Why is CSS not being edited through the developer panel?

Question

css

After refreshing the page, it becomes impossible to edit CSS through the developer panel
Before refresh:
After

Answer 1

The problem was in the code styling the scrollbar in Chrome. When I removed it everything worked. Thanks to those who responded)

Answer 2

This is most likely due to the fact that now you are embedding css code in the html file itself, and not connecting it as it was before.