三角css

http://www.jb51.net/article/42513.htm

http://blog.aizhet.com/web/4382.html

实现图片灰度效果

http://www.zhangxinxu.com/wordpress/2012/08/css-svg-filter-image-grayscale/

http://www.zhangxinxu.com/study/201208/css3-grayscale-filter.html

http://my.oschina.net/py115/blog/65196

http://www.526net.com/blog/qianduan/226.html