:root {
  --bg: #f5f8ff;
  --bg-alt: #eef3ff;
  --panel: rgba(255, 255, 255, 0.88);
  --panel-solid: #ffffff;
  --line: #dfe7fb;
  --text: #182033;
  --muted: #5e6a85;
  --primary: #3f6fff;
  --primary-dark: #2f59d9;
  --shadow: 0 18px 45px rgba(52, 84, 160, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f7f9ff 0%, #f2f6ff 100%);
  line-height: 1.65;
}

.container {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  padding: 20px 0 56px;
  background:
    radial-gradient(circle at top left, rgba(108, 147, 255, 0.20), transparent 28%),
    radial-gradient(circle at 88% 16%, rgba(148, 174, 255, 0.22), transparent 20%),
    linear-gradient(180deg, #eef4ff 0%, #f7f9ff 100%);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 8px 0 28px;
}

.logo {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.2px;
}

.nav-links {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.nav-links a,
.footer a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}

.nav-links a:hover,
.footer a:hover {
  color: var(--primary-dark);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.24fr) minmax(320px, 0.76fr);
  gap: 18px;
  align-items: stretch;
}

.badge {
  display: inline-block;
  margin-bottom: 14px;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(63, 111, 255, 0.10);
  color: var(--primary-dark);
  font-weight: 700;
  font-size: 14px;
}

h1 {
  margin: 0;
  font-size: clamp(38px, 5vw, 62px);
  line-height: 1.12;
  letter-spacing: -1px;
}

.hero-text {
  margin: 18px 0 24px;
  max-width: 720px;
  font-size: 19px;
  color: var(--muted);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 14px;
  text-decoration: none;
  font-weight: 700;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn.primary {
  color: #fff;
  background: linear-gradient(135deg, var(--primary), #5d86ff);
  box-shadow: 0 14px 28px rgba(63, 111, 255, 0.24);
}

.btn.ghost {
  color: var(--primary-dark);
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(63, 111, 255, 0.15);
}

.hero-card,
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}

.hero-card {
  padding: 22px 22px 18px;
  align-self: start;
}

.hero-card h3,
.card h3 {
  margin: 0 0 10px;
  font-size: 22px;
}

.hero-card ul,
.list-card ul {
  margin: 0;
  padding-left: 20px;
}

.hero-card li,
.list-card li {
  margin-bottom: 8px;
  font-size: 17px;
}

.section {
  padding: 64px 0;
}

.section.alt {
  background: linear-gradient(180deg, var(--bg-alt) 0%, #f7f9ff 100%);
}

.section-head {
  margin-bottom: 24px;
}

.section-head span {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--primary-dark);
  font-weight: 800;
  letter-spacing: 0.4px;
}

.section-head h2 {
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.2;
}

.section-head p {
  margin: 0;
  font-size: 18px;
  color: var(--muted);
}

.grid {
  display: grid;
  gap: 16px;
}

.grid.three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

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

.card {
  padding: 22px 20px;
}

.step {
  min-height: 182px;
}

.step-no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  margin-bottom: 12px;
  border-radius: 14px;
  background: rgba(63, 111, 255, 0.12);
  color: var(--primary-dark);
  font-weight: 800;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.code-card pre {
  margin: 0;
  padding: 16px;
  overflow: auto;
  border-radius: 16px;
  background: #172033;
  color: #eaf1ff;
  font-size: 16px;
  line-height: 1.6;
}

.cheatsheet .card {
  min-height: 100%;
}

.footer {
  padding: 24px 0 34px;
  border-top: 1px solid var(--line);
  background: #fbfcff;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}

.footer p {
  margin: 6px 0 0;
  color: var(--muted);
}

@media (max-width: 980px) {
  .hero-grid,
  .grid.three,
  .grid.two {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-bottom: 44px;
  }

  .nav {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-card {
    width: 100%;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 22px, 1180px);
  }

  h1 {
    font-size: 34px;
  }

  .hero-text,
  .section-head p,
  .card p,
  .hero-card li,
  .list-card li {
    font-size: 16px;
  }

  .card,
  .hero-card {
    padding: 18px;
  }

  .section {
    padding: 48px 0;
  }
}