fix: onhover link icon color in dark mode

[barefootstache]

fix: onhover link icon color in dark mode from the existing black to white.

Cannot use the existing system, since the link.svg icon is being imported as an image, thus one needs to use the filter property in CSS.

[chipzoller]

Thanks for the contribution!

[gefloh]

@barefootstache @chipzoller Hm for me this destroys the colors of the icon in the footer, left of the copyright in dark mode. In the example site this looks ok, but if you use a more sophisticated icon with more colors, this is not good.

[chipzoller]

Can you provide an example?

[gefloh]

Before:

Now:

[barefootstache]

If this is the only place, then we could prepend

body > :not(footer)

into the variables to catch the case with the icon in the footer to stay static between dark/light mode.