How do you use CSS variables?

Short answer: Define a variable with --name and access it with var().

Example code

:root { -main-color: #007bff; -padding: 10px; } button { background: var(--main-color); padding: var(--padding); } Follow me on LinkedIn: Key Takeaway: CSS variables make styles dynamic and reusable.

Real-world example (ShopNest)

In ShopNest’s cart UI, a click handler closes over productId. Use let in loops so each button keeps the correct id.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.