[wruza]

What's stopping you from using cm/in as your unit

Not gonna rewrite or patch a whole CSS framework to make a dashboard. One can avoid using it in the first place, but then has to cope with elusive y-scroll in line inputs, misalignments and so on. There's always something strange out of box even if you target a specific browser.

[zamadatix]

Which CSS framework out of curiosity? I don't know many that won't let you use px, which is 1/96th an inch at any DPI, and if it really doesn't let you use the most basic sizing element on the web then the problem seems more with the chosen framework than anything to do with browsers :p.