Q1. How is class selector written?

Class selector uses dot: .btn { }

Q2. What is advantage of class over ID?

Classes can be reused on multiple elements, ideal for reusable components.

Q3. Can an element have multiple classes?

Yes, separate with spaces: <div class="box large center">

Q4. What is the specificity of class selector?

Class specificity is 10, higher than element (1) but lower than ID (100).

Q5. How do you select element with both classes?

Use .box.large { } - no space, selects elements with both box and large classes.