AI 编程工具<html><head><meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> <style> p:nth-last-child(3n+0){ background:#ff0000;}</style></head><body><p>The first paragraph.</p><p>The second paragraph.</p><p>The third paragraph.</p><p>The fourth paragraph.</p><p>The fifth paragraph.</p><p>The sixth paragraph.</p><p>The seventh paragraph.</p><p>The eight paragraph.</p><p>The ninth paragraph.</p><p><b>注意:</b> Internet Explorer 8 以及更早版本的浏览器不支持:nth-last-child()属性.</p></body></html>