HTML and CSS

HTML codifies the structure and format of a page. CSS codifies the style to determine what it will look like.

Getting started

HTML is the markup that contains all the actual stuff that a web page has. All the text on this page you're reading right now lives inside HTML tags that tell your browser how to order the content on the page. Go on, right click any element on the page and choose "Inspect Element" to open up your browser's Developer Tools and it will show you the structure of the page.

CSS tells the browser if you want to display any of those tags a particular way, for instance, turning its background blue and pushing it a little to the left. In your Developer Tools, you can see the CSS styles in another panel, usually showing which specific properties were inherited from which lines of CSS.

Learning outcomes

Look through these now and then use them to test yourself after doing the assignment:

  • Why do we separate HTML and CSS?

  • What are classes and IDs (and how are they different)?

  • What are elements?

  • What are tags?

  • What are attributes?

  • What are forms?

  • What is a div?

  • What are selectors?

  • What are properties?

  • What are values?

  • What is the "query string" in a URL and what does it do?

  • What is the difference between "pixels" and "ems"?

  • How do CSS styles for a particular element get inherited? i.e. how does an element get its "default" styles?

  • What are two CSS attributes you can change to push an element around on the page?

  • What are the three different ways to include CSS in your project or use CSS to style a particular element?

  • What is the "default stylesheet" or "user agent stylesheet"?

  • Why use a CSS reset file?

Assignment

  1. Dive right into learning HTML and CSS with freeCodeCamp's interactive tutorials. Do the entire section labeled "Responsive Web Design Certification" only. It's long and, if you're new, might take you at least a few days to get through, but it will give you a really solid foundation to build on moving forward. They also have some projects at the end of this section. They're good practice, but you can consider them optional. (A large part of their proposed '300 hours' for completion comes from these projects, so it probably won't take you that long if you only do the exercises).

    Note: If you are using a browser add-on such as Dark Reader (or a similar add-on that creates a "dark mode" for a website), it may interfere with certain exercises. If your solution isn't accepted, try disabling the browser add-on and submitting it again.

  2. Optional: Learn about your browser's default stylesheet and CSS resets in this video (resets are mentioned starting at the 2:00 mark). This is why there are some spaces that show up in your layout even if you haven't specified CSS. Real developers almost always use a CSS reset to blow away the default stylesheet and let them work from scratch. If you're still curious, here's a longer video on resets.

Additional resources

This section contains helpful links to other content. It isn't required, so consider it supplemental for if you need to dive deeper into something.

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