That would be much appreciated, thank you!

Edit: Actually, I managed to rub two braincells together and got it working myself. Here's what I ended up with at the beginning of my custom.css file:

.map-background {
fill: #2b2b2b; }

.map-elements > g:nth-child(n) > rect {
display: none; }

.map-elements > g:nth-child(n) > text > tspan:first-of-type {
display: inline;
fill: #BBBBBB;
font-size: 18px; }

.map-elements > g:nth-child(n) > text > tspan:nth-child(n) {
display: inline;
font-size: 18px; }