01.margin的问题 · 学习笔记

~~~ <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> <style> /* 给父元素的第一个子元素,margin-top会有问题 */ .parent{ width:400px; height:400px; background: red; overflow:hidden; } .child{ width:100px; height:100px; background: yellow; margin-top:100px; } /* 1.让它变成老二 */ /* .parent::before{ content:""; display:table; } */ /* 2.给父元素,overflow:hidden */ </style> </head> <body> <div class="parent"> <div class="child"> </div> </div> </body> ~~~