<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> </head> <body> <style> *{ margin: 0px; padding:0px; } .a{ width: 120px; height: 120px; background: red; } .b{ border: 1px solid; margin: 10px; } </style> <div> <div> 头快坏了 </div> </div> </body> </html>
为什么会是这个样子?