/* ==========================================================================
   银河66YH 官方双语指引站 · 共享样式 /assets/site.css
   星图导览母题 · 深空黑基底 · 电光青单一强锚点
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 140px;
}

body {
  margin: 0;
  background-color: var(--deep-space);
  color: var(--mist-white);
  font-family: var(--font-zh);
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: .01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; }
[hidden] { display: none !important; }

:focus-visible {
  outline: 2px solid var(--ion-cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 色彩 */
  --deep-space: #05060E;
  --orbital-navy: #0B1024;
  --nebula-mid: #131A3A;
  --ion-cyan: #2FE3D6;
  --nebula-violet: #6C4BF6;
  --solar-gold: #F2B95C;
  --mist-white: #F5F7FF;
  --alloy-grey: #A8B0C8;
  --aurora-green: #7BE0A8;
  --coral-alert: #FF7A6B;

  --line: rgba(168, 176, 200, .18);
  --line-strong: rgba(168, 176, 200, .34);
  --cyan-08: rgba(47, 227, 214, .08);
  --cyan-16: rgba(47, 227, 214, .16);
  --violet-16: rgba(108, 75, 246, .16);
  --gold-16: rgba(242, 185, 92, .16);
  --glass: rgba(11, 16, 36, .82);

  /* 字体 */
  --font-zh: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-en: "Space Grotesk", "Poppins", "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  /* 字号阶梯 12 / 14 / 16 / 20 / 28 / 44 / 72 / 96 */
  --fs-12: 0.75rem;
  --fs-14: 0.875rem;
  --fs-16: 1rem;
  --fs-20: 1.25rem;
  --fs-28: 1.75rem;
  --fs-44: 2.75rem;
  --fs-72: 4.5rem;
  --fs-96: 6rem;
  --fs-body: clamp(16px, 1.05vw, 18px);
  --fs-display: clamp(44px, 7.4vw, 96px);
  --fs-title: clamp(28px, 3.6vw, 44px);

  /* 间距与形状 */
  --shell: 1240px;
  --gutter: clamp(20px, 4.4vw, 56px);
  --section-gap: clamp(64px, 9vw, 160px);
  --block-gap: clamp(24px, 3vw, 40px);
  --r-sm: 10px;
  --r-md: 18px;
  --r-lg: 28px;
  --r-xl: 44px;
  --r-pill: 999px;

  /* 动效 */
  --ease: cubic-bezier(.22, .61, .36, 1);
  --dur: .45s;
}

html[data-lang="zh"] [data-lang-minor="en"] { opacity: .45; }
html[data-lang="en"] [data-lang-minor="zh"] { opacity: .45; }
[data-lang-minor] { transition: opacity .3s var(--ease); }

/* ---------- 3. 基础版式 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: var(--section-gap);
}

.section-head {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 780px;
  margin-bottom: clamp(28px, 4vw, 56px);
}

.section-title {
  font-size: var(--fs-title);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -.01em;
  color: var(--mist-white);
}

.section-sub {
  max-width: 62ch;
  color: var(--alloy-grey);
  font-size: var(--fs-16);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-en);
  font-size: var(--fs-12);
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--ion-cyan);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: currentColor;
}

.vert-mark {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-en);
  font-size: var(--fs-12);
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--alloy-grey);
}

.divider {
  height: 1px;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
}

.prose {
  max-width: 70ch;
  color: var(--alloy-grey);
  font-size: var(--fs-body);
}

.prose h2 {
  margin: var(--block-gap) 0 12px;
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--mist-white);
}

.prose h3 {
  margin: 28px 0 10px;
  font-size: var(--fs-20);
  font-weight: 700;
  color: var(--mist-white);
}

.prose p { margin: 0 0 1.1em; }
.prose ul, .prose ol { margin: 0 0 1.2em; }
.prose li { position: relative; padding-left: 24px; margin-bottom: .5em; }

.prose li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: .72em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ion-cyan);
}

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

.prose a {
  color: var(--ion-cyan);
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 1px;
}

/* ---------- 4. 通用组件 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  font-size: var(--fs-14);
  font-weight: 600;
  letter-spacing: .08em;
  transition: transform .25s var(--ease), background-color .25s var(--ease),
              color .25s var(--ease), border-color .25s var(--ease), box-shadow .25s var(--ease);
}

.btn--primary {
  background: var(--ion-cyan);
  color: var(--deep-space);
  box-shadow: 0 14px 34px -18px rgba(47, 227, 214, .9);
}

.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 20px 40px -16px rgba(47, 227, 214, .75); }

.btn--ghost { border-color: var(--line-strong); color: var(--mist-white); }
.btn--ghost:hover { border-color: var(--ion-cyan); color: var(--ion-cyan); }

