CSS

Tutorials

Our CSS Learning Area features multiple modules that teach CSS from the ground up — no previous knowledge required.

Introduction to CSS

This module gets you started with the basics of how CSS works, including selectors and properties, writing CSS rules, applying CSS to HTML, how to specify length, color, and other units in CSS, cascade and inheritance, box model basics, and debugging CSS.

Styling text

Here we look at text styling fundamentals, including setting font, boldness, and italics, line and letter spacing, and drop shadows and other text features. We round off the module by looking at applying custom fonts to your page, and styling lists and links.

Styling boxes

Next up, we look at styling boxes, one of the fundamental steps towards laying out a web page. In this module we recap the box model then look at controlling box layouts by setting padding, borders and margins, setting custom background colors, images and other features, and fancy features such drop shadows and filters on boxes.

CSS layout

At this point we've already looked at CSS fundamentals, how to style text, and how to style and manipulate the boxes that your content sits inside. Now it's time to look at how to place your boxes in the right place in relation to the viewport, and one another. We have covered the necessary prerequisites so you can now dive deep into CSS layout, looking at different display settings, traditional layout methods involving float and positioning, and new fangled layout tools like flexbox.

Reference

• CSS Reference: An exhaustive reference for seasoned Web developers describing every property and concept of CSS.
• CSS key concepts:
  • The syntax and forms of the language
  • Specificity and inheritance
  • Box model and margin collapse
  • The Containing Block
  • Stacking and block-formatting contexts
  • Initial, computed, used, and actual values
  • CSS shorthand properties
  • CSS Flexible Box Layout
  • CSS Grid Layout

Tools for CSS development

• The W3C CSS Validation Service checks if CSS is valid. This is an invaluable debugging tool.
• Firefox Developer Tools allow viewing and editing live CSS of a page via the Inspector and Style Editor tools.
• Firebug extension for Firefox, a popular extension of that navigator that allows to edit live CSS on watched sites. Very practical to test some changes, though this extension does much more.
• Web Developer extension for Firefox also allows to watch and edit live CSS on watched sites. Simpler than Firebug, though less powerful.
• Miscellaneous CSS tools.

Meta bugs

• Firefox: bug 1323667