/* ============================================================
   /assets/site.css — 大发电子中文官网 共享外壳与通用组件
   夜航目录仪：深空底 + 珠宝色分区 + 霓虹仪表读数
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 18px);
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--void);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.014) 0 1px, transparent 1px 3px),
    radial-gradient(62vw 42vw at 6% -6%, rgba(36, 19, 56, 0.78), transparent 70%),
    radial-gradient(56vw 40vw at 102% 6%, rgba(18, 46, 54, 0.66), transparent 72%),
    radial-gradient(52vw 42vw at 48% 112%, rgba(58, 18, 36, 0.55), transparent 74%);
}

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

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

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

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

h1, h2, h3, h4, h5, h6, p, figure, blockquote { margin: 0; }

input, select, textarea { font: inherit; color: inherit; }

::selection { background: var(--cyan); color: #03131a; }

/* ---------- 2. 令牌 ---------- */
:root {
  --void: #05070F;
  --panel: #0B1220;
  --teal: #122E36;
  --indigo: #241338;
  --wine: #3A1224;
  --cyan: #5CF2E6;
  --violet: #9B7BFF;
  --amber: #FFB84D;
  --ink: #E9EEF8;
  --muted: #9AA8C0;
  --white: #FFFFFF;
  --warn: #FF7A59;

  --line: rgba(92, 242, 230, 0.18);
  --line-soft: rgba(154, 168, 192, 0.14);

  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --font-sans: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Consolas, monospace;

  --shell: 1280px;
  --gutter: 28px;
  --header-h: 74px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 可访问性 ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  box-shadow: 0 0 0 4px rgba(92, 242, 230, 0.16);
}

.skip-link {
  position: fixed;
  top: -120px;
  left: 16px;
  z-index: 220;
  padding: 12px 20px;
  background: var(--cyan);
  color: #03131a;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  border: 1px solid rgba(255, 255, 255, 0.4);
  transition: top 0.22s var(--ease);
}

.skip-link:focus { top: 14px; }

/* ---------- 4. 滚动读数带 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  z-index: 130;
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
  background: linear-gradient(90deg, var(--cyan), var(--violet) 56%, var(--amber));
  box-shadow: 0 0 14px rgba(92, 242, 230, 0.55);
}

/* ---------- 5. 头部命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(180deg, rgba(5, 7, 15, 0.975), rgba(11, 18, 32, 0.94));
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line-soft);
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  pointer-events: none;
  background: linear-gradient(90deg, transparent, rgba(92, 242, 230, 0.6) 18%, rgba(155, 123, 255, 0.6) 64%, transparent);
}

.header-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 26px;
}

.brand {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 0;
}

.brand-mark {
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  background: linear-gradient(150deg, rgba(92, 242, 230, 0.16), rgba(155, 123, 255, 0.1));
  border: 1px solid rgba(92, 242, 230, 0.45);
  box-shadow: inset 0 0 0 1px rgba(5, 7, 15, 0.9), 0 0 18px rgba(92, 242, 230, 0.16);
  transition: box-shadow 0.25s var(--ease), color 0.25s var(--ease);
}

.brand:hover .brand-mark,
.footer-brand-link:hover .brand-mark {
  color: var(--white);
  box-shadow: inset 0 0 0 1px rgba(5, 7, 15, 0.9), 0 0 28px rgba(92, 242, 230, 0.36);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.015em;
  color: var(--white);
  white-space: nowrap;
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  line-height: 1;
  letter-spacing: 0.14em;
  color: var(--muted);
  white-space: nowrap;
}

/* 导航 */
.primary-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 9px 11px;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--muted);
  white-space: nowrap;
  transition: color 0.22s var(--ease);
}

.nav-label { position: relative; }

.nav-idx {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: rgba(154, 168, 192, 0.5);
  transition: color 0.22s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 2px;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.3s var(--ease);
}

