html - Weird Error on bootstrap

Question

I'm using bootstrap for a long time. I'm noticing a weird error today. I'm opening mozilla console and there at least hundred errors showing on twitter-bootsrap source. then I tried to insert bootsrap cdn, but still the same errors. Here is a list of some errors:

Unknown pseudo-class or pseudo-element '-webkit-inner-spin-button'. 
Ruleset ignored due to bad selector.

Expected color but found 'auto'.  Expected color but found
'-webkit-focus-ring-color'.  Expected end of value but found
'-webkit-focus-ring-color'.  Error in parsing value for 'outline'. 
Declaration dropped.


Expected end of value but found '9 '.  Error in parsing value for
'width'.  Declaration dropped.

Error in parsing value for 'background-image'.  Declaration dropped.

Is there anything wrong with bootstrap?

Answer 1

Some CSS elements have not passed validation in Mozilla but is accepted in Chrome. The same case is with Opera, Safari, especially IE and other browsers. Each browser has different rules that must be followed. Bootstrap and every quality CSS must be adapted to all browsers in order to work correctly. Therefore, some of the elements you'll find in consoles as invalid but in every browser shows different errors.

W3 Validator is guide only, in reality, the story is quite different.