/* =========================================================
   赢咖主站 · 共享样式 /assets/site.css
   蓝图网格 + 霓虹灯箱 + 街机切角
   ========================================================= */

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: #0A0E1F;
}

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

ul, ol { padding: 0; }

img, svg, video { max-width: 100%; height: auto; }

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

a { color: inherit; }

/* ---------- 变量 ---------- */
:root {
  --midnight: #0A0E1F;
  --charcoal: #12141F;
  --violet: #7A2BFF;
  --cyan: #14E0D2;
  --orange: #FF6A1F;
  --yellow: #E6FF3D;
  --white: #EAF0FF;
  --muted: #9C97CC;
  --line: #2A3354;

  --maxw: 1240px;
  --header-h: 72px;

  --font-body: "PingFang SC", "HarmonyOS Sans SC", "Inter", "Noto Sans SC",
    system-ui, -apple-system, "Microsoft YaHei", sans-serif;
  --font-display: "Inter", "Helvetica Neue", "PingFang SC", "HarmonyOS Sans SC",
    system-ui, -apple-system, sans-serif;
  --font-mono: "SFMono-Regular", ui-monospace, Menlo, Consolas,
    "Roboto Mono", "Courier New", monospace;

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

/* ---------- 基础排版 ---------- */
body {
  min-height: 100vh;
  color: var(--white);
  background-color: var(--midnight);
  background-image:
    radial-gradient(900px 560px at 84% -8%, rgba(122, 43, 255, 0.26), transparent 62%),
    radial-gradient(760px 480px at 2% 8%, rgba(20, 224, 210, 0.12), transparent 58%),
    linear-gradient(rgba(42, 51, 84, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 51, 84, 0.22) 1px, transparent 1px);
  background-size: auto, auto, 72px 72px, 72px 72px;
  background-repeat: no-repeat, no-repeat, repeat, repeat;
  background-attachment: fixed, fixed, fixed, fixed;
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

#main-content {
  display: block;
  padding-top: var(--header-h);
}

:focus-visible {
  outline: 2px solid var(--yellow);
  outline-offset: 2px;
  border-radius: 1px;
}

::selection {
  background: var(--violet);
  color: #fff;
}

/* ---------- 工具类 ---------- */
.skip-link {
  position: absolute;
  left: 14px;
  top: -72px;
  z-index: 200;
  padding: 11px 18px;
  background: var(--yellow);
  color: #0A0E1F;
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
  transition: top 0.2s var(--ease);
}

.skip-link:focus {
  top: 12px;
}

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

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* =========================================================
   头部
   ========================================================= */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.3s var(--ease), border-color 0.3s var(--ease),
    box-shadow 0.3s var(--ease);
}

.site-header.is-solid {
  background: rgba(18, 20, 31, 0.96);
  border-bottom-color: var(--line);
  box-shadow: 0 12px 34px rgba(4, 7, 18, 0.65);
}

@supports (backdrop-filter: blur(8px)) {
  .site-header.is-solid {
    background: rgba(18, 20, 31, 0.84);
    backdrop-filter: blur(12px);
  }
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 3;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--violet), var(--cyan) 62%, var(--yellow));
  box-shadow: 0 0 10px rgba(20, 224, 210, 0.75);
  pointer-events: none;
  will-change: transform;
}

.header-inner {
  position: relative;
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 18px;
}

/* 品牌 */
.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--white);
}

.brand-mark {
  position: relative;
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  background: conic-gradient(from 140deg, var(--violet), var(--cyan) 55%, var(--violet));
  clip-path: polygon(50% 0, 100% 25%, 100% 75%, 50% 100%, 0 75%, 0 25%);
  box-shadow: 0 0 14px rgba(122, 43, 255, 0.8);
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 7px;
  background: var(--midnight);
  clip-path: polygon(50% 0, 100% 25%, 100% 75%, 50% 100%, 0 75%, 0 25%);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.08;
}

