0.参考 https://developer.mozilla.org/zh-CN/docs/Web/CSS/Pseudo-elements https://developer.mozilla.org/zh-CN/docs/Web/CSS/::before https://developer.mozilla.org/en-US/docs/Web/API/Window/getComputedStyle 0.1 Use with pseudo-elements getComputedStyle can
CSS伪元素 伪元素的语法: selector:pseudo-element {property:value;} 作 用 添加特殊样式 :first-line 伪元素 "first-line" 伪元素用于向某个选择器中的文字的首行添加特殊样式: p{font-size: 12pt}p:first-line{color: #0000FF;font-variant:small-caps;}<p>Some text that ends up on two or more l