New Post: Stylesheet XML changes not reflected in NB_Store webpages?

I want to get rid of (in webpages):

.Detail .Name h1{line-height: 24px;}

I removed the line in ManagerMenuDefault.xml but that has no effect.

Can be its parsed from this xml file once into the database during module installation and read always from the database?

I need to get rid of this css or be able to change it. How do I do that? PurchasingPanel is now not responsive design.