/* ==========================================================================
   尊龙A9旗舰厅 · 共享样式 /assets/site.css
   坐标叙事 · 夜间旗舰厅 · 极细边界与刻度导视
   ========================================================================== */

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

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

body, h1, h2, h3, h4, h5, h6, p, ul, ol, li, figure, blockquote, dl, dd {
  margin: 0;
  padding: 0;
}

ul, ol { 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; width: 100%; }
main { display: block; }

/* ---------- 2. 设计变量 ---------- */
:root {
  /* 矿物与金属色 */
  --ink-900: #07111F;
  --ink-800: #0D1B2E;
  --ink-700: #132A42;
  --gold: #D6A85A;
  --gold-bright: #F2C879;
  --cyan: #38E1D6;
  --copper: #B7744A;
  --crimson: #7A2E3A;
  --moss: #5A6B62;
  --slate: #8A96A3;
  --ivory: #F4EFE6;

  /* 语义 */
  --bg: var(--ink-900);
  --bg-raised: var(--ink-800);
  --bg-inset: var(--ink-700);
  --text: var(--ivory);
  --text-dim: var(--slate);
  --line: rgba(214, 168, 90, 0.22);
  --line-strong: rgba(214, 168, 90, 0.45);
  --line-soft: rgba(138, 150, 163, 0.18);
  --accent: var(--gold);
  --accent-hot: var(--cyan);

  /* 字体 */
  --font-display: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", "Cascadia Mono", Menlo, Consolas, "Liberation Mono", monospace;

  /* 尺寸与节奏 */
  --container: 1240px;
  --gutter: clamp(20px, 4vw, 48px);
  --radius: 2px;
  --dur: 220ms;
  --dur-slow: 420ms;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --header-h: 72px;
}

/* ---------- 3. 中文排版基线 ---------- */
body {
  min-height: 100vh;
  background-color: var(--bg);
  background-image:
    repeating-linear-gradient(0deg, rgba(19, 42, 66, 0.42) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(90deg, rgba(19, 42, 66, 0.42) 0 1px, transparent 1px 96px);
  background-attachment: fixed;
  color: var(--text);
  font-family: var(--font-body);
  font-size: clamp(15px, 0.55vw + 14px, 17px);
  line-height: 1.85;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.012em;
  color: var(--ivory);
}

.display-1 {
  font-family: var(--font-display);
  font-size: clamp(40px, 6vw, 88px);
  line-height: 0.98;
  letter-spacing: -0.035em;
  font-weight: 800;
}

.h2 {
  font-size: clamp(22px, 2.6vw, 34px);
  line-height: 1.14;
}

.h3 {
  font-size: clamp(17px, 1.6vw, 21px);
  line-height: 1.32;
}

.lead {
  font-size: clamp(16px, 0.7vw + 14px, 19px);
  line-height: 1.85;
  color: #C8CFD7;
  max-width: 62ch;
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--gold);
  opacity: 0.8;
}

.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--line), var(--line-soft) 60%, transparent);
  margin-block: clamp(24px, 3vw, 40px);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--cyan);
  border-bottom: 1px solid rgba(56, 225, 214, 0.35);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), gap var(--dur) var(--ease);
}

.link-arrow::after { content: "→"; font-family: var(--font-mono); }
.link-arrow:hover { color: var(--gold-bright); border-color: var(--gold); gap: 12px; }

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

/* ---------- 4. 焦点与跳转 ---------- */
:focus-visible {
  outline: 2px solid var(--gold-bright);
  outline-offset: 3px;
  box-shadow: 0 0 0 5px rgba(56, 225, 214, 0.24);
  border-radius: var(--radius);
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  padding: 11px 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--ink-900);
  background: var(--gold-bright);
  border-radius: var(--radius);
  transform: translateY(-220%);
  transition: transform var(--dur) var(--ease);
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 容器与网格 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(44px, 6.5vw, 92px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 32px;
  padding-bottom: 16px;
  margin-bottom: clamp(24px, 3.2vw, 44px);
  border-bottom: 1px solid var(--line-soft);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.12;
  letter-spacing: -0.018em;
  font-weight: 700;
}

