让孩子与父节点等高 <!DOCTYPE html> <html> <head> <title>让孩子与父节点等高</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <style> html,body{ height:100%; margin: 0; padding: 0; } .parent{ position: relative; background:violet; height: 90%; } .son{ *height:expression(this.parentNode.offsetHeight + "px"); position: absolute; top:0px; bottom: 0px; 800px; background: red; } </style> </head> <body> <div class="parent"> <div class="son">TODO write content</div> </div> </body> </html> 运行代码