title: How create a sticky Navbar that is changing the color while scrolling? [with Typescript in Angular]
body: <p>I want to create a navbar like here: <a href="http://www.devoncrawford.io/" rel="nofollow noreferrer">http://www.devoncrawford.io/</a></p>
  
  <p>I couldn't figure it out how to interact with css elements through my ts code.
  Maybe you can give me a tip, where I could research a bit more. 
  I would also love to get this autoscrollbutoon and just be able to interact with my css stuff.</p>
  
  <p>I found a lot of jQuery stuff, but I am not familiar with it. Is that working in angular and should I learn it? </p>
  
  <p>Thanks for your time. Sorry, it is a little bit general question, but I hope you can give me some advice</p>