Cascading Style Sheets (CSS) is a document type and the associated scripting language that describes the presentation of HTML documents. Using the CSS language, you can control the look and feel of web pages by defining layout, text, and image properties to be applied in a wide array of contexts.

This course is a comprehensive introduction to both writing and implementing CSS. Using the document hierarchy model, you’ll learn how to tailor web styles to specific areas. With your hierarchy defined, you’ll dive deep into CSS fundamentals, adding colors, text styles, and backgrounds to your web page. After you’ve defined these elements, you’ll use CSS to define layouts around pictures and text flow and completely control your web page’s look. You’ll wrap up by exploring the essential animation functions of CSS.

By the end of this course, you’ll have functional mastery of Cascading Style Sheets and the CSS scripting language. You’ll be prepared to build professional web pages with your code.

Luka

Highly recommended! Tim covers everything & gets right to the important stuff!

Frontend dev

The Complete Beginner’s Guide to CSS

## The z-axis
In CSS, each box can be thought of as having a `position` in 3D. So far, we’ve seen positioning related to both the horizontal x-axis and vertical y-axis, but boxes also have a **z-axis** where they stack on top of each other.

The `z-index` property sets the stacking order of all elements on the z-axis. It only works on elements that have a defined `position`  that’s anything other than the default `position:static;`.

So, when we have multiple overlapping elements on a web page, the `z-index` property lets us decide which one is visible (or nearest to the user) and the order of any element(s) that sit behind it.
## Example

# The z-axis
In CSS, each box can be thought of as having a `position` in 3D. So far, we’ve seen positioning related to both the horizontal x-axis and vertical y-axis, but boxes also have a **z-axis** where they stack on top of each other.

The `z-index` property sets the stacking order of all elements on the z-axis. It only works on elements that have a defined `position`  that’s anything other than the default `position:static;`.

So, when we have multiple overlapping elements on a web page, the `z-index` property lets us decide which one is visible (or nearest to the user) and the order of any element(s) that sit behind it.
# Example

Learn how to stack elements with z-index.

Introduction to CSS

CSS Selectors

CSS Core Concepts

CSS Units

CSS Fundamentals

Backgrounds & Colors

CSS Layout

Animating Your CSS

CSS Architecture

Conclusion

The z-index Property

The z-axis

Example