An experiment with supporting a custom !--immutable annotation for CSS style properties that would lock a specific value for an element once set in a way that could not be changed from other CSS styles or JavaScript.
Experimental support in process-css-demo, try it out without installing using the following command, and copy the JS output to any page with an H1 tag on it to see how it works:
npx process-css-demo 'h1 { color: red !--immutable }' -b
