<!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-repe...