class selector ; ID selector; pseudo-class. Type selector. 與HTML 的element type 的名稱(也就是HTML tag 名稱) match。 ... <看更多>

Introduced in CSS2, the :first-child pseudo-class represents the very first child of its parent. That's it. There's a very common misconception that it picks up ... ... <看更多>

Classes are a group of CSS properties that can be applied to any tag. To use a class you have to add the ... ... <看更多>

If no element matches the CSS selectors, the querySelector() returns null . ... the element with a given class attribute, you use the class selector syntax:. ... <看更多>