Scaling CSS Components with BEM, REMs, & EMs | Lullabot

How a little BEM and cleverness can make extensive use of EMs worth doing, and how it can up your game. Using relative units for measurements has a lot of advantages, but can cause a lot of heartache if inheritance goes wrong. But as I’ll demonstrate, BEM methodology and some clever standardization can reduce or eliminate the downsides. A little vocab before we get too far into this: em units CSS

[tacamy]

コンポーネントのroot要素をremで指定、elementはemで指定。emのpx相当のサイズ計算がめんどくさい問題はSassで計算しようという話。

[yomotsu]

コンポーネントのルートをremにする、必要ならルートのモディファイアでルートのremを変える その2