/* ============================================================
   布局层：页头导航 · 移动端抽屉 · 页脚 · 页面主视觉
   ============================================================ */

/* ---------------- 页头 ---------------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: var(--z-header);
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid transparent;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease),
    box-shadow var(--dur-fast) var(--ease);
}
.site-header.is-stuck {
  background: rgba(255, 255, 255, 0.92);
  border-bottom-color: var(--line-soft);
  box-shadow: 0 1px 20px rgba(24, 40, 72, 0.05);
}
/* 首页：Hero 为浅色，页头初始透明 */
.site-header--over { background: transparent; backdrop-filter: none; -webkit-backdrop-filter: none; }
.site-header--over.is-stuck { background: rgba(255, 255, 255, 0.92); backdrop-filter: saturate(180%) blur(16px); -webkit-backdrop-filter: saturate(180%) blur(16px); }

.header-inner {
  width: 100%;
  max-width: var(--container-wide);
  margin-inline: auto;
  padding-inline: clamp(20px, 4vw, 40px);
  display: flex;
  align-items: center;
  gap: clamp(20px, 3vw, 48px);
}

.brand { display: flex; align-items: center; gap: 10px; flex: 0 0 auto; }
.brand img { height: 34px; width: auto; }
.brand__text { display: flex; flex-direction: column; line-height: 1.1; }
.brand__cn { font-size: 1.05rem; font-weight: var(--fw-semibold); letter-spacing: 0.04em; }
.brand__en { font-size: 0.62rem; letter-spacing: 0.28em; color: var(--ink-3); text-transform: uppercase; }

/* 导航紧贴 LOGO 左对齐；CTA 按钮推到最右 */
.nav {
  display: flex;
  align-items: center;
  gap: clamp(6px, 1.6vw, 24px);
  margin-inline-start: clamp(4px, 1.2vw, 20px);
}
.nav__link {
  position: relative;
  padding: 8px 4px;
  font-size: 0.95rem;
  color: var(--ink-2);
  transition: color var(--dur-fast) var(--ease);
  white-space: nowrap;
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 4px; right: 4px; bottom: 0;
  height: 2px;
  background: var(--grad-brand);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur-fast) var(--ease);
}
.nav__link:hover { color: var(--ink); }
.nav__link:hover::after,
.nav__link[aria-current="page"]::after { transform: scaleX(1); }
.nav__link[aria-current="page"] { color: var(--brand); font-weight: var(--fw-medium); }

.header-cta { display: flex; align-items: center; gap: 12px; flex: 0 0 auto; margin-inline-start: auto; }

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  width: 42px; height: 42px;
  border-radius: var(--r-sm);
  align-items: center;
  justify-content: center;
  gap: 5px;
  flex-direction: column;
}
.nav-toggle span {
  display: block;
  width: 20px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform var(--dur-fast) var(--ease), opacity var(--dur-fast) var(--ease);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 移动端抽屉 */
.drawer {
  position: fixed;
  inset: var(--header-h) 0 0 0;
  z-index: var(--z-drawer);
  background: #fff;
  padding: 28px clamp(20px, 6vw, 40px) 40px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transform: translateY(-8px);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease), visibility var(--dur-fast);
  overflow-y: auto;
}
.drawer.is-open { opacity: 1; visibility: visible; transform: none; }
.drawer a {
  padding: 16px 4px;
  font-size: 1.1rem;
  border-bottom: 1px solid var(--line-soft);
  color: var(--ink);
}
.drawer .btn { margin-top: 24px; justify-content: center; }
body.is-locked { overflow: hidden; }

@media (max-width: 980px) {
  .nav, .header-cta .btn { display: none; }
  .nav-toggle { display: inline-flex; margin-inline-start: auto; }
}
@media (min-width: 981px) { .drawer { display: none; } }

