.themes div {
    background: #eee;
    padding: 5px 20px;
    box-shadow: -0px 0px 0px rgba(0, 0, 0, 0.4);
    transition: box-shadow 300ms;
    cursor: pointer;
}
.themes div:hover {
    box-shadow: -2px 2px 2px rgba(0, 0, 0, 0.4);
}
.chapitres div {
    background: #eee;
    padding: 5px 20px;
    box-shadow: -0px 0px 0px rgba(0, 0, 0, 0.4);
    transition: box-shadow 300ms;
}
.chapitres div:hover {
    box-shadow: -2px 2px 2px rgba(0, 0, 0, 0.4);
}
#documents {
    margin-top: 25px;
}
.cours .row div, #documents .row div {
    margin-bottom: 12px;
}
.apercu {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: rgba(0,0,0,0.85);
    pointer-events: none;
    opacity: 0;
    transition: 300ms ease-in-out opacity;
}
.apercu.active {
    pointer-events: auto;
    opacity: 1;
}
.apercu img {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    max-width: 90%;
    max-height: 85vh;
    margin: auto;
}
.apercu .options {
    position: absolute;
    top: 1vh; right: 5%;
    color: #fff;
}
.ajouter-m .row.hidden, .ajouter-t .row.hidden, .ajouter-c .row.hidden {
    display: none;
}
.importer {
    margin: 25px 0;
}
#loader {
    display: none;
    width: 50px;
}
#loader.active {
    display: inline-block;
}