/* ==========================================================================
   博鱼品牌站 · 共享站点样式 /assets/site.css
   深海服务舱：轨道导航 + 玻璃/实色层并置 + 刻度与悬浮标签
   ========================================================================== */

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

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

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

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

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

a { color: inherit; }

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

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

/* ---------- 2. Tokens ---------- */
:root {
  /* 色彩 */
  --deep: #061A2B;
  --deep-2: #0B2E47;
  --panel: #123F5A;
  --silver: #6C7C8A;
  --silver-2: #DCE7EE;
  --ice: #F5FAFC;
  --aqua: #1FE0C0;
  --coral: #FF6B4A;
  --violet: #8B6CFF;
  --ink: #081018;
  --white: #FFFFFF;

  /* 版面 */
  --rail-w: 92px;
  --strip-h: 64px;
  --page-max: 1240px;
  --gutter: clamp(18px, 4vw, 56px);

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

  /* 动效 */
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 中文排版基底 ---------- */
body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.75;
  color: var(--ice);
  background:
    radial-gradient(1200px 620px at 84% -10%, rgba(31, 224, 192, 0.11), transparent 62%),
    radial-gradient(920px 540px at 6% 106%, rgba(139, 108, 255, 0.10), transparent 62%),
    var(--deep);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--white);
}

h1 { font-size: clamp(2.8rem, 7vw, 6rem); letter-spacing: -0.045em; line-height: 1.02; }
h2 { font-size: clamp(1.8rem, 3.2vw, 3rem); }
h3 { font-size: clamp(1.15rem, 1.9vw, 1.6rem); letter-spacing: -0.02em; }
h4 { font-size: 1.05rem; letter-spacing: 0; }

p { line-height: 1.75; }

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

::selection {
  background: rgba(31, 224, 192, 0.28);
  color: var(--white);
}

/* ---------- 4. 工具类 ---------- */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.prose { max-width: 36em; }
.prose p + p { margin-top: 1em; }

.surface-light { background: var(--ice); color: var(--ink); }
.surface-mist { background: var(--silver-2); color: var(--ink); }

.surface-light h1, .surface-light h2, .surface-light h3, .surface-light h4,
.surface-mist h1, .surface-mist h2, .surface-mist h3, .surface-mist h4 { color: var(--ink); }

.rule {
  height: 1px;
  border: 0;
  background-image: repeating-linear-gradient(90deg, rgba(108, 124, 138, 0.6) 0 1px, transparent 1px 18px);
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: 50%;
  z-index: 400;
  transform: translate(-50%, -180%);
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--aqua);
  color: #052A25;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-decoration: none;
  box-shadow: 0 10px 30px -12px rgba(31, 224, 192, 0.9);
  transition: transform 0.22s var(--ease);
}

.skip-link:focus {
  transform: translate(-50%, 0);
}

/* ---------- 6. 滚动进度标尺 ---------- */
.scroll-meter {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 300;
  height: 2px;
  pointer-events: none;
  background: rgba(108, 124, 138, 0.22);
}

.scroll-meter > span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--aqua), var(--coral));
}

/* ---------- 7. 头部 ---------- */
.site-header {
  position: relative;
  z-index: 120;
}

/* 7.1 侧边轨道 */
.rail {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 140;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 20px 0 18px;
  border-right: 1px solid rgba(108, 124, 138, 0.38);
  overflow: hidden;
}

.rail::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(31, 224, 192, 0.10), rgba(139, 108, 255, 0.07) 46%, rgba(6, 26, 43, 0.94) 100%),
    rgba(6, 26, 43, 0.82);
  backdrop-filter: blur(18px) saturate(130%);
  -webkit-backdrop-filter: blur(18px) saturate(130%);
}

.rail > * {
  position: relative;
  z-index: 1;
}

/* 7.2 品牌 */
.brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  text-decoration: none;
  color: var(--white);
}

.brand-mark {
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: radial-gradient(circle at 34% 30%, var(--aqua), #0D8076 60%, #05413C 100%);
  box-shadow: 0 0 0 1px rgba(31, 224, 192, 0.5), 0 0 24px -4px rgba(31, 224, 192, 0.6);
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 50%;
  border: 1px solid rgba(245, 250, 252, 0.8);
  border-right-color: transparent;
  border-bottom-color: transparent;
}

.brand-text {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.92rem;
  letter-spacing: 0.2em;
  writing-mode: vertical-rl;
  color: var(--white);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.56rem;
  letter-spacing: 0.2em;
  writing-mode: vertical-rl;
  color: var(--aqua);
  opacity: 0.8;
}

