#gonggao {width: 1080px;height: 119px;position: absolute;z-index: 1500;left: 50%;margin-left: -571px;margin-top: 899px; }
#downloada { float: left; width: 1280px; height: 119px; overflow: hidden; margin-right: 20px; margin-top: 10px; }
#downloada .btn_downa { float: left; width: 379px; height: 119px; position: relative; text-indent: -9999em; background: url("../images/fast_down1.png") left bottom no-repeat; display: block; margin-top: 0px; }
#downloada .btn_downa:hover { text-decoration: none; background: url("../images/fast_down1_hover.png") left top no-repeat; }
#downloada .btn_downb { float: left; width: 379px; height: 119px; position: relative; text-indent: -9999em; background: url("../images/fast_down2.png") left bottom no-repeat; display: block; margin-left: 0px; }
#downloada .btn_downb:hover { text-decoration: none; background: url("../images/fast_down2_hover.png") left top no-repeat; }
#downloada .btn_downc { float: left; width: 379px; height: 119px; position: relative; text-indent: -9999em; background: url("../images/fast_down3.png") left bottom no-repeat; display: block; margin-left: 0px; margin-top: 0px; }
#downloada .btn_downc:hover { text-decoration: none; background: url("../images/fast_down3_hover.png") left top no-repeat; }