:root {
  --brand: #2563eb;
  --brand-dark: #1d4ed8;
  --brand-soft: #eaf1ff;
  --ink: #0f172a;
  --muted: #5b667a;
  --line: #e3e9f2;
  --bg: #f6f8fc;
  --card: #ffffff;
  --ok: #0f9d58;
  --warn: #b45309;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(15, 23, 42, .06);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 22px; }

/* header */
.site-header {
  background: rgba(255, 255, 255, .92);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(8px);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  gap: 26px;
  height: 66px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--ink);
  letter-spacing: .01em;
}
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 30px; height: 30px; border-radius: 9px;
  background: linear-gradient(135deg, #3b82f6, #1d4ed8);
  display: grid; place-items: center; color: #fff;
  font-size: 15px; font-weight: 700;
}
.nav { display: flex; gap: 22px; margin-left: auto; }
.nav a { color: var(--muted); font-size: 15px; }
.nav a:hover, .nav a.active { color: var(--ink); text-decoration: none; }
.nav .btn { color: #fff; }
.nav .btn:hover { color: #fff; }

/* buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; height: 42px; padding: 0 20px;
  border-radius: 10px; border: 1px solid transparent;
  background: var(--brand); color: #fff;
  font-size: 15px; font-weight: 600; cursor: pointer;
  transition: background .15s ease, transform .05s ease;
}
.btn:hover { background: var(--brand-dark); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn.ghost {
  background: #fff; color: var(--brand);
  border-color: #cfe0ff;
}
.btn.ghost:hover { background: var(--brand-soft); }
.btn.lg { height: 48px; padding: 0 26px; font-size: 16px; border-radius: 12px; }
.btn[disabled] { opacity: .55; cursor: not-allowed; }

/* hero */
.hero {
  padding: 68px 0 46px;
  background:
    radial-gradient(900px 360px at 15% -10%, #dbeafe 0%, rgba(219, 234, 254, 0) 70%),
    radial-gradient(700px 300px at 95% 0%, #ede9fe 0%, rgba(237, 233, 254, 0) 70%);
}
.eyebrow {
  display: inline-block; padding: 5px 12px; border-radius: 999px;
  background: #fff; border: 1px solid var(--line);
  color: var(--brand); font-size: 13px; font-weight: 600;
  margin-bottom: 18px;
}
.hero h1 {
  font-size: clamp(30px, 4.6vw, 46px);
  line-height: 1.2; margin: 0 0 16px; letter-spacing: -.015em;
}
.hero p.lead {
  color: var(--muted); font-size: 17px; max-width: 40em; margin: 0 0 26px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-points {
  display: flex; gap: 26px; flex-wrap: wrap;
  margin-top: 30px; color: var(--muted); font-size: 14px;
}
.hero-points span::before {
  content: "✓"; color: var(--ok); font-weight: 700; margin-right: 6px;
}

/* sections */
.section { padding: 54px 0; }
.section h2 {
  font-size: 26px; margin: 0 0 8px; letter-spacing: -.01em;
}
.section .sub { color: var(--muted); margin: 0 0 26px; }
.grid-3 {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}
.grid-4 {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px;
  box-shadow: var(--shadow);
}
.card h3 { font-size: 17px; margin: 0 0 8px; }
.card p { margin: 0; color: var(--muted); font-size: 14.5px; }
.icon {
  width: 40px; height: 40px; border-radius: 11px;
  background: var(--brand-soft); color: var(--brand-dark);
  display: grid; place-items: center; font-size: 19px; margin-bottom: 14px;
}

/* pricing */
.plan {
  position: relative;
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px 22px;
  box-shadow: var(--shadow); display: flex; flex-direction: column;
}
.plan.featured { border-color: #b9d2ff; box-shadow: 0 16px 40px rgba(37, 99, 235, .14); }
.plan .tag {
  position: absolute; top: -11px; right: 18px;
  background: var(--brand); color: #fff;
  font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 999px;
}
.plan h3 { margin: 0 0 4px; font-size: 16px; }
.plan .price { font-size: 34px; font-weight: 700; margin: 6px 0 2px; }
.plan .price small { font-size: 15px; font-weight: 500; color: var(--muted); }
.plan .desc { color: var(--muted); font-size: 14px; margin: 0 0 18px; }
.plan ul { list-style: none; padding: 0; margin: 0 0 22px; color: var(--muted); font-size: 14px; }
.plan li { padding: 6px 0; border-bottom: 1px dashed var(--line); }
.plan li:last-child { border-bottom: 0; }
.plan .btn { margin-top: auto; width: 100%; }

