Alternative use for “Aber”

I always thought that “aber” only meant “but”. However, after reading several sentences with the word it seems like it means different things.
I have checked with this dictionary (https://www.collinsdictionary.com/dictionary/german-english/aber) and saw these examples of how it can be used:
trotzdem but still
oder aber or else
aber ja! oh, yes!
aber nein! oh, no!
aber, aber! now, now!
das mach ich aber nicht! I will NOT do that!
dann ist er aber wütend geworden then he really got mad
das ist aber heiß/schön! that’s really hot/nice
bist du aber braun! aren’t you brown!
das geht aber zu weit! that’s just or really going too far!
schreib das noch mal ab, aber sauber! write it out again, and do it neatly!
 
Is there a chapter where the use of “aber” is explained or a good external resource?
 

You can see more examples in the Leo dictionary:
https://dict.leo.org/german-english/aber

And German with Jenny has a video on the use of aber as a modal particle.
A modal particle expresses how the speaker feels about what is being said.
https://www.youtube.com/watch?v=2se5NPY94FQ