3 Column Layout: 1col = 1/3 and 1 col 2/3 width

[ScottDaniels]

Go to this page and upvote percentage-based use:

Use percentages for heights, widths, margins, gutters in auto layout

This makes it easier to use components in designs for different screen sizes. And then you don’t have to calculate every time what 40% or 60% of the width is. This also makes it easier to design scalable applications that grow with the width of the screen.