Minor (no functional change) tweak to the JS to measure grid unit width.
Minor (no functional change) tweak to the JS to measure grid unit width.

theroyalstudent/unsemantic-100-grid,nathansmith/unsemantic,theroyalstudent/unsemantic-100-grid,nathansmith/unsemantic,nathansmith/unsemantic,theroyalstudent/unsemantic-100-grid