Is markup allowed in CSS

It sounds like you're wanting to re-use your header on multiple site pages.  In that case, look up Dreamweaver Templates in your Help Menu (F1).  Or consider using server-side technologies like includes.  See link below.

https://alt-web.blogspot.com/2015/07/server-side-includes-with-php.html

Hope that helps.

[Moderator moved from Using the Community (forums) to Dreamweaver.]

===========

Hi @WeavingMyDreams,

Short answer: No.

Long answer:  HTML = content and markup structure.  CSS = styles.  Markup and styles are 2 totally different things.

In order to build websites, you need a working knowledge of HTML and CSS and how they work together. Read the chapters, do code exercises and take quizzes at the end.
- https://www.w3schools.com/html/
- https://www.w3schools.com/css/

Don't use image maps if you can avoid them.  They won't work well in responsive layouts because the hotspots invariably drift out of register when the image is re-scaled for smaller/larger devices.  Image maps were popular in the last century but not anymore.   As a workaround use a responsive SVG image map instead.  See this JS Fiddle for a working example.  

https://jsfiddle.net/NancyO/6k3v4ge1/21/

Post back if you have any questions.