A VSCode extension that allows you to use browser devtools from within the editor. The devtools will connect to an instance of Microsoft Edge giving you the ability to alter CSS styling, perform diagnostics, and debugging. Get it now at http://aka.ms/devtools-for-code
Like the live-preview extension (as seen in the screenshot), I recommend to add a preview toolbar action that opens with the embedded edge browser:
There are many such preview commands already in VS Code (e.g. for markdown files).