With CSS, for years now, I thought that we could only use an element once as a selector to increase the overall specificity. e.g. .my-class to div .my-class.
However, I learnt very recently that we can repeat selectors more than once and it adds to the specificity value, as each is matched individually (it made sense when I thought about it like that!). e.g. you could do .my-class.my-class to target an element with class my-class – but with more specificity.
I used this to work around a core block in WordPress which had something like div .something .my-class.my-class with div .something .my-class.my-class.my-class!
Paul Gibbs 