/* ============================================================
   万博全站 · 共享样式表 /assets/site.css
   01 设计令牌  02 重置与基础  03 中文排版  04 通用组件
   05 头部      06 页脚        07 全局控件  08 响应式  09 减少动态
   ============================================================ */

/* ---------- 01 设计令牌 ---------- */
:root {
  --ink-blue: #0B1A2E;
  --steel-blue: #12263F;
  --edge-blue: #1D3A5C;
  --signal-orange: #FF6A1F;
  --amber: #FFB547;
  --neon-cyan: #17E0C8;
  --neutral-blue: #8FA3BC;
  --mist-white: #F2F5F9;
  --paper-grey: #E3E9F1;
  --charcoal: #0A0F16;
  --alert-red: #C8480F;

  --font-narrow: "Archivo Narrow", "Arial Narrow", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", Georgia, "SimSun", serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --shell: 1220px;
  --pad-inline: clamp(16px, 4vw, 32px);
  --header-h: 76px;

  --radius-s: 8px;
  --radius-m: 14px;
  --radius-l: 24px;

  --ease: cubic-bezier(.32, .72, 0, 1);
  --dur: 260ms;

  --shadow-float: 0 18px 48px -22px rgba(0, 0, 0, .85);
}

/* ---------- 02 重置与基础 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  padding-top: var(--header-h);
  background: var(--ink-blue);
  color: var(--mist-white);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: .012em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

body.nav-open { overflow: hidden; }

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

a { color: inherit; }

button { font: inherit; color: inherit; }

main:focus { outline: none; }

:where(a, button, [tabindex], summary):focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
  border-radius: 6px;
}

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

.skip-link {
  position: fixed;
  top: 10px; left: 10px;
  z-index: 200;
  transform: translateY(-180%);
  background: var(--amber);
  color: var(--charcoal);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .04em;
  padding: 10px 18px;
  border-radius: 999px;
  text-decoration: none;
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 03 中文排版 ---------- */
h1, h2, h3, h4, h5 {
  margin: 0;
  font-family: var(--font-narrow);
  font-weight: 700;
  line-height: 1.16;
  letter-spacing: .005em;
}

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

ul, ol { margin: 0 0 1.05em; padding-left: 1.2em; }

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

.mono-id {
  display: inline-block;
  font-size: 16px;
  letter-spacing: .08em;
  color: var(--neon-cyan);
  background: rgba(23, 224, 200, .1);
  border: 1px solid rgba(23, 224, 200, .28);
  border-radius: 6px;
  padding: 2px 10px;
}

.prose {
  max-width: 36em;
  font-size: 17px;
  line-height: 1.78;
  color: rgba(242, 245, 249, .88);
}
.prose h2 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(24px, 3vw, 32px);
  color: var(--mist-white);
  margin: 1.8em 0 .55em;
  letter-spacing: 0;
}
.prose h3 {
  font-size: 20px;
  color: var(--mist-white);
  margin: 1.6em 0 .45em;
}
.prose > :first-child { margin-top: 0; }
.prose a { color: var(--neon-cyan); text-underline-offset: 3px; }

/* ---------- 04 通用组件 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--pad-inline);
}
.shell--narrow { max-width: 820px; }

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

.panel {
  background: var(--steel-blue);
  border: 1px solid var(--edge-blue);
  border-radius: var(--radius-m);
  padding: clamp(18px, 2.4vw, 28px);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 20px;
  margin-bottom: clamp(18px, 3vw, 32px);
}
.section-head__title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: .015em;
  color: var(--mist-white);
}
.section-head__meta {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .14em;
  color: var(--neutral-blue);
}

