這個代碼怎么用？body { font-family:Verdana; font-size:14px; margin:0; line-height:150%;}#container {margin:0 auto; width:900px;}#header { height:100px; background:#6cf; margin-bottom:5px;}#menu { height:30px; background:#09c; margin-bottom:5px;}#mainContent {}#sidebar { float:right; width:200px; background:#9ff; margin-bottom:5px;}#content { float:left; width:675px; padding:10px; background:#cff; margin-bottom:5px;}/*因為是固定寬度，采用左右浮動方法可有效避免ie 3像素bug*/#footer { height:60px; background:#6cf;}.clearfloat { clear:both; height:0; font-size: 1px; line-height: 0px;}