.grid { display: grid; gap: clamp(16px, 2vw, 26px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1.2;
  white-space: nowrap;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition:
    background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--gold {
  background: linear-gradient(180deg, var(--gold-bright), var(--gold));
  border-color: var(--gold-bright);
  color: #0A1524;
}

.btn--gold:hover { box-shadow: 0 8px 24px -8px rgba(214, 168, 90, 0.55); }

.btn--ghost {
  background: transparent;
  border-color: rgba(214, 168, 90, 0.45);
  color: var(--ivory);
}

.btn--ghost:hover {
  background: rgba(214, 168, 90, 0.09);
  border-color: var(--gold);
  color: var(--gold-bright);
}

.btn--cyan {
  background: transparent;
  border-color: rgba(56, 225, 214, 0.42);
  color: var(--cyan);
}

.btn--cyan:hover {
  background: rgba(56, 225, 214, 0.1);
  border-color: var(--cyan);
  box-shadow: 0 8px 24px -12px rgba(56, 225, 214, 0.6);
}

.btn--sm { padding: 9px 14px; font-size: 12px; letter-spacing: 0.05em; }

/* ---------- 7. 站点头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: rgba(7, 17, 31, 0.94);
  border-bottom: 1px solid var(--line-soft);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold) 22%, var(--gold) 78%, transparent);
  opacity: 0.55;
  pointer-events: none;
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--cyan));
  box-shadow: 0 0 12px rgba(56, 225, 214, 0.35);
  pointer-events: none;
  transition: width 90ms linear;
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  width: 100%;
  max-width: var(--container);
  min-height: var(--header-h);
  margin-inline: auto;
  padding: 12px var(--gutter);
}

/* 品牌与定位标 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  padding-block: 4px;
}

.brand-mark {
  position: relative;
  display: block;
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
  border: 1px solid var(--gold);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  background: var(--gold);
  opacity: 0.85;
}

.brand-mark::before {
  left: 50%;
  top: -5px;
  bottom: -5px;
  width: 1px;
  transform: translateX(-50%);
}

.brand-mark::after {
  top: 50%;
  left: -5px;
  right: -5px;
  height: 1px;
  transform: translateY(-50%);
}

.brand:hover .brand-mark {
  border-color: var(--gold-bright);
  transform: rotate(45deg);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  line-height: 1.15;
}

.brand-label {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ivory);
}

.brand-subline {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--slate);
}

/* 导航：左右分置 */
.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(6px, 1vw, 16px);
  margin-inline-start: auto;
}

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

.nav-item { position: relative; }

.nav-link {
  position: relative;
  display: inline-block;
  padding: 10px 6px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--slate);
  white-space: nowrap;
  transition: color var(--dur) var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 6px;
  right: 6px;
  bottom: 4px;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.nav-link:hover,
.nav-link:focus-visible { color: var(--ivory); }
.nav-link:hover::after,
.nav-link:focus-visible::after { transform: scaleX(1); }

.nav-link[aria-current="page"] { color: var(--gold-bright); }
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--cyan);
}

.nav-split {
  position: relative;
  align-self: stretch;
  width: clamp(14px, 2vw, 32px);
  min-height: 18px;
}

.nav-split::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold) 30%, var(--gold) 70%, transparent);
  opacity: 0.5;
}

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

.header-extra { letter-spacing: 0.04em; }

/* 移动端开关 */
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
  border: 1px solid rgba(214, 168, 90, 0.4);
  border-radius: var(--radius);
  background: rgba(19, 42, 66, 0.55);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.nav-toggle:hover { border-color: var(--gold); background: rgba(19, 42, 66, 0.9); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 1.5px;
  background: var(--gold);
  transition: background-color var(--dur) var(--ease);
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 1.5px;
  background: var(--gold);
  transition: top var(--dur) var(--ease), transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.nav-toggle-bars::before { top: -6px; }
.nav-toggle-bars::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background-color: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before {
  top: 0;
  transform: rotate(45deg);
  background: var(--cyan);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after {
  top: 0;
  transform: rotate(-45deg);
  background: var(--cyan);
}

