/* ============================================================
   完美平台 · 中国服务中心 — /assets/site.css
   共享外壳：reset / tokens / 中文排版 / 头部 / 页脚 / 通用组件
   ============================================================ */

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

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

body,
h1, h2, h3, h4, p, figure, blockquote, dl, dd { margin: 0; }

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

body {
  min-height: 100vh;
  background-color: var(--c-ink);
  color: var(--c-bone);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

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

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

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

:root {
  /* ---- 色板 ---- */
  --c-ink: #06111F;
  --c-navy: #0B1D31;
  --c-slate: #2E3C43;
  --c-moss: #657A5E;
  --c-clay: #B86B4B;
  --c-bone: #F1E9DD;
  --c-cyan: #35E0D0;
  --c-orange: #FF9B4A;
  --c-mist: #9BA9B2;
  --c-sand: #D9CDBB;

  /* ---- 语义层 ---- */
  --surface-deep: var(--c-ink);
  --surface-panel: #0E2137;
  --surface-soft: rgba(241, 233, 221, 0.045);
  --line-hair: rgba(241, 233, 221, 0.14);
  --line-cyan: rgba(53, 224, 208, 0.42);
  --line-orange: rgba(255, 155, 74, 0.46);
  --text-main: var(--c-bone);
  --text-dim: var(--c-mist);
  --text-faint: rgba(155, 169, 178, 0.72);

  /* ---- 字体 ---- */
  --font-display: "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  --fs-body: 16px;
  --fs-lead: 18px;
  --fs-small: 14px;
  --fs-index: 13px;
  --fs-micro: 12px;

  /* ---- 尺度 ---- */
  --rail-w: 112px;
  --gutter: clamp(18px, 4vw, 56px);
  --stage-max: 1360px;
  --radius-s: 4px;
  --radius-m: 10px;
  --radius-l: 22px;
  --shadow-panel: 0 24px 60px -32px rgba(0, 0, 0, 0.85);
  --ease-out: cubic-bezier(0.22, 0.68, 0.24, 1);
  --dur-fast: 160ms;
  --dur-mid: 260ms;
}

/* ---- 夜间颗粒与微光：单一背景层，避免每页重复 ---- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(1100px 640px at 82% -8%, rgba(53, 224, 208, 0.09), transparent 62%),
    radial-gradient(900px 620px at -6% 92%, rgba(184, 107, 75, 0.10), transparent 60%),
    radial-gradient(760px 480px at 44% 40%, rgba(46, 60, 67, 0.28), transparent 68%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.16;
  background-image:
    repeating-linear-gradient(0deg, rgba(241, 233, 221, 0.07) 0 1px, transparent 1px 3px),
    repeating-linear-gradient(90deg, rgba(241, 233, 221, 0.05) 0 1px, transparent 1px 5px);
  mix-blend-mode: soft-light;
}

/* ---- 无障碍 ---- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 400;
  padding: 12px 20px;
  color: var(--c-ink);
  background: var(--c-cyan);
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.06em;
  border-radius: var(--radius-s);
  transform: translateY(-160%);
  transition: transform var(--dur-fast) var(--ease-out);
}
.skip-link:focus-visible { transform: translateY(0); }

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

::selection { background: rgba(53, 224, 208, 0.28); color: var(--c-bone); }

/* ---- 中文排版基线 ---- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

strong { font-weight: 700; }

.mono-note,
.kicker,
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 400;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.mono-note { color: var(--text-faint); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--c-cyan);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--c-cyan);
}

.kicker { color: var(--c-orange); }

/* ============================================================
   布局容器
   ============================================================ */
.container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--stage-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow { max-width: 780px; }

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

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

.grid--split { grid-template-columns: 7fr 5fr; }

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

/* ============================================================
   顶部捷径条
   ============================================================ */
.shortcut-rail {
  position: relative;
  z-index: 220;
  background: linear-gradient(90deg, #04101C 0%, #0B1D31 58%, #0E2137 100%);
  border-bottom: 1px solid var(--line-hair);
}

