body {
    margin: 0;
    font-family: Arial, sans-serif;
}

section {
    padding: 2rem;
}

#bereich-1 {
    background: #222;
}

#bereich-2 {
    background: #f2f2f2;
    min-height: 30vh;
}

#bereich-3 {
    background: #e2ffe2;
}

/* Navigation */
.nav {
    display: flex;
    gap: 1rem;
}

.nav button {
    padding: 0.5rem 1rem;
    border: none;
    cursor: pointer;
}

.nav button.active {
    background: #4caf50;
    color: white;
}