Box-sizing

Defines how the width and height of the element are calculated: whether they include the borders and padding or not.

Classes

Class name	Value
`.content-box`	content-box

<div class="content-box">...</div>

$ npm install @citizensadvice/box-sizing

now import into your stylesheet...

@import '@citizensadvice/box-sizing/index.scss';

You can also make use of the unpkg service, try adding the link below to the head of your HTML file

<link src="https://unpkg.com/@citizensadvice/box-sizing@latest/build/box-sizing.css" />