.nav-link:hover { color: var(--ink); }
.nav-link:hover .nav-idx { color: var(--violet); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] { color: var(--cyan); }
.nav-link[aria-current="page"] .nav-idx { color: var(--cyan); }
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  box-shadow: 0 0 12px rgba(92, 242, 230, 0.75);
}

/* 移动端导航内行动区 */
.nav-foot { display: none; }

.nav-cta,
.nav-cta--ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 18px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.12em;
  line-height: 1;
  background: var(--cyan);
  color: #03131a;
  border: 1px solid var(--cyan);
  transition: background 0.22s var(--ease), color 0.22s var(--ease), border-color 0.22s var(--ease);
}

.nav-cta--ghost {
  background: transparent;
  color: var(--ink);
  border-color: rgba(154, 168, 192, 0.34);
}

.nav-cta:hover { background: #8dfff7; border-color: #8dfff7; }
.nav-cta--ghost:hover { color: var(--cyan); border-color: var(--cyan); background: rgba(92, 242, 230, 0.07); }

/* 工具区 */
.header-tools {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

.tool-link {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  line-height: 1;
  color: var(--amber);
  padding: 9px 13px;
  border: 1px solid rgba(255, 184, 77, 0.45);
  background: rgba(255, 184, 77, 0.05);
  transition: background 0.22s var(--ease), color 0.22s var(--ease), border-color 0.22s var(--ease), box-shadow 0.22s var(--ease);
}

.tool-link:hover {
  background: rgba(255, 184, 77, 0.16);
  border-color: var(--amber);
  color: var(--white);
  box-shadow: 0 0 20px rgba(255, 184, 77, 0.24);
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 10px 12px;
  cursor: pointer;
  border: 1px solid var(--line);
  color: var(--ink);
  transition: border-color 0.22s var(--ease), background 0.22s var(--ease);
}

.nav-toggle:hover { border-color: var(--cyan); background: rgba(92, 242, 230, 0.08); }

.nav-toggle-label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  line-height: 1;
}

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
  flex: 0 0 auto;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: var(--cyan);
  transition: transform 0.25s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }

.nav-toggle[data-open] .nav-toggle-bars::before { transform: translateY(4.25px) rotate(45deg); }
.nav-toggle[data-open] .nav-toggle-bars::after { transform: translateY(-4.25px) rotate(-45deg); }

/* 手机端固定入口 */
.mobile-cta {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 95;
  display: none;
  align-items: center;
  gap: 8px;
  padding: 12px 18px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.1em;
  line-height: 1;
  color: #03131a;
  background: linear-gradient(135deg, var(--cyan), #35cfc6);
  border: 1px solid rgba(255, 255, 255, 0.42);
  box-shadow: 0 12px 32px rgba(92, 242, 230, 0.3);
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.mobile-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 38px rgba(92, 242, 230, 0.42);
}

.mobile-cta-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #03131a;
  box-shadow: 0 0 0 3px rgba(3, 19, 26, 0.18);
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 96px;
  background: linear-gradient(180deg, #060912 0%, #0B1220 36%, #05070F 100%);
  border-top: 1px solid rgba(154, 168, 192, 0.16);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 1px;
  pointer-events: none;
  background: linear-gradient(90deg, transparent, rgba(92, 242, 230, 0.62), rgba(155, 123, 255, 0.62), transparent);
}

.footer-inner {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 60px var(--gutter) 44px;
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.5fr;
  gap: 40px 36px;
}

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

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.brand-mark--sm {
  width: 32px;
  height: 32px;
  font-size: 16px;
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--white);
}

.footer-brand-line {
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.footer-note {
  margin-top: 12px;
  max-width: 26em;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

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

.footer-col--contact {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.footer-title {
  position: relative;
  margin-bottom: 16px;
  padding-left: 15px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  line-height: 1.6;
  color: var(--ink);
}

.footer-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(92, 242, 230, 0.85);
}

.footer-links { display: flex; flex-direction: column; }
.footer-links li + li { margin-top: 10px; }

