.bg{
    top: 0px;
    left: 0px;
    z-index: -10;
    position: fixed;
    width: 100%;
    height: 100vh;
    background: linear-gradient(#45545F, #535353);
}
.spacer{
    height: 50px;
    opacity: 0%;
}
.main-content{
    width: 90%;
    position: relative;
    display: flex;
    flex-flow: row wrap;
}
.cours{
    width: 75%;
    display: flex;
    flex-flow: column nowrap;
}
.plan{
    padding-top: 3%;
    display: flex;
    flex-flow: column nowrap;
    align-items: center;
    min-width: 20%;
    max-width: 20%;
    position: fixed;
    height: max-content;
    width: max-content;
    top: 2%;
    height: 94vh;
    bottom: 2%;
    overflow-y: hidden;
    right: 2%;
    background-color: #222;
    box-shadow: #838383 0px 0px 10px;
    text-align: center;
    border-radius: 10px;
}
.plan:hover{
    overflow-y: scroll;
}
.plan p, .plan h4{ 
    padding: 1em 0 0 0;
}
.plan h4{
    text-decoration: none;
}
.plan a, .plan p, .plan h3{
    font-size: 1rem;
    border-radius: 5px;
}
.plan summary{
    cursor: pointer;
}
.first{
    padding-top: 5%;
}