html,
body{
    height: 100%;
    overflow-y: hidden; 
    overflow-x: hidden;
}

#cover {
    background: #e3e7ed url('') center center no-repeat;
    background-size: cover;
    height: 100%;
    text-align: center;
    display: flex;
    align-items: center;
}

#cover-caption {
    width: 100%;
}

#form-box {
    background-color: #fff;
    padding: 20px;
    border-radius: 5px
}