We currently load an additional external script that ensures CSS variables support on all browsers. This is actually only needed for a small part of browsers, so in probably over 99% of cases this degrades the performance with no benefit.

I already tried using feature detection, but that didn't work reliably for me on Opera Mini.

Options:

• Feature detection
• PostCSS plugin to include fallbacks (graceful degradation, won't support custom settings e.g. campaign sidebar)
• Simply remove the script without alternative if the result looks acceptable.

 Previous attempt https://github.com/greenpeace/planet4-master-theme/compare/css-vars-feature-detection uses document.write, but it didn't work reliably on Opera mini. 

Some info on this closed PR too https://github.com/greenpeace/planet4-master-theme/pull/1195 

Tasks:

• Investigate if it's worth it based on % of affected browsers
• Implement solution if needed