/* ============================================================
   链接赛场 · 共享样式表 /assets/site.css
   路线图隐喻：玻璃浮岛 / 实色阅读面 / 绿色节点 / 暖橙旧版
   ============================================================ */

/* ---------- 1. 设计变量 ---------- */
:root {
  --ink: #0B1F3A;
  --paper: #F7F9F2;
  --card: #FFFFFF;
  --kiwi: #8DC63F;
  --kiwi-deep: #5E8F24;
  --kiwi-soft: #DDEBC8;
  --orange: #FF8A3D;
  --orange-deep: #B5501B;
  --black: #111827;
  --slate: #5B6577;
  --mist: #E8EDF5;

  --line: rgba(11, 31, 58, .12);
  --line-soft: rgba(11, 31, 58, .07);

  --font-display: "HarmonyOS Sans SC", "MiSans", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", SFMono-Regular, ui-monospace, Menlo, Consolas, monospace;

  --radius-pill: 999px;
  --radius-lg: 22px;
  --radius-md: 14px;
  --radius-sm: 10px;

  --shell: 1320px;
  --gutter: clamp(18px, 3.2vw, 34px);
  --header-h: 74px;
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--black);
  font-family: var(--font-body);
  font-size: clamp(16px, .55rem + .42vw, 17.5px);
  line-height: 1.78;
  letter-spacing: .008em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

ul, ol { margin: 0 0 1.05em; padding-left: 1.25em; }

/* ---------- 3. 中文排版 ---------- */
h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  color: var(--ink);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.18;
  margin: 0 0 .55em;
}

h1 { font-size: clamp(2.4rem, 5.4vw, 4.4rem); line-height: 1.08; }
h2 { font-size: clamp(1.55rem, 2.9vw, 2.35rem); }
h3 { font-size: clamp(1.1rem, 1.6vw, 1.35rem); line-height: 1.38; }
h4 { font-size: 1rem; letter-spacing: -.01em; }

p { margin: 0 0 1.05em; }
p:last-child { margin-bottom: 0; }

a {
  color: var(--kiwi-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
a:hover { color: var(--ink); }

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

code, kbd, samp, .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

hr {
  border: 0;
  border-top: 1px solid var(--line-soft);
  margin: clamp(28px, 4vw, 48px) 0;
}

:focus-visible {
  outline: 3px solid var(--kiwi-deep);
  outline-offset: 3px;
  border-radius: 6px;
}

#main-content { scroll-margin-top: calc(var(--header-h) + 26px); }

/* ---------- 4. 容器与网格 ---------- */
.container {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(22px, 2.8vw, 40px);
  align-items: start;
}

.rail-col { grid-column: 1 / span 3; min-width: 0; }
.main-col { grid-column: 4 / span 9; min-width: 0; }

.rail-sticky {
  position: sticky;
  top: 96px;
}

@media (max-width: 940px) {
  .content-grid { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .rail-col, .main-col { grid-column: 1 / -1; }
  .rail-sticky { position: static; }
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: 0;
  transform: translate(-50%, -150%);
  z-index: 400;
  padding: 12px 24px;
  border-radius: 0 0 14px 14px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-display);
  font-size: .86rem;
  font-weight: 700;
  text-decoration: none;
  transition: transform .2s ease;
}
.skip-link:focus-visible {
  transform: translate(-50%, 0);
  outline-offset: -4px;
}

/* ---------- 6. 头部：三座轻量浮岛 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  padding: 14px var(--gutter) 10px;
  transition: padding .3s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0 0 -22px;
  background: linear-gradient(180deg, rgba(247, 249, 242, .97) 34%, rgba(247, 249, 242, 0));
  pointer-events: none;
}

.header-shell {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: var(--shell);
  margin-inline: auto;
}

.site-header.is-condensed { padding-top: 8px; padding-bottom: 6px; }

/* 品牌浮岛 */
.brand-island {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px 8px 12px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, .80);
  border: 1px solid var(--line);
  -webkit-backdrop-filter: blur(12px) saturate(1.25);
  backdrop-filter: blur(12px) saturate(1.25);
  text-decoration: none;
  color: var(--ink);
  transition: border-color .2s ease, background-color .2s ease;
}
.brand-island:hover { border-color: rgba(94, 143, 36, .55); }

.brand-mark {
  position: relative;
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--ink);
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, .16);
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background: var(--kiwi);
  box-shadow: 0 0 0 3px rgba(141, 198, 63, .24);
}

