/* ============================================================
   宝马740线上娱乐 · 共享站点样式 /assets/site.css
   框架式导航 + 夜间车库数据面板视觉系统
   ============================================================ */

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

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

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

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

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; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 8px;
}

::selection { background: rgba(58, 242, 255, 0.28); color: #001018; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #050B14;
  --panel: #0B1726;
  --bmw: #1C69D4;
  --navy: #0E3B7A;
  --mist: #F4F8FF;
  --cool: #9FB0C4;
  --cyan: #3AF2FF;
  --orange: #FF8B3D;
  --steel: #5C6F86;
  --mint: #4FE0B0;

  --rail: 248px;
  --strip: 52px;
  --bar-m: 64px;

  --r-lg: 34px;
  --r-md: 20px;
  --r-sm: 12px;

  --font-cn: "HarmonyOS Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-en: "Space Grotesk", "HarmonyOS Sans SC", "PingFang SC", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --shadow-deep: 0 24px 60px rgba(3, 8, 16, 0.55);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  padding-left: var(--rail);
  padding-top: var(--strip);
  background:
    radial-gradient(1200px 620px at 88% -12%, rgba(28, 105, 212, 0.22), transparent 62%),
    radial-gradient(920px 540px at 10% 108%, rgba(14, 59, 122, 0.30), transparent 60%),
    var(--ink);
  color: var(--mist);
  font-family: var(--font-cn);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

/* ---------- 4. Skip link ---------- */
.skip-link {
  position: fixed;
  top: 14px;
  left: 14px;
  z-index: 130;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--cyan);
  color: #001018;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transform: translateY(-180%);
  transition: transform 200ms var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline-offset: 2px;
}

/* ---------- 5. 头部：左侧框架轨道 ---------- */
.site-header {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--rail);
  z-index: 80;
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding: 26px 20px 24px;
  background: linear-gradient(180deg, #071120 0%, #050B14 58%, #04080F 100%);
  border-right: 1px solid rgba(92, 111, 134, 0.34);
}

.site-header::after {
  content: "";
  position: absolute;
  top: 0;
  right: -1px;
  width: 2px;
  height: 100%;
  pointer-events: none;
  opacity: 0.68;
  background: linear-gradient(
    180deg,
    transparent,
    rgba(28, 105, 212, 0.9) 16%,
    var(--cyan) 50%,
    rgba(28, 105, 212, 0.9) 84%,
    transparent
  );
}

/* 顶部状态条：沿框架上边延伸 */
.top-strip {
  position: fixed;
  top: 0;
  left: var(--rail);
  right: 0;
  height: var(--strip);
  z-index: 79;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 0 26px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--cool);
  background: rgba(5, 11, 20, 0.86);
  border-bottom: 1px solid rgba(92, 111, 134, 0.26);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.top-strip__badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  border-radius: 999px;
  border: 1px solid rgba(58, 242, 255, 0.4);
  background: rgba(58, 242, 255, 0.07);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.top-strip__meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.top-strip__meta .mono { color: var(--mist); opacity: 0.85; }

.top-strip__spacer { flex: 1 1 auto; }

.top-strip__link {
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid rgba(28, 105, 212, 0.6);
  background: rgba(28, 105, 212, 0.16);
  color: var(--mist);
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  transition: background 180ms var(--ease), border-color 180ms var(--ease), color 180ms var(--ease);
}

.top-strip__link:hover {
  background: rgba(58, 242, 255, 0.14);
  border-color: rgba(58, 242, 255, 0.7);
  color: var(--cyan);
}

/* 品牌 */
.header-brand { display: flex; align-items: center; min-width: 0; }

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  min-width: 0;
  border-radius: var(--r-sm);
}

.brand-mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 15px;
  background: linear-gradient(140deg, #1C69D4, #0E3B7A 70%);
  box-shadow: 0 8px 22px rgba(28, 105, 212, 0.35), inset 0 1px 0 rgba(244, 248, 255, 0.28);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.03em;
}

