .nav-item { width: 100%; }

  .nav-link {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    gap: 14px;
    min-height: 54px;
    padding: 16px var(--gutter);
    border-bottom: 1px solid var(--line-faint);
  }

  .nav-link::after { display: none; }

  .nav-link[aria-current="page"] {
    background: rgba(140, 196, 255, 0.1);
  }

  .nav-link[aria-current="page"]::before { width: 3px; }

  .nav-index {
    width: 26px;
    flex: none;
    font-size: 11px;
  }

  .nav-label { font-size: 16px; font-weight: 700; }

  /* 台阶式缩进 */
  .nav-item:nth-child(2) .nav-link { padding-left: calc(var(--gutter) + 14px); }
  .nav-item:nth-child(3) .nav-link { padding-left: calc(var(--gutter) + 28px); }
  .nav-item:nth-child(4) .nav-link { padding-left: calc(var(--gutter) + 42px); }
  .nav-item:nth-child(5) .nav-link { padding-left: calc(var(--gutter) + 56px); }
  .nav-item:nth-child(6) .nav-link { padding-left: calc(var(--gutter) + 70px); }

  .nav-foot {
    display: block;
    padding: 18px var(--gutter) 10px;
    background: var(--navy-2);
    border-top: 1px solid var(--line-soft);
  }

  .nav-foot-note {
    margin-top: 8px;
    font-size: 12px;
    color: var(--mist);
  }

  .grid-split,
  .grid-split-rev {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .grid-split > .col-narrow,
  .grid-split > .col-wide,
  .grid-split-rev > .col-narrow,
  .grid-split-rev > .col-wide { grid-column: 1 / -1; }

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--sp-4);
  }

  .footer-brand { grid-column: 1 / -1; }
}

/* ---------- 15. 手机 ---------- */
@media (max-width: 640px) {
  :root { --header-h: 64px; }

  body { font-size: 16px; }

  .header-rail-inner { min-height: 30px; }

  .rail-label { display: none; }
  .rail-status { font-size: 11.5px; }
  .rail-meta { font-size: 9.5px; letter-spacing: 0.12em; }
  .rail-meta > span:first-child { display: none; }
  .rail-meta-sep { display: none; }

  .brand-mark { height: 22px; }
  .brand-name { font-size: 17px; }
  .brand-sub { font-size: 8.5px; letter-spacing: 0.2em; }

  .nav-toggle { padding: 10px 12px; }

  .nav-item:nth-child(2) .nav-link { padding-left: calc(var(--gutter) + 10px); }
  .nav-item:nth-child(3) .nav-link { padding-left: calc(var(--gutter) + 20px); }
  .nav-item:nth-child(4) .nav-link { padding-left: calc(var(--gutter) + 30px); }
  .nav-item:nth-child(5) .nav-link { padding-left: calc(var(--gutter) + 40px); }
  .nav-item:nth-child(6) .nav-link { padding-left: calc(var(--gutter) + 50px); }

  .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .site-footer { margin-top: var(--sp-6); }
  .footer-inner { padding-block: var(--sp-5) var(--sp-2); }

  .footer-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-4);
    padding-bottom: var(--sp-4);
  }

  .footer-brand-line { font-size: 18px; }
  .footer-bottom { gap: 6px 18px; }
  .footer-legal { width: 100%; }
  .to-top { margin-left: 0; }
  .footer-copy { order: 3; }
}

/* ---------- 16. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .btn:hover,
  .footer-brand-link:hover { transform: none; }
}