漂亮的雪花图案：

<!DOCTYPE HTML><html><head><meta charset="UTF-8"><title>CSSAAA TEST DEMO</title><style type="text/css">#snow { margin:160px;position:relative; width:200px;height:20px; border-radius:25px; background-color:#09f;}.flake { position:absolute;left:0;right:0;top:0;bottom:0;margin:auto; width:35px;height:10px;border-radius:10px;}#snow:before, #snow:after, .flake:before, .flake:after { content:" ";position:absolute; width:inherit;height:inherit; border-radius:inherit; background-color:inherit;}#snow:before, .flake:before { transform:rotate(-60deg);}#snow:after, .flake:after { transform:rotate(60deg);}.flake, .flake:before, .flake:after { box-shadow:45px 50px 0 2px #09f,-45px -50px 0 2px #09f, 45px -50px 0 2px #09f,-45px 50px 0 2px #09f;}</style><script src="https://cdn.bootcss.com/prefixfree/1.0.7/prefixfree.min.js"></script></head><body><div id="snow"> <div class="flake"></div></div></body></html>

代码来自：http://www.cssaaa.com/css3/158.html