.brand-text { display: flex; flex-direction: column; line-height: 1.15; }

.brand-name {
  font-family: var(--font-display);
  font-size: .96rem;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
}

.brand-tagline {
  font-size: .66rem;
  letter-spacing: .14em;
  color: var(--slate);
  max-height: 16px;
  overflow: hidden;
  transition: opacity .22s ease, max-height .22s ease;
}

.site-header.is-condensed .brand-tagline { opacity: 0; max-height: 0; }

/* 栏目胶囊 */
.site-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: center;
}

.nav-list {
  list-style: none;
  margin: 0;
  padding: 5px;
  display: flex;
  align-items: center;
  gap: 2px;
  max-width: 100%;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, .62);
  border: 1px solid var(--line-soft);
  -webkit-backdrop-filter: blur(14px) saturate(1.3);
  backdrop-filter: blur(14px) saturate(1.3);
  overflow-x: auto;
  scrollbar-width: none;
}
.nav-list::-webkit-scrollbar { display: none; }

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 13px;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .01em;
  color: var(--slate);
  text-decoration: none;
  white-space: nowrap;
  min-height: 38px;
  transition: color .18s ease, background-color .18s ease;
}
.nav-link:hover { color: var(--ink); background: rgba(11, 31, 58, .06); }

.nav-link[aria-current="page"] {
  color: var(--ink);
  background: var(--kiwi-soft);
  box-shadow: inset 0 0 0 1px rgba(94, 143, 36, .34);
}
.nav-link[aria-current="page"]::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--kiwi-deep);
  flex: 0 0 auto;
}

/* 行动岛 */
.header-cta {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius-pill);
  background: var(--kiwi);
  border: 1px solid rgba(11, 31, 58, .16);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: .85rem;
  font-weight: 800;
  letter-spacing: .02em;
  text-decoration: none;
  box-shadow: 0 8px 22px -14px rgba(94, 143, 36, .95);
  transition: transform .18s ease, background-color .18s ease, box-shadow .18s ease;
}
.header-cta:hover {
  background: #9AD24C;
  color: var(--ink);
  transform: translateY(-1px);
  box-shadow: 0 12px 26px -14px rgba(94, 143, 36, 1);
}
.header-cta-arrow { transition: transform .18s ease; }
.header-cta:hover .header-cta-arrow { transform: translateX(3px); }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  min-height: 44px;
  padding: 0 15px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, .84);
  border: 1px solid var(--line);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: .82rem;
  font-weight: 700;
  cursor: pointer;
}
.nav-toggle:hover { border-color: rgba(94, 143, 36, .55); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
}
.nav-toggle-bars span {
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--ink);
  transition: transform .22s ease;
}
.nav-toggle-bars span:nth-child(1) { top: 0; }
.nav-toggle-bars span:nth-child(2) { bottom: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(2) { transform: translateY(-4px) rotate(-45deg); }

/* ---------- 7. 头部响应式 ---------- */
@media (max-width: 1180px) {
  .nav-link { padding: 9px 10px; font-size: .78rem; }
}

@media (max-width: 1080px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    display: none;
    z-index: 6;
  }
  .site-nav[data-open] { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 10px;
    border-radius: 24px;
    background: rgba(255, 255, 255, .95);
    -webkit-backdrop-filter: blur(18px) saturate(1.4);
    backdrop-filter: blur(18px) saturate(1.4);
    box-shadow: 0 26px 50px -28px rgba(11, 31, 58, .65);
    max-height: min(70vh, 540px);
    overflow-y: auto;
    overflow-x: hidden;
  }

  .nav-link {
    min-height: 48px;
    padding: 0 16px;
    font-size: .95rem;
    justify-content: flex-start;
    border-radius: 16px;
  }
}

@media (max-width: 560px) {
  .site-header { padding-inline: 12px; }
  .brand-tagline { display: none; }
  .header-cta { padding: 0 15px; font-size: .8rem; }
  .nav-toggle-text { display: none; }
  .nav-toggle { padding: 0 13px; }
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 118px);
  background: var(--ink);
  color: rgba(247, 249, 242, .74);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(680px 320px at 6% -12%, rgba(141, 198, 63, .22), transparent 62%),
    radial-gradient(520px 280px at 94% 112%, rgba(255, 138, 61, .14), transparent 60%),
    repeating-linear-gradient(115deg, rgba(255, 255, 255, .045) 0 1px, transparent 1px 70px);
}