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

.brand-line {
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.01em;
  color: var(--mist);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand-sub {
  font-size: 11px;
  line-height: 1.4;
  letter-spacing: 0.14em;
  color: var(--steel);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 导航 */
.header-nav {
  display: flex;
  flex-direction: column;
  gap: 18px;
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

.nav-list { display: flex; flex-direction: column; gap: 4px; }

.nav-item { display: block; }

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 12px;
  border-radius: 14px;
  border: 1px solid transparent;
  color: var(--cool);
  font-size: 15px;
  line-height: 1.4;
  transition: background 180ms var(--ease), color 180ms var(--ease),
              transform 180ms var(--ease), border-color 180ms var(--ease),
              box-shadow 180ms var(--ease);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--steel);
  transition: color 180ms var(--ease);
}

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

.nav-link:hover {
  background: rgba(28, 105, 212, 0.16);
  color: var(--mist);
  transform: translateX(3px);
}

.nav-link:hover .nav-index { color: var(--cyan); }

.nav-link[aria-current="page"] {
  color: var(--mist);
  font-weight: 600;
  background: linear-gradient(90deg, rgba(28, 105, 212, 0.42), rgba(28, 105, 212, 0.06));
  border-color: rgba(28, 105, 212, 0.55);
  box-shadow: inset 3px 0 0 0 var(--cyan);
}

.nav-link[aria-current="page"] .nav-index { color: var(--cyan); }

.nav-link[aria-current="page"]::after {
  content: "";
  width: 6px;
  height: 6px;
  margin-left: auto;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(58, 242, 255, 0.9);
}

/* 轨道底部服务信息 */
.nav-utility {
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px dashed rgba(92, 111, 134, 0.4);
}

.nav-utility__title {
  margin-bottom: 12px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--steel);
}

.utility-list { display: grid; gap: 9px; }

.utility-item {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  font-size: 12px;
  line-height: 1.5;
}

.utility-key { color: var(--steel); white-space: nowrap; }

.utility-value {
  color: var(--cool);
  text-align: right;
  overflow-wrap: anywhere;
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 14px 9px 12px;
  border-radius: 14px;
  border: 1px solid rgba(92, 111, 134, 0.5);
  background: rgba(11, 23, 38, 0.7);
  color: var(--mist);
  transition: border-color 180ms var(--ease), background 180ms var(--ease);
}

.nav-toggle__bars { display: grid; gap: 4px; width: 20px; }

.nav-toggle__bar {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  transition: transform 200ms var(--ease), opacity 200ms var(--ease);
}

.nav-toggle__text {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.site-header[data-open] .nav-toggle {
  border-color: rgba(58, 242, 255, 0.7);
  background: rgba(28, 105, 212, 0.2);
}

.site-header[data-open] .nav-toggle__bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle__bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ---------- 6. 通用按钮 ---------- */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  transition: transform 180ms var(--ease), background 180ms var(--ease),
              border-color 180ms var(--ease), color 180ms var(--ease),
              box-shadow 180ms var(--ease);
}

.button:hover { transform: translateY(-1px); }

.button--accent {
  background: linear-gradient(135deg, #FF8B3D, #FF6A18);
  color: #1A0A00;
  box-shadow: 0 10px 26px rgba(255, 139, 61, 0.28);
}

.button--accent:hover { box-shadow: 0 14px 32px rgba(255, 139, 61, 0.4); }

.button--ghost {
  border-color: rgba(159, 176, 196, 0.45);
  background: rgba(11, 23, 38, 0.5);
  color: var(--mist);
}

.button--ghost:hover {
  border-color: rgba(58, 242, 255, 0.7);
  color: var(--cyan);
}

.button--quiet {
  background: rgba(28, 105, 212, 0.2);
  border-color: rgba(28, 105, 212, 0.55);
  color: var(--mist);
}

.nav-cta {
  width: 100%;
  margin-top: 14px;
  padding: 12px 18px;
  font-size: 14px;
}

/* ---------- 7. 页面容器与章节 ---------- */
.page-shell {
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding: clamp(28px, 4vw, 56px) clamp(20px, 3.4vw, 48px) clamp(56px, 6vw, 96px);
}