.brand-name {
  font-size: 17px;
  font-weight: 800;
  font-style: italic;
  letter-spacing: 0.02em;
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  opacity: 0.85;
}

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

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 9px 12px;
  color: var(--white);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.18s var(--ease);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--muted);
  transition: color 0.18s var(--ease);
}

.nav-label {
  white-space: nowrap;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--cyan);
}

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

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

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

.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 1px;
  height: 2px;
  background: var(--cyan);
  box-shadow: 0 0 9px var(--cyan);
}

/* 头部工具 */
.header-tools {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-shortcut {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  background: rgba(122, 43, 255, 0.14);
  color: var(--white);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease),
    box-shadow 0.18s var(--ease);
}

.search-shortcut:hover,
.search-shortcut:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
  box-shadow: 0 0 14px rgba(20, 224, 210, 0.35);
}

.search-shortcut-icon {
  position: relative;
  flex: 0 0 auto;
  width: 11px;
  height: 11px;
}

.search-shortcut-icon::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 1.5px solid currentColor;
  border-radius: 50%;
}

.search-shortcut-icon::after {
  content: "";
  position: absolute;
  right: -4px;
  bottom: -2px;
  width: 6px;
  height: 1.5px;
  background: currentColor;
  transform: rotate(45deg);
}

/* 移动开关 */
.nav-toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 40px;
  padding: 0;
  border: 1px solid var(--line);
  background: rgba(18, 20, 31, 0.72);
  color: var(--white);
  cursor: pointer;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.nav-toggle:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.nav-toggle-bars {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 18px;
  height: 2px;
  background: currentColor;
  transform: translate(-50%, -50%);
  transition: background-color 0.22s var(--ease);
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 0.22s var(--ease), top 0.22s var(--ease);
}

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

.site-header[data-open] .nav-toggle-bars { background: transparent; }
.site-header[data-open] .nav-toggle-bars::before { top: 0; transform: rotate(45deg); }
.site-header[data-open] .nav-toggle-bars::after { top: 0; transform: rotate(-45deg); }

/* =========================================================
   页脚
   ========================================================= */
.site-footer {
  position: relative;
  margin-top: 96px;
  background: linear-gradient(180deg, rgba(18, 20, 31, 0.4), var(--charcoal) 28%, #0B0D17);
  border-top: 1px solid var(--line);
  color: var(--white);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--violet) 18%, var(--cyan) 55%, var(--orange) 84%, transparent);
  opacity: 0.9;
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 58px 20px 26px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.35fr;
  gap: 40px 28px;
}

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

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--white);
}

.footer-brand-name {
  font-size: 18px;
  font-weight: 800;
  font-style: italic;
  letter-spacing: 0.02em;
}

.footer-tagline {
  margin-top: 16px;
  max-width: 34ch;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.footer-mono {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  opacity: 0.8;
}

.footer-title {
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-link {
  display: inline-block;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.16s var(--ease), transform 0.16s var(--ease);
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--cyan);
  transform: translateX(3px);
}

.support-link {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  padding: 11px 12px;
  border: 1px solid var(--line);
  background: rgba(122, 43, 255, 0.1);
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
  font-style: italic;
  text-decoration: none;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease),
    box-shadow 0.18s var(--ease), transform 0.18s var(--ease);
}

.support-link:hover,
.support-link:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
  box-shadow: 0 0 0 1px rgba(20, 224, 210, 0.32), 0 0 18px rgba(20, 224, 210, 0.22);
  transform: translateY(-1px);
}

.support-link-index {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border: 1px solid rgba(230, 255, 61, 0.45);
  color: var(--yellow);
  font-family: var(--font-mono);
  font-size: 10px;
  font-style: normal;
}

.support-link-text { min-width: 0; }

.support-hint {
  margin-top: 12px;
  color: var(--orange);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.footer-list--contact { gap: 14px; }

.footer-list--contact li {
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 6px 12px;
  align-items: start;
}

