Q1. What is an outline in CSS?

Outline is a line drawn outside the element's border, which does not take up space in the layout.

Q2. What is the difference between outline and border?

Outline does not affect layout dimensions, cannot be rounded with border-radius, and is often used for focus indicators.

Q3. What is outline-offset?

outline-offset creates space between the outline and the element's border/edge.

Q4. When are outlines commonly used?

Outlines are used for focus indicators (accessibility) and temporary debugging to see element boundaries.

Q5. How do you remove the default focus outline?

Use outline: none; or outline: 0; but be careful for accessibility - provide alternative focus styles.