Background
Basically, the background color palette was increased and several responsive utilities were added.
Increase the color palette of backgrounds.
Striped background colors inspired from progress bar component.
Standard and new background colors with opacity in the range from 0.1 to 0.9.
State backgrounds inspired from Bootstrap alerts and can be used to identify block state.
Change background colors only by hover or focusing on element.
Background hover colors with opacity in the range from 0.1 to 0.9.
This utility implements background-size: contain css style which can change size of background image to scale the width and height in an element.
Mostly used for creating full width hero headers with background image and implements background-size: cover css style.