<html><head lang="en"> <meta charset="UTF-8"> <title></title> <style> div{ background-color: red; 250px; height: 250px; margin: 130px; /*设置边框: 边框宽度 边框样式 边框颜色*/ border: 10px solid green; /*内边距: 上右下左*/ padding:20px 40px 100px 20px; } </style> </head> <body> <div>122112</div> </body></html>