/* 7.3 导航容器（桌面：轨道内竖排） */
.site-nav {
  flex: 1 1 auto;
  min-height: 0;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;
}

.site-nav::-webkit-scrollbar { display: none; }

.nav-list {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding-block: 8px;
}

.nav-item { display: block; }

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 11px 7px;
  border-radius: 8px;
  writing-mode: vertical-rl;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.22em;
  text-decoration: none;
  color: rgba(245, 250, 252, 0.6);
  transition: color 0.2s var(--ease), background 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.nav-text { display: inline-block; }

.nav-link:hover {
  color: var(--aqua);
  background: rgba(31, 224, 192, 0.08);
}

.nav-link:focus-visible {
  color: var(--aqua);
}

.nav-link[aria-current="page"] {
  color: var(--white);
  background: linear-gradient(180deg, rgba(31, 224, 192, 0.18), rgba(139, 108, 255, 0.12));
  box-shadow: inset 0 0 0 1px rgba(31, 224, 192, 0.5), 0 0 22px -12px rgba(31, 224, 192, 0.9);
}

.nav-idx {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  opacity: 0.55;
}

.nav-tail { display: none; }

/* 7.4 移动导航按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid rgba(31, 224, 192, 0.45);
  background: rgba(31, 224, 192, 0.09);
  color: var(--aqua);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
}

.nav-toggle-bars {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 16px;
  height: 14px;
}

.nav-toggle-bars span {
  display: block;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}

.site-header[data-open="true"] .nav-toggle-bars span:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle-bars span:nth-child(2) { opacity: 0; }
.site-header[data-open="true"] .nav-toggle-bars span:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }

/* 7.5 轨道底部状态 */
.rail-status {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--aqua);
  box-shadow: 0 0 10px rgba(31, 224, 192, 0.8);
}

.status-text {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.24em;
  color: rgba(245, 250, 252, 0.4);
}

/* 7.6 顶部信息条 */
.header-strip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px clamp(14px, 2.4vw, 28px);
  min-height: var(--strip-h);
  padding: 10px var(--gutter);
  background: linear-gradient(90deg, rgba(11, 46, 71, 0.72), rgba(6, 26, 43, 0.5));
  border-bottom: 1px solid rgba(108, 124, 138, 0.3);
  backdrop-filter: blur(12px) saturate(120%);
  -webkit-backdrop-filter: blur(12px) saturate(120%);
}

.strip-line {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  color: rgba(245, 250, 252, 0.94);
  white-space: nowrap;
}

.strip-note {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: rgba(245, 250, 252, 0.55);
}

.strip-note::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--coral);
  box-shadow: 0 0 0 3px rgba(255, 107, 74, 0.18);
  animation: pulse-dot 3.6s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 0.5; }
  50% { opacity: 1; }
}

.strip-cta { margin-left: auto; }

/* ---------- 8. 按钮 ---------- */
.btn {
  --btn-bg: transparent;
  --btn-fg: var(--ice);
  --btn-bd: rgba(108, 124, 138, 0.55);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border: 1px solid var(--btn-bd);
  border-radius: 999px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-decoration: none;
  white-space: nowrap;
  transition: transform 0.18s var(--ease), background 0.18s var(--ease),
              border-color 0.18s var(--ease), color 0.18s var(--ease);
}

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

.btn-primary {
  --btn-bg: var(--coral);
  --btn-fg: #150704;
  --btn-bd: rgba(255, 107, 74, 0.9);
  box-shadow: 0 8px 24px -12px rgba(255, 107, 74, 0.95);
}

.btn-primary:hover {
  --btn-bg: #FF8163;
  --btn-bd: #FF8163;
}

.btn-ghost {
  --btn-bg: rgba(31, 224, 192, 0.08);
  --btn-fg: var(--aqua);
  --btn-bd: rgba(31, 224, 192, 0.55);
}

.btn-ghost:hover { --btn-bg: rgba(31, 224, 192, 0.16); }

.btn-sm { padding: 8px 16px; font-size: 0.72rem; }
.btn-block { width: 100%; }

/* ---------- 9. 版面容器与章节 ---------- */
.shell {
  width: 100%;
  max-width: var(--page-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(44px, 6.5vw, 96px);
}

.section-head {
  display: grid;
  gap: 10px;
  max-width: 46rem;
  margin-bottom: clamp(22px, 3vw, 40px);
}

.section-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.9rem, 4.4vw, 3.2rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--aqua);
  opacity: 0.55;
}

