https://www.polymer-project.org/articles/styling-elements.html

http://blog.bingo929.com/custom-elements-html-web-components.html

http://www.tuicool.com/articles/iIvmaa

http://www.html5rocks.com/zh/tutorials/webcomponents/customelements/

http://www.html5rocks.com/en/tutorials/webcomponents/template/?redirect_from_locale=zh

http://www.zhangxinxu.com/wordpress/2014/07/hello-html5-template-tag/

customElement