#left-content{
    width: 333px;
    -ms-overflow-style: none; /* Internet Explorer 10+ */
    scrollbar-width: none; /* Firefox */
}

#left-content:hover{
    overflow-y: scroll;
}

#left-content::-webkit-scrollbar { 
    display: none;  /* Safari and Chrome */
}

#contacts{
    width: 300px;
    -ms-overflow-style: none; /* Internet Explorer 10+ */
    scrollbar-width: none; /* Firefox */
}

#contacts:hover{
    overflow-y: scroll;
    overflow-x: hidden;
}

#contacts::-webkit-scrollbar { 
    display: none;  /* Safari and Chrome */
}

#conversations{
    -ms-overflow-style: none; /* Internet Explorer 10+ */
    scrollbar-width: none; /* Firefox */
}

#conversations:hover{
    overflow-y: scroll;
    overflow-x: hidden;
}

#conversations::-webkit-scrollbar { 
    display: none;  /* Safari and Chrome */
}