.btn--gold { border-color: rgba(242, 185, 92, .5); color: var(--solar-gold); }
.btn--gold:hover { background: var(--gold-16); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: var(--fs-12);
  letter-spacing: .06em;
  color: var(--alloy-grey);
}

.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb__item a { transition: color .2s var(--ease); }
.breadcrumb__item a:hover { color: var(--ion-cyan); }
.breadcrumb__sep { color: rgba(168, 176, 200, .45); }

.grid { display: grid; gap: var(--block-gap); }
.grid--stars { grid-template-columns: repeat(12, minmax(0, 1fr)); }

.node {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 26px 26px 30px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(160deg, rgba(19, 26, 58, .92), rgba(11, 16, 36, .62));
  overflow: hidden;
  transition: transform .35s var(--ease), border-color .35s var(--ease);
}

.node::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 86% 8%, var(--cyan-16), transparent 58%);
  opacity: 0;
  transition: opacity .35s var(--ease);
  pointer-events: none;
}

.node:hover,
.node:focus-within { transform: scale(1.04); border-color: var(--ion-cyan); }
.node:hover::before,
.node:focus-within::before { opacity: 1; }

.plate {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(16px, 3vw, 32px);
  padding: 22px 0;
  border-top: 1px solid var(--line);
}

.plate__index {
  font-family: var(--font-mono);
  font-size: var(--fs-28);
  line-height: 1;
  color: var(--ion-cyan);
}

.plate__body { color: var(--alloy-grey); }
.plate__body strong { color: var(--mist-white); }

.orbit-band {
  position: relative;
  padding: clamp(24px, 4vw, 48px);
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  background: linear-gradient(120deg, rgba(11, 16, 36, .96), rgba(19, 26, 58, .72));
  overflow: hidden;
}

.orbit-band::after {
  content: "";
  position: absolute;
  right: -18%;
  top: -40%;
  width: 58%;
  aspect-ratio: 1 / 1;
  border: 1px solid rgba(108, 75, 246, .35);
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px rgba(47, 227, 214, .12);
  pointer-events: none;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 28px;
  padding: 0 12px;
  border: 1px solid rgba(108, 75, 246, .5);
  border-radius: var(--r-pill);
  background: var(--violet-16);
  color: #C7B8FF;
  font-size: var(--fs-12);
  letter-spacing: .1em;
}

.tag--gold { border-color: rgba(242, 185, 92, .5); background: var(--gold-16); color: var(--solar-gold); }
.tag--green { border-color: rgba(123, 224, 168, .45); background: rgba(123, 224, 168, .1); color: var(--aurora-green); }
.tag--alert { border-color: rgba(255, 122, 107, .5); background: rgba(255, 122, 107, .1); color: var(--coral-alert); }

.step-list { display: flex; flex-direction: column; }
.step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(16px, 3vw, 32px);
  padding: clamp(20px, 3vw, 32px) 0;
  border-top: 1px solid var(--line);
}
.step:last-child { border-bottom: 1px solid var(--line); }
.step__num {
  font-family: var(--font-mono);
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1;
  color: var(--ion-cyan);
}

.table-scroll {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
}
.table-scroll table { width: 100%; min-width: 640px; font-size: var(--fs-14); }
.table-scroll th,
.table-scroll td { padding: 14px 18px; text-align: left; border-bottom: 1px solid var(--line); }
.table-scroll th { color: var(--mist-white); font-weight: 700; background: rgba(19, 26, 58, .6); }

.accordion { border-top: 1px solid var(--line); }
.accordion__item { border-bottom: 1px solid var(--line); }
.accordion__btn {
  display: flex;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 56px;
  padding: 18px 0;
  text-align: left;
  font-size: var(--fs-16);
  font-weight: 600;
  color: var(--mist-white);
}
.accordion__btn::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--ion-cyan);
  font-size: var(--fs-20);
  line-height: 1;
}
.accordion__item[data-open="true"] .accordion__btn::after { content: "−"; }
.accordion__panel { display: none; padding-bottom: 20px; color: var(--alloy-grey); }
.accordion__item[data-open="true"] .accordion__panel { display: block; }

.tabs {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(11, 16, 36, .7);
}
.tabs__btn {
  min-height: 40px;
  padding: 0 18px;
  border-radius: var(--r-pill);
  font-size: var(--fs-14);
  letter-spacing: .06em;
  color: var(--alloy-grey);
  transition: background-color .25s var(--ease), color .25s var(--ease);
}
.tabs__btn[aria-selected="true"] { background: var(--ion-cyan); color: var(--deep-space); }

