Note: After saving, you have to bypass your browser's cache to see the changes. Internet Explorer: press Ctrl-F5, Mozilla: hold down Shift while clicking Reload (or press Ctrl-Shift-R), Opera/Konqueror: press F5, Safari: hold down Shift + Alt while clicking Reload, Chrome: hold down Shift while clicking Reload.
    /* Covers most text */  
    body { 
        font-family: "Arial", "DFKai-SB", sans-serif 
    } 
     
    /* Covers some headers */  
    .mw-body h1, .mw-body h2 { 
        font-family: "Arial", "DFKai-SB", fantasy, serif  
    }