:root {
  color-scheme: light;
  --ink: #17202a;
  --muted: #64707d;
  --line: #dfe5eb;
  --surface: rgba(255, 255, 255, 0.94);
  --brand: #5b5be7;
  --brand-soft: #efefff;
  --notice: #fff8e7;
  --notice-line: #eed99b;
}

* {
  box-sizing: border-box;
}

html {
  background: #f4f6f9;
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  background:
    radial-gradient(circle at 12% 0%, rgba(91, 91, 231, 0.13), transparent 28rem),
    radial-gradient(circle at 92% 12%, rgba(54, 194, 180, 0.1), transparent 24rem),
    #f4f6f9;
  color: var(--ink);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei",
    sans-serif;
  line-height: 1.78;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--brand);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.shell {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  padding: 24px 0 64px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 750;
  letter-spacing: 0.02em;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 11px;
  background: linear-gradient(145deg, #7775f7, #4e4dd5);
  box-shadow: 0 8px 20px rgba(91, 91, 231, 0.24);
  color: #fff;
  font-size: 17px;
}

.topnav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px 18px;
  font-size: 14px;
}

.hero {
  padding: 34px clamp(22px, 5vw, 48px);
  border: 1px solid rgba(255, 255, 255, 0.7);
  border-radius: 28px;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.98), rgba(247, 247, 255, 0.92));
  box-shadow: 0 22px 60px rgba(32, 40, 54, 0.08);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--brand);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(30px, 6vw, 46px);
  line-height: 1.2;
  letter-spacing: -0.035em;
}

.lead {
  max-width: 680px;
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 16px;
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 20px;
  color: var(--muted);
  font-size: 13px;
}

.product-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin: 24px 0 0;
}

.product-meta div {
  padding: 13px 15px;
  border: 1px solid rgba(91, 91, 231, 0.16);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.72);
}

.product-meta dt {
  color: var(--muted);
  font-size: 12px;
}

.product-meta dd {
  margin: 2px 0 0;
  font-size: 14px;
  font-weight: 720;
}

.notice {
  margin: 22px 0 0;
  padding: 14px 16px;
  border: 1px solid var(--notice-line);
  border-radius: 14px;
  background: var(--notice);
  color: #655326;
  font-size: 14px;
}

.content {
  margin-top: 20px;
  padding: 12px clamp(22px, 5vw, 48px) 36px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 0 14px 40px rgba(32, 40, 54, 0.05);
}

h2 {
  margin: 34px 0 10px;
  font-size: 20px;
  line-height: 1.42;
  letter-spacing: -0.015em;
}

h3 {
  margin: 22px 0 8px;
  font-size: 16px;
}

p,
li {
  font-size: 15px;
}

p {
  margin: 8px 0;
}

ul,
ol {
  margin: 8px 0;
  padding-left: 1.35em;
}

li + li {
  margin-top: 6px;
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 20px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 14px;
}

.feature-card {
  position: relative;
  min-height: 164px;
  padding: 22px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: linear-gradient(145deg, #fff, #fafaff);
}

.feature-card::after {
  position: absolute;
  right: -22px;
  bottom: -30px;
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: rgba(91, 91, 231, 0.06);
  content: "";
}

.feature-index {
  display: block;
  margin-bottom: 16px;
  color: var(--brand);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.feature-card strong {
  display: block;
  font-size: 17px;
}

.feature-card p {
  position: relative;
  z-index: 1;
  margin: 7px 0 0;
  color: var(--muted);
}

.support-card {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #fff;
}

.support-card strong {
  display: block;
  margin-bottom: 6px;
  font-size: 17px;
}

.support-card p {
  margin: 0;
  color: var(--muted);
}

.support-card.primary {
  border-color: #ceceff;
  background: var(--brand-soft);
}

.steps {
  counter-reset: support-step;
  list-style: none;
  padding: 0;
}

.steps li {
  position: relative;
  min-height: 38px;
  padding: 7px 0 7px 46px;
  counter-increment: support-step;
}

.steps li::before {
  position: absolute;
  top: 5px;
  left: 0;
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border-radius: 11px;
  background: var(--brand-soft);
  color: var(--brand);
  content: counter(support-step);
  font-weight: 750;
}

.footer {
  padding: 24px 8px 0;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

@media (max-width: 640px) {
  .shell {
    width: min(100% - 20px, 920px);
    padding-top: 14px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
    margin-bottom: 18px;
  }

  .topnav {
    justify-content: flex-start;
  }

  .hero,
  .content {
    border-radius: 20px;
  }

  .support-grid {
    grid-template-columns: 1fr;
  }

  .product-meta,
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature-card {
    min-height: 0;
  }
}