Hi FelixHalim,
There’s no easy way to do this, as the hexagon isn’t a geometric shape built into CSS. You would need to use the before and after pseudo elements to create a hexagon. You’ll find some info on creating the geometric shape here: http://jtauber.github.io/articles/css-hexagon.html
The easiest way to do this (while still pretty complicated) would probably be to remove the logo element in Lingonberry altogether and add a new Hexagon element using the code in the link above.