.footer-links a {
  position: relative;
  display: inline-block;
  font-size: 14px;
  color: var(--muted);
  transition: color 0.2s var(--ease);
}

.footer-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.28s var(--ease);
}

.footer-links a:hover { color: var(--cyan); }
.footer-links a:hover::after { transform: scaleX(1); }

.footer-contact {
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
}

.footer-contact + .footer-contact { margin-top: 12px; }

.footer-strong {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--amber);
}

.footer-base {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 18px var(--gutter) 36px;
  border-top: 1px solid rgba(154, 168, 192, 0.12);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 26px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 12px;
  align-items: center;
}

.footer-icp { color: rgba(233, 238, 248, 0.72); }
.footer-meta { color: rgba(154, 168, 192, 0.8); }

/* ---------- 7. 版心与排版 ---------- */
.container {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.prose {
  max-width: 38em;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--ink);
}

.prose p + p { margin-top: 1.05em; }

.prose a {
  color: var(--cyan);
  border-bottom: 1px solid rgba(92, 242, 230, 0.42);
  transition: border-color 0.2s var(--ease);
}

.prose a:hover { border-bottom-color: var(--cyan); }

.section { padding: 72px 0; }
.section--tight { padding: 44px 0; }

.grid {
  display: grid;
  gap: 24px;
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.divider {
  height: 1px;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, transparent, rgba(154, 168, 192, 0.24), transparent);
}

/* ---------- 8. 面板与叠层 ---------- */
.panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  padding: 26px;
}

.panel::before {
  content: "";
  position: absolute;
  inset: 5px;
  border: 1px solid rgba(154, 168, 192, 0.07);
  pointer-events: none;
}

.stack {
  position: relative;
  isolation: isolate;
}

.stack::after {
  content: "";
  position: absolute;
  inset: 9px -9px -9px 9px;
  z-index: -1;
  border: 1px solid rgba(92, 242, 230, 0.2);
  background: rgba(92, 242, 230, 0.025);
  pointer-events: none;
}

/* ---------- 9. 图片容器 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  isolation: isolate;
  background: linear-gradient(140deg, #0B1220 0%, #122E36 46%, #241338 100%);
  border: 1px solid rgba(154, 168, 192, 0.18);
}

.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(115deg, rgba(92, 242, 230, 0.16) 0%, transparent 38%, transparent 62%, rgba(155, 123, 255, 0.16) 100%);
}

.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--21x9 { aspect-ratio: 21 / 9; }

.media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 10. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 24px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  line-height: 1;
  text-transform: uppercase;
  cursor: pointer;
  border: 1px solid transparent;
  background: none;
  transition: background 0.22s var(--ease), color 0.22s var(--ease), border-color 0.22s var(--ease), box-shadow 0.22s var(--ease), transform 0.22s var(--ease);
}

.btn--primary {
  background: var(--cyan);
  color: #03131a;
  border-color: var(--cyan);
  box-shadow: 0 8px 26px rgba(92, 242, 230, 0.22);
}

.btn--primary:hover {
  background: #8dfff7;
  border-color: #8dfff7;
  box-shadow: 0 10px 32px rgba(92, 242, 230, 0.36);
}

.btn--ghost {
  color: var(--ink);
  border-color: rgba(154, 168, 192, 0.34);
}

.btn--ghost:hover {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(92, 242, 230, 0.07);
}

.btn--amber {
  background: var(--amber);
  color: #1b1103;
  border-color: var(--amber);
  box-shadow: 0 8px 26px rgba(255, 184, 77, 0.18);
}

.btn--amber:hover {
  background: #ffca77;
  border-color: #ffca77;
  box-shadow: 0 10px 32px rgba(255, 184, 77, 0.3);
}

/* ---------- 11. 索引与标签 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  line-height: 1.6;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  flex: 0 0 auto;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(92, 242, 230, 0.85);
}

.idx {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1.4;
  color: var(--violet);
  border: 1px solid rgba(155, 123, 255, 0.4);
  background: rgba(155, 123, 255, 0.08);
}