.page-head {
  display: grid;
  gap: 14px;
  padding-bottom: clamp(24px, 3vw, 40px);
  border-bottom: 1px solid rgba(92, 111, 134, 0.24);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-title {
  font-size: clamp(36px, 5vw, 68px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.02em;
}

.section-title {
  font-size: clamp(24px, 2.6vw, 38px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.lede {
  max-width: 62ch;
  font-size: clamp(16px, 1.3vw, 18px);
  color: var(--cool);
}

.section {
  display: grid;
  gap: clamp(18px, 2.4vw, 30px);
  padding: clamp(28px, 3.6vw, 52px) 0;
  border-bottom: 1px solid rgba(92, 111, 134, 0.18);
}

.section--tight { padding: clamp(20px, 2.4vw, 32px) 0; }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px 20px;
}

.section-index {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 34px);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: rgba(28, 105, 212, 0.95);
}

.section-note {
  margin-left: auto;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--steel);
}

/* 面包屑 */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--steel);
}

.breadcrumbs__link { color: var(--cool); transition: color 160ms var(--ease); }
.breadcrumbs__link:hover { color: var(--cyan); }
.breadcrumbs__sep { color: rgba(92, 111, 134, 0.7); }

/* 网格 */
.grid-auto {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

/* ---------- 8. 卡片与折叠 ---------- */
.card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(18px, 2vw, 26px);
  border-radius: var(--r-md);
  border: 1px solid rgba(92, 111, 134, 0.28);
  background: linear-gradient(160deg, rgba(11, 23, 38, 0.95), rgba(6, 13, 23, 0.95));
  transition: border-color 200ms var(--ease), transform 200ms var(--ease);
}

.card:hover {
  border-color: rgba(58, 242, 255, 0.4);
  transform: translateY(-2px);
}

.card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.card__title { font-size: 19px; font-weight: 700; line-height: 1.35; }

.card__meta {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--steel);
}

.card__body { font-size: 15px; line-height: 1.7; color: var(--cool); }

.card__foot { margin-top: auto; padding-top: 10px; }

.fold {
  border-radius: var(--r-md);
  border: 1px solid rgba(92, 111, 134, 0.28);
  background: rgba(11, 23, 38, 0.72);
  overflow: hidden;
}

.fold__summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.fold__summary::-webkit-details-marker { display: none; }

.fold__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
}

.fold[open] .fold__summary::after { content: "–"; }

.fold__body {
  padding: 0 20px 18px;
  font-size: 15px;
  color: var(--cool);
}

/* ---------- 9. 标签、筛选、标签页 ---------- */
.pill-row { display: flex; flex-wrap: wrap; gap: 10px; }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  border-radius: 999px;
  border: 1px solid rgba(58, 242, 255, 0.34);
  background: rgba(58, 242, 255, 0.08);
  color: var(--cyan);
  font-size: 12.5px;
  letter-spacing: 0.05em;
}

.pill--mint {
  color: var(--mint);
  background: rgba(79, 224, 176, 0.1);
  border-color: rgba(79, 224, 176, 0.36);
}

.pill--orange {
  color: var(--orange);
  background: rgba(255, 139, 61, 0.1);
  border-color: rgba(255, 139, 61, 0.36);
}

.chip {
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px solid rgba(92, 111, 134, 0.4);
  background: rgba(11, 23, 38, 0.8);
  color: var(--cool);
  font-size: 13.5px;
  transition: color 180ms var(--ease), border-color 180ms var(--ease),
              background 180ms var(--ease);
}

.chip:hover { color: var(--mist); border-color: rgba(58, 242, 255, 0.6); }

.chip[aria-pressed="true"],
.chip[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #001018;
  font-weight: 600;
}

.tabs { display: grid; gap: 20px; }

.tablist {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
  border-radius: 999px;
  border: 1px solid rgba(92, 111, 134, 0.34);
  background: rgba(11, 23, 38, 0.9);
}

.tab {
  padding: 9px 18px;
  border-radius: 999px;
  color: var(--cool);
  font-size: 14px;
  transition: color 180ms var(--ease), background 180ms var(--ease),
              box-shadow 180ms var(--ease);
}