/* ---------- 8. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 16px 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--slate);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb-list li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb-list li + li::before {
  content: "/";
  color: rgba(214, 168, 90, 0.5);
}

.breadcrumb a { color: var(--slate); transition: color var(--dur) var(--ease); }
.breadcrumb a:hover { color: var(--gold-bright); }
.breadcrumb [aria-current="page"] { color: var(--ivory); }

/* ---------- 9. 卡片 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background: linear-gradient(180deg, rgba(19, 42, 66, 0.55), rgba(13, 27, 46, 0.88));
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  transition:
    border-color var(--dur) var(--ease),
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.card::before,
.card::after {
  content: "";
  position: absolute;
  width: 12px;
  height: 12px;
  pointer-events: none;
  opacity: 0.75;
  transition: opacity var(--dur) var(--ease), width var(--dur) var(--ease), height var(--dur) var(--ease);
}

.card::before {
  top: -1px;
  left: -1px;
  border-top: 1px solid var(--gold);
  border-left: 1px solid var(--gold);
}

.card::after {
  bottom: -1px;
  right: -1px;
  border-bottom: 1px solid var(--gold);
  border-right: 1px solid var(--gold);
}

.card:hover {
  transform: translateY(-2px);
  border-color: rgba(214, 168, 90, 0.42);
  box-shadow: 0 20px 44px -26px rgba(0, 0, 0, 0.92);
}

.card:hover::before,
.card:hover::after { width: 20px; height: 20px; opacity: 1; }

.card-title {
  font-family: var(--font-display);
  font-size: clamp(16px, 1.5vw, 19px);
  font-weight: 700;
  line-height: 1.34;
  color: var(--ivory);
  margin-bottom: 10px;
}

.card-text {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--slate);
  font-variant-numeric: tabular-nums;
}

/* ---------- 10. 坐标标签与徽标 ---------- */
.coord {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.coord::before {
  content: "";
  width: 6px;
  height: 6px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
  flex: 0 0 auto;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.6;
  color: var(--gold);
  background: rgba(214, 168, 90, 0.08);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  white-space: nowrap;
}

.tag--cyan {
  color: var(--cyan);
  background: rgba(56, 225, 214, 0.08);
  border-color: rgba(56, 225, 214, 0.36);
}

.tag--copper {
  color: #D0946B;
  background: rgba(183, 116, 74, 0.12);
  border-color: rgba(183, 116, 74, 0.42);
}

.tag--crimson {
  color: #E7AFB7;
  background: rgba(122, 46, 58, 0.3);
  border-color: rgba(122, 46, 58, 0.65);
}

/* ---------- 11. 图片容器（页面阶段落图） ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background:
    linear-gradient(155deg, rgba(19, 42, 66, 0.9), rgba(7, 17, 31, 1));
}

.media::before {
  content: "";
  position: absolute;
  inset: 12px;
  border: 1px solid rgba(214, 168, 90, 0.16);
  pointer-events: none;
  z-index: 2;
}

.media::after {
  content: "";
  position: absolute;
  left: 12px;
  bottom: 12px;
  width: 28px;
  height: 1px;
  background: var(--gold);
  opacity: 0.8;
  pointer-events: none;
  z-index: 2;
}

.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: relative;
  z-index: 1;
}

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x5 { aspect-ratio: 4 / 5; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 3 / 4; }

.media--placeholder {
  display: grid;
  place-items: center;
  background-image:
    repeating-linear-gradient(0deg, rgba(19, 42, 66, 0.75) 0 1px, transparent 1px 44px),
    repeating-linear-gradient(90deg, rgba(19, 42, 66, 0.75) 0 1px, transparent 1px 44px);
}

.media--placeholder > .coord { position: relative; z-index: 2; }

.media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--slate);
}

/* ---------- 12. 显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity var(--dur-slow) var(--ease), transform var(--dur-slow) var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 13. 站点页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 120px);
  background: linear-gradient(180deg, rgba(13, 27, 46, 0.92) 0%, var(--ink-900) 78%);
  border-top: 1px solid var(--line);
}

