footer{
    position:fixed;
    bottom:0;
    left:0;
    right:0;
    height:50px;
    background-color:#f8f9fa;
    text-align:center;
    padding:10px;
}
.list-group-item{
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
}
main {
    height: calc(100vh - 100px);
    display: flex;
    justify-content: center;
    align-items: center;
}

.off{
    visibility: hidden;
    display:none;
}

.on{
    visibility: visible;
    display:block;
}

#popup, #delete-popup{
    width:100%;
    height:100%;
    display:flex;
    justify-content:center;
    align-items:center;
    position:absolute;
    top:0%;
    left:0%;
    background-color:rgba(200,200,200,0.9);
    color:white;
}