font-size: 1rem is applied on the for easy responsive type-scaling via media queries while respecting user preferences and ensuring a more accessible approach. No base font-size is declared on the, but 16px is assumed (the browser default).This ensures that the declared width of element is never exceeded due to padding or border. The box-sizing is globally set on every element-including *::before and *::after, to border-box.The and elements are updated to provide better page-wide defaults. Keep declarations of font-related properties to a minimum, using inherit whenever possible.For easier scaling across device sizes, block elements should use rems for margins.More importantly though, a single direction of margin is a simpler mental model. Vertical margins can collapse, yielding unexpected results. Update some browser default values to use rems instead of ems for scalable component spacing.Here are our guidelines and reasons for choosing what to override in Reboot: For example, we reboot some styles for a simpler baseline and later provide.
Additional styling is done only with classes. Reboot builds upon Normalize, providing many HTML elements with somewhat opinionated styles using only element selectors. Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon.
