Reboot defaults and basics
Let's start this chapter by reviewing the basics of Reboot when using content components in Bootstrap. One of the main changes for content components in Bootstrap 4 is the switch from em
to rem
units of measure. rem
is short for root em and is a little bit different from a regular em
unit. em
is a relative unit to the font-size of the parent element it is contained within. This can cause a compounding issue in your code that can be difficult to deal with when you have a highly nested set of selectors. The rem
unit is not relative to its parent, it is relative to the root or HTML element. This makes it much easier to determine the actual size of text or other content components that will appear on the screen.
The box-sizing
property is globally set to border-box
on every element. This is good because it ensures that the declared width of an element doesn't exceed its size due to excess margins or padding.
The base font-size
for Bootstrap 4 is 16px
and it is declared...