W3c is the human body that tries to standardize these items, they publish The foundations, then programmers generate their rendering motor to interpret Those people principles. Which means where models conflict on an element, those described with the more unique selector will override considerably less particular selectors. For example, specified https://reallivesocial.com/story4948116/the-fact-about-prestashop-geoip-popup-message-and-redirect-links-based-on-country-that-no-one-is-suggesting