初始化默认样式

body,h1,h2,h3,h4,h5,h6,hr,p,blockquote,dl,dt,dd,ul,ol,li,pre,form,fieldset,legend,button,input,textarea,th,td { margin: 0; padding: 0;}body,button,input,select,textarea { font:12px;}h1,h2,h3,h4,h5,h6 { font-size: 100%;}address,cite,dfn,em,var { font-style: normal;}code,kbd,pre,samp { font-family: couriernew, courier, monospace;}small { font-size: 12px;}ul,ol { list-style: none;}a { text-decoration: none;}a:hover { text-decoration: underline;}sup { vertical-align: text-top;}sub { vertical-align: text-bottom;}legend { color: #000;}fieldset,img { border: 0;}button,input,select,textarea { font-size: 100%;}table { border-collapse: collapse; border-spacing: 0;}