.shortcut-rail__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 26px);
  max-width: var(--stage-max);
  margin-inline: auto;
  padding: 8px var(--gutter);
  overflow-x: auto;
  scrollbar-width: none;
}
.shortcut-rail__inner::-webkit-scrollbar { display: none; }

.shortcut-rail__label {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.16em;
  color: var(--c-cyan);
  text-transform: uppercase;
}
.shortcut-rail__label--soft { color: var(--text-faint); letter-spacing: 0.1em; }

.shortcut-rail__link {
  position: relative;
  flex: 0 0 auto;
  padding-block: 2px;
  font-size: var(--fs-index);
  color: var(--text-dim);
  white-space: nowrap;
  transition: color var(--dur-fast) var(--ease-out);
}
.shortcut-rail__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 0;
  height: 1px;
  background: var(--c-cyan);
  transition: width var(--dur-mid) var(--ease-out);
}
.shortcut-rail__link:hover { color: var(--c-bone); }
.shortcut-rail__link:hover::after { width: 100%; }

.shortcut-rail__link--accent {
  margin-left: auto;
  color: var(--c-ink);
  background: var(--c-orange);
  padding: 4px 12px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.04em;
}
.shortcut-rail__link--accent::after { display: none; }
.shortcut-rail__link--accent:hover { background: var(--c-bone); color: var(--c-ink); }

/* ============================================================
   页头：左侧品牌轨道 + 右侧导航坞
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: rgba(6, 17, 31, 0.94);
  border-bottom: 1px solid var(--line-hair);
  backdrop-filter: blur(10px);
}

.header-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: stretch;
  gap: clamp(16px, 3vw, 48px);
  max-width: var(--stage-max);
  margin-inline: auto;
  padding: 0 var(--gutter);
  min-height: 84px;
}

/* ---- 左：品牌轨道 ---- */
.brand-rail {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 20px);
  padding-block: 14px 16px;
  min-width: 0;
}

.brand-rail::before {
  content: "";
  position: absolute;
  left: calc(var(--gutter) * -1 + 24px);
  top: 14px;
  bottom: 16px;
  width: 1px;
  background: linear-gradient(180deg, transparent, var(--line-cyan) 22%, var(--line-hair) 78%, transparent);
}

.brand-rail__pulse {
  position: relative;
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 208, 0.14);
}
.brand-rail__pulse::after {
  content: "";
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 1px solid rgba(53, 224, 208, 0.34);
  animation: rail-pulse 3.4s var(--ease-out) infinite;
}

@keyframes rail-pulse {
  0%, 100% { transform: scale(0.78); opacity: 0.9; }
  55% { transform: scale(1.22); opacity: 0.18; }
}

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

.brand-rail__cn {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.1vw, 25px);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.1;
  color: var(--c-bone);
  white-space: nowrap;
}

.brand-rail__sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.26em;
  color: var(--c-moss);
  text-transform: uppercase;
  white-space: nowrap;
}

.brand-rail__meta {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-left: clamp(8px, 1.4vw, 18px);
  border-left: 1px solid var(--line-hair);
  min-width: 0;
}

.brand-rail__ver {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.08em;
  color: var(--c-orange);
  white-space: nowrap;
}

.brand-rail__line {
  width: 26px;
  height: 1px;
  background: var(--line-orange);
}

.brand-rail__tag {
  font-size: var(--fs-micro);
  color: var(--text-faint);
  letter-spacing: 0.1em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ---- 右：导航坞 ---- */
.nav-dock {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  min-width: 0;
}

