为什么Visual Studio无法解析我的CSS类名？

Whenever I am working in Visual Studio I always found that it will not resolve the css class names in my html. The CSS Class names will appear with the green squiggly line in Visual Studio but then the page will render fine when viewing it in the browser. So I know the css file is referenced correctly in my master page but Visual Studio is just failing to resolve it. Also the Design View will not show any of the css styles either.Whenever I am working in Visual Studio I always