Device-forced darkmode break constrast on some texts.

[MentorFilou]

Issue exists in Samsung Internet browser and probably others.

"When using darkmode from my phone and visiting flashtrace.github.io in Samsung browser I encounter that the websites theme is dark in both modes, although the website's dark mode is a little more dark then its light mode. This leads to the hero text ("Lightning-fast, reference-based requirement tracing") becoming almost unreadable due to bad contrast (dark text on dark background). Some other parts are also minorly affected (e.g. the NavBar looks almost disabled, the version tag is also pretty dark).