Custom login screen not working post 2026.3 upgrade

Hello Darrell,

Thank you for the clear description and the CSS sample.

The cause is a change in the new 2026.3 login page design.

The login page now sets its own background image on .ant-layout, and that rule also uses !important.

This built-in rule loads after your login stylesheet.

When two rules have the same selector and both use !important, the one that loads last wins.

Your stylesheet still loads, but it is now outranked.

You can get your image back with a more specific selector.

You also need !important on the other background properties, since the built-in rule sets them too.

Please replace your current rule with this one:


html body section.ant-layout,
:root[data-theme="dark"] body section.ant-layout {
background-image: url('/assets/backgroundLogo.jpg') !important;
background-position: center top !important;
background-repeat: no-repeat !important;
background-size: cover !important;
}
The second selector covers the dark theme, which has its own built-in background.

After you save the file, reload the login page with Ctrl+F5 so the browser does not use a cached copy.

We tested this rule against the 2026.3 login page, in both the light and dark themes, and the custom image displays.

If the image still does not show, open the browser developer tools on the login page and check the Network tab.

In a private window, before anyone signs in, both your stylesheet and the image should load with a 200 status.

If either one returns 401 or 404, please tell me how the stylesheet is set, from Settings, Branding or from the branding.ps1 file.

A screenshot of that Network tab would also help.

I will also share this with our development team, so a custom login stylesheet can override the default background again without these extra selectors.

Best regards,