I have a better understanding of HTML and CSS semantics, particularly naming them based on their function.
It is important to tailor your web site to your target audience, such as predicting which browser they would most likely use to access your web site and to bear in mind that different browsers display websites differently.
It is also best practice to keep HTML and CSS separate as it not only keeps your work organized, but allows you to focus on the functionality of each.
3 things I have learned: