CSS, or Cascading Style Sheets, defines the look and formatting of that HTML. Both are essential to coding your own website, and here's how to get acquainted with them.

Make sure you validate your HTML and CSS, using a service like the W3C’s validator. This will warn you about obsolete tags and other errors that may make your HTML less robust.

We’ll use three essential tools: HTML, CSS, and JavaScript (see graphic). ... Enlarge fonts to make sure everyone can comfortably use your page. Then, add images and photos to the page.