<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <style> .big_box{ width: 400px; height: 260px; overflow: hidden; } .box{ width: 400px; height: 200px; background: #0f0; border-bottom: 20px solid transparent; border-image: url(img/三角形.png); border-image-width: 20px; border-image-slice: 72; border-image-repeat: repeat; border-image-outset: 20px; box-shadow: 0 0 30px #000; } </style> </head> <body> <div class="big_box"> <div class="box"></div> </div> </body> </html>
三角形png:
最终效果: