.login-form {

    background: gray;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 10px;
}

.login-form input[type="email"],input[type="password"] {
    width: 95%;
}

.login-form input[type="submit"] {
    width: 98%;
    margin-top: 10px;
}