/* 响应式图片容器（页面阶段放置 <img>，未放图时呈星云渐变底） */
.img-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  isolation: isolate;
  background:
    radial-gradient(80% 70% at 20% 12%, rgba(108, 75, 246, .35), transparent 70%),
    radial-gradient(60% 60% at 82% 78%, rgba(47, 227, 214, .22), transparent 72%),
    linear-gradient(160deg, var(--nebula-mid), var(--orbital-navy) 70%);
}
.img-frame img { width: 100%; height: 100%; object-fit: cover; }
.img-frame--wide { aspect-ratio: 16 / 9; }
.img-frame--video { aspect-ratio: 21 / 9; }
.img-frame--square { aspect-ratio: 1 / 1; }
.img-frame--tall { aspect-ratio: 4 / 5; }
.img-frame--phone { aspect-ratio: 9 / 19; max-width: 320px; margin-inline: auto; border-radius: 36px; }
.img-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 18px 22px;
  font-size: var(--fs-12);
  letter-spacing: .06em;
  color: var(--mist-white);
  background: linear-gradient(180deg, transparent, rgba(5, 6, 14, .92));
}

[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
[data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 5. 头部 ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: 0;
  z-index: 200;
  padding: 12px 22px;
  border-radius: 0 0 var(--r-md) var(--r-md);
  background: var(--ion-cyan);
  color: var(--deep-space);
  font-size: var(--fs-14);
  font-weight: 700;
  transform: translate(-50%, -140%);
  transition: transform .25s var(--ease);
}
.skip-link:focus { transform: translate(-50%, 0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: linear-gradient(180deg, rgba(5, 6, 14, .97) 0%, rgba(5, 6, 14, .88) 100%);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.header-upper {
  position: relative;
  border-bottom: 1px solid var(--line);
}

.header-upper__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(16px, 3vw, 40px);
  min-height: 72px;
  padding-block: 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.brand__mark {
  position: relative;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: radial-gradient(circle at 32% 28%, var(--nebula-violet), rgba(11, 16, 36, .25) 64%);
}

.brand__mark::after {
  content: "";
  position: absolute;
  inset: -5px;
  border: 1px dashed rgba(47, 227, 214, .35);
  border-radius: 50%;
}

.brand__core {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ion-cyan);
  box-shadow: 0 0 14px 2px rgba(47, 227, 214, .65);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand__name {
  font-size: clamp(14px, 1.5vw, 16px);
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: .02em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand__tag {
  font-size: var(--fs-12);
  line-height: 1.4;
  color: var(--alloy-grey);
}

.brand__tag--en {
  font-family: var(--font-en);
  font-size: 10.5px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--ion-cyan);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 0 0 auto;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(19, 26, 58, .55);
}

.lang-switch__btn {
  min-width: 44px;
  min-height: 40px;
  padding: 0 12px;
  border-radius: var(--r-pill);
  font-size: var(--fs-12);
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--alloy-grey);
  transition: background-color .25s var(--ease), color .25s var(--ease);
}

.lang-switch__btn[aria-pressed="true"] {
  background: var(--ion-cyan);
  color: var(--deep-space);
}

.header-legacy {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 40px;
  font-size: var(--fs-12);
  letter-spacing: .08em;
  color: var(--alloy-grey);
  transition: color .25s var(--ease);
}

.header-legacy::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--solar-gold);
  box-shadow: 0 0 10px rgba(242, 185, 92, .85);
}

.header-legacy:hover { color: var(--solar-gold); }

.progress-rail {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(168, 176, 200, .12);
}

.progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--nebula-violet), var(--ion-cyan) 60%, var(--solar-gold));
  transition: width .12s linear;
}

.header-lower { position: relative; }

.nav-bar {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 16px;
  min-height: 62px;
}

.nav-panel { min-width: 0; }

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  font-size: var(--fs-14);
  letter-spacing: .04em;
  white-space: nowrap;
  color: var(--alloy-grey);
  transition: color .25s var(--ease), border-color .25s var(--ease),
              background-color .25s var(--ease), box-shadow .25s var(--ease);
}

.nav-link:hover {
  color: var(--mist-white);
  border-color: var(--line-strong);
}

.nav-link[aria-current="page"] {
  background: var(--ion-cyan);
  border-color: var(--ion-cyan);
  color: var(--deep-space);
  font-weight: 700;
  box-shadow: 0 0 0 6px var(--cyan-08);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid var(--line-strong);
  border-radius: var(--r-pill);
  font-size: var(--fs-14);
  letter-spacing: .08em;
  color: var(--mist-white);
  transition: border-color .25s var(--ease);
}

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

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: background-color .25s 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 .3s 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); }

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: var(--section-gap);
  border-top: 1px solid var(--line-strong);
  background: linear-gradient(180deg, var(--orbital-navy) 0%, var(--deep-space) 80%);
  overflow: hidden;
}