/* ---------------- 首页 Hero ---------------- */
.hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(64px, 9vw, 128px));
  padding-bottom: clamp(40px, 5vw, 72px);
  overflow: hidden;
  text-align: center;
}
.hero__glow {
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 120%;
  background:
    radial-gradient(760px 420px at 50% -6%, rgba(46, 124, 246, 0.16), transparent 66%),
    radial-gradient(560px 340px at 12% 26%, rgba(15, 178, 157, 0.12), transparent 62%),
    radial-gradient(620px 360px at 88% 18%, rgba(91, 75, 214, 0.13), transparent 64%);
  pointer-events: none;
  z-index: 0;
}
.hero__inner { position: relative; z-index: 1; }
.hero .eyebrow { margin-bottom: 26px; justify-content: center; }
.hero .eyebrow::after { content: ""; width: 22px; height: 2px; background: var(--grad-brand); border-radius: 2px; }
.hero__title {
  font-size: var(--fs-hero);
  font-weight: var(--fw-light);
  letter-spacing: -0.035em;
  line-height: 1.08;
  margin: 0 auto 28px;
  max-width: 16em;
}
.hero__lead { max-width: 720px; margin: 0 auto clamp(32px, 4vw, 44px); }
.hero__actions {
  display: flex; justify-content: center; flex-wrap: wrap; gap: 14px;
  margin-bottom: clamp(44px, 5vw, 72px);
}
.hero__wave { max-width: 1040px; margin: 0 auto; }
.hero__wave img { width: 100%; height: auto; }
.hero__wave .band-labels { justify-content: center; margin-top: 10px; }

.hero__matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: clamp(40px, 5vw, 68px);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.hero__matrix li {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  padding: 24px 10px;
  border-right: 1px solid var(--line);
  transition: background var(--dur-fast) var(--ease);
}
.hero__matrix li:last-child { border-right: 0; }
.hero__matrix li:hover { background: var(--bg-soft); }
.hero__matrix b { font-size: 0.7rem; letter-spacing: 0.2em; color: var(--accent, var(--brand)); font-weight: var(--fw-semibold); }
.hero__matrix span { display: flex; flex-direction: column; align-items: center; gap: 3px; font-size: 1rem; font-weight: var(--fw-medium); }
.hero__matrix em { font-style: normal; font-size: 0.72rem; color: var(--ink-3); font-weight: 400; letter-spacing: 0.04em; }
@media (max-width: 820px) {
  .hero__matrix { grid-template-columns: repeat(2, 1fr); }
  .hero__matrix li:nth-child(2) { border-right: 0; }
  .hero__matrix li:nth-child(-n + 2) { border-bottom: 1px solid var(--line); }
}
@media (max-width: 480px) {
  .hero { text-align: left; }
  .hero .eyebrow, .hero__wave .band-labels { justify-content: flex-start; }
  .hero__actions { justify-content: flex-start; }
}

/* ---------------- 页面主视觉（内页） ---------------- */
.page-hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(56px, 7vw, 104px));
  padding-bottom: clamp(48px, 5vw, 88px);
  background:
    radial-gradient(1100px 420px at 78% -12%, rgba(46, 124, 246, 0.1), transparent 62%),
    radial-gradient(760px 360px at 8% 4%, rgba(15, 178, 157, 0.08), transparent 60%),
    var(--bg);
  overflow: hidden;
}
.page-hero__deco {
  position: absolute;
  right: -70px;
  top: clamp(96px, 12vw, 168px);
  width: min(560px, 44vw);
  opacity: 0.42;
  pointer-events: none;
  mask-image: linear-gradient(90deg, transparent, #000 45%);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 45%);
}
@media (max-width: 900px) { .page-hero__deco { display: none; } }
.page-hero__inner { position: relative; z-index: 1; max-width: 820px; }
.page-hero h1 { margin-bottom: 20px; font-weight: var(--fw-light); }
.page-hero .lead { max-width: 660px; }

