Extremely low map contrast on `element.io/en/matrix-in-europe`

The map on https://element.io/en/matrix-in-europe has extremely low contrast. It was so low that I thought it was broken until I moved it to another part of my screen with less glare and could finally see the country outlines.

### Potential solutions

I remember this looking a lot better but perhaps I'm thinking of this image (which is also on the page):

Open https://element.io/en/matrix-in-europe and inspect how the map is rendered and styled, using the supplied screenshots as visual context. Done means the country outlines and map details are clearly visible without moving the page away from screen glare, with improved contrast.

Written by the indexing model from the issue text.