body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f8fafc;
  color: #0f172a;
}
header {
  border-bottom: 1px solid #e2e8f0;
  background: #ffffff;
}
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 1.5rem;
}
.nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}
.nav a {
  text-decoration: none;
  color: #0f172a;
}
.nav a:hover {
  text-decoration: underline;
}
main {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
}
.card {
  background: #ffffff;
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 10px 25px rgba(0,0,0,0.06);
}
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 600;
}
.btn-primary {
  background: #2d77f5;
  color: #ffffff;
}
.btn-secondary {
  background: #1e59c3;
  color: #ffffff;
}
.btn-primary:hover,
.btn-secondary:hover {
  filter: brightness(0.95);
}
footer {
  border-top: 1px solid #e2e8f0;
  background: #ffffff;
}
footer small {
  color: #64748b;
}
h1 {
  font-size: 2rem;
  margin: 0 0 0.5rem;
}
p.lead {
  color: #475569;
  margin-top: 0;
}