Give visual feedback after actions like "save"

[jmuheim]

At the time being, no visual feedback is given after pressing "Save", for example at the book options page. This could be something like H2 Settings successfully saved.

I don't know whether there is aural feedback. This could happen in the page title.

[qtnc]

NO, there is no special oral feedback.

However, the save button normally become disabled after you saved: Isn't
it the case, or isn't it sufficient ?

[jmuheim]

Ah, this isn't perceivable visually. @AntonBolfing, you should add a CSS rule like this:

button[disabled]
  color: gray