The likely problems are incorrect ordering in HTML files or incorrect usage of the "float" CSS command. Open your HTML file in a text editor. Ensure that the divider for the navigation bar ...

Left navigation bars display the links for your readers to find categories and topic pages. By default, the navigation bar stops rendering after the last link displays. You can use the CSS "height ...

The navigation bar will now look like: As you can see, we have a problem. The list items are presented together with no spaces between items. We can solve this by adding: nav ul li {float ...