#btn-back {
    position: absolute;
    top: 13px;
    right: 13px;
    width: 27px;
}

#btn-valid {
    margin-top: 20px;
    width: 170px;
    height: auto;
    opacity: 0;
}

#btn-upload {
    width: 54%;
    height: auto;
    margin-top: 3px;
    margin-bottom: 10px;
    pointer-events: auto;
    cursor: pointer;
    opacity: 0;
}