.tab:hover { color: var(--mist); }

.tab[aria-selected="true"] {
  background: linear-gradient(135deg, rgba(28, 105, 212, 0.95), rgba(14, 59, 122, 0.95));
  color: var(--mist);
  font-weight: 600;
  box-shadow: 0 6px 18px rgba(28, 105, 212, 0.35);
}

.tabpanel { display: grid; gap: 14px; }
.tabpanel[hidden] { display: none; }

/* ---------- 10. 仪表板与流程 ---------- */
.stat-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}

.stat {
  display: grid;
  gap: 6px;
  padding: 18px 20px;
  border-radius: var(--r-md);
  border: 1px solid rgba(92, 111, 134, 0.26);
  background: rgba(11, 23, 38, 0.8);
}

.stat__value {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--mist);
}

.stat__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel);
}

.steps { display: grid; gap: 14px; }

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px 16px;
  padding: 18px 20px;
  border-radius: var(--r-md);
  border: 1px solid rgba(92, 111, 134, 0.24);
  background: rgba(8, 17, 29, 0.7);
}

.step__num {
  grid-row: span 2;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
}

.step__title { font-size: 16.5px; font-weight: 700; }
.step__text { font-size: 14.5px; color: var(--cool); }

/* ---------- 11. 图片容器（页面阶段放占位） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: var(--r-lg);
  border: 1px solid rgba(92, 111, 134, 0.3);
  background:
    radial-gradient(120% 90% at 85% 10%, rgba(28, 105, 212, 0.28), transparent 60%),
    linear-gradient(140deg, #0B1726, #050B14 70%);
}

.media-frame__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame__caption {
  position: absolute;
  left: 16px;
  bottom: 14px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cool);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }

/* ---------- 12. 提示与正文 ---------- */
.callout {
  display: grid;
  gap: 8px;
  padding: 20px 24px;
  border-radius: var(--r-md);
  border: 1px solid rgba(28, 105, 212, 0.45);
  border-left: 3px solid var(--cyan);
  background: rgba(14, 59, 122, 0.22);
}

.callout--accent {
  border-color: rgba(255, 139, 61, 0.4);
  border-left-color: var(--orange);
  background: rgba(255, 139, 61, 0.1);
}

.prose {
  display: grid;
  gap: 16px;
  max-width: 72ch;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--cool);
}

.prose h2,
.prose h3 {
  color: var(--mist);
  line-height: 1.35;
}

.prose ul {
  display: grid;
  gap: 8px;
  padding-left: 1.3em;
  list-style: disc;
}

.prose strong { color: var(--mist); }

/* ---------- 13. 阅读进度与入场 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 110;
  background: rgba(92, 111, 134, 0.18);
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--bmw), var(--cyan));
  box-shadow: 0 0 12px rgba(58, 242, 255, 0.7);
  transition: width 120ms linear;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 560ms var(--ease), transform 560ms var(--ease);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 14. 页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: clamp(40px, 5vw, 72px);
  border-top: 1px solid rgba(92, 111, 134, 0.3);
  background: linear-gradient(180deg, #071120 0%, #050B14 72%);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -220px;
  right: -120px;
  width: 620px;
  height: 420px;
  pointer-events: none;
  background: radial-gradient(closest-side, rgba(28, 105, 212, 0.34), transparent 72%);
}

.footer-frame {
  position: relative;
  max-width: 1440px;
  margin: 0 auto;
  padding: clamp(40px, 5vw, 64px) clamp(20px, 3.4vw, 48px) 26px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
  gap: clamp(24px, 4vw, 48px);
  padding-bottom: clamp(24px, 3vw, 36px);
  border-bottom: 1px solid rgba(92, 111, 134, 0.22);
}

.footer-brand { display: flex; align-items: flex-start; gap: 16px; }

.footer-mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: 18px;
  background: linear-gradient(140deg, #1C69D4, #0E3B7A 70%);
  box-shadow: 0 10px 26px rgba(28, 105, 212, 0.34), inset 0 1px 0 rgba(244, 248, 255, 0.26);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.03em;
}

