/* ==========================================================================
   XBET主页 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 页头 / 页脚 / 通用组件 / 响应式
   ========================================================================== */

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

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

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

ul, ol { list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }

/* --- 变量 ----------------------------------------------------------------- */
:root {
  --deep-ink: #070B24;
  --indigo-core: #121A45;
  --surface-glass: #1C2559;
  --electric-cyan: #00E9FF;
  --neon-orange: #FF6A1F;
  --neon-purple: #8B5CF6;
  --slate-text: #C3CEE8;
  --muted-gray-blue: #6E7CA8;
  --data-mint: #2BE39A;
  --alert-amber: #FFC24B;

  --ink-strong: #F3F7FF;
  --line: rgba(0, 233, 255, .18);
  --line-soft: rgba(110, 124, 168, .22);

  --header-h: 84px;
  --rail: 1280px;
  --gutter: clamp(18px, 4vw, 56px);

  --radius: 18px;
  --radius-sm: 12px;

  --font-display: "Arial Black", "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-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  --ease-out: cubic-bezier(.22, .8, .28, 1);
}

/* --- 基底与中文排版 -------------------------------------------------------- */
body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--deep-ink);
  background-image:
    linear-gradient(rgba(0, 233, 255, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 233, 255, .045) 1px, transparent 1px);
  background-size: 72px 72px;
  color: var(--slate-text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: .012em;
  text-rendering: optimizeLegibility;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(58% 46% at 10% -4%, rgba(139, 92, 246, .16), transparent 70%),
    radial-gradient(48% 38% at 102% 10%, rgba(0, 233, 255, .12), transparent 70%),
    radial-gradient(42% 40% at 50% 106%, rgba(255, 106, 31, .09), transparent 72%);
}

header,
main,
.site-footer { position: relative; z-index: 1; }

main { padding-top: var(--header-h); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: .04em;
  line-height: 1.18;
  color: var(--ink-strong);
}

h1 { font-size: clamp(34px, 6vw, 64px); }
h2 { font-size: clamp(26px, 4vw, 40px); }
h3 { font-size: clamp(20px, 2.4vw, 24px); }
h4 { font-size: 19px; }

p { max-width: 40em; }

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

::selection { background: rgba(0, 233, 255, .28); color: #FFFFFF; }

:focus-visible {
  outline: 2px solid var(--electric-cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

/* --- 布局工具 ------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: 820px; }
.container--prose { max-width: 760px; }

.grid {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }

.stack > * + * { margin-top: clamp(14px, 2vw, 22px); }

.prose { max-width: 38em; }
.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.text-muted { color: var(--muted-gray-blue); }

main:focus { outline: none; }

/* --- 跳转链接与进度条 ----------------------------------------------------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  display: inline-block;
  padding: 12px 22px;
  border-radius: 999px;
  background: var(--electric-cyan);
  color: var(--deep-ink);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: .06em;
  transform: translateY(-180%);
  transition: transform .22s var(--ease-out);
}
.skip-link:focus { transform: translateY(0); }

.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  z-index: 260;
  pointer-events: none;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--electric-cyan) 0%, var(--neon-purple) 58%, var(--neon-orange) 100%);
  box-shadow: 0 0 14px rgba(0, 233, 255, .55);
}

/* --- 按钮 ----------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .04em;
  white-space: nowrap;
  cursor: pointer;
  transition: transform .25s var(--ease-out), box-shadow .25s var(--ease-out),
              background-color .25s var(--ease-out), color .25s var(--ease-out),
              border-color .25s var(--ease-out);
}
.btn--primary {
  background: var(--electric-cyan);
  color: var(--deep-ink);
  box-shadow: 0 0 0 1px rgba(0, 233, 255, .45), 0 12px 32px rgba(0, 233, 255, .22);
}
.btn--primary:hover,
.btn--primary:focus-visible {
  background: var(--neon-orange);
  color: var(--deep-ink);
  box-shadow: 0 0 0 1px rgba(255, 106, 31, .6), 0 16px 40px rgba(255, 106, 31, .34);
  transform: translateY(-2px);
}
.btn--ghost {
  background: rgba(0, 233, 255, .06);
  border-color: var(--line);
  color: var(--electric-cyan);
}
.btn--ghost:hover,
.btn--ghost:focus-visible {
  background: rgba(0, 233, 255, .14);
  border-color: rgba(0, 233, 255, .6);
  transform: translateY(-2px);
}

