/*
 * 全站页眉、页脚（按客户 2026-10-31 首页设计稿）：白色毛玻璃导航条、渐变方块标识、圆角导航项、渐变“开始实验”按钮；
 * 页脚四栏（简介 / 平台 / 技术支持 / 联系我们）。所有页面共用，类名以 sx- 开头，不与 Bootstrap 冲突。
 * 导航条保留 .site-nav 类名：lab-flow.js 用它计算顶部遮挡高度。
 */
.sx-nav, .sx-foot {
  --sx-ink: #0F172A; --sx-ink-2: #475569; --sx-ink-3: #64748B; --sx-indigo: #6366F1;
  --sx-line: #E6EAF2; --sx-line-soft: #EEF1F7;
  --sx-grad: linear-gradient(135deg, #6366F1 0%, #8B5CF6 48%, #D946EF 100%);
  font-family: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.sx-nav { position: relative; top: 0; z-index: 1030; background: rgba(255, 255, 255, .88); backdrop-filter: blur(20px) saturate(150%); -webkit-backdrop-filter: blur(20px) saturate(150%);
  border-bottom: 1px solid var(--sx-line-soft); transition: box-shadow .3s; }
.sx-nav.scrolled { box-shadow: 0 8px 24px -16px rgba(15, 23, 42, .18); }
/* 页眉在页面顶部时是普通文档流（浏览器“捕获整页”截图会隐藏固定/粘性元素，放在文档流里才能截进去），
   向下滚动后再固定在顶部；固定时由 body 的 padding-top 占住原来的高度，页面不跳动 */
.sx-nav.stuck { position: fixed; left: 0; right: 0; }
body.sx-stuck { padding-top: var(--sx-nav-h, 68px); }
.sx-nav-inner { width: min(1440px, 96%); margin: 0 auto; height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.sx-brand { display: flex; align-items: center; gap: 11px; min-width: 0; text-decoration: none; }
.sx-brand:hover { text-decoration: none; }
.sx-mark { flex: none; width: 40px; height: 40px; border-radius: 12px; background: var(--sx-grad); display: grid; place-items: center; box-shadow: 0 8px 20px -8px rgba(139, 92, 246, .7); }
.sx-mark svg { width: 22px; height: 22px; stroke: #fff; fill: none; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; display: block; }
.sx-brand .sx-txt { display: flex; flex-direction: column; line-height: 1.28; min-width: 0; }
.sx-brand .sx-txt b { font-weight: 700; font-size: 1rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--sx-ink); }
.sx-brand .sx-txt span { font-size: .74rem; color: var(--sx-ink-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.sx-links { display: flex; align-items: center; gap: 2px; }
.sx-links a { font-size: .86rem; font-weight: 500; color: var(--sx-ink-2); padding: 8px 12px; border-radius: 9px; white-space: nowrap; transition: .22s; text-decoration: none; }
.sx-links a:hover { color: var(--sx-indigo); background: rgba(99, 102, 241, .08); text-decoration: none; }
.sx-links a.active { color: var(--sx-indigo); background: rgba(99, 102, 241, .1); }
.sx-links a.sx-cta { margin-left: 8px; font-size: .88rem; color: #fff; background: var(--sx-grad); padding: 9px 18px; box-shadow: 0 10px 22px -10px rgba(139, 92, 246, .75); }
.sx-links a.sx-cta:hover { color: #fff; background: var(--sx-grad); transform: translateY(-1px); }
.sx-tools { display: flex; align-items: center; gap: 4px; }
.sx-ico { width: 38px; height: 38px; border-radius: 10px; display: grid; place-items: center; color: var(--sx-ink-2); transition: .2s; border: 0; background: none; padding: 0; cursor: pointer; }
.sx-ico:hover { color: var(--sx-indigo); background: rgba(99, 102, 241, .08); }
.sx-ico svg { width: 19px; height: 19px; stroke: currentColor; fill: none; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; display: block; }
.sx-burger { display: none; }
@media (max-width: 1180px) {
  .sx-links { position: fixed; top: 68px; left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 4px; background: #fff; border-bottom: 1px solid var(--sx-line);
    padding: 14px 18px 18px; box-shadow: 0 24px 40px -24px rgba(15, 23, 42, .2); transform: translateY(-120%); visibility: hidden; transition: transform .3s, visibility .3s; max-height: calc(100vh - 68px); overflow: auto; }
  .sx-links.open { transform: translateY(0); visibility: visible; }
  .sx-links a { padding: 13px; font-size: .98rem; border-bottom: 1px solid var(--sx-line-soft); }
  .sx-links a.sx-cta { margin: 8px 0 0; text-align: center; }
  .sx-burger { display: grid; }
}
@media (max-width: 575.98px) { .sx-brand .sx-txt span { display: none; } }

/* ---------- 页脚 ---------- */
.sx-foot { background: #fff; border-top: 1px solid var(--sx-line); padding: 52px 0 28px; margin-top: 28px; color: var(--sx-ink-3); }
.sx-foot-wrap { width: min(1440px, 94%); margin: 0 auto; }
.sx-foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 40px; }
.sx-foot .sx-brand { margin-bottom: 16px; }
.sx-foot .sx-mark { width: 34px; height: 34px; }
.sx-foot-brand p { font-size: .86rem; color: var(--sx-ink-3); max-width: 340px; line-height: 1.7; margin: 0; }
.sx-foot-col h3 { font-family: "Space Grotesk", "Noto Sans SC", sans-serif; font-size: .92rem; font-weight: 700; margin: 0 0 16px; color: var(--sx-ink); }
.sx-foot-col ul { list-style: none; display: flex; flex-direction: column; gap: 11px; margin: 0; padding: 0; }
.sx-foot-col li, .sx-foot-col a { font-size: .84rem; color: var(--sx-ink-3); transition: .2s; text-decoration: none; }
.sx-foot-col a:hover { color: var(--sx-indigo); }
.sx-foot-col li { display: flex; align-items: flex-start; gap: 9px; }
.sx-foot-col li svg { flex: none; width: 15px; height: 15px; stroke: var(--sx-indigo); fill: none; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; margin-top: 3px; display: block; }
/* 页脚 QQ 即时通讯按钮 */
.sx-foot-col li.sx-im span { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 8px; }
.sx-foot-col a.sx-qq { display: inline-flex; align-items: center; padding: 3px 12px; border-radius: 999px; background: linear-gradient(135deg, #4F46E5, #7C3AED); color: #fff; font-weight: 600; font-size: .8rem; line-height: 1.6; }
.sx-foot-col a.sx-qq:hover { color: #fff; filter: brightness(1.08); box-shadow: 0 6px 14px -6px rgba(79, 70, 229, .6); }
.sx-foot-col a.sx-qq:focus-visible { outline: 2px solid #4F46E5; outline-offset: 2px; }
.sx-foot-col li.sx-im small { font-size: .78rem; color: var(--sx-ink-3); }
.sx-foot-bottom { margin-top: 40px; padding-top: 22px; border-top: 1px solid var(--sx-line-soft); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: .78rem; color: var(--sx-ink-3); }
.sx-foot-bottom p { margin: 0; }
@media (max-width: 1080px) { .sx-foot-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 640px) { .sx-foot-grid { grid-template-columns: 1fr; } .sx-foot { padding-top: 44px; } }

/* 首页主体全宽（设计稿各区块自带内边距） */
main.home-main { padding: 0 !important; }
main.home-main + .sx-foot { margin-top: 0; }