These are also small text documents, although they end in .css, and you need to add code to link them to your HTML pages. How to learn HTML, CSS and web design on your Mac: What are HTML and CSS?

HTML div containers make ... Although this example uses headings as the contents of the div containers, you can place any type of text element you like in the divs and set their width and height ...

HTML doesn't offer as clean a solution for vertical lines as it does for horizontal lines -- a vertical equivalent to the Set your image up within your text and add a "style" attribute tag.