/* --- 页头 ----------------------------------------------------------------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 150;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color .35s var(--ease-out), border-color .35s var(--ease-out),
              box-shadow .35s var(--ease-out);
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(7, 11, 36, .82), rgba(7, 11, 36, 0));
  opacity: 1;
  transition: opacity .35s var(--ease-out);
}
.site-header.is-scrolled {
  background: rgba(7, 11, 36, .9);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  backdrop-filter: blur(14px) saturate(150%);
  border-bottom-color: var(--line);
  box-shadow: 0 14px 42px rgba(2, 5, 18, .6);
}
.site-header.is-scrolled::before { opacity: 0; }

.header-rail {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  min-height: var(--header-h);
  padding: 14px var(--gutter);
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 30px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}
.brand__mark {
  width: 40px;
  height: 40px;
  flex: none;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  color: var(--deep-ink);
  background: linear-gradient(135deg, var(--electric-cyan) 0%, var(--neon-purple) 78%);
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
  box-shadow: 0 0 26px rgba(0, 233, 255, .35);
}
.brand__text { display: block; }
.brand__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  letter-spacing: .06em;
  line-height: 1.25;
  color: var(--ink-strong);
}
.brand__locale {
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .12em;
  line-height: 1.5;
  color: var(--muted-gray-blue);
}

.site-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: center;
}
.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1.4vw, 20px);
}
.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 10px 4px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .02em;
  white-space: nowrap;
  color: var(--slate-text);
  transition: color .25s var(--ease-out);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 4px;
  right: 4px;
  bottom: 3px;
  height: 2px;
  background: var(--electric-cyan);
  box-shadow: 0 0 12px rgba(0, 233, 255, .6);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .3s var(--ease-out);
}
.site-nav__link:hover,
.site-nav__link:focus-visible { color: var(--electric-cyan); }
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] { color: #FFFFFF; }
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: linear-gradient(90deg, var(--electric-cyan), var(--neon-orange));
  box-shadow: 0 0 14px rgba(0, 233, 255, .55);
}

.header-actions {
  margin-left: auto;
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(28, 37, 89, .7);
  color: var(--slate-text);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color .25s var(--ease-out), border-color .25s var(--ease-out),
              background-color .25s var(--ease-out);
}
.search-toggle:hover,
.search-toggle[aria-expanded="true"] {
  color: var(--electric-cyan);
  border-color: rgba(0, 233, 255, .55);
  background: rgba(0, 233, 255, .1);
}
.search-toggle__dot {
  width: 7px;
  height: 7px;
  flex: none;
  border-radius: 50%;
  background: var(--electric-cyan);
  box-shadow: 0 0 10px var(--electric-cyan);
}

.header-cta { padding: 11px 20px; font-size: 14px; }

.nav-toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  flex: none;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(28, 37, 89, .75);
  cursor: pointer;
  transition: border-color .25s var(--ease-out), background-color .25s var(--ease-out);
}
.nav-toggle:hover { border-color: rgba(0, 233, 255, .55); }
.nav-toggle__bar {
  position: absolute;
  left: 10px;
  right: 10px;
  height: 2px;
  border-radius: 2px;
  background: var(--electric-cyan);
  transition: transform .3s var(--ease-out), opacity .25s var(--ease-out);
}
.nav-toggle__bar:nth-child(1) { top: 15px; }
.nav-toggle__bar:nth-child(2) { top: 21px; }
.nav-toggle__bar:nth-child(3) { top: 27px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* --- 检索面板 ------------------------------------------------------------- */
.search-dock {
  border-top: 1px solid var(--line);
  background: rgba(9, 14, 42, .96);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  backdrop-filter: blur(18px) saturate(150%);
  box-shadow: 0 30px 70px rgba(2, 5, 18, .6);
}
.search-dock[hidden] { display: none; }