.nav-dock__inner { display: flex; align-items: center; }

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(2px, 0.9vw, 14px);
}

.nav-list__item { display: flex; }

.nav-link {
  position: relative;
  display: inline-block;
  padding: 10px clamp(8px, 1.1vw, 15px);
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--text-dim);
  white-space: nowrap;
  transition: color var(--dur-fast) var(--ease-out);
}
.nav-link::before {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 4px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--c-orange);
  opacity: 0;
  transform: translateX(-50%) scale(0.4);
  transition: opacity var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: clamp(8px, 1.1vw, 15px);
  right: clamp(8px, 1.1vw, 15px);
  bottom: 2px;
  height: 1px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur-mid) var(--ease-out);
}
.nav-link:hover { color: var(--c-bone); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] {
  color: var(--c-bone);
  font-weight: 700;
}
.nav-link[aria-current="page"]::before { opacity: 1; transform: translateX(-50%) scale(1); }
.nav-link[aria-current="page"]::after { transform: scaleX(1); background: var(--line-orange); }

/* ---- 移动按钮 ---- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: 1px solid var(--line-hair);
  border-radius: 999px;
  color: var(--c-bone);
  background: rgba(46, 60, 67, 0.35);
  transition: border-color var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}
.nav-toggle[aria-expanded="true"] {
  border-color: var(--line-cyan);
  background: rgba(53, 224, 208, 0.12);
}

.nav-toggle__bar {
  display: block;
  width: 16px;
  height: 1.5px;
  background: currentColor;
  transition: transform var(--dur-mid) var(--ease-out), opacity var(--dur-fast) var(--ease-out);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:first-child { transform: translateY(4.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { opacity: 0; }

.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.12em;
}

/* ---- 滚动进度 ---- */
.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(241, 233, 221, 0.07);
  overflow: hidden;
}
.scroll-meter__fill {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: left center;
  background: linear-gradient(90deg, var(--c-moss), var(--c-cyan) 58%, var(--c-orange));
  transition: transform 90ms linear;
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 9vw, 132px);
  background:
    linear-gradient(180deg, #06111F 0%, #0B1D31 46%, #081726 100%);
  border-top: 1px solid var(--line-hair);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(680px 320px at 88% 0%, rgba(53, 224, 208, 0.10), transparent 66%),
    radial-gradient(520px 300px at 6% 100%, rgba(184, 107, 75, 0.12), transparent 64%);
}

.footer-shell {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1.5fr);
  gap: clamp(32px, 4vw, 72px);
  max-width: var(--stage-max);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 76px) var(--gutter) 26px;
}

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

.footer-brand__mark {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(21px, 2.4vw, 29px);
  font-weight: 800;
  letter-spacing: -0.012em;
  line-height: 1.14;
  color: var(--c-bone);
}

.footer-motto {
  margin-top: 14px;
  max-width: 30ch;
  font-size: var(--fs-small);
  line-height: 1.8;
  color: var(--text-dim);
}

.footer-version {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px dashed var(--line-hair);
}

.copy-chip {
  padding: 4px 10px;
  border: 1px solid var(--line-orange);
  border-radius: 999px;
  color: var(--c-orange);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  transition: background var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.copy-chip:hover { background: var(--c-orange); color: var(--c-ink); }
.copy-chip[data-copied="true"] {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  color: var(--c-ink);
}

/* ---- 折叠规程列 ---- */
.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 36px);
  align-content: start;
}

.footer-col {
  padding-top: 12px;
  border-top: 1px solid var(--line-hair);
}

.footer-col__heading {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 400;
  letter-spacing: 0.2em;
  color: var(--c-moss);
  text-transform: uppercase;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 9px;
  margin-top: 14px;
}

.footer-link {
  position: relative;
  width: fit-content;
  font-size: var(--fs-small);
  color: var(--text-dim);
  transition: color var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out);
}
.footer-link::before {
  content: "";
  position: absolute;
  left: -14px;
  top: 50%;
  width: 6px;
  height: 1px;
  background: var(--c-cyan);
  opacity: 0;
  transform: translateY(-50%);
  transition: opacity var(--dur-fast) var(--ease-out);
}
.footer-link:hover { color: var(--c-bone); transform: translateX(4px); }
.footer-link:hover::before { opacity: 1; }