.theme-band {
  position: relative;
  margin: clamp(40px, 6vw, 80px) 0;
  padding: clamp(20px, 3vw, 32px) clamp(18px, 3vw, 36px);
  background: linear-gradient(100deg, var(--steel-blue) 0%, rgba(18, 38, 63, .45) 62%, rgba(18, 38, 63, 0) 100%);
  border-left: 3px solid var(--neon-cyan);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .04em;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--dur) var(--ease), background-color var(--dur) var(--ease),
              color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn--lineup { background: var(--signal-orange); color: var(--charcoal); }
.btn--lineup:hover { background: var(--amber); }
.btn--v4 { background: var(--neon-cyan); color: var(--charcoal); }
.btn--v4:hover { background: #5BF0DC; }
.btn--help {
  background: rgba(143, 163, 188, .08);
  color: var(--neutral-blue);
  border-color: var(--edge-blue);
}
.btn--help:hover { color: var(--mist-white); border-color: var(--neutral-blue); }
.btn--ghost {
  background: transparent;
  color: var(--mist-white);
  border-color: var(--edge-blue);
}
.btn--ghost:hover { border-color: var(--amber); color: var(--amber); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border: 1px solid;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  line-height: 1.6;
}
.tag--lineup { color: var(--signal-orange); border-color: rgba(255, 106, 31, .42); background: rgba(255, 106, 31, .1); }
.tag--v4 { color: var(--neon-cyan); border-color: rgba(23, 224, 200, .42); background: rgba(23, 224, 200, .1); }
.tag--help { color: var(--neutral-blue); border-color: rgba(143, 163, 188, .42); background: rgba(143, 163, 188, .1); }

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--neutral-blue);
}
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.breadcrumb__list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--edge-blue);
}
.breadcrumb a { color: var(--neutral-blue); text-decoration: none; }
.breadcrumb a:hover { color: var(--neon-cyan); }

.toc { list-style: none; margin: 0; padding: 0; }
.toc__link {
  display: block;
  padding: 9px 0 9px 14px;
  border-left: 2px solid var(--edge-blue);
  color: var(--neutral-blue);
  font-size: 14.5px;
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.toc__link:hover { color: var(--mist-white); border-color: var(--neutral-blue); }
.toc__link[aria-current="true"] {
  color: var(--signal-orange);
  border-color: var(--signal-orange);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}
.data-table th,
.data-table td {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 1px solid var(--edge-blue);
  vertical-align: top;
}
.data-table thead th {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .12em;
  color: var(--neutral-blue);
}
.data-table tbody tr:nth-child(even) { background: rgba(29, 58, 92, .28); }

.pulse-strip {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding: 12px 0;
  border-top: 1px solid var(--edge-blue);
  border-bottom: 1px solid var(--edge-blue);
  scrollbar-width: none;
}
.pulse-strip::-webkit-scrollbar { display: none; }
.pulse-strip__item {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--neutral-blue);
  padding: 3px 12px;
  border-radius: 999px;
  border: 1px solid var(--edge-blue);
  background: rgba(18, 38, 63, .7);
}

.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--edge-blue);
  border-radius: var(--radius-m);
  background: linear-gradient(135deg, var(--steel-blue), var(--ink-blue) 65%);
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 600ms var(--ease);
}
.media-frame:hover img { transform: scale(1.03); }
.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--scrim::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(10, 15, 22, 0) 45%, rgba(10, 15, 22, .8) 100%);
}
.media-frame__placeholder {
  display: grid;
  place-items: center;
  width: 100%;
  min-height: 190px;
  height: 100%;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: rgba(143, 163, 188, .7);
}

/* ---------- 05 头部 ---------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 90;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(10, 15, 22, .74), rgba(10, 15, 22, 0));
  transition: opacity var(--dur) var(--ease);
}
.site-header::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  pointer-events: none;
  opacity: .55;
  background: linear-gradient(90deg,
      var(--signal-orange) 0%,
      var(--amber) 18%,
      var(--neon-cyan) 48%,
      rgba(23, 224, 200, 0) 88%);
}
.site-header.is-solid {
  background: var(--ink-blue);
  border-bottom-color: var(--edge-blue);
}
.site-header.is-solid::before { opacity: 0; }

.header-shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--pad-inline);
  min-height: 76px;
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.2vw, 30px);
  transition: min-height var(--dur) var(--ease);
}
.site-header.is-solid .header-shell { min-height: 64px; }

.brand {
  display: flex;
  flex-direction: column;
  gap: 1px;
  flex: 0 0 auto;
  padding-block: 8px;
  text-decoration: none;
  color: var(--mist-white);
}
.brand__mark {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-narrow);
  font-size: 21px;
  font-weight: 800;
  letter-spacing: .17em;
  line-height: 1.1;
}
.brand__mark::before {
  content: "";
  width: 10px;
  height: 10px;
  flex: 0 0 auto;
  background: var(--signal-orange);
  transform: rotate(45deg);
  box-shadow: 0 0 0 3px rgba(255, 106, 31, .18);
}
.brand__sub {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .22em;
  color: var(--neutral-blue);
  padding-left: 19px;
}

