.center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

#myULContainer {
    list-style: none;
    -webkit-padding-start: 0;
    -webkit-margin-after: 0;
    -webkit-margin-before: 1em;
    border: 1px solid #000;
    overflow-y: auto;
    width: 100%;
    background: #333;
    color: rgb(128, 120, 120);
}