.contact-label {
  grid-column: 1;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.contact-value {
  grid-column: 2;
  color: var(--white);
  font-size: 14px;
  line-height: 1.7;
  word-break: break-word;
}

.copy-chip {
  grid-column: 2;
  justify-self: start;
  margin-top: 4px;
  padding: 3px 10px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: border-color 0.16s var(--ease), color 0.16s var(--ease),
    background-color 0.16s var(--ease);
}

.copy-chip:hover,
.copy-chip:focus-visible {
  border-color: var(--yellow);
  color: var(--yellow);
}

.copy-chip.is-copied {
  border-color: var(--yellow);
  background: rgba(230, 255, 61, 0.14);
  color: var(--yellow);
}

.footer-note {
  margin-top: 18px;
  padding-left: 12px;
  border-left: 2px solid rgba(255, 106, 31, 0.6);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.85;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  margin-top: 44px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.footer-legal,
.footer-copy { margin: 0; }

/* =========================================================
   通用组件
   ========================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 24px;
  border: 0;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 800;
  font-style: italic;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  clip-path: polygon(11px 0, 100% 0, 100% calc(100% - 11px), calc(100% - 11px) 100%, 0 100%, 0 11px);
  transition: transform 0.16s var(--ease), box-shadow 0.2s var(--ease),
    background-color 0.2s var(--ease), color 0.2s var(--ease);
}

.btn-primary {
  background: var(--violet);
  color: #FFFFFF;
  box-shadow: inset 0 0 0 1px rgba(122, 43, 255, 0.7), 0 0 20px rgba(122, 43, 255, 0.4);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: #8D47FF;
  box-shadow: inset 0 0 0 1px var(--cyan), 0 0 26px rgba(20, 224, 210, 0.5);
  transform: translateY(-1px);
}

.btn-ghost {
  background: rgba(18, 20, 31, 0.6);
  color: var(--white);
  box-shadow: inset 0 0 0 1px var(--line);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  color: var(--cyan);
  box-shadow: inset 0 0 0 1px var(--cyan), 0 0 18px rgba(20, 224, 210, 0.3);
  transform: translateY(-1px);
}

.breadcrumbs {
  padding-top: 22px;
}

.breadcrumbs-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.breadcrumbs-list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.breadcrumbs-list a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.16s var(--ease);
}

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

.section {
  position: relative;
  padding: 80px 0;
}

.section--tight { padding: 52px 0; }
.section--flush { padding-top: 0; }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 36px;
}

.section-head-text { max-width: 64ch; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
}

.section-title {
  margin-top: 12px;
  font-family: var(--font-display);
  font-size: clamp(28px, 4.2vw, 40px);
  font-weight: 200;
  line-height: 1.16;
  letter-spacing: -0.005em;
  color: var(--white);
}

.section-sub {
  margin-top: 14px;
  max-width: 62ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.display-title {
  font-family: var(--font-display);
  font-size: clamp(40px, 8vw, 88px);
  font-weight: 200;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--white);
  text-shadow: 0 0 26px rgba(122, 43, 255, 0.45), 0 0 62px rgba(20, 224, 210, 0.18);
}

.neon-text {
  text-shadow: 0 0 18px rgba(122, 43, 255, 0.55), 0 0 44px rgba(20, 224, 210, 0.24);
}

/* 网格 */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 22px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 22px;
}

.grid-blueprint {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
}

/* 面板 */
.panel {
  position: relative;
  padding: 26px;
  background: rgba(18, 20, 31, 0.86);
  border: 1px solid var(--line);
}

.panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 36px;
  height: 1px;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(20, 224, 210, 0.7);
}

.panel-cut {
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 16px;
}

.panel-title {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--white);
}

.panel-text {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line);
  background: rgba(42, 51, 84, 0.25);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.tag--event {
  border-color: rgba(255, 106, 31, 0.55);
  background: rgba(255, 106, 31, 0.12);
  color: var(--orange);
}

