/* ==========================================================================
   OwnAgent — 站点样式
   布局参数（栅格、字号、圆角、间距、轮播几何）按 deepmind.google 实测值复刻，
   样式代码为本项目原创实现。
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 设计令牌
   -------------------------------------------------------------------------- */
:root {
  /* 表面 */
  --surface: #ffffff;
  --on-surface: #121317;
  --on-surface-variant: #45474d;
  --surface-container: #18191d;
  --surface-container-high: #212226;
  --surface-container-higher: #2f3034;
  --surface-container-highest: #45474d;

  /* 描边 */
  --outline: #d0d0d0;
  --outline-variant: #e0e0e0;
  --card-border-color: rgba(47, 48, 52, 0.15);

  /* 主色 */
  --primary-gradient: linear-gradient(90deg, #3b6bff 0%, #2e96ff 65%, #acb7ff 100%);
  --primary: #2b4fda;

  /* 媒体之上的文字 */
  --on-media: #ffffff;
  --on-media-variant: rgba(255, 255, 255, 0.72);

  /* 装饰色（用于占位图渐变） */
  --tint-blue: #dcf1ff;
  --tint-red: #ffeef7;
  --tint-green: #daf9d4;
  --tint-yellow: #fcffad;
  --deep-blue: #1e2867;
  --deep-green: #005143;
  --deep-amber: #9e3d02;
  --deep-grey: #212226;

  /* 字体 */
  --font-sans: "Roboto Flex", "Noto Sans SC", "PingFang SC", "Microsoft YaHei",
    Arial, Helvetica, sans-serif;

  /* 栅格 */
  --gutter: 48px;
  --page-pad: 72px;
  --columns: 12;

  /* 圆角 */
  --radius-card: 24px;
  --radius-pill: 9999px;

  /* 头部 */
  --header-h: 64px;
}

@media (max-width: 1023px) {
  :root { --page-pad: 40px; --gutter: 32px; }
}
@media (max-width: 767px) {
  :root { --page-pad: 20px; --gutter: 16px; }
}

/* --------------------------------------------------------------------------
   2. 基础
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  /* 锚点滚动要给吸顶头部让出位置 */
  scroll-padding-top: calc(var(--header-h) + 16px);

  /* 不做整页/板块吸附：纵向滚动完全交给用户，任何形式的接管都别加回来。 */
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  padding-top: var(--header-h);
  background: var(--surface);
  color: var(--on-surface);
  font-family: var(--font-sans);
  font-size: 17.5px;
  font-weight: 400;
  line-height: 1.45;
  letter-spacing: 0.208px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, picture, video { display: block; max-width: 100%; }
a { color: inherit; }
button { font: inherit; color: inherit; }

:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

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

.skip-link {
  position: fixed; top: 8px; left: 8px; z-index: 200;
  transform: translateY(-200%);
  transition: transform 0.2s ease;
}
.skip-link:focus-within { transform: translateY(0); }

/* ---- 滚动条 ----
   页面滚动条改成「浮层」：叠在内容上，不占布局宽度。

   为什么要自己做：原生滚动条在 Windows 的 Chrome/Firefox 上是 classic 模式，
   会实打实占掉一列（约 10~15px），把内容挤窄；macOS 才是默认浮层。
   CSS 没有任何属性能把 classic 改成 overlay，所以只能隐藏原生的、自己画一根。
   滚动行为仍然完全是原生的（滚轮、键盘、触控板、拖拽都不受影响），
   我们替换的只是那根可视的滑块。

   注意：这里只隐藏「文档」的滚动条。页面内部的滚动容器
   （移动端菜单等）仍然用下面那套 ::-webkit-scrollbar 样式。 */
html {
  scrollbar-width: none;              /* Firefox */
  -ms-overflow-style: none;
}
html::-webkit-scrollbar {             /* Chrome / Edge / Safari */
  display: none;
}

/* 浮层滚动条本体。结构由 site.js 建，DOM 里不用写。 */
.scrollbar {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 10px;
  z-index: 2100;                      /* 要压过 header 的 2000 */
  pointer-events: none;               /* 轨道不挡内容，只有滑块可交互 */
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s;
}
.scrollbar.is-visible {
  opacity: 1;
  visibility: visible;
}