.primary-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: center;
}
.primary-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(6px, 1.5vw, 20px);
  margin: 0;
  padding: 0;
  list-style: none;
}
.primary-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 8px 2px;
  color: rgba(242, 245, 249, .72);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .045em;
  white-space: nowrap;
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}
.primary-nav__link::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 2px;
  height: 2px;
  background: var(--signal-orange);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}
.primary-nav__link:hover { color: var(--mist-white); }
.primary-nav__link:hover::after { transform: scaleX(1); }
.primary-nav__link[aria-current="page"] { color: var(--mist-white); }
.primary-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.header-quick {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}
.quick-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 13px;
  border: 1px solid;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .05em;
  white-space: nowrap;
  text-decoration: none;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}
.quick-pill--lineup {
  color: var(--signal-orange);
  border-color: rgba(255, 106, 31, .45);
  background: rgba(255, 106, 31, .1);
}
.quick-pill--lineup:hover { background: rgba(255, 106, 31, .24); color: var(--amber); }
.quick-pill--v4 {
  color: var(--neon-cyan);
  border-color: rgba(23, 224, 200, .45);
  background: rgba(23, 224, 200, .1);
}
.quick-pill--v4:hover { background: rgba(23, 224, 200, .24); }
.quick-pill--help {
  color: var(--neutral-blue);
  border-color: rgba(143, 163, 188, .45);
  background: rgba(143, 163, 188, .1);
}
.quick-pill--help:hover { background: rgba(143, 163, 188, .24); color: var(--mist-white); }

.nav-toggle {
  display: none;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 42px;
  padding: 0;
  background: rgba(29, 58, 92, .6);
  border: 1px solid var(--edge-blue);
  border-radius: 12px;
  cursor: pointer;
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--neutral-blue); }
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: background-color var(--dur) var(--ease);
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease);
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

/* ---------- 06 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 120px);
  background: var(--charcoal);
  color: rgba(242, 245, 249, .8);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg,
      var(--signal-orange) 0 22%,
      var(--amber) 22% 30%,
      var(--neon-cyan) 30% 58%,
      var(--neutral-blue) 58% 74%,
      var(--edge-blue) 74% 100%);
}
.footer-shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 72px) var(--pad-inline) clamp(28px, 4vw, 44px);
  display: grid;
  grid-template-columns: minmax(220px, 1.15fr) minmax(0, 2fr) minmax(230px, 1.05fr);
  gap: clamp(28px, 5vw, 64px);
}

.footer-brand__mark {
  display: block;
  font-family: var(--font-narrow);
  font-size: 24px;
  font-weight: 800;
  letter-spacing: .17em;
  color: var(--mist-white);
}
.footer-brand__line {
  margin: 12px 0 0;
  font-size: 15px;
  color: var(--neutral-blue);
  max-width: 22em;
}
.footer-brand__meta {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .07em;
  color: rgba(143, 163, 188, .78);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 36px);
}
.footer-col__title {
  margin: 0 0 14px;
  font-family: var(--font-narrow);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--mist-white);
}
.footer-col__list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.footer-col__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  color: rgba(242, 245, 249, .66);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}
.footer-col__link::before {
  content: "";
  width: 7px;
  height: 1px;
  background: var(--edge-blue);
  transition: width var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.footer-col__link:hover { color: var(--mist-white); }
.footer-col__link:hover::before { width: 16px; background: var(--signal-orange); }

.footer-contact { font-size: 14px; }
.footer-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 10px;
}
.footer-contact__value {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: .02em;
  color: var(--mist-white);
  word-break: break-all;
}
.footer-contact__addr {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--neutral-blue);
}
.footer-contact__note {
  margin: 10px 0 0;
  font-size: 12.5px;
  color: rgba(143, 163, 188, .8);
}
.copy-btn {
  padding: 3px 11px;
  background: transparent;
  border: 1px solid var(--edge-blue);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--neutral-blue);
  cursor: pointer;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}
.copy-btn:hover { color: var(--neon-cyan); border-color: rgba(23, 224, 200, .5); }
.copy-btn.is-done {
  color: var(--charcoal);
  background: var(--neon-cyan);
  border-color: var(--neon-cyan);
}

