Demos:
- https://georgecrawford.com/portfolio/font-baseline
- https://georgecrawford.com/portfolio/font-baseline/fonts
- https://georgecrawford.com/portfolio/font-baseline/metrics
Based on an original idea by Alan Stearns
see also:
- http://stackoverflow.com/questions/23247467/how-css-line-height-is-measured
- http://blog.typekit.com/2010/07/14/font-metrics-and-vertical-space-in-css/
- http://static.zealous-studios.co.uk/projects/web_tests/line%20box.xhtml
- http://jeffyam.com/node/189
- https://mudcu.be/journal/2011/01/html5-typographic-metrics/#baselineCSS
- http://dev.labs.ft.com/george/baseline/
- http://christopheraue.net/2014/03/05/vertical-align/