header{
    padding: 100px 25px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 50px;
    flex-wrap: wrap;
    background-image: url(img/Schule.png);
    background-position: center; 
    background-size: cover;
   }
    .header_text{
    width: 850px;
    
    }
    .circle{
    height: 600px;
    width: 600px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 1);
    
    max-height: 80vw;
    max-width: 80vw;
    overflow: hidden;
    border-radius:50%;
    border: 10px solid var(--border-color);
    
    display: flex;
    justify-content: center;
    align-content: center;
    }
    .circle img{
    width: 100%;
    height: 100%;
    
    }
    nav{
    margin-bottom: 120px;
    }
    nav ul{
    list-style: none;
    display: flex;
    gap: 20px;
    }
    nav a{
    color: var(--text-color);
    text-decoration: none;
    position: relative;
    padding: 3px;
    }
    nav a:hover{
    color: rgb(203, 203, 203);
    }
    nav a::after{
    content: '';
    height: 2px;
    width: 0%;
    background-color: var(--main-brand-color);
    position: absolute;
    bottom: 0;
    left: 0;
    transition: 150ms ease-in-out;
    }
    nav a:hover::after{
    width:100%
    }
    #toggle_button{
    display: none;
    }
    label[for="toggle_button"]{
    display: none;
    }
    label[for="toggle_button"] span{
    font-size: 40px;
    }
    @media(max-width: 800px){
    nav{
    position: absolute;
    top: 0;
    left: 0;
    background: var(--secondary-color);
    padding: 15px;
    border-radius: 0 0 25px 0;
    }
    nav ul{
    display: none;
    flex-direction: column;
    }
    #toggle_button:checked ~ ul{
    display: flex;
    }
    label[for="toggle_button"]{
    display: block;
    }
    }