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What advices would you give to developers learning Sass for the first time?
Sass is often times one of the first languages people learn. One of the great parts, is that if you only know CSS and HTML, you can just start using Sass just like you used CSS, and you can slowly add in features as you learn them. Nesting is usually the first thing people refactor their CSS to do, but there are lots of other features to familiarize yourself with.
If you are familiar with other languages, then there are only a couple unique concepts that you need to learn. Most everything else is pretty freaking boring (in the good way!).