<html><head><style>img { filter: grayscale(100%); /* Chrome, Safari, Opera */ filter: grayscale(100%);}</style></head><body><p>将图像转换为灰度：</p><img src="pineapple.jpg" alt="菠萝" width="300" height="300"><p><strong>注意：</strong> Internet Explorer 不支持 filter 属性。</p></body></html>