.btn{
    padding: 1rem 2rem;
    border-radius: 2rem;
    font-size: 1rem;
    text-decoration: none;
    border: none;
    outline: none;
    color: #fff;
    background-color: green;
    display: inline-block;
}

@media screen and (max-width: 650px) {
    .btn{
        font-size: .9rem;
        padding: .5rem 1.3rem;
    }
}

form{
    padding: 2rem;
    background-color: #ffffff;
    border-radius: 1rem;
    max-width: 35rem;
}