allows styling group drawers in css based on state

[multyfora]

upper one is base waybar
lower one is with this change

example 1

region-2026-01-02_03-20-42.mp4

code:

#tray.drawer-open #custom-traybtn { 
    opacity: 1.0;
    background-color: red;
}

example 2

region-2026-01-02_03-19-59.mp4

code:

#tray.drawer-open #custom-traybtn { 
    opacity: 1.0;
}
#tray.drawer-closed #custom-traybtn { 
opacity: 0.6; 
}

the config code is

    "group/tray": {
        "orientation": "inherit",
        "drawer": {
            "click-to-reveal": true
        },

        "modules": [
            "custom/traybtn",                
            "tray"
        ]

    },

    "custom/traybtn": {
        "format": ""
    },

    "tray": {
        "icon-size": 16,
        "spacing": 8,
        "show-passive-items": true,
        "reverse-direction": false
    },