The CSS selector represents a particular pattern of element or elements in a tree structure. The term "selector" can refer to a simple selector, a compound selector, or a complex selector. When included in the :has()
pseudo-class as a parameter, these selectors are referred to as relative selectors, representing elements relative to one or more anchor elements.
These selectors can be combined into a comma-separated selector list. If any selector in a non-forgiving selector list is invalid, the entire selector list is invalidated.