css3 rotate style not supporting in c# code

Question

watermarkContent = "Viewed by " + dsUserDetails.Tables[0].Rows[0]["ContactFirstName"].ToString() + " " + dsUserDetails.Tables[0].Rows[0]["ContactLastName"].ToString() + " " + dsUserDetails.Tables[0].Rows[0]["OrgTimeZone"].ToString(); 

 

strBody.Append("<span style='-moz-transform: rotate(-90deg);color: #7a7a7c;font-size: 13px;font-family: Arial;line-height: 30px;margin:0 15px 0 0;padding:0;'>" + watermarkContent + "");

 

I used as per browser but still i am not getting  rotate style . please help me.

.vertical-text {

/* Safari */
-webkit-transform: rotate(-90deg);

/* Firefox */
-moz-transform: rotate(-90deg);

/* IE */
-ms-transform: rotate(-90deg);

/* Opera */
-o-transform: rotate(-90deg);

/* Internet Explorer */
filter: progid:DXImageTransform.Microsoft;
font-size:14px;
display: block;
white-space: nowrap;
width: 40px;
margin-left:-10px;
margin-right:-10px;

}