:root {
  --bg: #f5f7fb;
  --panel: #ffffff;
  --panel-soft: #edf3fb;
  --text: #172033;
  --muted: #607086;
  --line: #dfe7f1;
  --primary: #4457f2;
  --primary-2: #06b6d4;
  --accent: #db2777;
  --shadow: 0 24px 70px rgba(38, 55, 94, 0.16);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    linear-gradient(135deg, rgba(68, 87, 242, 0.10), transparent 32%),
    linear-gradient(225deg, rgba(6, 182, 212, 0.13), transparent 34%),
    var(--bg);
  font-family: "Microsoft YaHei UI", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1180px;
  margin: 0 auto;
  padding: 18px 28px;
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 18px;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  box-shadow: 0 10px 28px rgba(68, 87, 242, 0.28);
}

nav {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
}

nav a:hover {
  color: var(--primary);
}

main {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(480px, 1.08fr);
  gap: 48px;
  align-items: center;
  min-height: calc(100vh - 120px);
  padding: 26px 0 70px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 18px;
  font-size: 52px;
  line-height: 1.08;
}

h2 {
  margin-bottom: 14px;
  font-size: 30px;
  line-height: 1.18;
}

h3 {
  margin-bottom: 10px;
  font-size: 18px;
}

.lead,
.section p,
.policy-card p {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.primary-link,
.secondary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 700;
}

.primary-link {
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  box-shadow: 0 16px 34px rgba(68, 87, 242, 0.26);
}

.secondary-link {
  color: var(--text);
  background: rgba(255, 255, 255, 0.76);
  border: 1px solid var(--line);
}

.product-preview {
  overflow: hidden;
  border: 1px solid rgba(99, 117, 153, 0.22);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: var(--shadow);
}

.preview-titlebar {
  display: flex;
  gap: 7px;
  padding: 16px;
  background: linear-gradient(135deg, rgba(68, 87, 242, 0.92), rgba(6, 182, 212, 0.82));
}

.preview-titlebar span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.78);
}

.preview-layout {
  display: grid;
  grid-template-columns: 72px 200px 1fr;
  min-height: 386px;
}

.preview-layout aside,
.preview-layout section,
.preview-layout article {
  padding: 18px;
}

.preview-layout aside {
  background: #172033;
}

.nav-pill {
  width: 34px;
  height: 34px;
  margin: 0 auto 12px;
  border-radius: 11px;
  background: rgba(255, 255, 255, 0.16);
}

.nav-pill.active {
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
}

.preview-layout section {
  background: #eef4fb;
  border-right: 1px solid var(--line);
}

.note-card {
  padding: 14px;
  margin-bottom: 12px;
  border: 1px solid transparent;
  border-radius: 14px;
  background: #fff;
}

.note-card.active {
  border-color: rgba(68, 87, 242, 0.30);
  box-shadow: 0 14px 28px rgba(68, 87, 242, 0.12);
}

.note-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
}

.note-card p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.preview-layout article h2 {
  font-size: 24px;
}

.editor-line {
  height: 12px;
  width: 74%;
  margin: 18px 0 0;
  border-radius: 8px;
  background: #d9e3f0;
}

.editor-line.wide {
  width: 92%;
}

.code-block {
  height: 88px;
  margin-top: 22px;
  border-radius: 14px;
  background:
    linear-gradient(#21304a 0 0) 20px 18px / 56% 8px no-repeat,
    linear-gradient(#3dd9eb 0 0) 20px 40px / 70% 8px no-repeat,
    linear-gradient(#a78bfa 0 0) 20px 62px / 46% 8px no-repeat,
    #111827;
}

.section {
  padding: 70px 0;
}

.section-heading {
  max-width: 620px;
  margin-bottom: 28px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.login-panel,
.policy-card,
.callback-card {
  border: 1px solid rgba(99, 117, 153, 0.18);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.80);
  box-shadow: 0 18px 48px rgba(38, 55, 94, 0.10);
}

.feature-card {
  padding: 22px;
}

.feature-card p {
  margin-bottom: 0;
  font-size: 14px;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 38px;
  align-items: center;
}

.login-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 260px;
  padding: 28px;
  text-align: center;
}

.login-panel img,
.callback-card img {
  width: 76px;
  height: 76px;
  margin-bottom: 18px;
  border-radius: 20px;
  box-shadow: 0 18px 36px rgba(68, 87, 242, 0.20);
}

.login-panel strong {
  margin-bottom: 8px;
  font-size: 18px;
}

.login-panel span {
  color: var(--muted);
  font-size: 14px;
}

footer {
  display: flex;
  justify-content: space-between;
  max-width: 1180px;
  margin: 0 auto;
  padding: 24px 28px 42px;
  color: var(--muted);
  font-size: 14px;
}

footer a:hover {
  color: var(--primary);
}

.policy-page {
  max-width: 920px;
}

.policy-card {
  padding: 38px;
}

.policy-card h1 {
  font-size: 38px;
}

.policy-card h2 {
  margin-top: 28px;
  font-size: 20px;
}

.updated {
  color: var(--muted);
  font-size: 14px;
}

.callback-body {
  display: grid;
  place-items: center;
  padding: 24px;
}

.callback-card {
  width: min(420px, 100%);
  padding: 42px 28px;
  text-align: center;
}

.callback-card h1 {
  font-size: 30px;
}

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

@media (max-width: 940px) {
  .hero,
  .split-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 14px;
  }

  nav {
    flex-wrap: wrap;
    gap: 14px;
  }

  main {
    padding: 22px;
  }

  h1 {
    font-size: 38px;
  }

  .preview-layout {
    grid-template-columns: 52px 1fr;
  }

  .preview-layout article {
    grid-column: 1 / -1;
  }

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

  footer {
    flex-direction: column;
    gap: 10px;
  }
}