Apply code when sidebar is expanded

Using Firefox-Developer-Edition Hi, I would like to know how to apply this code only when sidebar is expanded:

    
.tools-and-extensions[orientation="vertical"] {
    flex-direction: row !important;
}


  

I tried to use this before the previous code but didn't work: :root:has(sidebar-main[expanded])

I didn't be able to apply any style conditioning the sidebar expanded or not for any button inside .tools-and-extension, in the original code it seems to use :host but that didn't work, apparently.