Does not work in Vaadin 25.2.0 due to css compilation issues

[Totremont]

Describe the bug

When trying to build the frontend in a project using Vaadin 25.2.0 this error occurs :
transforming...✓ 423 modules transformed.
        ✗ Build failed in 1.05s
        error during build:
        Build failed with 1 error:

        [plugin vite:css-post] /<my_path>/fc-chat-assistant-style.css?inline:67:63
        SyntaxError: [lightningcss minify] Pseudo-elements like '::before' or '::after' can't be followed by selectors like 'Delim('>')'
        65 |
        66 |  /* Let the chat overlay Div shrink so its VirtualList scrolls internally under the clamp. */
        67 |  vaadin-popover-overlay.fc-chat-assistant-popover::part(content) > * {
           |                                                                 ^
        68 |      min-height: 0;
        69 |      min-width: 0;
            at Module.

Expected behavior

css compilation should succeed

Minimal reproducible example

Just create a vaadin starter with 25.2.0 and add this addon as a dependency

Add-on Version

5.0.1

Vaadin Version

25.2.0

Additional information

No response