approach says avoid location-dependent styles. Does that mean I shouldn’t use descendent selectors like .myModule .title?
No—descendant selectors are not discouraged, but putting them too high in the DOM tree is. Avoid putting a wide-net class or id way up on the body or outermost divs of a page, and then writing lots of styles to generate variants of objects. It’s not reusable, and it slows down page rendering. Instead, make a more “local” variant by adding a class directly onto the object (and add descendent styles to its children). A good rule of thumb is that anything within the body of a container is clearly a separate object.
