css背景颜色设置后不变色_html/css_WEB-ITnose: #mainaboutus { BACKGROUND:#00FFFF;MARGIN: 75px auto; WIDTH: 1000px; HEIGHT: auto}.aboutus { WIDTH: 1000px}.aboutus LI { WIDTH: 250px; FLOAT: left}.aboutus LI A { TEXT-INDENT: -998em; MARGIN: 0px auto; WIDTH: 150px; DISPLAY: block; HEIGHT: