/* 重置样式 */
section, body, div, p, span, h1, h2, h3, h4, h5, h6, form,  a, ul, li, dt, dd, dl, ol, header, nav, footer {margin: 0;padding: 0;box-sizing: border-box;line-height: 1;}
a {text-decoration: none;}
li {list-style: none;}