wlr taskbar :hover selector

[KamiKarsten]

Hei everyone. How do I configure the hover effect for the wlr taskbar in waybar? I tried the :hover selector in CSS, but it doesn't seem to work. I would be grateful for any help.
The green color on the active workspace is where i want to go.

[KamiKarsten]

Dont know what I changed but it works now...

For anyone wondering

#taskbar,
#taskbar button {
    margin-top: 0px;
    border-radius: 15px;
    background: transparent;
}

#taskbar button:hover {
    box-shadow: inherit;  /* needed to remove old hover behavior with white border */ 
    text-shadow: inherit; /* needed to remove old hover behavior with white border */ 
    background: @backgroundgreen;
}