header{
    padding: 100px 25px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 50px;
    flex-wrap: wrap;
}
.header_text{
    width: 850px;

}
.iframe{
    width: 100%;
    height: 400px;
    padding-bottom: 33px;
}
li{
    font-size: 30px;
}
.circle{
    background-color: black;
    height: 600px;
    width: 600px;

    max-width: 80vw;
    max-height: 80vw;

    overflow: hidden;
    border-radius: 50%;
    border: 20px solid rgba(250, 12, 12, 0.801);

    display: flex;
    justify-content: center;
    align-items: center;

    box-shadow: 0 0 25px var(--main-brand-color);
    transition: 0.4s ease-in-out;
}
.circle:hover{
    box-shadow: 0 0 25px var(--main-brand-color),
                0 0 50px var(--main-brand-color),
                0 0 100px var(--main-brand-color)
}
.circle img{
    width: 75%;
}
nav{
    margin-bottom: 120px;
}
nav ul{
    list-style: none;
    display: flex;
    gap: 20px;
}
nav a{
    color: var(--secondary-text-color);
    text-decoration: none;
    position: relative;
    padding: 3px;
}
nav a:hover{
    color: var(--text-color);
}
/* nav a untere 2 sind für die blaue Linie unterden links*/
nav a::after{
    content: '';
    height: 4px;
    width: 0;
    background: 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: 650px){
    nav{
        position: absolute;
        top: 0;
        left: 0;
        background-color: var(--secondary-color);
        padding: 15px;
        border-radius: 0 0 25px 0;
    }
    nav ul{
        display: none;
        flex-direction: column;
        padding-top: 35px;
    }
    #toggle_button:checked ~ ul{
        display: flex;
    }
    label[for="toggle_button"]{
        display: block;
    }
}