As far as I know there is no CSS3 support now, it may be include in next service pack.
but you can try this..
The prob is that you need the CSS 3.0 schema. If you want you can try to create one yourself and this is how. I assume that you are using a x64 Windows:
Copy the file CSS21.xml to CSS30.xml in the following directory:
C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\Packages\1033\schemas\CSS\
Open the Registry Editor and navigate to the following key:
Add a new key named Schema 5.
Under the key Schema 5 add a new string value named File and set the value to css30.xml
Under the key Schema 5 add a new string value named Friendly Name and set the value to CSS 3.0
Start Visual Studio 2010 and open a CSS file and you will see a new entry in the list dropdown list named "CSS 3.0"
All that you need to do is modify the css30.xml, find an existing one on the internet or wait for Microsoft or someone else to release one.
Prabu_Spark, if this helps please login to Mark As Answer. | Alert Moderator