Kostiantyn Rudenko

Edit: found a [benchmark](https://benfrain.com/css-performance-revisited-selectors-bloat-expensive-styles/) Curiously, it reports a rather small difference on IE9 in light of the issue linked above. I ran the benchmark above in IE11 and attribute selectors...

Found another [anecdote](https://medium.com/@aantipov/ie11-performance-bottleneck-de304569361d) of attribute selectors being slow in IE11, though I did not observe this issue when running the [benchmark](https://benfrain.com/css-performance-revisited-selectors-bloat-expensive-styles/) on IE11. Perhaps there was an update to IE11...

Have you tried restarting VSCode? IIRC it needs a full restart to pick up code completion sometimes.