Some inherit in CSS

Line Height Inherit

You don't need to add line-height to each <p>, <h*>. separately. This way textual elements can inherit from body easily.

body {  
  line-height: 1;

Box-sizing Inherit

Letting box-sizing be inheritted from html makes it easier to change box-sizing in plugins or other components that leverage other behavior.

html {  
  box-sizing: border-box;
*, *:before, *:after {
  box-sizing: inherit;