Still duplicating the same colors, fonts, or sizes in your CSS? There’s a better way — CSS variables! Also called custom properties, CSS variables help you write DRY (Don’t Repeat Yourself) code that’s easy to scale and maintain. Update a value once, and it changes everywhere it’s used. In this MiniCoursey quick guide, you’ll learn what CSS variables are, how to use them, and best practices for modern, maintainable stylesheets.
What Are CSS Variables?
CSS variables store reusable values that you can apply throughout your stylesheets. They’re defined with -- and accessed with var().
Basic Syntax
Define variables in a selector, often :root so they’re available globally.
:root {
–primary-color: #007bff;
–spacing-unit: 1rem;
}
.button {
background: var(–primary-color);
padding: var(–spacing-unit);
}
Now, updating --primary-color changes every .button at once!
Why Use CSS Variables?
- Keep design tokens like colors and spacing consistent.
- Make large projects easier to update.
- Support themes and dynamic styling with simple overrides.
💡 Pro Tip: Scope variables locally in components for reusable, isolated styles.
⚠️ Common Mistake: Don’t confuse CSS variables with preprocessor variables — they’re dynamic and cascade!
FAQ
Q: Can I use CSS variables in media queries?
A: Yes! Variables work anywhere in CSS — update them inside media queries for responsive values.
Q: Are they supported everywhere?
A: Yes — all modern browsers fully support CSS variables.
Related Link
👉 Check out previous: CSS Performance — Best Practices for Faster Styles
Where to Learn More
Explore MDN’s custom properties guide and practice converting old fixed values to variables for cleaner code.
Conclusion
Congrats — you now know how to use CSS variables for DRY, scalable, future-friendly styles!
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