/* ==========================================================================
   尊龙 CN · 共享样式表 /assets/site.css
   结构：重置 → 变量 → 中文排版 → 外壳 → 头部 → 页脚 → 通用组件 → 响应式
   ========================================================================== */

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

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

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

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

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

button { font: inherit; color: inherit; }

a { color: inherit; }

table { border-collapse: collapse; }

/* --- 2. 变量 ------------------------------------------------------------- */
:root {
  /* 主色 */
  --ink: #0B0D10;
  --panel: #151A20;
  --panel-2: #10151A;
  --gold: #D4A653;
  --gold-hi: #F2D08A;
  --ink-on-gold: #12100A;
  --fog: #8C97A3;
  --paper: #E9ECEF;
  --signal: #FF6B2C;
  /* 分区 */
  --teal: #0E2A2B;
  --wine: #3E1A24;
  --indigo: #221A38;
  --ok: #2FBF8F;
  /* 线与层 */
  --line: rgba(212, 166, 83, 0.34);
  --line-soft: rgba(233, 236, 239, 0.10);
  --line-faint: rgba(233, 236, 239, 0.06);
  --gold-wash: rgba(212, 166, 83, 0.12);
  /* 度量 */
  --shell: 1200px;
  --gutter: clamp(16px, 4vw, 56px);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 64px;
  --space-6: 96px;
  --space-7: 128px;
  /* 字体 */
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
  /* 动效 */
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --t-fast: 180ms;
  --t: 220ms;
  --t-slow: 260ms;
}

/* --- 3. 基础与中文排版 --------------------------------------------------- */
body {
  min-height: 100vh;
  background-color: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.006em;
  background-image:
    radial-gradient(1100px 560px at 88% -12%, rgba(212, 166, 83, 0.10), transparent 62%),
    radial-gradient(900px 520px at -8% 6%, rgba(14, 42, 43, 0.80), transparent 66%),
    repeating-linear-gradient(0deg, var(--line-faint) 0 1px, transparent 1px 24px),
    repeating-linear-gradient(90deg, var(--line-faint) 0 1px, transparent 1px 24px);
  background-attachment: fixed;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--paper);
  text-wrap: balance;
}

h1 { font-size: clamp(34px, 5.2vw, 64px); }
h2 { font-size: clamp(26px, 3.4vw, 44px); }
h3 { font-size: clamp(20px, 2.2vw, 28px); }
h4 { font-size: 19px; }

p { max-width: 68ch; }

strong { color: var(--gold-hi); font-weight: 600; }

small { font-size: 13px; color: var(--fog); }

a { text-decoration-thickness: 1px; text-underline-offset: 3px; }

:focus-visible {
  outline: 2px solid var(--gold-hi);
  outline-offset: 3px;
}

::selection {
  background: var(--gold);
  color: var(--ink-on-gold);
}

/* 工具类 */
.mono {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  font-feature-settings: "tnum" 1;
}

.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* --- 4. 头部：状态条 + 命令栏 ------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(11, 13, 16, 0.94);
  border-bottom: 1px solid var(--line-soft);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: 10px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--gold);
  color: var(--ink-on-gold);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  text-decoration: none;
  clip-path: polygon(10px 0, 100% 0, 100% 100%, 0 100%, 0 10px);
  transform: translateY(-240%);
  transition: transform var(--t-fast) var(--ease);
}

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

.status-strip {
  background: linear-gradient(90deg, rgba(14, 42, 43, 0.95), rgba(21, 26, 32, 0.9) 55%, rgba(34, 26, 56, 0.75));
  border-bottom: 1px solid rgba(212, 166, 83, 0.18);
}

.status-strip__inner {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 34px;
  padding-block: 5px;
}

.status-strip__dot {
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  background: var(--ok);
  transform: rotate(45deg);
  box-shadow: 0 0 0 3px rgba(47, 191, 143, 0.16);
}

.status-strip__text {
  margin: 0;
  max-width: none;
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.status-strip__code {
  margin-left: auto;
  font-size: 11.5px;
  letter-spacing: 0.10em;
  color: var(--gold);
  white-space: nowrap;
}

.command-bar__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  min-height: 74px;
  padding-block: 10px;
}

/* 品牌 / 呼号印章 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  text-decoration: none;
}

.brand__stamp {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink-on-gold);
  background: linear-gradient(150deg, var(--gold-hi), var(--gold));
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
  transition: filter var(--t) var(--ease);
}

