* {
  box-sizing: border-box;
}

body {
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  color: #222;
  background: #fafafa;
}

main {
  max-width: 70ch;
  margin: 2rem auto;
  padding: 0 1rem;
}

header {
  background: #fff;
  border-bottom: 1px solid #ddd;
}

nav ul {
  display: flex;
  gap: 5rem;
  list-style: none:
  padding: 1rem;
  margin: 0;
}

nav a {
  text-decoration: none;
  color: #0366d6
}

.level2 {
  padding: 5px 0;
  margin: 10px 0; 

.menu-list {
  list-style: none;
  padding: 0;
}

.menu-list li {
  margin-bottom: 1rem;
}

.menu-list a {
  Font-weight: 600;
}

.intro {
  max-width: 60ch;
  margin: 3rem auto;
  text-align: center;
}

.intro h1,
.intro h2 {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.intro p {
  font-size: 1.05rem;
  line-height: 1.7;
  color: #444;
  margin: 0 auto;
}