Set a background image on taskbar - Zorin OS

I have installed Zorin OS Core 17 and I am trying some customisations on it. I want to set an image as background on taskbar. I tried few things but could not find a proper solution. Below are the things I tried: modifying CSS in /usr/share/themes/ZorinGreen-Dark/gnome-shell/gnome-shell.css

#panel {
        background-color: rgba(255, 0, 0, 1);
    }

It seems taskbar is denoted with #panel. I currently have Zorin Dark mode with green accent active. On adding this code to CSS file, the color of taskbar changed to red. But this does not seem to work when setting color to transparent, or setting background-image property:

#panel {
    background-image: url('file:///home/username/Pictures/background.jpg');
    background-size: cover; /* Makes the image cover the entire panel */
    background-position: center; /* Centers the image */
    background-repeat: no-repeat; /* Ensures the image does not repeat */
}

The above code made taskbar grey in color. I also tried setting background-color: transparent on top of this, but no effect.

#panel {
    background-color: rgba(0, 0, 0, 0) !important; /* Fully transparent */
    background-image: url('file:///home/username/Pictures/background.jpg') !important;
    background-size: cover !important;
    background-position: center !important;
    background-repeat: no-repeat !important;
}

Similarly no effect due to above code. A workaround I found for this is to set the wallpaper with image of taskbar appended to its bottom, and then set taskbar transparent using 'Zorin Appearance' and setting taskbar opacity to 0, which makes it transparent and shows the image from wallpaper, mimicking image-on-taskbar effect. But this is a workaround, and in case of any other window behind the taskbar, covering the wallpaper, it will ruin this effect. Another observation: There is an extension zorin-taskbar@zorinos enabled that has some settings regarding transparency and image involved as found using LookingGlass. **It would be of help if someone could point out the way to actually put an image on background of taskbar.** *PS: I would appreciate someone guiding the way to debug and figure out custom UI tweaks for this Linux OS, as I am interested in making further tweaks and customisations.*