初始化-index.css
css样式初始化：首先：这是让app页面高度为屏幕的100%，而不是由内容撑开：html, body, #app{ height: 100%; margin: 0; padding: 0;}接下来是页面初始化：html,body,div,span,applet,object,iframe,h1,h2,h3,h4,h5,h6,p,blockquote,pre,a,abbr,acronym,address,big,cite,code,del,dfn,e