/* 滑块：10px 宽是为了好抓，真正可见的细条由 ::before 画出来 */
.scrollbar__thumb {
  position: absolute;
  top: 0;                             /* 位置由 JS 用 translateY 推，这里必须有基准 */
  right: 0;
  width: 10px;
  pointer-events: auto;
  touch-action: none;                 /* 拖拽时别让浏览器抢去做手势 */
}
.scrollbar__thumb::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 3px;
  right: 3px;
  border-radius: var(--radius-pill);
  background-color: rgba(33, 34, 38, 0.3);
  transition: background-color 0.18s ease, left 0.15s ease, right 0.15s ease;
}
.scrollbar__thumb:hover::before,
.scrollbar.is-dragging .scrollbar__thumb::before {
  left: 1px;
  right: 1px;
  background-color: rgba(33, 34, 38, 0.5);
}

/* 拖拽期间：锁住选中，避免把页面文字一起刷蓝；
   同时关掉平滑滚动 —— html 上有 scroll-behavior: smooth，
   拖拽时每帧都调 scrollTo，平滑会让滑块黏在手指后面一大截。 */
html.is-scrollbar-dragging,
html.is-scrollbar-dragging body {
  user-select: none;
}
html.is-scrollbar-dragging {
  scroll-behavior: auto;
}

@media (prefers-reduced-motion: reduce) {
  .scrollbar { transition: none; }
  .scrollbar__thumb::before { transition: none; }
}

/* ---- 页面内部滚动容器的滚动条（移动端菜单等） ---- */
::-webkit-scrollbar {
  width: 12px;
  height: 12px;
  background: transparent;
}
::-webkit-scrollbar-track,
::-webkit-scrollbar-track-piece,
::-webkit-scrollbar-corner {
  background: transparent;
}
::-webkit-scrollbar-button {
  display: none;
  width: 0;
  height: 0;
}
::-webkit-scrollbar-thumb {
  background-color: rgba(33, 34, 38, 0.22);
  background-clip: content-box;
  border: 3px solid transparent;
  border-radius: var(--radius-pill);
  transition: background-color 0.2s ease;
}
::-webkit-scrollbar-thumb:hover {
  background-color: rgba(33, 34, 38, 0.42);
}

/* --------------------------------------------------------------------------
   3. 排版比例
   -------------------------------------------------------------------------- */
.heading-1 { font-size: 54px; font-weight: 500; line-height: 1.04; letter-spacing: -1.215px; margin: 0; }
.heading-2 { font-size: 42px; font-weight: 450; line-height: 1.04; letter-spacing: -0.98px; margin: 0; }
.heading-3 { font-size: 32px; font-weight: 500; line-height: 1.06; letter-spacing: -0.544px; margin: 0; }
.heading-4 { font-size: 26px; font-weight: 500; line-height: 1.08; letter-spacing: -0.225px; margin: 0; }
.heading-5 { font-size: 24px; font-weight: 500; line-height: 1.08; letter-spacing: -0.168px; margin: 0; }
.heading-6 { font-size: 20px; font-weight: 500; line-height: 1.45; letter-spacing: -0.089px; margin: 0; }
.eyebrow   { font-size: 14.5px; font-weight: 500; line-height: 1.45; letter-spacing: 0.133px; color: var(--on-surface-variant); margin: 0; }

@media (max-width: 1023px) {
  .heading-1 { font-size: 40px; letter-spacing: -0.8px; }
  .heading-2 { font-size: 32px; letter-spacing: -0.6px; }
  .heading-3 { font-size: 26px; letter-spacing: -0.3px; }
}
@media (max-width: 599px) {
  .heading-1 { font-size: 32px; letter-spacing: -0.5px; }
  .heading-2 { font-size: 26px; }
}

/* --------------------------------------------------------------------------
   4. 栅格与区块间距
   -------------------------------------------------------------------------- */
.section { padding-inline: var(--page-pad); }
.section--pt-md { padding-top: 64px; }
.section--pt-xs { padding-top: 16px; }
.section--pt-sm { padding-top: 32px; }
.section--pb-md { padding-bottom: 64px; }
.section--pb-lg { padding-bottom: 96px; }
.section--pb-sm { padding-bottom: 32px; }
.section--pb-xs { padding-bottom: 16px; }

@media (max-width: 767px) {
  .section--pt-md { padding-top: 40px; }
  .section--pb-md { padding-bottom: 40px; }
  .section--pb-lg { padding-bottom: 56px; }
}

