html {
  box-sizing: border-box;
  font-size: 16px;
}

*,
*::before,
*::after {
  box-sizing: inherit;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background: #f4f7fb;
  color: #1b2432;
}

a {
  color: #0f7a6c;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.shell {
  max-width: 880px;
  margin: 0 auto;
  padding: 32px 20px 56px;
}

.card {
  background: #ffffff;
  border-radius: 20px;
  box-shadow: 0 12px 28px rgba(18, 32, 51, 0.08);
  padding: 28px 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  font-size: 1.9rem;
  font-weight: 700;
  color: #122033;
}

.brand-mark {
  width: 18px;
  height: 18px;
  border-radius: 999px;
  background: linear-gradient(135deg, #27dca5, #63c7b2);
}

h1 {
  margin: 0 0 8px;
  font-size: 2rem;
  line-height: 1.2;
}

h2 {
  margin-top: 28px;
  margin-bottom: 8px;
  font-size: 1.18rem;
}

h3 {
  margin-top: 20px;
  margin-bottom: 6px;
  font-size: 1rem;
}

p,
li {
  color: #2a3446;
}

ul {
  padding-left: 20px;
}

.meta {
  color: #607089;
  margin-bottom: 20px;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 16px 0 28px;
}

.nav a,
.button-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 10px 16px;
  border-radius: 999px;
  background: #122033;
  color: #ffffff;
  font-weight: 600;
}

.nav a.secondary,
.button-link.secondary {
  background: #e9eef6;
  color: #122033;
}

.note {
  padding: 14px 16px;
  border-radius: 14px;
  background: #effaf7;
  border: 1px solid #c8f0e6;
  color: #17433d;
}

.footer {
  margin-top: 28px;
  color: #607089;
  font-size: 0.95rem;
}

@media (max-width: 640px) {
  .shell {
    padding: 20px 14px 40px;
  }

  .card {
    padding: 22px 18px;
    border-radius: 16px;
  }

  h1 {
    font-size: 1.65rem;
  }
}