CSS Nesting

Microsoft Copilot AI Conversation

April: Explain the concept of CSS nesting. What are the origins of CSS nesting? What is the use of the ampersand as the nesting selector? Explain browser support based on data from the caniuse.com website.

Copilot: Sure, I'd be happy to explain CSS nesting!

Concept of CSS Nesting

CSS nesting allows you to nest your CSS selectors in a way that mirrors the structure of your HTML. This makes your CSS more readable and maintainable by visually grouping related styles together. Instead of writing long, repetitive selectors, you can nest them inside one another.

Origins of CSS Nesting

The concept of CSS nesting has its roots in preprocessor languages like Sass and Less, which introduced nesting to make writing CSS more efficient and organized. These preprocessors allowed developers to write nested rules, which would then be compiled into standard CSS. The popularity and utility of this feature led to discussions about incorporating it directly into the CSS specification.

Use of the Ampersand (&) as the Nesting Selector

In CSS nesting, the ampersand (&) is used as a reference to the parent selector. It allows you to create more specific selectors based on the parent. For example:

/* Without nesting */
.button {
  color: blue;
}
.button:hover {
  color: darkblue;
}

/* With nesting */
.button {
  color: blue;
  &:hover {
    color: darkblue;
  }
}

In the nested example, &:hover refers to .button:hover, making the code more concise and easier to read.

Browser Support

As of the latest data from caniuse.com, CSS nesting is still in the process of being fully supported across all major browsers. It is currently supported in some modern browsers, but not universally. For the most up-to-date information, you can check the specific support status on the caniuse website.

This conversation was generated by AI.

Copilot, 1.25034.133.0, Microsoft, 09 April 2025, https://copilot.cloud.microsoft/

CSS Nesting Example

The sentence below is being styled by CSS nesting code:

This code is nested.

The "&" is used as a nesting selector to change the background color of the text in the sentence above on hover.

Nesting can be used in pretty much any web project involving CSS to help simplify the CSS code. Nesting could be especially helpful in projects where there is a large amount of CSS code to help keep everything organized.