<!doctype html> <html lang="en"> <head> <meta charset="UTF-8"> <title>斜线布局</title> <style>
.x { border: solid 1px red; width: 100px; height: 100px; position: relative; background-color: transparent; } .x:before { position: absolute; top: 0px; right: 0; left: 0; bottom: 0; border-bottom: 100px solid red; border-left: 100px solid transparent; content: ""; } .x:after { position: absolute; left: 1px; right: 0; top: 1px; bottom: 0; border-bottom: 99px solid white; border-left: 99px solid transparent; content: ""; } .f { border: solid 1px red; width: 100px; height: 100px; position: relative; background-color: transparent; } .f:before { position: absolute; top: 0px; right: 0; left: 0; bottom: 0; border-bottom: 100px solid red; border-right: 100px solid transparent; content: ""; } .f:after { position: absolute; left: 0; right: 1px; top: 1px; bottom: 0; border-bottom: 99px solid white; border-right: 99px solid transparent; content: ""; } </style> </head> <body> <div class="x"> </div> </body> </html>