问一个asp.net 下css的问题 - Web 开发 / HTML(CSS)

<span id="ArticleContent1_ArticleContent1_lblContent"><style>
.btn {
 BORDER-RIGHT: #7b9ebd 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #7b9ebd 1px solid; PADDING-LEFT: 2px; FONT-SIZE: 12px; FILTER: progid:DXImageTransform.Microsoft.Gradient(GradientType=0, StartColorStr=#ffffff, EndColorStr=#cecfde); BORDER-LEFT: #7b9ebd 1px solid; CURSOR: hand; COLOR: black; PADDING-TOP: 2px; BORDER-BOTTOM: #7b9ebd 1px solid
}
.btn1_mouseout {
 BORDER-RIGHT: #7EBF4F 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #7EBF4F 1px solid; PADDING-LEFT: 2px; FONT-SIZE: 12px; FILTER: progid:DXImageTransform.Microsoft.Gradient(GradientType=0, StartColorStr=#ffffff, EndColorStr=#B3D997); BORDER-LEFT: #7EBF4F 1px solid; CURSOR: hand; COLOR: black; PADDING-TOP: 2px; BORDER-BOTTOM: #7EBF4F 1px solid
}
.btn1_mouseover {
 BORDER-RIGHT: #7EBF4F 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #7EBF4F 1px solid; PADDING-LEFT: 2px; FONT-SIZE: 12px; FILTER: progid:DXImageTransform.Microsoft.Gradient(GradientType=0, StartColorStr=#ffffff, EndColorStr=#CAE4B6); BORDER-LEFT: #7EBF4F 1px solid; CURSOR: hand; COLOR: black; PADDING-TOP: 2px; BORDER-BOTTOM: #7EBF4F 1px solid
}
.btn2 {padding: 2 4 0 4;font-size:12px;height:23;background-color:#ece9d8;border-width:1;}
.btn3_mouseout {
 BORDER-RIGHT: #2C59AA 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #2C59AA 1px solid; PADDING-LEFT: 2px; FONT-SIZE: 12px; FILTER: progid:DXImageT