样式重置 取消input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,
img{border:medium none;margin: 0;padding: 0;list-style-type: none;}