Re purpose CSS code

[tristenturner101 (Tristen Turner)]

Hello, how can to change this CSS to also work with the sign up page

.login-modal.in .modal-inner-container {
    background: url(imageurlhere);
    background-size: contain;
    background-repeat: no-repeat;
    background-color: #fff;
}```

[Canapin (Coin-coin le Canapin)]

This should work.

.login-modal.in, .create-account {
    .modal-inner-container {
        background: url(imageurlhere);
        background-size: contain;
        background-repeat: no-repeat;
        background-color: #fff;
    }
}

You can inspect the HTML code of your page with your browsers dev tools (F12, Elements tab) to see which element should be targetted.