.footer-scale {
  height: 10px;
  background: repeating-linear-gradient(
    90deg,
    rgba(214, 168, 90, 0.55) 0 1px,
    transparent 1px 40px
  );
  border-bottom: 1px solid var(--line-soft);
  opacity: 0.65;
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1.4fr) minmax(0, 1fr);
  gap: clamp(26px, 3.6vw, 56px);
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: clamp(34px, 4.6vw, 62px) var(--gutter) clamp(26px, 3.4vw, 44px);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
}

.brand--footer { padding-block: 0; }

.footer-summary {
  font-size: 14px;
  line-height: 1.85;
  color: var(--text-dim);
  max-width: 34ch;
}

.footer-stamp {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--copper);
  text-transform: uppercase;
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}

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

.footer-col-title {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 15px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--gold);
}

.footer-col-title::after {
  content: "";
  flex: 1 1 auto;
  height: 1px;
  background: var(--line-soft);
}

.footer-links > li + li { margin-top: 10px; }

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--slate);
  transition: color var(--dur) var(--ease);
}

.footer-link::before {
  content: "";
  width: 0;
  height: 1px;
  background: var(--gold);
  transition: width var(--dur) var(--ease), margin-right var(--dur) var(--ease);
}

.footer-link:hover,
.footer-link:focus-visible { color: var(--ivory); }

.footer-link:hover::before,
.footer-link:focus-visible::before {
  width: 12px;
  margin-right: 8px;
}

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

.contact-list > li + li { margin-top: 12px; }

.contact-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.contact-key {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.2em;
  color: var(--copper);
  text-transform: uppercase;
}

.contact-value {
  font-size: 13.5px;
  line-height: 1.7;
  color: #CBD2D9;
  word-break: break-word;
}

.footer-note {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--slate);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 28px;
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: 16px var(--gutter) 28px;
  border-top: 1px solid var(--line-soft);
}

.footer-legal {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--slate);
  font-variant-numeric: tabular-nums;
}

/* ---------- 14. 平板 ---------- */
@media (max-width: 1080px) {
  .header-extra { display: none; }
  .nav-link { padding-inline: 4px; }
}

@media (max-width: 1023px) {
  .footer-inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-brand { grid-column: 1 / -1; }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- 15. 移动导航与手机 ---------- */
@media (max-width: 899px) {
  :root { --header-h: 64px; }

  .nav-toggle { display: inline-flex; margin-inline-start: auto; }

  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-inline-start: 0;
    padding: 6px var(--gutter) 22px;
    background: rgba(13, 27, 46, 0.985);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line-strong);
    box-shadow: 0 26px 52px -18px rgba(0, 0, 0, 0.85);
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }

  .site-nav[data-open="true"] { display: flex; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }

  .nav-split {
    width: 100%;
    min-height: 1px;
    height: 1px;
    margin-block: 8px;
    background: linear-gradient(90deg, var(--line-strong), transparent);
  }

  .nav-split::before { display: none; }

  .nav-link {
    display: block;
    padding: 14px 0;
    font-size: 15px;
    font-weight: 500;
    color: #B9C2CC;
    border-bottom: 1px solid var(--line-soft);
  }

  .nav-link::after { display: none; }

  .nav-link[aria-current="page"] {
    color: var(--gold-bright);
    padding-left: 14px;
    box-shadow: inset 2px 0 0 var(--cyan);
  }

  .header-actions { margin-inline-start: 0; }
}

@media (max-width: 767px) {
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }

  .footer-nav { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 719px) {
  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-brand { grid-column: auto; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 559px) {
  .brand-subline { display: none; }
  .header-inner { gap: 10px; padding-block: 10px; }
  .header-actions .btn { padding: 9px 12px; font-size: 12px; letter-spacing: 0.02em; }
  .footer-nav { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .display-1 { letter-spacing: -0.025em; }
}

/* ---------- 16. 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;
    scroll-behavior: auto !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }

  .btn:hover,
  .card:hover { transform: none; }

  .brand:hover .brand-mark { transform: none; }

  .scroll-progress { transition: none; }
}