.grid {
  display: grid;
  grid-template-columns: repeat(var(--columns), minmax(0, 1fr));
  column-gap: var(--gutter);
}
@media (max-width: 767px) {
  .grid { --columns: 4; }
}

.span-12 { grid-column: span 12; }
.span-8-offset-2 { grid-column: 3 / span 8; }
.span-6-offset-3 { grid-column: 4 / span 6; }
.span-6 { grid-column: span 6; }
.span-4 { grid-column: span 4; }

@media (max-width: 1023px) {
  .span-6-offset-3 { grid-column: 2 / span 10; }
}
@media (max-width: 767px) {
  .span-12, .span-8-offset-2, .span-6-offset-3, .span-6, .span-4 { grid-column: span 4; }
}

/* --------------------------------------------------------------------------
   5. 按钮
   -------------------------------------------------------------------------- */
.button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  min-height: 34px;
  border: 0;
  border-radius: var(--radius-pill);
  font-size: 14.5px;
  font-weight: 450;
  line-height: 18px;
  letter-spacing: 0.133px;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease, opacity 0.2s ease;
}
.button--filled { background: #f8f9fc; color: #121317; }
.button--filled:hover { background: #ffffff; }

.button--tonal { background: rgba(47, 48, 52, 0.08); color: var(--on-surface); }
.button--tonal:hover { background: rgba(47, 48, 52, 0.14); }

.button--outlined {
  background: transparent;
  color: var(--on-surface);
  box-shadow: inset 0 0 0 1px var(--outline);
}
.button--outlined:hover { background: rgba(47, 48, 52, 0.06); }

/* 主行动：企业站的标准做法是一枚实心深色按钮，不用玻璃态 */
.button--dark { background: #121317; color: #ffffff; }
.button--dark:hover { background: #2f3034; }

/* 次行动：无底无框，只在 hover 时给一层极淡的底 */
.button--ghost { background: transparent; color: var(--on-surface); }
.button--ghost:hover { background: rgba(47, 48, 52, 0.07); }

.button--lg { padding: 13px 24px; min-height: 48px; font-size: 16px; }

.button--icon {
  padding: 8px;
  min-width: 40px;
  min-height: 40px;
  justify-content: center;
}
.button svg { width: 20px; height: 20px; fill: currentColor; flex: none; }

.button-group { display: flex; flex-wrap: wrap; gap: 8px; }
.button-group--stacked { flex-direction: column; align-items: flex-start; gap: 12px; }

/* --------------------------------------------------------------------------
   6. 头部导航
   --------------------------------------------------------------------------
   几何与层次按原站实测值还原：
   - header 固定定位，自身完全透明，内容从它下方滚过
   - .header-bar 高 64px，左右 72px，三段之间 gap 48px
   - 模糊层向下多探出 16px（inset: 0 0 -16px），5 层渐进模糊 + 一层白色渐变遮罩
   -------------------------------------------------------------------------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  z-index: 2000;
  background: transparent;
}

.header-bar {
  position: relative;
  z-index: 3;
  display: flex;
  align-items: center;
  gap: 48px;
  height: var(--header-h);
  padding-inline: var(--page-pad);
}
@media (max-width: 1023px) {
  .header-bar { gap: 24px; }
}

