Revert "Remove visual divider between prominent sections on index pages."

This reverts commit daed7b05d594ca7b50a8ac95113bb34f9f710feb.
Semantic markup for the `#photo-buttons`, harmonized & slimmer styling.
Merge branch 'master' into tumblr

Conflicts:
	web/index.html
Apply CSS from `master` to embedded style sheet.
Fix missed merge segment.