:root {
  --brand: #0b6068;
  --brand-dark: #084b52;
  --brand-soft: #e2f1f0;
  --bg: #f7faf9;
  --text: #1f2929;
  --muted: #5c6b6b;
  --card: #ffffff;
  --danger: #a12b2b;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}
header {
  background: linear-gradient(135deg, var(--brand-dark), var(--brand));
  color: white;
  padding: 24px 20px;
}
.nav {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.brand { font-size: 1.35rem; font-weight: 800; }
.nav a { color: white; text-decoration: none; margin-left: 16px; }
main {
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 20px 70px;
}
.hero {
  background: var(--brand-soft);
  padding: 28px;
  border-radius: 24px;
  margin-bottom: 28px;
}
h1 { margin: 0 0 8px; line-height: 1.2; }
h2 { margin-top: 32px; line-height: 1.3; }
.card {
  background: var(--card);
  padding: 22px;
  border-radius: 18px;
  border: 1px solid #dce7e6;
  margin: 18px 0;
}
.notice {
  border-left: 4px solid var(--brand);
  padding: 14px 16px;
  background: #eef7f6;
  border-radius: 8px;
}
.danger {
  border-left-color: var(--danger);
  background: #fff1f1;
}
.button {
  display: inline-block;
  background: var(--brand);
  color: white;
  padding: 12px 18px;
  border-radius: 12px;
  text-decoration: none;
  font-weight: 700;
}
footer {
  text-align: center;
  color: var(--muted);
  padding: 24px 20px 40px;
}
code {
  background: #eef1f1;
  padding: 2px 6px;
  border-radius: 6px;
}
.placeholder {
  color: var(--danger);
  font-weight: 700;
}
@media (max-width: 620px) {
  .nav a { margin-left: 0; margin-right: 12px; }
  main { padding-top: 24px; }
  .hero { padding: 20px; }
}