/* 顶部导航（玻璃拟态，品牌标 + 药丸链接 + CTA） */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.78);
  backdrop-filter: saturate(180%) blur(28px);
  -webkit-backdrop-filter: saturate(180%) blur(28px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .3s ease, border-color .3s ease, background .3s ease;
}
body.nav-scrolled .site-header {
  border-bottom: 1px solid rgba(210,210,215,.75);
  box-shadow: 0 10px 30px -18px rgba(0,0,0,.14);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 68px; gap: 16px; }
.nav__brand {
  display: flex; align-items: center; gap: 12px;
  color: var(--color-text); position: relative;
  padding: 4px 0;
}
.nav__brand:hover { text-decoration: none; }
.nav__logo {
  width: 42px; height: 42px; border-radius: 13px; flex: 0 0 auto;
  background:
    radial-gradient(120% 120% at 30% 18%, rgba(255,255,255,.34) 0%, rgba(255,255,255,0) 42%),
    linear-gradient(145deg, #0A66C2 0%, #06C 55%, #0EA5E9 100%);
  color: #fff;
  font-size: 21px; font-weight: 700; line-height: 1;
  display: flex; align-items: center; justify-content: center;
  box-shadow:
    0 10px 24px -8px rgba(0,113,227,.70),
    inset 0 0 0 1px rgba(255,255,255,.28),
    inset 0 -8px 16px -10px rgba(0,0,0,.25);
  position: relative;
  letter-spacing: 0;
  transition: transform .25s var(--ease-out), box-shadow .25s ease;
}
.nav__logo::after {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,.28);
  pointer-events: none;
}
.nav__brand:hover .nav__logo {
  transform: translateY(-1px) scale(1.02);
  box-shadow:
    0 14px 30px -8px rgba(0,113,227,.75),
    inset 0 0 0 1px rgba(255,255,255,.32),
    inset 0 -8px 16px -10px rgba(0,0,0,.25);
}
.nav__brandtext { display: flex; flex-direction: column; line-height: 1.05; gap: 3px; }
.nav__brandtitle { font-size: 19px; font-weight: 800; letter-spacing: .04em; color: var(--color-text); }
.nav__brandsub {
  font-size: 10.5px; font-weight: 600; letter-spacing: .18em; text-transform: uppercase;
  color: transparent;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  background-clip: text;
}
.nav__brandname { font-size: 17px; font-weight: 600; letter-spacing: -.01em; }
.nav__links { display: flex; align-items: center; gap: 4px; }
.nav__links li > a:not(.btn) {
  display: inline-block; padding: 8px 15px; border-radius: var(--radius-pill);
  color: var(--color-text-soft); font-size: 14px; font-weight: 500;
  transition: color .2s ease, background .2s ease;
}
.nav__links li > a:not(.btn):hover { color: var(--color-text); background: rgba(0,0,0,.045); text-decoration: none; }
.nav__links li > a:not(.btn).active { color: var(--color-primary); background: rgba(0,113,227,.09); }
.nav__links .btn { margin-left: 12px; }
.nav__toggle { display: none; background: none; border: 0; font-size: 20px; cursor: pointer; color: var(--color-text); padding: 6px; border-radius: 8px; }

/* 首屏概念区（Apple 式留白） */
.page-head {
  position: relative;
  padding: 112px 0 96px;
  margin-bottom: 72px;
  text-align: center;
  overflow: hidden;
  background: var(--gradient-soft);
  border-bottom: 1px solid var(--color-border);
}
.page-head::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(720px 360px at 18% -5%, rgba(0,113,227,.12), transparent 62%),
    radial-gradient(720px 360px at 82% -5%, rgba(10,102,194,.10), transparent 62%);
  pointer-events: none;
}
.page-head > .container { position: relative; }
.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: rgba(0,113,227,.08);
  border-radius: var(--radius-pill);
  padding: 6px 16px;
  margin-bottom: 24px;
}
.page-head__title {
  font-size: 72px;
  font-weight: 700;
  line-height: 1.06;
  letter-spacing: -.035em;
  margin: 0;
  color: var(--color-text);
}
.page-head__title .hl { display: inline-block; }
.page-head__title .hl--grad {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.page-head__subtitle { margin: 22px auto 0; max-width: 680px; color: var(--color-text-soft); font-size: 21px; line-height: 1.5; }
.page-head__actions { margin-top: 36px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.page-head__note { margin-top: 22px; font-size: 13px; color: var(--color-muted); }

/* 主区域 */
main { padding-bottom: 64px; }
.section { margin-bottom: 80px; scroll-margin-top: 84px; }
.section__head { text-align: center; max-width: 680px; margin: 0 auto 44px; }
.section__eyebrow {
  display: inline-block;
  font-size: 12px; font-weight: 600; letter-spacing: .14em; text-transform: uppercase;
  color: var(--color-primary); margin-bottom: 12px;
}
.section__title { font-size: 40px; margin-bottom: 12px; letter-spacing: -.02em; }
.section__intro { margin: 0; color: var(--color-text-soft); font-size: 18px; }
.section--tint { background: var(--color-bg-soft); border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); padding: 80px 0; }
.section--tint .container { padding: 0 24px; }

/* 栅格 */
.grid { display: grid; gap: 28px; align-items: stretch; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--color-border); background: var(--color-bg-soft); padding: 40px 0; font-size: 13px; color: var(--color-text-soft); }
.site-footer__inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.site-footer__links a { color: var(--color-text-soft); }
.site-footer__links a:hover { color: var(--color-text); }

/* 移动端 */
@media (max-width: 720px) {
  .nav__toggle { display: block; }
  .nav__links {
    display: none; position: absolute; top: 68px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 4px;
    background: rgba(255,255,255,.98);
    backdrop-filter: saturate(180%) blur(28px);
    -webkit-backdrop-filter: saturate(180%) blur(28px);
    border-bottom: 1px solid var(--color-border);
    padding: 12px 16px 18px;
    box-shadow: 0 24px 34px -22px rgba(0,0,0,.18);
  }
  .nav__links.open { display: flex; }
  .nav__links li > a:not(.btn) { padding: 12px 16px; font-size: 15px; }
  .nav__links .btn { margin: 8px 0 0; }
  .grid--2, .grid--3 { grid-template-columns: 1fr; }
  .page-head { padding: 72px 0 64px; }
  .page-head__title { font-size: 42px; }
  .page-head__subtitle { font-size: 18px; }
  .section { margin-bottom: 56px; }
  .section__title { font-size: 30px; }
  .section--tint { padding: 56px 0; }
}

@media (min-width: 721px) {
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
}