blog: Mobile-friendly design

This change complements change golang/go#9062 (because godoc and
the blog share a style sheet) and makes the blog responsive for
mobile.

Change-Id: Ibcd415034c067a6ebc4489dc8b5f32ec9c1a38d6
Reviewed-on: https://go-review.googlesource.com/9063
Reviewed-by: Chris Broadfoot <cbro@golang.org>
1 file changed