[Fixed]-How can you separate the navigation bar list from the body list?

You are applying your li styles to every li which is why you are having trouble. In order to apply styles to a specific item you can use a class or ID like so:

li {
  float: right;
  display: inline;
}

becomes

li.nav_item {
  float: right;
  display: inline;
}

And

<nav><ul><li>... becomes <nav><ul><li class='nav_item'>...

There are many other ways to apply your styles to specific elements, but this should get you started. Read more here: https://css-tricks.com/how-css-selectors-work/