css选择器

参考:

• link

普通选择器

• tagName
• #id
• .class-name
• *
• [attr] [attr=value] [attr~=value] [attr|=value] [attr^=value] [attr$=value] [attr*=value]

组合选择

• A + B ex: h2 + p will match all <p> elements that directly follow an <h2>.
• A ~ B ex: p ~ span will match all <span> elements that follow a <p>
• A > B ex: ul > li will match all <li> elements that are nested directly inside a <ul> element.
• A B
• A || B ex: col || td will match all <td> elements that belong to the scope of the <col>.

伪类

link
Example: a:visited will match all <a> elements that have been visited by the user.

伪元素

link
Example: p::first-line will match the first line of all <p> elements.