Cascading Style Sheets
https://msdn.microsoft.com/en-us/library/ms531209(v=vs.85).aspx
Working with CSS Overview
https://msdn.microsoft.com/en-us/library/bb398931(v=vs.110).aspx
CSS
https://msdn.microsoft.com/en-us/library/hh673536(v=vs.85).aspx
How to make css shape on thead tag
https://stackoverflow.com/questions/44149707/how-to-make-css-shape-on-thead-tag
