:root {
  --bg: #ffffff;
  --bg-soft: #f5f7fa;
  --bg-dark: #0d1420;
  --line: #e4e8ee;
  --line-strong: #cfd6e0;
  --ink: #141a24;
  --ink-2: #4a5361;
  --ink-3: #8b95a5;
  --brand: #1d4ed8;
  --brand-2: #0891b2;
  --brand-soft: #eaeffd;
  --radius: 10px;
  --radius-lg: 14px;
  --maxw: 1120px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "SF Mono", "JetBrains Mono", Consolas, "Courier New", monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 17px;
  font-weight: 600;
}

.logo-mark {
  width: 30px;
  height: 29.51px;   /* viewBox 671x660 等比（logo.png 轮廓描摹） */
  flex: none;
  color: var(--brand);   /* 页头是白底，logo 必须用品牌色；原先的 #e8f2ff 在白底上几乎不可见 */
  display: grid;
  place-items: center;
}

.logo-mark svg {
  width: 100%;
  height: 100%;
  display: block;
}

.logo-sub {
  font-size: 12.5px;
  color: var(--ink-3);
  font-weight: 400;
  padding-left: 10px;
  margin-left: 4px;
  border-left: 1px solid var(--line-strong);
}

.nav { display: flex; align-items: center; gap: 28px; }

.nav a { font-size: 15px; color: var(--ink-2); transition: color 0.18s; }
.nav a:hover { color: var(--brand); }

.nav .btn-nav {
  padding: 8px 18px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  color: var(--ink);
  font-size: 14px;
}
.nav .btn-nav:hover { border-color: var(--brand); color: var(--brand); }

.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  width: 38px;
  height: 34px;
  cursor: pointer;
  color: var(--ink-2);
  font-size: 16px;
  line-height: 1;
}

/* ---------- hero ---------- */
.hero {
  position: relative;
  padding: 96px 0 88px;
  background: var(--bg-dark);
  color: #fff;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 70% 30%, #000 0%, transparent 72%);
  -webkit-mask-image: radial-gradient(circle at 70% 30%, #000 0%, transparent 72%);
  pointer-events: none;
}

.hero .wrap { position: relative; z-index: 1; }

.hero-grid { max-width: 760px; display: grid; gap: 18px; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  padding: 5px 13px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
  color: #c7d6f5;
  border-radius: 100px;
  font-size: 13px;
}

.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #38bdf8;
}

h1 {
  font-size: 45px;
  line-height: 1.26;
  font-weight: 600;
  letter-spacing: -0.6px;
}

h1 .grad {
  background: linear-gradient(100deg, #60a5fa 10%, #38bdf8 55%, #2dd4bf 95%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p.lead {
  font-size: 17.5px;
  color: rgba(255, 255, 255, 0.72);
  max-width: 640px;
}

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 10px; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: 9px;
  font-size: 15px;
  font-weight: 500;
  transition: all 0.18s;
  cursor: pointer;
  border: 1px solid transparent;
}

.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: #1a43b8; }

.btn-outline {
  background: transparent;
  border-color: rgba(255, 255, 255, 0.24);
  color: #fff;
}
.btn-outline:hover { border-color: rgba(255, 255, 255, 0.5); background: rgba(255, 255, 255, 0.05); }

.btn-solid { background: var(--brand); color: #fff; }
.btn-solid:hover { background: #1a43b8; }

.btn-ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink);
}
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }

/* ---------- stats ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-top: 56px;
  position: relative;
  z-index: 1;
}

.stat { background: var(--bg); padding: 26px 24px; }
.stat dt { font-size: 13px; color: var(--ink-3); margin-bottom: 6px; }
.stat dd { font-size: 26px; font-weight: 600; letter-spacing: -0.4px; color: var(--brand); }

/* ---------- section ---------- */
section { padding: 78px 0; }

.section-soft { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section-head { max-width: 640px; margin-bottom: 46px; }

