```css
/* Grundlayout */

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
  background-color: #f5f5f5;
  color: #333;
}

/* Inhalt */

main {
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1rem;
}

section {
  background-color: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* Überschriften */

h1 {
  text-align: center;
  margin-bottom: 2rem;
  color: #2c3e50;
}

h2 {
  margin-top: 2rem;
  color: #34495e;
}

h3 {
  margin-top: 1.5rem;
  color: #555;
}

/* Text */

p {
  margin-bottom: 1rem;
}

/* Links */

a {
  color: #0066cc;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Trennlinie */

hr {
  margin: 2rem 0;
  border: none;
  border-top: 1px solid #ccc;
}

/* Handy */

@media (max-width: 600px) {
  section {
    padding: 1rem;
  }

  h1 {
    font-size: 1.8rem;
  }
}
```