.w3-main,
#main {
    transition: margin-left 0.4s;
}
.w3-modal {
    z-index: 99;
    display: none;
    padding-top: 100px;
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgb(0, 0, 0);
    background-color: rgba(0, 0, 0, 0.4);
}
.w3-modal-content {
    margin: auto;
    background-color: #fff;
    position: relative;
    padding: 0;
    outline: 0;
    width: 600px;
}