css清除不需要属性及边距

a, address, b, big, blockquote, body, center, cite, code, dd, del, div, dl, dt, em, fieldset, font, form, h1, h2, h3, h4, h5, h6, html, i, iframe, img, ins, label, legend, li, ol, p, pre, small, span, strong, u, ul, var{
padding: 0px;
margin: 0px;
}

a{
text-decoration: none;
color: black;
}

ul{
list-style: none;
}