/* ---- 底部注脚 ---- */
.footer-meta {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-top: clamp(28px, 4vw, 48px);
  padding-top: 22px;
  border-top: 1px solid var(--line-hair);
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
  flex: 1 1 420px;
}

.footer-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-size: var(--fs-index);
  color: var(--text-dim);
}

.footer-contact__key {
  flex: 0 0 auto;
  min-width: 60px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-moss);
  text-transform: uppercase;
}

.footer-contact__val {
  color: var(--c-bone);
  word-break: break-word;
}
a.footer-contact__val { border-bottom: 1px solid transparent; transition: border-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out); }
a.footer-contact__val:hover { color: var(--c-cyan); border-bottom-color: var(--line-cyan); }

.footer-contact__row--note { margin-top: 2px; }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-faint);
}
.footer-legal__sep { color: var(--c-clay); }

/* ============================================================
   通用按钮
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 26px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.06em;
  line-height: 1.2;
  transition: background var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out);
}
.btn:hover { transform: translateY(-1px); }

.btn--primary { background: var(--c-cyan); color: var(--c-ink); font-weight: 700; }
.btn--primary:hover { background: var(--c-bone); }

.btn--ghost { border-color: var(--line-hair); color: var(--c-bone); }
.btn--ghost:hover { border-color: var(--line-cyan); color: var(--c-cyan); }

.btn--quiet {
  padding: 8px 0;
  border-radius: 0;
  border-bottom: 1px solid var(--line-orange);
  color: var(--c-orange);
}
.btn--quiet:hover { color: var(--c-bone); border-bottom-color: var(--c-bone); }

.btn__icon {
  font-family: var(--font-mono);
  font-size: 1.1em;
  line-height: 1;
}

/* ============================================================
   面包屑
   ============================================================ */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-faint);
}
.breadcrumbs__item { color: inherit; }
a.breadcrumbs__item:hover { color: var(--c-cyan); }
.breadcrumbs__item[aria-current="page"] { color: var(--c-sand); }
.breadcrumbs__sep { color: var(--c-clay); }

/* ============================================================
   面板 / 章节 / 标签
   ============================================================ */
.panel {
  position: relative;
  padding: clamp(18px, 2.6vw, 32px);
  background: linear-gradient(160deg, rgba(46, 60, 67, 0.30), rgba(11, 29, 49, 0.55));
  border: 1px solid var(--line-hair);
  border-radius: var(--radius-m);
  box-shadow: var(--shadow-panel);
  overflow: hidden;
}

.panel--rise { transform: translateY(0); }

.panel--rule::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan), transparent 70%);
}

.section-heading {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.section-heading h2,
.section-heading h1 {
  font-size: clamp(26px, 3.4vw, 44px);
  color: var(--c-bone);
}

.section-heading__index {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.14em;
  color: var(--c-orange);
}

.rule-line {
  display: block;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, var(--line-hair), transparent);
  margin-block: clamp(20px, 3vw, 34px);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line-hair);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
}
.tag--cyan { border-color: var(--line-cyan); color: var(--c-cyan); background: rgba(53, 224, 208, 0.08); }
.tag--orange { border-color: var(--line-orange); color: var(--c-orange); background: rgba(255, 155, 74, 0.08); }
.tag--moss { border-color: rgba(101, 122, 94, 0.55); color: var(--c-moss); background: rgba(101, 122, 94, 0.12); }

/* ============================================================
   图片容器基础规则
   ============================================================ */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-m);
  border: 1px solid var(--line-hair);
  background:
    linear-gradient(140deg, rgba(46, 60, 67, 0.55), rgba(11, 29, 49, 0.85));
  overflow: hidden;
}
.media-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.86) contrast(1.06);
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame__caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-faint);
}