/* steps */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; counter-reset: step; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.step::before {
  counter-increment: step; content: counter(step);
  display: grid; place-items: center;
  width: 30px; height: 30px; border-radius: 50%;
  background: var(--brand-soft); color: var(--brand-dark);
  font-weight: 700; font-size: 14px; margin-bottom: 12px;
}
.step h3 { font-size: 16px; margin: 0 0 6px; }
.step p { margin: 0; color: var(--muted); font-size: 14px; }

/* table */
table.spec {
  width: 100%; border-collapse: collapse; background: #fff;
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
}
table.spec th, table.spec td {
  padding: 14px 16px; text-align: left; font-size: 14.5px;
  border-bottom: 1px solid var(--line);
}
table.spec th { background: #f9fbff; color: var(--ink); font-weight: 600; }
table.spec tr:last-child td { border-bottom: 0; }
table.spec td { color: var(--muted); }

/* checkout */
.checkout {
  display: grid; grid-template-columns: 1.5fr 1fr; gap: 20px;
  align-items: start; padding: 44px 0 64px;
}
.panel {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden;
}
.panel-head {
  padding: 20px 24px; border-bottom: 1px solid var(--line);
  font-weight: 600; font-size: 16px; background: #fbfcff;
}
.panel-body { padding: 24px; }
.summary { list-style: none; padding: 0; margin: 0; }
.summary li {
  display: flex; justify-content: space-between; gap: 16px;
  padding: 13px 0; border-bottom: 1px dashed var(--line);
  font-size: 14.5px; color: var(--muted);
}
.summary li:last-child { border-bottom: 0; }
.summary li strong { color: var(--ink); font-weight: 600; }
.summary .total { font-size: 16px; }
.summary .total strong { font-size: 24px; color: #e11d48; }
.pay-method {
  display: flex; align-items: center; gap: 12px;
  border: 1px solid #b9d2ff; background: #f7faff;
  border-radius: 12px; padding: 14px 16px; margin: 18px 0;
}
.alipay-logo {
  width: 40px; height: 40px; border-radius: 10px;
  background: #1677ff; color: #fff; display: grid; place-items: center;
  font-size: 13px; font-weight: 700;
}
.pay-method b { display: block; font-size: 15px; }
.pay-method span { color: var(--muted); font-size: 13px; }
.notice {
  background: #fffbeb; border: 1px solid #fde68a; color: #92400e;
  border-radius: 10px; padding: 12px 14px; font-size: 13.5px; margin-top: 16px;
}
.notice.blue { background: #eff6ff; border-color: #bfdbfe; color: #1e40af; }
.safe-note { color: var(--muted); font-size: 13px; margin-top: 14px; }

/* prose */
.prose {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px; margin: 40px 0 60px; box-shadow: var(--shadow);
}
.prose h1 { font-size: 26px; margin: 0 0 6px; }
.prose .meta { color: var(--muted); font-size: 13px; margin-bottom: 24px; }
.prose h2 { font-size: 18px; margin: 26px 0 8px; }
.prose p, .prose li { color: var(--muted); font-size: 14.5px; }
.prose ul { padding-left: 22px; }

/* footer */
.site-footer {
  background: #0f172a; color: #c7d2e4; margin-top: 40px;
  padding: 38px 0 30px; font-size: 13.5px;
}
.site-footer a { color: #c7d2e4; }
.site-footer a:hover { color: #fff; }
.footer-grid {
  display: flex; justify-content: space-between; gap: 26px; flex-wrap: wrap;
  padding-bottom: 22px; border-bottom: 1px solid rgba(255, 255, 255, .12);
}
.footer-brand b { color: #fff; font-size: 16px; }
.footer-links { display: flex; gap: 22px; flex-wrap: wrap; }
.footer-bottom { padding-top: 18px; color: #93a2ba; font-size: 12.5px; }
.footer-bottom p { margin: 0 0 4px; }

/* dialog */
.dialog-mask {
  position: fixed; inset: 0; background: rgba(15, 23, 42, .45);
  display: none; place-items: center; z-index: 50; padding: 20px;
}
.dialog-mask.open { display: grid; }
.dialog {
  width: min(460px, 100%); background: #fff; border-radius: 16px;
  padding: 26px; box-shadow: 0 30px 80px rgba(15, 23, 42, .25);
}
.dialog h3 { margin: 0 0 10px; font-size: 19px; }
.dialog p { color: var(--muted); font-size: 14.5px; margin: 0 0 12px; }
.dialog .btn { width: 100%; }

@media (max-width: 860px) {
  .checkout { grid-template-columns: 1fr; }
  .nav { gap: 14px; }
  .nav a:not(.btn) { display: none; }
  .hero { padding: 46px 0 30px; }
  .section { padding: 40px 0; }
}