Idea Summary
CSS nesting is now supported in all major browsers. When using css files in APEX, the editor will highlight nested css selectors as invalid. More importantly, the file minifier will strip nested css that it sees as invalid. Currently the workaround is to skip minification on css files that have nesting, but this workaround doesn't work for inline page css.
Use Case
Support web standards and ease of use features for developers.
In APEX, you can see this happening by using a nested selector, then looking at the minified file. Here's a simple nested selector:
body {
background: gainsboro;
a {
background: tomato;
}
}
https://caniuse.com/css-nesting