/* ============================================================
   分段切换（页面阶段填充面板）
   ============================================================ */
.segmented { position: relative; }

.segmented__list {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: 4px;
}
.segmented__list::-webkit-scrollbar { display: none; }

.segmented__tab {
  flex: 0 0 auto;
  padding: 9px 18px;
  border: 1px solid var(--line-hair);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.06em;
  color: var(--text-dim);
  transition: color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}
.segmented__tab:hover { color: var(--c-bone); border-color: var(--line-cyan); }
.segmented__tab[aria-selected="true"] {
  color: var(--c-ink);
  background: var(--c-cyan);
  border-color: var(--c-cyan);
}

.segmented__panel { margin-top: clamp(16px, 2.4vw, 26px); }
.segmented__panel[hidden] { display: none; }

/* ============================================================
   显现 / 返回顶部
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 520ms var(--ease-out), transform 520ms var(--ease-out);
}
.reveal[data-visible="true"] { opacity: 1; transform: translateY(0); }

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 180;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid var(--line-cyan);
  border-radius: 999px;
  background: rgba(6, 17, 31, 0.9);
  color: var(--c-cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity var(--dur-mid) var(--ease-out), transform var(--dur-mid) var(--ease-out);
}
.to-top[data-visible="true"] { opacity: 1; transform: translateY(0); pointer-events: auto; }
.to-top:hover { background: var(--c-cyan); color: var(--c-ink); }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1100px) {
  :root { --rail-w: 88px; }
  .header-shell { min-height: 76px; gap: 18px; }
  .brand-rail__tag { display: none; }
  .nav-link { padding: 10px 9px; font-size: 13.5px; }
  .footer-shell { grid-template-columns: 1fr; gap: 34px; }
}

@media (max-width: 920px) {
  .grid--split { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 820px) {
  .header-shell {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding-inline: var(--gutter);
  }

  .brand-rail { padding-block: 12px; }
  .brand-rail::before { display: none; }
  .brand-rail__meta { border-left: 0; padding-left: 0; }
  .brand-rail__sub { letter-spacing: 0.18em; }

  .nav-toggle { display: inline-flex; }

  .nav-dock__inner {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: block;
    padding: 0 var(--gutter);
    background: rgba(6, 17, 31, 0.985);
    border-bottom: 1px solid var(--line-hair);
    box-shadow: 0 26px 46px -24px rgba(0, 0, 0, 0.9);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transition: max-height var(--dur-mid) var(--ease-out), opacity var(--dur-mid) var(--ease-out), visibility var(--dur-mid) linear;
  }
  .nav-dock__inner[data-open="true"] {
    max-height: min(72vh, 560px);
    overflow-y: auto;
    opacity: 1;
    visibility: visible;
    padding-block: 14px 22px;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-list__item { width: 100%; }

  .nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 14px 6px;
    font-size: 15.5px;
    border-bottom: 1px solid rgba(241, 233, 221, 0.08);
  }
  .nav-link::after { left: 6px; right: auto; width: 30px; bottom: 8px; }
  .nav-link::before { left: auto; right: 6px; bottom: auto; top: 50%; transform: translateY(-50%) scale(0.4); }
  .nav-link[aria-current="page"]::before { transform: translateY(-50%) scale(1); }

  .shortcut-rail__link--accent { margin-left: 0; }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px; }
  .footer-meta { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 560px) {
  :root {
    --fs-body: 15px;
    --fs-lead: 16.5px;
    --gutter: 16px;
  }
  body { line-height: 1.72; }

  .shortcut-rail__inner { gap: 14px; padding-block: 7px; }
  .brand-rail__cn { font-size: 18px; }
  .brand-rail__sub { font-size: 9px; }
  .brand-rail__meta { display: none; }

  .footer-grid { grid-template-columns: 1fr; }
  .footer-contact__row { gap: 6px 10px; }
  .footer-legal { font-size: 10px; }
  .btn { padding: 12px 20px; font-size: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}