.footer-brand__text { display: grid; gap: 4px; }

.footer-brand__line {
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.footer-brand__sub {
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--steel);
}

.footer-intro { display: grid; gap: 14px; }

.footer-statement {
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--cool);
}

.footer-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  width: fit-content;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid rgba(79, 224, 176, 0.36);
  background: rgba(79, 224, 176, 0.1);
  color: var(--mint);
  font-size: 12.5px;
  letter-spacing: 0.05em;
}

.footer-badge__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 10px rgba(79, 224, 176, 0.9);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 28px;
  padding: clamp(28px, 3.4vw, 40px) 0;
}

.footer-col { display: grid; gap: 12px; align-content: start; }

.footer-heading {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--steel);
}

.footer-links { display: grid; gap: 10px; }

.footer-link {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  color: var(--cool);
  font-size: 15px;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--cyan);
  border-bottom-color: rgba(58, 242, 255, 0.6);
}

.footer-link--sm { font-size: 13px; }

.footer-col--contact .footer-contact { display: grid; gap: 14px; }

.footer-contact__item { display: grid; gap: 4px; }

.footer-contact__key {
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--steel);
}

.footer-contact__value {
  font-size: 14.5px;
  color: var(--mist);
  overflow-wrap: anywhere;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-top: 22px;
  border-top: 1px solid rgba(92, 111, 134, 0.22);
  font-size: 12.5px;
  color: var(--steel);
}

.footer-copy { color: var(--cool); }

.footer-icp { color: var(--steel); }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

/* ---------- 15. 平板与桌面微调 ---------- */
@media (max-width: 1279px) and (min-width: 1080px) {
  :root { --rail: 220px; --strip: 48px; }
}

@media (max-width: 979px) {
  .footer-top { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- 16. 移动端：折叠为侧滑抽屉 ---------- */
@media (max-width: 1079px) {
  :root { --rail: 0px; --strip: 0px; --bar-m: 64px; }

  body {
    padding-left: 0;
    padding-top: 0;
  }

  .site-header {
    position: sticky;
    inset: auto;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--bar-m);
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    padding: 0 16px;
    border-right: 0;
    border-bottom: 1px solid rgba(92, 111, 134, 0.32);
    background: rgba(5, 11, 20, 0.94);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    z-index: 90;
  }

  .site-header::after { display: none; }

  .top-strip { display: none; }

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

  .header-brand { flex: 1 1 auto; min-width: 0; }

  .brand-mark { width: 38px; height: 38px; border-radius: 12px; font-size: 12px; }
  .brand-line { font-size: 15px; }
  .brand-sub { font-size: 10px; letter-spacing: 0.1em; }

  .header-nav {
    position: fixed;
    top: var(--bar-m);
    left: 0;
    bottom: 0;
    width: min(86vw, 344px);
    padding: 22px 18px 36px;
    gap: 20px;
    overflow-y: auto;
    border-right: 1px solid rgba(92, 111, 134, 0.42);
    background: linear-gradient(180deg, #0B1726, #050B14);
    box-shadow: 40px 0 80px rgba(0, 0, 0, 0.55);
    transform: translateX(-104%);
    visibility: hidden;
    transition: transform 240ms var(--ease), visibility 240ms var(--ease);
    z-index: 88;
  }

  .site-header[data-open] .header-nav {
    transform: translateX(0);
    visibility: visible;
  }

  .nav-link { padding: 13px 14px; font-size: 16px; }

  .nav-list { gap: 6px; }

  body.is-nav-open { overflow: hidden; }
}

@media (max-width: 600px) {
  body { font-size: 16px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .step { grid-template-columns: auto 1fr; }
  .tablist { width: 100%; justify-content: space-between; }
}

/* ---------- 17. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .nav-link:hover { transform: none; }
  .button:hover { transform: none; }
  .card:hover { transform: none; }
  [data-reveal] { opacity: 1; transform: none; }
  .scroll-progress__bar { transition: none; }
}