Irrespective of changing it on different places like, .claro-details.hidden, ...

Irrespective of changing it on different places like, .claro-details.hidden, button and other elements. Its better to change it on hidden class.
Not continuing with MR, as both the MR are fixing for one element and the problem with hidden is global. I have adapted the different approach (using important on display: none itself), attached patch for same. Please review