/* 渐进式模糊：越靠顶部越糊，向下渐隐 */
.header-bar__blur {
  position: absolute;
  inset: 0 0 -16px;
  z-index: -1;
  pointer-events: none;
}
/* 白色渐变遮罩，让文字压在任何底图上都读得清 */
.header-bar__blur::after {
  content: "";
  position: absolute;
  inset: -20px;
  pointer-events: none;
  filter: blur(12px);
  background: linear-gradient(
    #ffffff 0%,
    rgba(255, 255, 255, 0.85) 20%,
    rgba(255, 255, 255, 0.55) 45%,
    rgba(255, 255, 255, 0.3) 70%,
    rgba(255, 255, 255, 0) 100%
  );
}
.header-bar__blur-layer {
  position: absolute;
  inset: 0;
  display: block;
}
.header-bar__blur-layer--1 {
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  -webkit-mask-image: linear-gradient(transparent 0%, transparent 40%, #000 60%, #000 80%, transparent 100%);
  mask-image: linear-gradient(transparent 0%, transparent 40%, #000 60%, #000 80%, transparent 100%);
}
.header-bar__blur-layer--2 {
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  -webkit-mask-image: linear-gradient(transparent 0%, transparent 20%, #000 40%, #000 60%, transparent 80%, transparent 100%);
  mask-image: linear-gradient(transparent 0%, transparent 20%, #000 40%, #000 60%, transparent 80%, transparent 100%);
}
.header-bar__blur-layer--3 {
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  -webkit-mask-image: linear-gradient(transparent 0%, #000 20%, #000 40%, transparent 60%, transparent 100%);
  mask-image: linear-gradient(transparent 0%, #000 20%, #000 40%, transparent 60%, transparent 100%);
}
.header-bar__blur-layer--4 {
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  -webkit-mask-image: linear-gradient(#000 0%, #000 20%, transparent 40%, transparent 100%);
  mask-image: linear-gradient(#000 0%, #000 20%, transparent 40%, transparent 100%);
}
.header-bar__blur-layer--5 {
  -webkit-backdrop-filter: blur(34px);
  backdrop-filter: blur(34px);
  -webkit-mask-image: linear-gradient(#000 0%, transparent 20%, transparent 100%);
  mask-image: linear-gradient(#000 0%, transparent 20%, transparent 100%);
}

/* ---- 左：站点标识 ---- */
.left-menu {
  display: flex;
  align-items: center;
  gap: 16px;
  height: 48px;
  flex: none;
}
.site-switcher {
  position: relative;
  z-index: 100;
  display: flex;
  align-items: center;
  height: 48px;
}
.site-switcher__home {
  display: flex;
  align-items: center;
  gap: 9px;
  height: 48px;
  text-decoration: none;
  color: var(--on-surface);
  font-size: 17.5px;
  font-weight: 500;
  letter-spacing: -0.1px;
  white-space: nowrap;
}
.site-switcher__home img { height: 26px; width: auto; flex: none; }

/* ---- 中：主导航（紧贴 logo 左对齐，不居中） ---- */
.main-menu {
  flex: 1 1 auto;
  min-width: 0;
}
.main-menu__container {
  display: flex;
  align-items: stretch;
  /* 撑满整条 header，让下拉面板 top:100% 正好落在 header 底边，
     同时触发项与面板之间没有空隙，hover 不会中断 */
  height: var(--header-h);
  gap: 4px;
}
.main-menu__label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  font-size: 14.5px;
  font-weight: 500;
  line-height: 21px;
  letter-spacing: 0.133px;
  color: var(--on-surface);
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: box-shadow 0.2s ease, background-color 0.2s ease;
}
.main-menu__label:hover,
.main-menu__label[aria-current="true"],
.main-menu__label[aria-current="page"] {
  box-shadow: 0 0 0 1px rgba(33, 34, 38, 0.12);
  background-color: rgba(255, 255, 255, 0.8);
  -webkit-backdrop-filter: blur(28px) saturate(150%);
  backdrop-filter: blur(28px) saturate(150%);
}

/* --------------------------------------------------------------------------
   下拉面板（flyout）—— 按 deepmind.google 实测值还原
   --------------------------------------------------------------------------
   原站结构：.flyout__desktop-container（毛玻璃卡片外壳，JS 设 left 对齐触发项）
             └ .flyout.desktop（做 opacity/scale 动画的内层）
               └ .flyout__container > .subnav
   实测：top=header 高；absolute 定位（不是通栏）；bg rgba(255,255,255,.8)；
        backdrop-filter blur(20px)；圆角 24px；padding 24px；1px 描边；无阴影；
        动画 opacity+transform(scale .98→1) 0.25s cubic-bezier(.16,1,.3,1)
   -------------------------------------------------------------------------- */
.main-menu__item { position: relative; display: flex; align-items: center; }

