Fix bug in .mainFooter caused by fixed .chimps section
#22
Add CSS to devices in portrait
Remove fixed .chimps section made to #2

Commit with original changes: 6e7c23e2d61c3f0d9673bc0c1e90dd1b800a4079

I’m rolling back it because in mobile devices, if this section is
fixed, the content is bigger than the screen size and the user can’t
read all the text.