.darkenScreen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 10;
    display: none;
}

.signupboxclass {
    position: relative; 
    z-index: 20; 
}