/* ---- 卡片外壳 ---- */
.flyout__desktop-container {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 2;
  padding: 24px;
  border: 0.8px solid rgba(33, 34, 38, 0.06);
  border-radius: 24px;
  background-color: rgba(255, 255, 255, 0.68);
  overflow: hidden;
  white-space: normal;
  pointer-events: none;
  opacity: 0;
  transform: scale(0.98);
  transition: opacity 0.1s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.1s cubic-bezier(0.16, 1, 0.3, 1),
              visibility 0.1s;
  visibility: hidden;
}
@supports (backdrop-filter: blur(20px)) or (-webkit-backdrop-filter: blur(20px)) {
  /* 底色从 .8 透到 .68 之后，模糊要跟着加大，
     否则面板底下的内容会透上来、条目文字读不清 */
  .flyout__desktop-container {
    -webkit-backdrop-filter: blur(28px) saturate(150%);
    backdrop-filter: blur(28px) saturate(150%);
  }
}
.flyout__desktop-container.is-open {
  visibility: visible;
  opacity: 1;
  transform: scale(1);
  pointer-events: auto;
  border-bottom-color: rgba(23, 24, 31, 0.12);
  transition: opacity 0.25s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ---- 内层：做 scale/opacity 的那一层 ---- */
.flyout {
  position: relative;
  z-index: 3;
  width: 100%;
  background-color: transparent;
  opacity: 0;
  transform: scale(0.98);
  transition: opacity 0.25s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}
.flyout.is-in { opacity: 1; transform: scale(1); }

.flyout__container { max-width: 1440px; }

/* ---- 分组栅格：实测 2 列 × 256px，列间距 36px，第 3 项起 margin-top 36px ---- */
.subnav {
  display: grid;
  grid-template-columns: repeat(2, 256px);
  column-gap: 36px;
  row-gap: 0;
  align-items: start;
}
/* 只有一个分组的栏目（算力）用单列，不要撑出半边空白 */
.subnav--single { grid-template-columns: 264px; }
.subnav__column { display: flex; flex-direction: column; align-items: start; }
.subnav__column:nth-child(n + 3) { margin-top: 36px; }

.subnav__header { margin: 0 0 16px; }
.subnav__title {
  font-size: 14.5px;
  font-weight: 500;
  line-height: 21px;
  letter-spacing: 0.208px;
  color: var(--on-surface-variant);
}
.subnav__links { display: flex; flex-direction: column; width: 100%; }

/* ---- 条目：48px 圆角图标 + 标题 + 描述，hover 用 ::before 撑出 -8px 的药丸 ---- */
.subnav__link {
  position: relative;
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 0;
  color: var(--on-surface);
  text-decoration: none;
}
.subnav__link::before {
  content: "";
  position: absolute;
  inset: 0 -8px;
  z-index: -1;
  border-radius: 24px;
  background-color: transparent;
  transition: background-color 0.15s ease;
}
.subnav__link:hover::before { background-color: rgba(33, 34, 38, 0.04); }
.subnav__link:focus-visible { outline: none; }
.subnav__link:focus-visible::before {
  background-color: rgba(33, 34, 38, 0.04);
  box-shadow: 0 0 0 2px #fff, 0 0 0 4px var(--primary);
}
.subnav__link-image {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 16px;
  background: var(--tint-blue);
  color: var(--deep-blue);
}
.subnav__link-image svg { width: 24px; height: 24px; fill: currentColor; }
/* 条目配色跟着自己的 data-hue 走（色值见 pages.css 的 [data-hue]） */
.subnav__link-image[data-hue] { background: var(--hue-tint); color: var(--hue-mid); }
/* 人物条目放真人照片：整块铺满，去掉底色，免得圆角外透出浅蓝 */
.subnav__link-image--photo { background: #eef0f4; border-radius: 12px; overflow: hidden; }
.subnav__link-image--photo img { width: 100%; height: 100%; object-fit: cover; display: block; }
/* 三个都是 span，需要显式转块，否则标题和描述会挤在同一行 */
.subnav__link-text { display: block; min-width: 0; }
.subnav__link-label {
  display: block;
  font-size: 14.5px;
  font-weight: 500;
  line-height: 21px;
  letter-spacing: 0.133px;
  color: var(--on-surface);
}
.subnav__link-description {
  display: block;
  font-size: 11px;
  font-weight: 400;
  line-height: 15px;
  letter-spacing: 0.092px;
  color: var(--on-surface-variant);
}

/* 窄一点的桌面放不下 2×256+36，退回单列，避免面板顶出视口 */
@media (min-width: 900px) and (max-width: 1199px) {
  .subnav { grid-template-columns: 256px; }
  .subnav__column:nth-child(n + 2) { margin-top: 36px; }
}

/* 原站 prefers-reduced-motion 下直接显示，不做位移/缩放 */
@media (prefers-reduced-motion: reduce) {
  .flyout__desktop-container,
  .flyout,
  .flyout__desktop-container.is-open,
  .flyout.is-in,
  .subnav__link::before {
    transition: none !important;
    transform: none !important;
  }
}

