How to style DetailsView control using CSS in ASP.Net

Try This

.Grid { border: solid 1px #FFFFFF; }
.Grid td
{
border: solid 1px #FFFFFF;
margin: 1px 1px 1px 1px;
padding: 1px 1px 1px 1px;
text-align: center;
}
.GridHeader
{
font-weight: bold;
background-color: #8b8dbb;
}
.GridItem
{
background-color: #e6e6e6;
}

.GridAltItem
{
background-color: white;
}

 <asp:DetailsView ID="DetailsView1" CssClass=”Grid”>
 </asp:DetailsView>

 or

Refer

http://www.asp.net/cssadapters/detailsview.aspx