Dev mode: changes to CSS files are reset after refresh

[Macil]

If you run the hello-world example in dev mode and make an edit to examples/hello-world/style/index.css (such as adding background: blue; on the main element), then it will apply immediately. But if you refresh the page, the CSS will switch back to how it was when you started the dev server (until you make another change).

If you make any change to the page itself, then the CSS changes made up to that point will be remembered after a refresh.