What is CSS for?

HTML is (mostly) by default : responsive, vector, and highly readable on any device.

If you find yourself writing CSS that removes any of these three features, take a minute to stop and rethink its purpose. What problem could be so important that it’s worth solving at the cost of universal access to your content & readability?

I like to think of CSS as a chance to enhance the usability of the web for our users. CSS should never limit usability.