Incomplete CSS

[Maria Jose Esteve]

Hi, I find myself with a problem that I don't know how to solve, and I thought 
that, perhaps, some of you have also suffered from it... it is also possible 
that I am doing it wrong...

I have in defaults.css, of the application, all the custom styles: own styles 
of the application or customizations of styles established in components of 
some library.
The problem is that it moves "some of these css's" to App.css and not others.
Ex:
 .vscomp-wrapper {
   font-family: 'Open Sans', serif, sans-serif !important;
   color: #333333 !important;
}

mark {
   background-color: #04a3b3;
   color: #fff;
}
 .vscomp-royale {
   background-color: #333333 !important;
   color: #04a3b3 !important;
}
 .jewel.drawer .drawermain {
   background-color: #333333 !important;
   border-left: 0;
  display: inline-flex;
   ...;
}

Of these 4 styles all of them are transferred to App.css except for "mark", do 
you have any idea what the reason might be?

Thx.
Hiedra