Love the customisability of this addon however custom CSS doesn't seem to work. Here's the CSS I'm using:

#pages>li>a{
background: transparent !important;
border: none !important;
}


My font selection also seems to have been ignored when I've chosen Helvetica though that may just be to do with not supporting fonts not installed on the computer?

Tested without other addons running with the same experience. Windows 10 64-bit, Firefox 57.0.2

Regardless, thanks for the great product!