.footer-inner {
  position: relative;
  z-index: 1;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(46px, 7vw, 84px) var(--gutter) 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) repeat(3, minmax(0, 1fr));
  gap: clamp(28px, 4vw, 56px);
}

.footer-brand { min-width: 0; }

.brand-island--footer {
  background: rgba(255, 255, 255, .07);
  border-color: rgba(255, 255, 255, .16);
  color: var(--paper);
}
.brand-island--footer:hover { border-color: rgba(141, 198, 63, .65); }
.brand-island--footer .brand-mark { background: var(--kiwi); box-shadow: none; }
.brand-island--footer .brand-mark::after { background: var(--ink); box-shadow: 0 0 0 3px rgba(11, 31, 58, .35); }
.brand-island--footer .brand-name { color: var(--paper); }
.brand-island--footer .brand-tagline { color: rgba(247, 249, 242, .58); }

.footer-summary {
  margin-top: 18px;
  max-width: 34ch;
  font-size: .92rem;
  line-height: 1.75;
  color: rgba(247, 249, 242, .80);
}

.footer-note {
  margin-top: 14px;
  max-width: 38ch;
  font-size: .76rem;
  line-height: 1.7;
  color: rgba(247, 249, 242, .48);
}

.footer-col { min-width: 0; }

.footer-title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--kiwi);
}

.footer-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: .88rem;
}

.footer-link {
  display: inline-block;
  color: rgba(247, 249, 242, .78);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s ease, border-color .18s ease;
  word-break: break-word;
}
.footer-link:hover,
.footer-link:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--kiwi);
}

.footer-static {
  color: rgba(247, 249, 242, .60);
  font-size: .84rem;
  line-height: 1.7;
  display: inline-block;
  word-break: break-word;
}

.footer-bar {
  margin-top: clamp(34px, 5vw, 62px);
  padding: 20px 0 30px;
  border-top: 1px solid rgba(247, 249, 242, .14);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
}

.footer-legal {
  margin: 0;
  font-size: .76rem;
  letter-spacing: .02em;
  color: rgba(247, 249, 242, .52);
}

.footer-mark {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .12em;
  color: rgba(141, 198, 63, .9);
}
.footer-mark::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--kiwi);
  box-shadow: 0 0 0 4px rgba(141, 198, 63, .18);
}

@media (max-width: 980px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 600px) {
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-bar { flex-direction: column; align-items: flex-start; }
}

/* ---------- 9. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-family: var(--font-display);
  font-size: .9rem;
  font-weight: 700;
  letter-spacing: .02em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .18s ease, background-color .18s ease, color .18s ease, border-color .18s ease, box-shadow .18s ease;
}
.btn:hover { transform: translateY(-1px); }

.btn--primary {
  background: var(--kiwi);
  color: var(--ink);
  border-color: rgba(11, 31, 58, .16);
  box-shadow: 0 12px 26px -16px rgba(94, 143, 36, .95);
}
.btn--primary:hover { background: #9AD24C; color: var(--ink); }

.btn--ink { background: var(--ink); color: var(--paper); }
.btn--ink:hover { background: #122C4D; color: var(--paper); }

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

.btn--legacy {
  background: transparent;
  color: var(--orange-deep);
  border-color: rgba(255, 138, 61, .65);
}
.btn--legacy:hover { background: rgba(255, 138, 61, .14); color: var(--orange-deep); }

.btn--sm { min-height: 38px; padding: 0 16px; font-size: .82rem; }

/* ---------- 10. 章节、标签、面包屑 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--kiwi-deep);
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--kiwi);
}

.section-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px clamp(12px, 2vw, 22px);
  margin-bottom: clamp(20px, 3vw, 34px);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-soft);
}
.section-head h2,
.section-head h3 { margin: 0; }

.section-num {
  font-family: var(--font-mono);
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  font-weight: 700;
  line-height: .92;
  letter-spacing: -.05em;
  color: var(--kiwi-deep);
}

.breadcrumb {
  margin-bottom: clamp(16px, 2.2vw, 26px);
  font-size: .78rem;
  color: var(--slate);
}
.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
}
.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 6px;
}
.breadcrumb li + li::before {
  content: "›";
  color: rgba(11, 31, 58, .32);
}
.breadcrumb a { color: var(--slate); text-decoration: none; }
.breadcrumb a:hover { color: var(--kiwi-deep); text-decoration: underline; }
.breadcrumb [aria-current="page"] { color: var(--ink); font-weight: 600; }

