When working with your CSS you will often have instances where something should include all of the styling associated with a class, in addition to a few extras that are specific to just that item. In regular CSS you would normally put the general class on the item, and add a more specific class with the additional styling. With the Sass @extend directive, you can have the more specific class inherit the styling of another class, so that you can just use the specific class in your HTML, keeping you HTML markup nice and concise.
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