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: var(--fs-xs);
  color: var(--ink-3);
  margin-bottom: 22px;
}
.breadcrumb a:hover { color: var(--brand); }
.breadcrumb span { opacity: 0.5; }

/* ---------------- 页脚 ---------------- */
.site-footer {
  background: var(--grad-night);
  color: var(--ink-inv);
  padding-top: clamp(56px, 6vw, 88px);
  padding-bottom: 32px;
  position: relative;
  overflow: hidden;
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(760px 320px at 88% 0%, rgba(46, 124, 246, 0.18), transparent 60%);
  pointer-events: none;
}
.footer-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(240px, 1.4fr) repeat(3, minmax(140px, 1fr));
  gap: clamp(28px, 3vw, 56px);
  padding-bottom: 48px;
}
.footer-brand img { height: 40px; width: auto; margin-bottom: 20px; }
.footer-brand p { color: var(--ink-inv-2); font-size: var(--fs-sm); max-width: 340px; }
.footer-col h4 {
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.52);
  font-weight: var(--fw-semibold);
  margin-bottom: 18px;
}
.footer-col li { margin-bottom: 12px; }
.footer-col a { color: var(--ink-inv-2); font-size: var(--fs-sm); transition: color var(--dur-fast) var(--ease); }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  position: relative;
  border-top: 1px solid var(--night-line);
  padding-top: 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: var(--fs-xs);
  color: rgba(255, 255, 255, 0.5);
}
@media (max-width: 820px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

/* ---------------- 通用栅格 ---------------- */
.grid { display: grid; gap: var(--gap); }
.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)); }
@media (max-width: 980px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(32px, 5vw, 80px);
  align-items: center;
}
.split--wide-left { grid-template-columns: 1.15fr 0.85fr; }
.split--wide-right { grid-template-columns: 0.85fr 1.15fr; }
@media (max-width: 900px) { .split, .split--wide-left, .split--wide-right { grid-template-columns: 1fr; } }

.stack { display: flex; flex-direction: column; }
.stack-3 { gap: 12px; } .stack-4 { gap: 16px; } .stack-5 { gap: 24px; } .stack-6 { gap: 32px; }
.row { display: flex; align-items: center; }
.row-gap-3 { gap: 12px; } .row-gap-4 { gap: 16px; } .row-gap-5 { gap: 24px; }
.wrap { flex-wrap: wrap; }
.mt-5 { margin-top: 24px; } .mt-6 { margin-top: 32px; } .mt-7 { margin-top: 48px; }
@media (max-width: 640px) { .split { gap: 28px; } }

/* ---------------- 深色首屏上的页头（透明 + 反白） ----------------
   用法：在带深色大图首屏的页面给 header 加 site-header--dark
   滚动后 is-stuck 生效，自动恢复为浅色实底 + 深色文字                 */
.site-header--over.site-header--dark:not(.is-stuck),
.site-header--dark:not(.is-stuck) {
  background: transparent;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border-bottom-color: transparent;
  box-shadow: none;
}
.site-header--dark:not(.is-stuck) .nav__link { color: rgba(255, 255, 255, 0.8); }
.site-header--dark:not(.is-stuck) .nav__link::after { background: #fff; }
.site-header--dark:not(.is-stuck) .nav__link:hover,
.site-header--dark:not(.is-stuck) .nav__link[aria-current="page"] { color: #fff; }
.site-header--dark:not(.is-stuck) .brand__cn { color: #fff; }
.site-header--dark:not(.is-stuck) .brand__en { color: rgba(255, 255, 255, 0.55); }
.site-header--dark:not(.is-stuck) .nav-toggle span { background: #fff; }
.site-header--dark:not(.is-stuck) .header-cta .btn--primary {
  background: #fff;
  color: var(--brand);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
}

/* LOGO 在深浅底之间自动切换 */
.brand__logo--light { display: none; }
.site-header--dark:not(.is-stuck) .brand__logo--dark { display: none; }
.site-header--dark:not(.is-stuck) .brand__logo--light { display: block; }