/* ---------- 11. 卡片与徽标 ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 2.4vw, 30px);
}

.card--glass {
  background: rgba(255, 255, 255, .66);
  border-color: rgba(255, 255, 255, .72);
  -webkit-backdrop-filter: blur(14px) saturate(1.25);
  backdrop-filter: blur(14px) saturate(1.25);
  box-shadow: 0 20px 44px -32px rgba(11, 31, 58, .6);
}

.card--ink {
  background: var(--ink);
  border-color: rgba(255, 255, 255, .12);
  color: rgba(247, 249, 242, .80);
}
.card--ink h2,
.card--ink h3,
.card--ink h4 { color: var(--paper); }

.card--offset { transform: translateY(clamp(0px, 1.6vw, 22px)); }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: var(--mist);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .04em;
}
.badge--new { background: var(--kiwi-soft); color: var(--kiwi-deep); }
.badge--legacy { background: rgba(255, 138, 61, .18); color: var(--orange-deep); }

/* ---------- 12. 可访问标签页 ---------- */
.tabs { display: block; }

.tablist {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: clamp(18px, 2.4vw, 26px);
  padding: 5px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, .62);
  border: 1px solid var(--line-soft);
  -webkit-backdrop-filter: blur(12px) saturate(1.2);
  backdrop-filter: blur(12px) saturate(1.2);
}

.tab {
  appearance: none;
  border: 0;
  background: transparent;
  padding: 9px 18px;
  min-height: 42px;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: .86rem;
  font-weight: 700;
  color: var(--slate);
  cursor: pointer;
  transition: color .18s ease, background-color .18s ease;
}
.tab:hover { color: var(--ink); background: rgba(11, 31, 58, .06); }
.tab[aria-selected="true"] { background: var(--ink); color: var(--paper); }

.tab-panel {
  animation: panel-in .18s ease both;
}
.tab-panel[hidden] { display: none; }

@keyframes panel-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 13. 筛选 chips ---------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 38px;
  padding: 0 15px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--slate);
  font-family: var(--font-body);
  font-size: .8rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}
.chip:hover { color: var(--ink); border-color: var(--kiwi-deep); }
.chip[aria-pressed="true"] {
  background: var(--kiwi-soft);
  border-color: rgba(94, 143, 36, .42);
  color: var(--ink);
}

/* ---------- 14. 表格 ---------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--card);
}

.data-table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: .9rem;
}
.data-table caption {
  caption-side: top;
  padding: 14px 16px;
  text-align: left;
  font-size: .8rem;
  color: var(--slate);
}
.data-table th,
.data-table td {
  padding: 12px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line-soft);
}
.data-table thead th {
  background: var(--ink);
  color: rgba(247, 249, 242, .88);
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.data-table tbody tr:nth-child(even) { background: rgba(232, 237, 245, .44); }
.data-table tbody tr:last-child td { border-bottom: 0; }

/* ---------- 15. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background-color: var(--mist);
  background-image:
    radial-gradient(120% 90% at 12% 8%, rgba(141, 198, 63, .30), transparent 58%),
    repeating-linear-gradient(118deg, rgba(11, 31, 58, .07) 0 2px, transparent 2px 26px);
  aspect-ratio: 16 / 9;
}
.media-frame > img,
.media-frame > svg,
.media-frame > picture > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--wide { aspect-ratio: 21 / 9; }

.media-frame--route::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 36%;
  background: linear-gradient(180deg, transparent, rgba(11, 31, 58, .30));
  pointer-events: none;
}

.media-caption {
  margin: 10px 2px 0;
  font-size: .76rem;
  line-height: 1.65;
  color: var(--slate);
}

/* ---------- 16. 滚动进度 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 200;
  pointer-events: none;
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--kiwi-deep), var(--kiwi) 62%, var(--orange));
}

/* ---------- 17. 工具类 ---------- */
.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;
}

.stack > * + * { margin-top: clamp(16px, 2vw, 26px); }

.cluster {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

/* ---------- 18. 动效与可访问降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

  .tab-panel { animation: none; }
  .btn:hover,
  .header-cta:hover { transform: none; }
  .card--offset { transform: none; }
  .header-cta:hover .header-cta-arrow { transform: none; }
}