/* ---- 右：CTA ---- */
.right-menu {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
}
/* 手机上只留主行动，次行动收进汉堡菜单也能到达（页脚有「联系我们」） */
@media (max-width: 599px) {
  .right-menu .button--ghost { display: none; }
}

/* ---- 移动端 ---- */
.nav-toggle { display: none; }

@media (max-width: 899px) {
  /* 原站手机版实测：bar 内边距 0 28px、gap 8px；
     汉堡在最左，logo 排在它右边（不是 logo 居左、汉堡靠右）；
     左区 flex:1 撑开，把右侧 CTA 顶到最右。
     与原站唯一的出入：原站在手机上把右侧 CTA 整个隐藏，这里按要求保留「立刻体验」。 */
  .header-bar {
    gap: 8px;
    padding-inline: 28px;
  }
  .left-menu {
    flex: 1 1 auto;
    gap: 16px;
    min-width: 0;
  }
  .main-menu {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex: none;
    padding: 8px 28px 16px;
    background: rgba(255, 255, 255, 0.95);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    box-shadow: 0 0 0 1px rgba(33, 34, 38, 0.08);
    display: none;
    /* 横屏或小屏时菜单可能超出视口，让它自己能滚 */
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    overscroll-behavior: contain;
  }
  .main-menu.is-open { display: block; }
  .main-menu__container { flex-direction: column; align-items: stretch; height: auto; gap: 2px; }
  .main-menu__label { padding: 12px 16px; font-size: 16px; border-radius: 12px; }

  /* 原站移动端是「手风琴」：面板不再浮层，而是在菜单里就地展开。
     这里复用同一套 DOM，把卡片外壳降级成普通块。 */
  .main-menu__item { display: block; }
  .main-menu__item > .main-menu__label { display: flex; }

  .flyout__desktop-container {
    position: static;
    visibility: visible;
    opacity: 1;
    transform: none;
    pointer-events: auto;
    display: none;
    padding: 0 0 8px 12px;
    border: 0;
    border-radius: 0;
    background: transparent;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    transition: none;
  }
  .flyout__desktop-container.is-open { display: block; border: 0; }
  .flyout { opacity: 1; transform: none; transition: none; }

  .subnav { grid-template-columns: 1fr; row-gap: 20px; }
  .subnav__column:nth-child(n + 3) { margin-top: 0; }
  .subnav__header { margin-bottom: 4px; }
  /* 二级条目留够 44px 点击区 */
  .subnav__link { min-height: 44px; padding: 8px 0; }
  .subnav__link-image { width: 36px; height: 36px; border-radius: 12px; }
  .subnav__link-image svg { width: 20px; height: 20px; }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    /* 排到最左：用 order 调顺序，不动 DOM 结构 */
    order: -1;
    margin-inline-start: 0;
    /* 原站的汉堡在 .left-menu 内部、吃的是它 16px 的 gap；
       我们的在外面，只吃到 bar 的 8px，补 8px 让间距一致 */
    margin-inline-end: 8px;
    width: 40px;
    height: 40px;
    padding: 0;
    background: transparent;
    border: 0;
    border-radius: var(--radius-pill);
    color: var(--on-surface);
    cursor: pointer;
    transition: background-color 0.2s ease;
  }
  .nav-toggle:hover { background: rgba(33, 34, 38, 0.08); }
  .nav-toggle svg { width: 24px; height: 24px; fill: currentColor; }

}

/* --------------------------------------------------------------------------
   8. 横向小卡（场景详情页的「相关场景」）
   --------------------------------------------------------------------------
   flex + gap 48px + 垂直居中；左侧内容列 flex column gap 24px；
   标题 28px/500，meta 17.5px 横排 gap 16px；右侧缩略图 176x176。
   -------------------------------------------------------------------------- */
.card-h {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--gutter);
  padding-bottom: 36px;
  text-decoration: none;
}
.card-h > div:first-child {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.card-h .card-h__title {
  margin: 0;
  font-size: 28px;
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.198px;
  color: var(--on-surface);
}
.card-h .meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin: 0;
  color: var(--on-surface-variant);
  font-size: 17.5px;
  font-weight: 400;
  letter-spacing: 0.208px;
}
.card-h__media {
  flex: 0 0 176px;
  width: 176px;
  height: 176px;
  border-radius: 16px;
  overflow: hidden;
  background-color: var(--surface-container);
  background-image: var(--slot-img, var(--slot-fallback));
  background-size: cover;
  background-position: center;
}
.card-h:hover .card-h__title { text-decoration: underline; text-underline-offset: 3px; }

