What are CSS Custom Properties (and How Do Double-Dash Prefixes Work)?

Decoding the Enigma of Double-Dash-Prefixed CSS Properties

Introduction:

In the realm of CSS, you may encounter unfamiliar properties adorned with double dashes prefixed to their names. These properties are known as custom properties and hold immense power within the CSS landscape.

The Essence of Custom Properties:

Custom properties offer a dynamic and robust solution for managing CSS styles. They allow developers to define and modify styles on the fly, providing flexibility and reusability across multiple elements and pages.

Defining Custom Properties:

Custom properties are declared within the root element (:root) using the '--' syntax. For instance:

:root {
  --color-primary: #04b;
  --font-heading: HelveticaNeue-bold, sans-serif;
  --spacing-margin: 1em;
}

Using Custom Properties:

To utilize custom properties, you can employ the 'var()' function within any CSS property value. For example:

h1 {
  color: var(--color-primary);
  font-family: var(--font-heading);
  margin: var(--spacing-margin);
}

Reference and Documentation:

The W3C specification provides comprehensive documentation on custom properties at:

https://www.w3.org/TR/css-variables/

Conclusion:

Custom properties empower CSS developers with immense flexibility and efficiency. By leveraging these double-dash-prefixed properties, you can elevate your CSS code to new heights, enhancing the maintainability, reusability, and dynamism of your web designs.

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