Better CSS for older/feature-constrained browsers like Netsurf

This is not very important but I would like to see Trisquel.info work better with older/feature-constrained browsers like Netsurf. Already it loads almost perfectly and is fully usuable, but does have some usability issues for example:

background: rgba(0, 0, 0, 0.2) none repeat scroll 0% 0%;

Netsurf seems to ignore the alpha part, so since the font color is (0,0,0,0.7), it ends up just black on black. The header bar also tends to go invisible.