<html><head><style>.mask1 { mask: url(/i/logo/w3.png) no-repeat 50% 50%;}</style></head><body><h1>mask 属性</h1><h3>带有遮罩层的图像：</h3><div class="mask1"><img src="/i/photo/beijing.jpg" alt="Beijing" width="600" height="400"></div><h3>Original image:</h3><img src="/i/photo/beijing.jpg" alt="Beijing" width="600" height="400"></body></html>