A web was created using html and css (provided). It looks like this:

The html code is:

What I have learned from this web creation is: 

1) The html is used for creating structure. The DOM structure of html file: html, head, body. The head part includes the meta, title, and the link to css file. The body parts includes several parallel div sub-parts, and then leads to even smaller sub-parts like img, p, a, ul, li, h1, h2, h3.  

2) The css is used for decorating the web. css file could be linked to the html file in head part. Some aggregated decoration styles for similar items could be incorporated into the html using id (#) or class (.).