.contain{
    display: flex;
    flex-direction: row;
}

#sidebar{
    min-width: 300px;
    top: 4em;
    position: sticky;
    height: 100%;
    overflow-y: scroll;
    overflow-x: hidden;
}

#sidebar details{
    display: block;
    margin-left: 1em;
}

#sidebar details .content a{
    display: block;
    padding: .3em;
    font-size: .8em;
}

.div3{
    padding: 1em;
    overflow-y:scroll ;
}

.div3 h1{
    font-size: 2em;
    margin-bottom: 2em;
}

.div3 h1:not(:first-child){
    margin-top: 2em;
}

.div h2{
    font-size: 2em;
}

.content_card{
    margin-top: 1em;
}