I never had a chance to play with the
:target pleudo-element selector.
It can be very useful to apply a specific style on an element when its identifier is part of current document URI.
This is especially usefull to build some custom style on element that are being navigated to.
I’m setup a small example on this codepen.
This is a classical and simple way to build a basic collapsed menu, such as navigation menu found under the (in)famous hamburger menu on mobile sites.
Clicking the menu activation link will navigate to the navigation element and, as it is now the target in the page, reveal its content.
Select one item of the navigation menu and it will hide again, switching to the new target.
Some more informations are available on MDN.