:root {
  --primary: #1A6FE8;
  --primary-dark: #1456B8;
  --primary-light: #EBF2FF;
  --text-primary: #1A1D23;
  --text-secondary: #5A6272;
  --text-tertiary: #9099AA;
  --background: #F4F6FA;
  --surface: #FFFFFF;
  --border: #E5E7EB;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  background: var(--background);
  color: var(--text-primary);
  line-height: 1.6;
}

header {
  background: var(--primary);
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  color: white;
  padding: 32px 24px;
  text-align: center;
}

header h1 {
  margin: 0 0 8px;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.3px;
}

header p {
  margin: 0;
  opacity: 0.9;
  font-size: 15px;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 24px 64px;
}

.card {
  background: var(--surface);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(26, 111, 232, 0.06);
  margin-bottom: 16px;
}

h2 {
  color: var(--text-primary);
  font-size: 20px;
  font-weight: 700;
  margin: 24px 0 12px;
}

h2:first-of-type {
  margin-top: 0;
}

h3 {
  color: var(--text-primary);
  font-size: 16px;
  font-weight: 600;
  margin: 20px 0 8px;
}

p, li {
  color: var(--text-secondary);
  font-size: 15px;
}

ul {
  padding-left: 24px;
}

li {
  margin-bottom: 6px;
}

a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

a:hover {
  text-decoration: underline;
}

.meta {
  color: var(--text-tertiary);
  font-size: 13px;
  margin-bottom: 24px;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 600;
  font-size: 14px;
  transition: background 0.15s;
}

.nav-links a:hover {
  background: var(--primary);
  color: white;
  text-decoration: none;
}

.back-link {
  display: inline-block;
  margin-bottom: 16px;
  color: var(--text-secondary);
  font-size: 14px;
}

footer {
  text-align: center;
  padding: 24px;
  color: var(--text-tertiary);
  font-size: 13px;
}

@media (max-width: 600px) {
  header { padding: 24px 16px; }
  header h1 { font-size: 22px; }
  main { padding: 24px 16px 48px; }
  .card { padding: 20px; border-radius: 12px; }
}