.section-title {
  font-size: clamp(1.5rem, 2.8vw, 2.4rem);
  color: var(--white);
}

.section-desc {
  max-width: 34em;
  font-size: 1rem;
  color: rgba(245, 250, 252, 0.66);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--aqua);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 1px;
  background: currentColor;
  opacity: 0.7;
}

/* ---------- 10. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid rgba(108, 124, 138, 0.5);
  border-radius: 999px;
  background: rgba(11, 46, 71, 0.55);
  color: var(--silver-2);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.tag-aqua {
  color: var(--aqua);
  border-color: rgba(31, 224, 192, 0.5);
  background: rgba(31, 224, 192, 0.1);
}

.tag-coral {
  color: var(--coral);
  border-color: rgba(255, 107, 74, 0.55);
  background: rgba(255, 107, 74, 0.12);
}

.tag-violet {
  color: var(--violet);
  border-color: rgba(139, 108, 255, 0.55);
  background: rgba(139, 108, 255, 0.12);
}

.tag-silver {
  color: rgba(245, 250, 252, 0.72);
}

/* ---------- 11. 面包屑 ---------- */
.breadcrumbs {
  padding-block: 20px 0;
}

.breadcrumbs-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: rgba(245, 250, 252, 0.5);
}

.breadcrumbs-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumbs-item + .breadcrumbs-item::before {
  content: "/";
  opacity: 0.45;
}

.breadcrumbs a {
  text-decoration: none;
  color: inherit;
  transition: color 0.18s var(--ease);
}

.breadcrumbs a:hover { color: var(--aqua); }

/* ---------- 12. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 2.2vw, 28px);
}

.grid-2,
.grid-3 {
  grid-template-columns: 1fr;
}

@media (min-width: 720px) {
  .grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1080px) {
  .grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

/* ---------- 13. 图片容器（共享基础规则） ---------- */
.media-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border-radius: 14px;
  border: 1px solid rgba(108, 124, 138, 0.42);
  background:
    linear-gradient(152deg, rgba(31, 224, 192, 0.16), rgba(11, 46, 71, 0.92) 55%, rgba(139, 108, 255, 0.16)),
    var(--panel);
  box-shadow: inset 0 0 0 1px rgba(245, 250, 252, 0.05);
}

.media-frame > img,
.media-frame > picture,
.media-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media-frame-wide { aspect-ratio: 21 / 9; }
.media-frame-tall { aspect-ratio: 4 / 5; }
.media-frame-square { aspect-ratio: 1 / 1; }

@media (max-width: 719px) {
  .media-frame-wide { aspect-ratio: 16 / 10; }
  .media-frame-tall { aspect-ratio: 5 / 4; }
}

/* ---------- 14. 显现协议 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

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

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(40px, 6vw, 96px);
  color: rgba(245, 250, 252, 0.72);
  border-top: 1px solid rgba(108, 124, 138, 0.34);
  background:
    radial-gradient(900px 420px at 88% 0%, rgba(31, 224, 192, 0.1), transparent 62%),
    linear-gradient(180deg, rgba(11, 46, 71, 0.94), rgba(6, 26, 43, 0.99));
}

.site-footer::before {
  content: "";
  display: block;
  height: 10px;
  opacity: 0.75;
  background-image: repeating-linear-gradient(90deg, rgba(108, 124, 138, 0.55) 0 1px, transparent 1px 20px);
}

.footer-tier {
  width: 100%;
  max-width: var(--page-max);
  margin-inline: auto;
  padding: clamp(32px, 4.6vw, 60px) var(--gutter) 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 3.6vw, 48px);
}

@media (min-width: 720px) {
  .footer-grid { grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); }
}

@media (min-width: 1024px) {
  .footer-grid { grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr) minmax(0, 0.75fr); }
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.1rem, 2vw, 1.45rem);
  letter-spacing: -0.02em;
  color: var(--white);
  margin-bottom: 10px;
}

.footer-lead {
  max-width: 26em;
  margin-bottom: 20px;
  font-size: 0.95rem;
  line-height: 1.72;
  color: rgba(245, 250, 252, 0.62);
}

.footer-label {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--aqua);
}

.footer-contact {
  display: grid;
  gap: 10px;
  font-size: 0.9rem;
}

.footer-contact li {
  display: flex;
  gap: 10px;
  line-height: 1.65;
}

.footer-k {
  flex: 0 0 auto;
  min-width: 2.6em;
  padding-top: 0.2em;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--silver);
}