@media (max-width: 1023px) {
  .card-h .card-h__title { font-size: 24px; }
}
@media (max-width: 599px) {
  .card-h { gap: 16px; }
  .card-h > div:first-child { gap: 12px; }
  .card-h .card-h__title { font-size: 20px; }
  .card-h .meta { font-size: 14.5px; gap: 10px; }
  .card-h__media { flex-basis: 104px; width: 104px; height: 104px; }
}

/* 9.2b 浅底面板（关于 / 相关阅读的外框）
   原站实测：底色 #f8f9fc、圆角 16px、内边距 72px；
   面板标题 42px/450，标题与内容之间 60px。 */
.panel {
  background: #f8f9fc;
  border-radius: 16px;
  padding: 72px;
}
.panel__header { margin-bottom: 60px; }
.panel__title {
  margin: 0;
  font-size: 42px;
  font-weight: 450;
  line-height: 1.04;
  letter-spacing: -0.98px;
  color: var(--on-surface);
}
@media (max-width: 1023px) {
  .panel { padding: 40px 28px; }
  .panel__header { margin-bottom: 36px; }
  .panel__title { font-size: 32px; letter-spacing: -0.6px; }
}

/* 占位图渐变（配图到位后替换 --slot-img 即可） */
.slot--blue   { --slot-fallback: linear-gradient(140deg, #1e2867 0%, #2b4fda 48%, #9dd2ff 100%); }
.slot--green  { --slot-fallback: linear-gradient(140deg, #00312a 0%, #005143 45%, #9be69a 100%); }
.slot--amber  { --slot-fallback: linear-gradient(140deg, #3a1a00 0%, #9e3d02 48%, #ffd08a 100%); }
.slot--pink   { --slot-fallback: linear-gradient(140deg, #3d0027 0%, #de249e 52%, #ffdbf5 100%); }
.slot--grey   { --slot-fallback: linear-gradient(140deg, #121317 0%, #2f3034 46%, #8f97a3 100%); }
.slot--indigo { --slot-fallback: linear-gradient(140deg, #101431 0%, #3b6bff 52%, #acb7ff 100%); }

/* --------------------------------------------------------------------------
   10. 案例详情页
   -------------------------------------------------------------------------- */
.cover { padding-top: 56px; padding-bottom: 40px; }
.cover__eyebrow { display: flex; flex-wrap: wrap; gap: 8px 16px; margin-bottom: 20px; }
.cover__title { margin: 0 0 20px; }
.cover__authors {
  margin: 0;
  color: var(--on-surface-variant);
  font-size: 20px;
  font-weight: 450;
  line-height: 1.4;
}

/* 顶部视频位 */
.hero-media { padding-inline: var(--page-pad); padding-bottom: 64px; }
.hero-media__frame {
  position: relative;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--slot-img, var(--slot-fallback));
  background-size: cover;
  background-position: center;
}
.hero-media__frame video,
.hero-media__frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
  object-fit: cover;
}
.hero-media__placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  color: var(--on-media);
  text-align: center;
  padding: 24px;
  background: rgba(10, 11, 15, 0.35);
}
.hero-media__placeholder svg { width: 56px; height: 56px; fill: currentColor; opacity: 0.9; }
.hero-media__placeholder span { font-size: 14.5px; color: var(--on-media-variant); }

/* 正文 */
.rich-text > * + * { margin-top: 24px; }
.rich-text p {
  margin: 0;
  color: var(--on-surface-variant);
  font-size: 17.5px;
  line-height: 1.45;
  letter-spacing: 0.208px;
}
.rich-text .lead-paragraph {
  color: var(--on-surface);
  font-size: 24px;
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.168px;
}
.rich-text h2 {
  margin: 56px 0 0;
  font-size: 42px;
  font-weight: 450;
  line-height: 1.04;
  letter-spacing: -0.98px;
  color: var(--on-surface);
}
.rich-text h3 {
  margin: 40px 0 0;
  font-size: 24px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: -0.168px;
  color: var(--on-surface);
}
.rich-text ul, .rich-text ol { margin: 0; padding-inline-start: 22px; color: var(--on-surface-variant); }
.rich-text li + li { margin-top: 10px; }
.rich-text a { color: var(--primary); text-underline-offset: 3px; }
.rich-text strong { color: var(--on-surface); font-weight: 500; }

