It looks nice and I'll definitely use it :). Just one thing I wanted to mention is that you append a new style element. If you switch a few times between light and dark you'll see a lot of style elements in the header.
I haven't seen that many (elderly) people in The Netherlands on e-bikes that used a helmet this year. The only people that wear helmets are the ones that have a speed padelec/mountainbiker or racing bikes.