Sticky (Fixed) Column of a table

#mousewheel_example{
    overflow-y:hidden;
    overflow-x:auto;
    margin-top:5px;
    padding:0;
}
#itable tr th, #itable tr td{
	width: 100px;
}
#itable{
    border-collapse: collapse;
    table-layout: fixed;
    max-width: none;
    width: max-content;
    border-collapse: separate;
}
#itable tr th{
    position: sticky;/*important*/
    left: 0;/*important*/
    top: 0;/*important*/
    z-index: 1;
    background-color: #5DCEAF;
    color: #FFFFFF;
    font-size: 16px;
    width: 180px;
    font-weight: bold;
    border: 1px solid #FFF;
    padding: 3px;
    font-weight: bold;
}
#itable tr td{
    padding: 3px;
    text-align: center;
    width: 130px;
    font-size: 15px;
    border: 1px solid #FFF;
    background-color: #DFF5EF;
}