.tag--cyan {
  color: var(--cyan);
  border-color: rgba(92, 242, 230, 0.4);
  background: rgba(92, 242, 230, 0.08);
}

.tag--amber {
  color: var(--amber);
  border-color: rgba(255, 184, 77, 0.4);
  background: rgba(255, 184, 77, 0.08);
}

/* ---------- 12. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  line-height: 1.8;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--muted);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.breadcrumb a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.breadcrumb-sep { color: rgba(154, 168, 192, 0.45); }

.breadcrumb [aria-current="page"] { color: var(--ink); }

/* ---------- 13. 标签页 ---------- */
.tabs { position: relative; }

.tablist {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  border-bottom: 1px solid rgba(154, 168, 192, 0.16);
  scrollbar-width: thin;
}

.tab {
  position: relative;
  flex: 0 0 auto;
  padding: 12px 18px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.12em;
  line-height: 1.5;
  color: var(--muted);
  transition: color 0.22s var(--ease), background 0.22s var(--ease);
}

.tab:hover { color: var(--ink); background: rgba(92, 242, 230, 0.05); }

.tab::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  transform: scaleX(0);
  transform-origin: 50% 50%;
  transition: transform 0.3s var(--ease);
}

.tab[aria-selected="true"] { color: var(--cyan); }
.tab[aria-selected="true"]::after { transform: scaleX(1); }

.tabpanel { padding-top: 26px; }
.tabpanel[hidden] { display: none; }

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1120px) {
  .nav-link { padding: 9px 8px; font-size: 13.5px; }
  .nav-idx { display: none; }
  .header-inner { gap: 18px; }
}

@media (max-width: 960px) {
  :root { --header-h: 64px; --gutter: 20px; }

  .brand-mark { width: 36px; height: 36px; font-size: 18px; }
  .brand-name { font-size: 15px; }
  .brand-tag { display: none; }

  .tool-link { display: none; }
  .nav-toggle { display: inline-flex; }

  .primary-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    z-index: 99;
    display: block;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 12px var(--gutter) 34px;
    background: linear-gradient(175deg, #0B1220 0%, #0A101C 56%, #05070F 100%);
    border-bottom: 1px solid rgba(92, 242, 230, 0.3);
    box-shadow: 0 24px 60px rgba(0, 0, 0, 0.66);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px);
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease), visibility 0.25s linear;
  }

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

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

  .nav-link {
    justify-content: flex-start;
    padding: 16px 6px;
    font-size: 16px;
    border-bottom: 1px solid rgba(154, 168, 192, 0.1);
  }

  .nav-idx { display: inline; font-size: 11px; }

  .nav-link::after {
    left: 6px;
    right: auto;
    width: calc(100% - 12px);
    bottom: 0;
    height: 1px;
  }

  .nav-foot {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 22px;
  }

  .nav-foot .nav-cta { flex: 1 1 auto; }

  .mobile-cta { display: inline-flex; }

  .footer-inner { grid-template-columns: 1fr 1fr; gap: 34px; padding-top: 46px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-col--contact { grid-column: 1 / -1; }
}

@media (max-width: 880px) {
  .grid--2 { grid-template-columns: minmax(0, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 700px) {
  .section { padding: 52px 0; }
  .section--tight { padding: 34px 0; }
  .footer-inner { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .footer-base { justify-content: flex-start; }
  .footer-inner { padding-bottom: 34px; }
  .site-footer { margin-top: 64px; }
  .panel { padding: 20px; }
}

@media (max-width: 560px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }

  .brand-name { font-size: 14px; }
  .prose { font-size: 16px; }
  .tablist { gap: 0; }
  .tab { padding: 12px 13px; }
}

/* ---------- 15. 动效降级 ---------- */
@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::after,
  .footer-links a::after,
  .tab::after { transition: none !important; }

  .mobile-cta:hover { transform: none; }
}