.section-head h2 {
  font-size: 29px;
  font-weight: 600;
  letter-spacing: -0.3px;
  margin-bottom: 12px;
}

.section-head p { color: var(--ink-2); }

/* ---------- capability ---------- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); gap: 20px; }

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px 26px;
  transition: border-color 0.18s, transform 0.18s;
}

.card:hover { border-color: var(--brand); transform: translateY(-2px); }

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: 11px;
  background: var(--brand-soft);
  color: var(--brand);
  display: grid;
  place-items: center;
  margin-bottom: 18px;
  font-size: 19px;
  font-weight: 600;
  font-family: var(--mono);
}

.card h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.card p { font-size: 14.5px; color: var(--ink-2); line-height: 1.68; }

/* ---------- scenarios ---------- */
.scenarios { display: grid; gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden; }

.scenario {
  background: #fff;
  padding: 26px 28px;
  display: grid;
  grid-template-columns: 210px 1fr;
  gap: 28px;
  align-items: start;
}

.scenario h3 { font-size: 16px; font-weight: 600; color: var(--brand); }
.scenario p { font-size: 14.5px; color: var(--ink-2); }

/* ---------- process ---------- */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px; }

.step { position: relative; padding-top: 22px; border-top: 2px solid var(--brand); }

.step-num {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--brand);
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: 0.5px;
}

.step h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.step p { font-size: 14.5px; color: var(--ink-2); }

/* ---------- faq ---------- */
.faq-list {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: #fff;
  overflow: hidden;
}

.faq {
  border-bottom: 1px solid var(--line);
  padding: 0 26px;
}

.faq:last-child { border-bottom: none; }

.faq summary {
  cursor: pointer;
  padding: 20px 0;
  font-size: 15.5px;
  font-weight: 500;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  font-size: 19px;
  color: var(--ink-3);
  flex-shrink: 0;
  transition: transform 0.18s;
}

.faq[open] summary::after { transform: rotate(45deg); }

.faq p {
  font-size: 14.5px;
  color: var(--ink-2);
  padding: 0 0 20px;
  max-width: 780px;
}

/* ---------- cta ---------- */
.cta-box {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 52px 46px;
  text-align: center;
  background: var(--bg-soft);
}

.cta-box h2 { font-size: 27px; font-weight: 600; margin-bottom: 12px; letter-spacing: -0.3px; }
.cta-box p { color: var(--ink-2); max-width: 540px; margin: 0 auto 26px; }

.cta-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 38px 0 32px; background: #fff; }

.footer-grid { display: flex; align-items: flex-start; justify-content: space-between; gap: 32px; flex-wrap: wrap; }

.footer-brand { max-width: 360px; }
.footer-brand p { font-size: 13.5px; color: var(--ink-3); margin-top: 10px; }

.footer-links { display: flex; gap: 56px; flex-wrap: wrap; }
.footer-col h4 { font-size: 13px; color: var(--ink-3); font-weight: 500; margin-bottom: 12px; }
.footer-col a { display: block; font-size: 14px; color: var(--ink-2); margin-bottom: 8px; }
.footer-col a:hover { color: var(--brand); }

.footer-bottom {
  margin-top: 32px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--ink-3);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- responsive ---------- */
@media (max-width: 880px) {
  h1 { font-size: 34px; }
  .hero { padding: 66px 0 60px; }
  section { padding: 58px 0; }
  .scenario { grid-template-columns: 1fr; gap: 10px; }
  .cta-box { padding: 36px 26px; }
  .footer-links { gap: 36px; }
}

@media (max-width: 720px) {
  .nav { display: none; }
  .nav.open {
    display: flex;
    position: absolute;
    top: 66px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 8px 24px 18px;
  }
  .nav.open a { padding: 11px 0; border-bottom: 1px solid var(--line); }
  .nav.open .btn-nav { border: none; padding: 11px 0; }
  .menu-toggle { display: block; }
  h1 { font-size: 29px; }
  .section-head h2 { font-size: 24px; }
  .logo-sub { display: none; }
}