.brand:hover .brand__stamp { filter: brightness(1.08); }

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  gap: 2px;
}

.brand__mark {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.brand__sub {
  font-size: 10.5px;
  letter-spacing: 0.10em;
  color: var(--fog);
  white-space: nowrap;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 9px 14px;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--gold-hi);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.10em;
  cursor: pointer;
  clip-path: polygon(9px 0, 100% 0, 100% 100%, 0 100%, 0 9px);
  transition: background var(--t) var(--ease), color var(--t) var(--ease);
}

.nav-toggle:hover { background: var(--gold-wash); }

.nav-toggle[aria-expanded="true"] {
  background: rgba(212, 166, 83, 0.18);
  color: var(--paper);
}

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars > span {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform var(--t) var(--ease), opacity var(--t-fast) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars > span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars > span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars > span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* 栏目索引 */
.nav-index {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  margin-left: auto;
}

.nav-index__list {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1.3vw, 18px);
}

.nav-index__item { display: block; }

.nav-index__link {
  position: relative;
  display: inline-block;
  padding: 8px 2px;
  font-size: 14.5px;
  color: var(--fog);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--t) var(--ease);
}

.nav-index__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 1px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--t) var(--ease), background var(--t) var(--ease);
}

.nav-index__link:hover { color: var(--paper); }

.nav-index__link:hover::after { transform: scaleX(1); }

.nav-index__link[aria-current="page"] {
  color: var(--gold-hi);
}

.nav-index__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--signal);
}

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

/* 滚动进度线 */
.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--signal));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 120ms linear;
  pointer-events: none;
}

/* --- 5. 页脚 ------------------------------------------------------------- */
.site-footer {
  position: relative;
  margin-top: var(--space-6);
  overflow: hidden;
  border-top: 1px solid var(--line);
  background:
    linear-gradient(168deg, rgba(14, 42, 43, 0.92) 0%, rgba(11, 13, 16, 0.96) 48%, rgba(34, 26, 56, 0.55) 100%),
    var(--ink);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, var(--line-faint) 0 1px, transparent 1px 24px),
    repeating-linear-gradient(90deg, var(--line-faint) 0 1px, transparent 1px 24px);
  opacity: 0.7;
  pointer-events: none;
}

.site-footer > .shell { position: relative; z-index: 1; }

.footer-top {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr 0.75fr 1.15fr;
  gap: clamp(28px, 3.4vw, 56px);
  padding-block: var(--space-5) var(--space-4);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: flex-start;
}

.footer-brand__stamp {
  display: inline-grid;
  grid-template-columns: 1fr;
  place-items: center;
  gap: 2px;
  width: 60px;
  height: 60px;
  padding: 6px;
  border: 2px solid var(--gold);
  color: var(--gold-hi);
  font-size: 15px;
  letter-spacing: 0.04em;
  line-height: 1;
  transform: rotate(-4deg);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
}

.footer-brand__stamp > span {
  display: block;
  font-size: 10px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.footer-brand__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 26px;
  line-height: 1.2;
  max-width: none;
  color: var(--paper);
}

.footer-brand__call {
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--fog);
  max-width: 24ch;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.footer-col__title {
  position: relative;
  padding-left: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--gold);
  line-height: 1.4;
}

.footer-col__title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 6px;
  height: 6px;
  background: var(--gold);
  transform: translateY(-50%) rotate(45deg);
}

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

.footer-link {
  position: relative;
  display: inline-block;
  padding-left: 14px;
  font-size: 14.5px;
  color: var(--fog);
  text-decoration: none;
  transition: color var(--t) var(--ease), padding-left var(--t) var(--ease);
}

.footer-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 7px;
  height: 1px;
  background: var(--line);
  transition: width var(--t) var(--ease), background var(--t) var(--ease);
}

.footer-link:hover {
  color: var(--gold-hi);
  padding-left: 18px;
}

.footer-link:hover::before {
  width: 12px;
  background: var(--signal);
}

.footer-contact-wrap { gap: 16px; }

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 18px 18px 16px;
  background: rgba(233, 236, 239, 0.035);
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--gold);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 14px 100%, 0 calc(100% - 14px));
}

.footer-contact__row {
  display: grid;
  gap: 2px;
}

.footer-contact__label {
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.footer-contact__value {
  font-size: 14px;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

.footer-note {
  max-width: 34ch;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--fog);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 20px 24px;
  border-top: 1px solid var(--line-soft);
}