.search-dock__inner {
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding: 22px var(--gutter) 28px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.search-dock__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--electric-cyan);
}
.search-dock__input {
  width: 100%;
  padding: 14px 18px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
  background: rgba(7, 11, 36, .92);
  color: #EAF2FF;
  font-size: 16px;
  outline: none;
  transition: border-color .25s var(--ease-out), box-shadow .25s var(--ease-out);
}
.search-dock__input::placeholder { color: rgba(110, 124, 168, .85); }
.search-dock__input:focus {
  border-color: var(--electric-cyan);
  box-shadow: 0 0 0 3px rgba(0, 233, 255, .18);
}
.search-dock__hint {
  font-size: 13.5px;
  color: var(--muted-gray-blue);
}
.search-dock__results {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 8px;
}
.search-dock__results li[hidden] { display: none; }
.search-dock__results a {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 11px 14px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: rgba(28, 37, 89, .55);
  transition: border-color .22s var(--ease-out), background-color .22s var(--ease-out),
              transform .22s var(--ease-out);
}
.search-dock__results a:hover,
.search-dock__results a:focus-visible {
  border-color: rgba(0, 233, 255, .6);
  background: rgba(0, 233, 255, .1);
  transform: translateY(-2px);
}
.search-dock__title {
  font-size: 14.5px;
  font-weight: 700;
  color: var(--ink-strong);
}
.search-dock__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .07em;
  color: var(--muted-gray-blue);
}
.search-dock__empty {
  font-size: 14px;
  color: var(--alert-amber);
}
.search-dock__empty[hidden] { display: none; }

/* --- 页脚 ----------------------------------------------------------------- */
.site-footer {
  margin-top: clamp(60px, 10vw, 140px);
  border-top: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(18, 26, 69, .32) 0%, rgba(7, 11, 36, .98) 46%),
    var(--deep-ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: min(460px, 62%);
  height: 2px;
  background: linear-gradient(90deg, var(--electric-cyan), var(--neon-purple) 58%, transparent);
}
.site-footer::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  width: min(920px, 92%);
  height: 320px;
  transform: translate(-50%, -52%);
  pointer-events: none;
  background: radial-gradient(50% 50% at 50% 50%, rgba(139, 92, 246, .18), transparent 70%);
}

.footer-grid {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding: clamp(44px, 6vw, 76px) var(--gutter) 38px;
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) repeat(3, minmax(0, 1fr));
  gap: clamp(26px, 4vw, 48px);
}

.footer-brand__name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 26px;
  letter-spacing: .06em;
  color: var(--ink-strong);
  line-height: 1.3;
}
.footer-brand__tagline {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--electric-cyan);
}
.footer-brand__note {
  margin-top: 18px;
  max-width: 34em;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--muted-gray-blue);
}

.footer-col__title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--electric-cyan);
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line-soft);
}
.footer-col__list { display: flex; flex-direction: column; gap: 2px; }
.footer-col__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 5px 0;
  font-size: 15px;
  color: var(--slate-text);
  transition: color .2s var(--ease-out), transform .2s var(--ease-out);
}
.footer-col__list a:hover,
.footer-col__list a:focus-visible {
  color: var(--electric-cyan);
  transform: translateX(3px);
}
.footer-col__meta {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--muted-gray-blue);
}

.footer-base {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding: 20px var(--gutter) 36px;
  border-top: 1px solid var(--line-soft);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .07em;
  color: var(--muted-gray-blue);
}
.footer-base__legal { max-width: none; }
.footer-base__links { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-base__links a {
  color: var(--muted-gray-blue);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out);
}
.footer-base__links a:hover,
.footer-base__links a:focus-visible {
  color: var(--electric-cyan);
  border-bottom-color: var(--electric-cyan);
}

/* --- 面包屑 --------------------------------------------------------------- */
.breadcrumbs {
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding: 22px var(--gutter) 0;
}
.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted-gray-blue);
}
.breadcrumbs li { display: inline-flex; align-items: center; }
.breadcrumbs li::after {
  content: "/";
  margin-left: 8px;
  color: rgba(110, 124, 168, .55);
}
.breadcrumbs li:last-child::after { content: ""; margin: 0; }
.breadcrumbs a { color: var(--muted-gray-blue); transition: color .2s var(--ease-out); }
.breadcrumbs a:hover { color: var(--electric-cyan); }
.breadcrumbs [aria-current="page"] { color: var(--slate-text); }