.footer-contact li > span:last-child {
  color: rgba(245, 250, 252, 0.8);
  word-break: break-word;
}

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

.footer-nav a {
  font-size: 0.9rem;
  text-decoration: none;
  color: rgba(245, 250, 252, 0.75);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-nav a:hover {
  color: var(--aqua);
  border-bottom-color: rgba(31, 224, 192, 0.6);
}

.footer-note {
  margin-top: clamp(26px, 3.6vw, 44px);
  padding-block: 16px;
  border-top: 1px solid rgba(108, 124, 138, 0.28);
  border-bottom: 1px solid rgba(108, 124, 138, 0.28);
  font-size: 0.8rem;
  line-height: 1.72;
  color: rgba(245, 250, 252, 0.52);
}

.footer-note p { max-width: 62em; }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 22px;
  padding-block: 18px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: rgba(245, 250, 252, 0.42);
}

.footer-region { margin-right: auto; }

.footer-copy { color: rgba(245, 250, 252, 0.55); }

.footer-icp { color: rgba(245, 250, 252, 0.42); }

/* ---------- 16. 平板与手机 ---------- */
@media (max-width: 1023px) {
  html.nav-locked,
  html.nav-locked body { overflow: hidden; }

  .rail {
    position: sticky;
    top: 0;
    left: 0;
    right: 0;
    bottom: auto;
    width: 100%;
    height: 64px;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 0 18px;
    border-right: 0;
    border-bottom: 1px solid rgba(108, 124, 138, 0.38);
  }

  .brand {
    flex-direction: row;
    align-items: center;
    gap: 10px;
  }

  .brand-mark { width: 28px; height: 28px; }

  .brand-mark::after { inset: 6px; }

  .brand-text {
    flex-direction: row;
    align-items: baseline;
    gap: 8px;
  }

  .brand-name {
    writing-mode: horizontal-tb;
    font-size: 1rem;
    letter-spacing: 0.1em;
  }

  .brand-sub {
    writing-mode: horizontal-tb;
    font-size: 0.6rem;
    letter-spacing: 0.16em;
  }

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

  .rail-status { display: none; }

  /* 抽屉导航 */
  .site-nav {
    position: fixed;
    inset: 0;
    z-index: 130;
    width: 100%;
    padding: 88px 22px calc(28px + env(safe-area-inset-bottom));
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 6px;
    overflow-y: auto;
    overscroll-behavior: contain;
    background:
      radial-gradient(640px 420px at 88% 0%, rgba(31, 224, 192, 0.14), transparent 60%),
      linear-gradient(168deg, rgba(11, 46, 71, 0.985), rgba(6, 26, 43, 0.995) 58%);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.22s var(--ease), transform 0.22s var(--ease), visibility 0.22s;
  }

  .site-header[data-open="true"] .site-nav {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-list {
    align-items: stretch;
    gap: 0;
    padding-block: 0;
  }

  .nav-link {
    writing-mode: horizontal-tb;
    width: 100%;
    justify-content: space-between;
    padding: 15px 4px;
    border-radius: 0;
    border-bottom: 1px solid rgba(108, 124, 138, 0.26);
    font-size: 1.05rem;
    letter-spacing: 0.06em;
    color: rgba(245, 250, 252, 0.75);
  }

  .nav-link[aria-current="page"] {
    background: linear-gradient(90deg, rgba(31, 224, 192, 0.16), transparent 78%);
    box-shadow: inset 2px 0 0 var(--aqua);
    color: var(--white);
    border-bottom-color: rgba(31, 224, 192, 0.45);
  }

  .nav-idx { display: inline; }

  .nav-tail {
    display: grid;
    gap: 14px;
    margin-top: auto;
    padding-top: 28px;
  }

  .nav-tail-note {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    letter-spacing: 0.08em;
    color: rgba(245, 250, 252, 0.55);
  }

  .header-strip {
    min-height: 0;
    padding: 10px 18px;
    gap: 6px 12px;
  }

  .strip-line { display: none; }

  .strip-note { font-size: 0.7rem; }

  .strip-cta { display: none; }
}

@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }
}

@media (min-width: 1024px) and (max-height: 700px) {
  .brand-sub { display: none; }
  .rail-status { display: none; }
  .nav-link { padding: 8px 6px; font-size: 0.76rem; }
}

/* ---------- 17. 减少动态偏好 ---------- */
@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;
  }

  .strip-note::before { animation: none; opacity: 1; }

  .btn:hover { transform: none; }
}