How to make a blogger template : the body and APIs

In previous post ,I told you about the header of a blogger template . The next part should be the CSS part  ,but as you know ,we use the CSS to define how elements in body displayed (post color ,font,size...),so in this post ,I want to show you what is in the body of a template APIs and HTML markup ,then we will back to the CSS to define how they displayed .The part of a template is made