How to Customize InstantChat.css
You can customize the appearance of the Instant Chat interface using Cascading Style Sheets (CSS). By default, the Instant Chat interface is determined by InstantChat.css. You can copy and edit InstantChat.css to create custom styling or you can create your own custom CSS. If you create a custom CSS file, you need to specify the path in your html page by adding the path to your hosted CSS:
ICLoader.HostedCSS = "http://[YourSite]/InstantChat.css";
The following samples show CSS classes and the user interface elements that these classes affect. For a complete list of CSS classes, see How to Customize InstantChat.css.