* {
  box-sizing: border-box;
}

body {
  max-width: 900px;
  margin: 0 auto;
  padding: 48px 24px;
  background: #f7f9fc;
  color: #222;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

header {
  margin-bottom: 40px;
  padding: 32px 0;
}

h1 {
  margin: 0 0 16px;
  font-size: 3rem;
  line-height: 1.1;
}

h2 {
  margin-top: 0;
}

main {
  display: grid;
  gap: 24px;
}

section {
  padding: 28px;
  background: #fff;
  border-radius: 14px;
  box-shadow: 0 12px 30px rgba(24, 39, 75, 0.08);
}

a {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 8px;
  background: #2563eb;
  color: #fff;
  font-weight: 600;
  text-decoration: none;
  transition: background 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

a:hover,
a:focus {
  background: #1d4ed8;
  box-shadow: 0 8px 18px rgba(37, 99, 235, 0.22);
  transform: translateY(-1px);
}

a:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.28);
  outline-offset: 3px;
}

ul {
  padding-left: 1.25rem;
}

@media (max-width: 767px) {
  body {
    padding: 32px 16px;
  }

  header {
    margin-bottom: 28px;
    padding: 20px 0;
  }

  h1 {
    font-size: 2.2rem;
  }

  section {
    padding: 22px;
    border-radius: 12px;
  }
}