.footer-aurora {
  position: absolute;
  inset: -30% -10% auto;
  height: 340px;
  pointer-events: none;
  background:
    radial-gradient(60% 100% at 30% 0%, rgba(108, 75, 246, .35), transparent 70%),
    radial-gradient(50% 100% at 78% 10%, rgba(47, 227, 214, .22), transparent 72%);
}

.footer-inner {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: clamp(32px, 5vw, 56px);
  padding-block: clamp(48px, 7vw, 96px) 28px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr);
  gap: clamp(28px, 5vw, 72px);
  align-items: start;
}

.footer-brand__name {
  font-size: var(--fs-20);
  font-weight: 800;
  line-height: 1.4;
}

.footer-brand__line {
  max-width: 34ch;
  margin-top: 10px;
  font-size: var(--fs-14);
  color: var(--alloy-grey);
}

.footer-brand__en {
  margin-top: 16px;
  font-family: var(--font-en);
  font-size: var(--fs-12);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--ion-cyan);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px 32px;
}

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  font-family: var(--font-en);
  font-size: var(--fs-12);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--mist-white);
}

.footer-col__title::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--nebula-violet);
  box-shadow: 0 0 10px rgba(108, 75, 246, .9);
}

.footer-list li + li { margin-top: 2px; }

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 34px;
  font-size: var(--fs-14);
  color: var(--alloy-grey);
  transition: color .22s var(--ease);
}

.footer-link::before {
  content: "";
  width: 0;
  height: 1px;
  background: var(--ion-cyan);
  transition: width .22s var(--ease);
}

.footer-link:hover { color: var(--mist-white); }
.footer-link:hover::before { width: 12px; }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px 32px;
  padding: clamp(20px, 3vw, 28px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: rgba(19, 26, 58, .5);
}

.footer-contact__row {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.footer-contact__key {
  font-family: var(--font-en);
  font-size: var(--fs-12);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--alloy-grey);
}

.footer-contact__val {
  font-size: var(--fs-14);
  color: var(--mist-white);
  word-break: break-all;
}

.copy-mail {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--r-pill);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: .04em;
  color: var(--ion-cyan);
  transition: border-color .25s var(--ease), background-color .25s var(--ease);
}

.copy-mail:hover {
  border-color: var(--ion-cyan);
  background: var(--cyan-08);
}

.copy-mail__hint {
  font-size: var(--fs-12);
  letter-spacing: .06em;
  color: var(--aurora-green);
}

.footer-note {
  font-size: var(--fs-12);
  line-height: 1.8;
  color: var(--alloy-grey);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 28px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: var(--fs-12);
  color: var(--alloy-grey);
}

.footer-legal { letter-spacing: .06em; }

.footer-copy {
  font-family: var(--font-en);
  letter-spacing: .1em;
}

.to-top {
  position: fixed;
  right: clamp(16px, 3vw, 32px);
  bottom: clamp(16px, 3vw, 32px);
  z-index: 70;
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: rgba(11, 16, 36, .9);
  color: var(--ion-cyan);
  font-size: 18px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: opacity .3s var(--ease), transform .3s var(--ease),
              visibility .3s, border-color .3s var(--ease);
}

.to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover { border-color: var(--ion-cyan); }

/* ---------- 7. 响应式：平板与手机 ---------- */
@media (max-width: 1100px) {
  .footer-top { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 920px) {
  html { scroll-padding-top: 118px; }

  .header-upper__inner { min-height: 58px; padding-block: 10px; }
  .header-legacy { display: none; }

  .nav-toggle { display: inline-flex; }
  .nav-bar { min-height: 58px; }

  .nav-panel { position: static; }

  .nav-list {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    max-height: 0;
    padding: 14px var(--gutter) 22px;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line-strong);
    background: linear-gradient(180deg, rgba(11, 16, 36, .99), rgba(5, 6, 14, .99));
    box-shadow: 0 30px 60px -30px rgba(0, 0, 0, .9);
    transition: max-height var(--dur) var(--ease), opacity .3s var(--ease), visibility .3s;
  }

  .nav-list[data-open="true"] {
    max-height: min(72vh, 520px);
    overflow-y: auto;
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    min-height: 48px;
    padding: 0 18px;
    font-size: var(--fs-16);
    border-color: var(--line);
  }

  .nav-list__item { width: 100%; }

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

@media (max-width: 560px) {
  .brand__mark { width: 34px; height: 34px; }
  .brand__core { width: 9px; height: 9px; }
  .brand__tag { display: none; }
  .brand__name { font-size: 13px; }
  .lang-switch__btn { min-width: 40px; padding: 0 10px; }

  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-contact { grid-template-columns: minmax(0, 1fr); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }

  .plate { grid-template-columns: minmax(0, 1fr); gap: 10px; }
  .step { grid-template-columns: minmax(0, 1fr); gap: 12px; }
}

/* ---------- 8. 无障碍与降级 ---------- */
@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;
  }

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