body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
}

#registration {
    width: 320px;
}
#registration h1 {
    margin: 0;
    padding: 0;
}
#registration form {
    padding: 15px;
    margin: 0;
}
#registration label{
    width: 100px;
    display: inline-block;
}
#registration input {
    border: 1px solid #ccc;
    border-radius: 4px;
}