@media (max-width: 1023px) {
  .rich-text h2 { margin-top: 40px; font-size: 32px; letter-spacing: -0.6px; }
  .rich-text .lead-paragraph { font-size: 20px; }
}
@media (max-width: 599px) {
  /* 小屏下 h1 已降到 32px，正文 h2 必须再小一档，否则标题层级分不出来 */
  .rich-text h2 { margin-top: 32px; font-size: 24px; letter-spacing: -0.3px; }
  .rich-text h3 { margin-top: 28px; font-size: 20px; }
  .rich-text > * + * { margin-top: 20px; }
}

/* 引用 */
.quote { margin: 0; }
.quote__text { margin: 0; }
.quote__text p {
  margin: 0;
  font-size: 32px;
  font-weight: 500;
  line-height: 1.06;
  letter-spacing: -0.544px;
  color: var(--on-surface);
}
.quote__author {
  margin-top: 24px;
  color: var(--on-surface-variant);
  font-size: 14.5px;
}
@media (max-width: 1023px) {
  .quote__text p { font-size: 24px; letter-spacing: -0.3px; }
}

/* 正文内配图 */
.figure { margin: 0; }
.figure__media {
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--slot-img, var(--slot-fallback));
  background-size: cover;
  background-position: center;
}
.figure figcaption {
  margin-top: 14px;
  color: var(--on-surface-variant);
  font-size: 14.5px;
  letter-spacing: 0.133px;
}

/* --------------------------------------------------------------------------
   11. 页脚
   -------------------------------------------------------------------------- */
.site-footer { border-top: 1px solid var(--outline-variant); }
.footer-main {
  padding: 64px var(--page-pad);
  display: grid;
  /* 链接从 3 列涨到 5 列，标题列要让出空间，否则「全部 FDE 专家」这类会折行 */
  grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
  gap: var(--gutter);
}
.footer-brand { max-width: 26ch; }
.footer-brand img { height: 30px; width: auto; }
.footer-brand__name { margin: 12px 0 0; font-size: 17.5px; font-weight: 500; letter-spacing: -0.1px; }
.footer-brand__line { margin: 8px 0 0; color: var(--on-surface-variant); font-size: 14.5px; line-height: 1.5; }
.footer-brand__org {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--outline-variant);
  color: var(--on-surface-variant);
  font-size: 13px;
  line-height: 1.5;
}
.footer-links {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 32px 24px;
}
.footer-links h4 {
  margin: 0 0 12px;
  font-size: 14.5px;
  font-weight: 500;
  letter-spacing: 0.133px;
}
.footer-links ul { margin: 0; padding: 0; list-style: none; }
.footer-links li + li { margin-top: 10px; }
.footer-links a {
  color: var(--on-surface-variant);
  font-size: 14.5px;
  text-decoration: none;
}
.footer-links a:hover { color: var(--on-surface); text-decoration: underline; }

.footer-legal {
  padding: 20px var(--page-pad) 32px;
  border-top: 1px solid var(--outline-variant);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 24px;
  color: var(--on-surface-variant);
  font-size: 14.5px;
}
.footer-legal a { color: inherit; text-decoration: none; }
.footer-legal a:hover { text-decoration: underline; }
.footer-legal__spacer { margin-inline-start: auto; }

@media (max-width: 1199px) {
  .footer-main { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 899px) {
  .footer-main { padding: 48px var(--page-pad); }
  .footer-links { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-legal__spacer { margin-inline-start: 0; }
}
@media (max-width: 599px) {
  /* 双列放不下「商机挖掘 & 运营管理」这类长条目 */
  .footer-links { grid-template-columns: 1fr; }
  .footer-links a { display: inline-block; padding: 4px 0; }
  .footer-legal { flex-direction: column; align-items: flex-start; gap: 6px; }
}

/* --------------------------------------------------------------------------
   12. 入场动画
   -------------------------------------------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s cubic-bezier(0.2, 0, 0, 1), transform 0.6s cubic-bezier(0.2, 0, 0, 1);
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}