.footer-bottom__legal {
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--fog);
  max-width: none;
}

.footer-bottom__links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 20px;
}

.footer-bottom__link {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--fog);
  text-decoration: none;
  transition: color var(--t) var(--ease);
}

.footer-bottom__link:hover { color: var(--gold-hi); }

/* --- 6. 通用组件 --------------------------------------------------------- */
/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  clip-path: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px);
  transition: background var(--t) var(--ease), color var(--t) var(--ease),
              transform var(--t) var(--ease), filter var(--t) var(--ease);
}

.btn--gold {
  background: linear-gradient(140deg, var(--gold-hi), var(--gold));
  border-color: transparent;
  color: var(--ink-on-gold);
  font-weight: 600;
}

.btn--gold:hover {
  filter: brightness(1.06);
  transform: translateY(-1px);
}

.btn--ghost {
  border-color: rgba(212, 166, 83, 0.5);
  color: var(--gold-hi);
}

.btn--ghost:hover {
  background: var(--gold-wash);
  color: var(--paper);
}

.btn:active { transform: translateY(0); }

.btn:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--gold-hi), 0 0 0 1px rgba(242, 208, 138, 0.45);
}

/* 区块与节奏 */
.section {
  padding-block: clamp(56px, 8vw, 112px);
}

.section-rule {
  width: 120px;
  height: 2px;
  border: 0;
  margin: 0 0 var(--space-4);
  background: linear-gradient(90deg, var(--gold), rgba(212, 166, 83, 0));
}

.band {
  position: relative;
  background: var(--panel-2);
}

.band--teal {
  background: linear-gradient(158deg, rgba(14, 42, 43, 0.96), rgba(11, 13, 16, 0.72));
}

.band--wine {
  background: linear-gradient(158deg, rgba(62, 26, 36, 0.94), rgba(11, 13, 16, 0.76));
}

.band--indigo {
  background: linear-gradient(158deg, rgba(34, 26, 56, 0.94), rgba(11, 13, 16, 0.76));
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.kicker::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--gold);
  transform: rotate(45deg);
}

/* 正文块 */
.prose {
  color: var(--paper);
  font-size: 17px;
  line-height: 1.8;
}

.prose > * + * { margin-top: 1em; }

.prose p,
.prose li { max-width: 68ch; }

.prose ul,
.prose ol {
  padding-left: 1.4em;
}

.prose ul li { list-style: none; position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -1em;
  top: 0.72em;
  width: 6px;
  height: 6px;
  background: var(--gold);
  transform: rotate(45deg);
}

.prose ol { list-style: decimal; }
.prose ol li::marker {
  font-family: var(--font-mono);
  color: var(--gold);
}

.prose a {
  color: var(--gold-hi);
  text-decoration: underline;
  text-decoration-color: rgba(212, 166, 83, 0.5);
}

.prose a:hover { text-decoration-color: var(--signal); }

/* 面包屑 */
.breadcrumb {
  margin-block: var(--space-3) var(--space-4);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  color: var(--fog);
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: rgba(140, 151, 163, 0.55);
}

.breadcrumb__link {
  color: var(--fog);
  text-decoration: none;
  transition: color var(--t) var(--ease);
}

.breadcrumb__link:hover { color: var(--gold-hi); }

.breadcrumb__current { color: var(--signal); }

/* 面板 */
.panel {
  padding: clamp(20px, 3vw, 32px);
  background: var(--panel);
  border: 1px solid var(--line-soft);
}

.panel--cut {
  clip-path: polygon(0 0, calc(100% - 32px) 0, 100% 32px, 100% 100%, 32px 100%, 0 calc(100% - 32px));
}

/* 网格 */
.grid {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
}

.grid--split {
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
}

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

/* 图片容器基础规则（页面阶段放入占位图即可） */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background:
    linear-gradient(150deg, rgba(14, 42, 43, 0.95), rgba(21, 26, 32, 0.9) 52%, rgba(34, 26, 56, 0.9));
  border: 1px solid var(--line-soft);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame::before,
.media-frame::after {
  content: "";
  position: absolute;
  width: 26px;
  height: 26px;
  border: 1px solid var(--gold);
  opacity: 0.75;
  pointer-events: none;
}

.media-frame::before {
  top: 10px;
  left: 10px;
  border-right: 0;
  border-bottom: 0;
}

