box-shadow is not recognized

I have this CSS code for a textbox class and I'm on working on linux. It's saved in a .css file and i'm using gedit. But the box-shadow property isn't recognized. All the others have that different font which shows a keyword or so. But not box-shadow. Any ideas please? It seems to work on windows when i use notepad++.

.textbox 
{ 
    background: white; 
    border: 1px solid #ffa853; 
    border-radius: 5px; 
    box-shadow: 0 0 5px 3px #00FFFF; 
    color: #666; 
    outline: none; 
    height:23px; 
    width: 275px; 
}