Select Page

Category: @supports

How @supports Works

CSS has a neat feature that allows us to test if the browser supports a particular property or property:value combination before applying a block of styles — like how a @media query matches when, say, the width of the browser window is narrower than some specified size and then the CSS within it takes effect. In the same spirit, the CSS inside this feature will take effect when the property:value pair being tested is supported in the current browser. That feature is called @supports and it looks like this: @supports (display: grid) { .main { display: grid; } } Why? Well, that’s a bit tricky. Personally, I find don’t need it all that regularly. CSS has natural fallback mechanisms such that if the browser doesn’t understand a property:value combination, then it will ignore it and use something declared before it if there is anything, thanks to the cascade. Sometimes that can be used to deal with fallbacks and the end result is a bit less verbose. I’m certainly not a it’s-gotta-be-the-same-in-every-browser kinda guy, but I’m also not a write-elaborate-fallbacks-to-get-close kinda guy either. I generally prefer a situation where a natural failure of a property:value doesn’t do anything drastic to destroy functionality. That said, @supports certainly has use cases! And as I found out while putting this post together, plenty of people use it for plenty of interesting situations. A...

Read More

Using feature detection to write CSS with cross-browser support

In early 2017, I presented a couple of workshops on the topic of CSS feature detection, titled CSS Feature Detection in 2017. A friend of mine, Justin Slack from New Media Labs, recently sent me a link to the phenomenal Feature Query Manager extension (available for both Chrome and Firefox), by Nigerian developer Ire Aderinokun. This seemed to be a perfect addition to my workshop material on the subject. However, upon returning to the material, I realized how much my work on the subject has aged in the last 18 months. The CSS landscape has undergone some tectonic shifts:...

Read More