Feature Queries Manager

How does it work?

It works by negating the feature query condition to give you the oppposite result. For example, it will turn the following feature query condition...

@supports (display: flex) { /* styles here */ }

Into the following...

@supports not ((display: flex)) { /* styles here */ }

Demo

Note: You need to install the Feature Queries Manager in your browser for this to work. Once installed, open up the "FQM" panel in devtools and toggle on/off the following styles:

5. Positive Condition with failure