Always have readable contrasting fore/back colours.
Only have large front page heading on larger screens.
Remove unnecessary width/floats so breadcrumbs appear in mobile view.

Floating means it appears within the purview of the main
content, and that being positioned: relative means the
background colour obscures it.
Remove floating of site header.
Prevent double line on blog list page.
Fix broken image links.
Improve footer display at varying widths.