.loginbox {
    position: absolute;
    top: 15%;
    left: 35%;
    background-color: rgba(255,255,255,.82);
    width: 100%;
    padding: 25px;
    border-radius: 5px;
    border: 1px solid #ccc;
    max-width: 21.25em;
}
@media screen and (max-width: 480px){
    
}
@media only screen and (max-width: 768px){
.loginbox {
    position: relative;
    top: 20%;
    left: 0;
    width: 100%;
    border-radius: 0;
    border: none;
    max-width: 100%;
}
}