.media-frame::after {
  right: 10px;
  bottom: 10px;
  border-left: 0;
  border-top: 0;
}

.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.94) contrast(1.03);
}

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 12px 16px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--paper);
  background: linear-gradient(180deg, rgba(11, 13, 16, 0), rgba(11, 13, 16, 0.88));
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid rgba(212, 166, 83, 0.4);
  color: var(--gold-hi);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  clip-path: polygon(6px 0, 100% 0, 100% 100%, 0 100%, 0 6px);
}

/* 分段切换 / 标签页 */
.segmented { display: block; }

.segmented__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: var(--space-3);
  border-bottom: 1px solid var(--line-soft);
  padding-bottom: 0;
}

.segmented__tab {
  position: relative;
  appearance: none;
  padding: 12px 18px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--fog);
  font-family: var(--font-body);
  font-size: 14.5px;
  letter-spacing: 0.02em;
  cursor: pointer;
  clip-path: polygon(10px 0, 100% 0, 100% 100%, 0 100%, 0 10px);
  transition: color var(--t) var(--ease), background var(--t) var(--ease);
}

.segmented__tab:hover {
  color: var(--paper);
  background: var(--gold-wash);
}

.segmented__tab[aria-selected="true"] {
  background: linear-gradient(140deg, var(--gold-hi), var(--gold));
  color: var(--ink-on-gold);
  font-weight: 600;
}

.segmented__tab:focus-visible {
  outline: 2px solid var(--gold-hi);
  outline-offset: 2px;
}

.segmented__panel[hidden] { display: none; }

.segmented__panel {
  animation: panel-in var(--t) var(--ease) both;
}

.segmented__panel:focus-visible {
  outline: 2px solid var(--gold-hi);
  outline-offset: 6px;
}

@keyframes panel-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 入场动效协议 */
html.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--t-slow) var(--ease), transform var(--t-slow) var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}

html.has-js [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- 7. 响应式 ----------------------------------------------------------- */
@media (max-width: 1080px) {
  .nav-index__list { gap: 10px; }
  .nav-index__link { font-size: 13.5px; }
  .btn { padding: 10px 16px; font-size: 13.5px; }
}

@media (max-width: 900px) {
  body { font-size: 16.5px; }

  .command-bar__inner { min-height: 66px; }

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

  .nav-index {
    position: absolute;
    top: 100%;
    left: calc(-1 * var(--gutter));
    right: calc(-1 * var(--gutter));
    z-index: 90;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-left: 0;
    padding: 20px var(--gutter) 26px;
    background: linear-gradient(180deg, var(--panel), var(--ink));
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.55);
    max-height: calc(100dvh - 104px);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity var(--t) var(--ease), transform var(--t) var(--ease),
                visibility var(--t) var(--ease);
  }

  .nav-index[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

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

  .nav-index__link {
    display: block;
    padding: 14px 0 14px 2px;
    font-size: 16px;
    border-bottom: 1px solid var(--line-soft);
  }

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

  .nav-index__link[aria-current="page"] {
    padding-left: 16px;
    color: var(--gold-hi);
    box-shadow: inset 3px 0 0 var(--signal);
    background: rgba(255, 107, 44, 0.06);
  }

  .nav-index__actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin-top: 20px;
  }

  .nav-index__actions .btn { width: 100%; }

  body.nav-open { overflow: hidden; }

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

  .footer-top {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding-block: var(--space-5) var(--space-3);
  }

  .footer-brand { grid-column: 1 / -1; }

  .footer-contact-wrap { grid-column: 1 / -1; }

  .footer-note { max-width: 52ch; }
}

@media (max-width: 640px) {
  .status-strip__code { display: none; }
  .status-strip__text { font-size: 12px; }
  .brand__mark { font-size: 18px; }
  .brand__sub { font-size: 9.5px; letter-spacing: 0.06em; }
  .brand__stamp { width: 38px; height: 38px; font-size: 12px; }
  .nav-toggle__label { display: none; }
  .nav-toggle { padding: 10px 12px; }

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

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-bottom__links { gap: 8px 16px; }

  .kicker { font-size: 11px; letter-spacing: 0.14em; }

  .segmented__tab { padding: 10px 14px; font-size: 13.5px; }

  .prose { font-size: 16.5px; }
}

/* --- 8. 降低动效偏好 ----------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    transition-delay: 0ms !important;
    scroll-behavior: auto !important;
  }

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

  .scroll-progress { transition: none; }
}