If you ever wanted an illustration of benefit of a broad skillset, this post is it. There’s so much benefit in understanding how both CSS and JavaScript work and where each technology thrives.
Heydon’s write up illustrates another great example of Custom Properties being bloody useful too. The relationship of JavaScript and Custom Properties is one of my favourite features because it aides in keeping your responsive to interaction-based CSS succinct, maintainable and above all-else, understandable, which Heydon outlines perfectly.
A must read.