.footer-base {
  border-top: 1px solid var(--edge-blue);
  background: rgba(11, 26, 46, .6);
}
.footer-base__inner {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 18px var(--pad-inline);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  font-size: 13px;
  color: var(--neutral-blue);
}
.footer-base__copy,
.footer-base__icp { margin: 0; }
.footer-base__icp { font-family: var(--font-mono); letter-spacing: .06em; }

/* ---------- 07 全局控件 ---------- */
.scroll-rail {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 3px;
  z-index: 120;
  pointer-events: none;
}
.scroll-rail__bar {
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--signal-orange), var(--amber) 40%, var(--neon-cyan));
  transition: transform 120ms linear;
}

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 110;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  padding: 0;
  background: var(--steel-blue);
  color: var(--mist-white);
  border: 1px solid var(--edge-blue);
  border-radius: 14px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  box-shadow: var(--shadow-float);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease),
              visibility 0s linear var(--dur), background-color var(--dur) var(--ease),
              border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition-delay: 0s;
}
.to-top:hover {
  background: var(--signal-orange);
  border-color: var(--amber);
  color: var(--charcoal);
}
.to-top__glyph {
  display: block;
  width: 12px;
  height: 12px;
  border-left: 2px solid currentColor;
  border-top: 2px solid currentColor;
  transform: translateY(2px) rotate(45deg);
}

/* ---------- 08 响应式 ---------- */
@media (max-width: 1023px) {
  :root { --header-h: 118px; }

  .header-shell {
    flex-wrap: wrap;
    align-content: center;
    row-gap: 8px;
    padding-block: 10px;
    min-height: var(--header-h);
  }
  .site-header.is-solid .header-shell { min-height: var(--header-h); }

  .brand { order: 1; flex: 1 1 auto; }
  .nav-toggle { order: 2; display: inline-flex; }

  .header-quick {
    order: 3;
    flex: 1 0 100%;
    overflow-x: auto;
    padding-bottom: 3px;
    scrollbar-width: none;
  }
  .header-quick::-webkit-scrollbar { display: none; }

  .primary-nav {
    order: 4;
    position: fixed;
    top: 0; right: 0; bottom: 0;
    width: min(340px, 86vw);
    z-index: 95;
    flex-direction: column;
    justify-content: flex-start;
    gap: 0;
    padding: calc(var(--header-h) + 20px) 22px 36px;
    background: var(--steel-blue);
    border-left: 1px solid var(--edge-blue);
    box-shadow: var(--shadow-float);
    overflow-y: auto;
    transform: translateX(100%);
    visibility: hidden;
    transition: transform var(--dur) var(--ease), visibility 0s linear var(--dur);
  }
  .primary-nav[data-open="true"] {
    transform: translateX(0);
    visibility: visible;
    transition: transform var(--dur) var(--ease), visibility 0s;
  }
  .primary-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }
  .primary-nav__list > li { border-bottom: 1px solid var(--edge-blue); }
  .primary-nav__link {
    padding: 16px 4px;
    font-size: 17px;
  }
  .primary-nav__link::after { display: none; }
  .primary-nav__link[aria-current="page"] { color: var(--signal-orange); }

  .footer-shell {
    grid-template-columns: minmax(0, 1fr);
    gap: 34px;
  }
}

@media (max-width: 700px) {
  body { font-size: 16px; }
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .footer-links { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .to-top { width: 44px; height: 44px; }
}

@media (max-width: 520px) {
  :root { --header-h: 110px; }
  .brand__mark { font-size: 19px; letter-spacing: .13em; }
  .brand__sub { font-size: 10px; letter-spacing: .16em; padding-left: 17px; }
  .quick-pill { font-size: 12px; padding: 6px 11px; }
  .footer-links { grid-template-columns: minmax(0, 1fr); }
  .footer-base__inner { justify-content: flex-start; }
}

/* ---------- 09 减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0s !important;
  }

  .media-frame:hover img { transform: none; }
  .btn:hover { transform: none; }
}