.tag--index {
  border-color: rgba(20, 224, 210, 0.45);
  background: rgba(20, 224, 210, 0.1);
  color: var(--cyan);
}

.tag--live {
  border-color: rgba(230, 255, 61, 0.5);
  background: rgba(230, 255, 61, 0.1);
  color: var(--yellow);
}

/* 元信息 */
.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  list-style: none;
}

.meta-item {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.meta-item strong {
  font-weight: 500;
  color: var(--cyan);
}

.divider {
  height: 1px;
  border: 0;
  margin: 48px 0;
  background: linear-gradient(90deg, var(--line), transparent);
}

/* 图片容器（页面阶段放置占位） */
.img-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line);
  background-color: var(--midnight);
  background-image:
    linear-gradient(135deg, rgba(122, 43, 255, 0.24), rgba(20, 224, 210, 0.12)),
    repeating-linear-gradient(0deg, rgba(42, 51, 84, 0.5) 0 1px, transparent 1px 6px);
}

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

.img-frame::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
  opacity: 0.85;
  z-index: 2;
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.5;
  background-image: repeating-linear-gradient(0deg, rgba(10, 14, 31, 0.38) 0 1px, transparent 1px 4px);
}

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

/* 正文 */
.prose {
  max-width: 70ch;
  color: var(--white);
  font-size: 17px;
  line-height: 1.85;
}

.prose h2 {
  margin: 38px 0 12px;
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 300;
  line-height: 1.3;
}

.prose h3 {
  margin: 28px 0 10px;
  font-size: 19px;
  font-weight: 600;
}

.prose p {
  margin-bottom: 16px;
  color: #CDD4EE;
}

.prose ul,
.prose ol {
  margin: 0 0 18px;
  padding-left: 22px;
}

.prose li { margin: 8px 0; }

.prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(20, 224, 210, 0.45);
}

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

.prose code {
  padding: 2px 6px;
  background: rgba(42, 51, 84, 0.45);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 14px;
}

/* 显现 */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
}

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

/* =========================================================
   断点
   ========================================================= */
@media (max-width: 1150px) and (min-width: 961px) {
  .nav-link { padding: 9px 8px; font-size: 13px; }
  .nav-index { font-size: 9px; }
  .search-shortcut-label { display: none; }
  .search-shortcut { padding: 9px 11px; }
}

@media (max-width: 1040px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

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

  .nav-toggle { display: block; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 14px 20px 26px;
    background: rgba(10, 14, 31, 0.98);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 52px rgba(3, 6, 16, 0.72);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    pointer-events: none;
    transition: opacity 0.22s var(--ease), transform 0.22s var(--ease),
      visibility 0.22s var(--ease);
  }

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

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

  .nav-link {
    justify-content: flex-start;
    gap: 12px;
    padding: 15px 8px;
    font-size: 17px;
    border-bottom: 1px solid rgba(42, 51, 84, 0.7);
  }

  .nav-index { font-size: 11px; }

  .nav-link[aria-current="page"] {
    background: rgba(20, 224, 210, 0.07);
    box-shadow: inset 3px 0 0 var(--cyan);
    padding-left: 14px;
  }

  .nav-link[aria-current="page"]::after { display: none; }

  .header-tools { margin-left: auto; }

  .site-footer { margin-top: 64px; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }

  .section { padding: 56px 0; }
  .section--tight { padding: 40px 0; }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-inner { padding: 44px 20px 22px; }

  .footer-bottom { margin-top: 32px; }

  .divider { margin: 32px 0; }
}

@media (max-width: 560px) {
  .search-shortcut-label { display: none; }
  .search-shortcut { padding: 9px 11px; }
}

@media (max-width: 400px) {
  .brand-sub { display: none; }
  .header-inner { gap: 12px; }
}

/* =========================================================
   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;
  }

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

  .scroll-progress { transition: none; }
}