/* --- 章节骨架 ------------------------------------------------------------- */
.section {
  position: relative;
  padding: clamp(48px, 8vw, 112px) 0;
}
.section__head {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 780px;
}
.section__index {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(46px, 7vw, 104px);
  line-height: .95;
  letter-spacing: -.01em;
  color: rgba(0, 233, 255, .16);
  -webkit-text-stroke: 1px rgba(0, 233, 255, .45);
}
.section__title { font-size: clamp(26px, 4vw, 40px); }
.section__lead {
  font-size: 17px;
  line-height: 1.9;
  color: var(--slate-text);
  max-width: 38em;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  align-self: flex-start;
  padding-bottom: 6px;
  border-bottom: 1px solid rgba(0, 233, 255, .42);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--electric-cyan);
}

/* --- 悬浮数据卡 ----------------------------------------------------------- */
.index-card {
  position: relative;
  padding: clamp(20px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(158deg, rgba(28, 37, 89, .92), rgba(18, 26, 69, .76));
  box-shadow: 0 26px 64px rgba(2, 5, 18, .55);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}
.index-card::after {
  content: "";
  position: absolute;
  left: 16%;
  right: 16%;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--electric-cyan), transparent);
  opacity: .75;
}

/* --- 图片容器 ------------------------------------------------------------- */
.figure { display: block; margin: 0; }
.figure__media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(150deg, rgba(18, 26, 69, .92), rgba(7, 11, 36, .96));
}
.figure__media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(140deg, rgba(0, 233, 255, .08), transparent 55%);
}
.figure__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure__media--wide { aspect-ratio: 21 / 9; }
.figure__media--tall { aspect-ratio: 4 / 5; }
.figure__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted-gray-blue);
}

/* --- 侧边章节索引 --------------------------------------------------------- */
.side-index {
  position: sticky;
  top: calc(var(--header-h) + 28px);
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 16px;
  border-left: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
}
.side-index__link {
  display: block;
  padding: 6px 0;
  color: var(--muted-gray-blue);
  transition: color .25s var(--ease-out), transform .25s var(--ease-out);
}
.side-index__link:hover { color: var(--slate-text); }
.side-index__link.is-active {
  color: var(--electric-cyan);
  transform: translateX(5px);
}

/* --- 显现动效 ------------------------------------------------------------- */
.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .4s var(--ease-out), transform .4s var(--ease-out);
}
.has-js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* --- 响应式 --------------------------------------------------------------- */
@media (max-width: 1180px) {
  .site-nav__link { font-size: 14px; }
  .brand__locale { display: none; }
}

@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 980px) {
  :root { --header-h: 72px; }

  .nav-toggle { display: block; }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    z-index: 140;
    width: min(88vw, 360px);
    height: 100vh;
    height: 100dvh;
    padding: calc(var(--header-h) + 24px) 26px 40px;
    display: block;
    overflow-y: auto;
    background: rgba(9, 14, 42, .98);
    -webkit-backdrop-filter: blur(18px);
    backdrop-filter: blur(18px);
    border-left: 1px solid var(--line);
    box-shadow: -24px 0 60px rgba(2, 5, 18, .7);
    transform: translateX(102%);
    transition: transform .38s var(--ease-out);
  }
  .site-nav[data-open] { transform: translateX(0); }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .site-nav__link {
    display: block;
    padding: 16px 4px;
    font-size: 17px;
    border-bottom: 1px solid var(--line-soft);
    white-space: normal;
  }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] { color: var(--electric-cyan); }

  .grid--split,
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }

  .side-index { position: static; }
}

@media (max-width: 760px) {
  body { font-size: 16px; }
  .header-cta { padding: 9px 15px; font-size: 13px; }
  .search-toggle { padding: 9px 12px; font-size: 11px; }
  .footer-base { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 620px) {
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .search-dock__results { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 520px) {
  .search-toggle__text { display: none; }
  .search-toggle { padding: 10px; }
  .brand { gap: 9px; }
  .brand__mark { width: 34px; height: 34px; font-size: 14px; }
  .brand__name { font-size: 15px; }
  .header-cta { padding: 8px 12px; font-size: 12.5px; }
  .header-actions { gap: 7px; }
}

/* --- 可访问性偏好 --------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

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

  .progress-bar { transition: none !important; }
}