CSS debugging: A semi-transparent overlay should cover the viewport behind a modal.. What is the proper fix for a site header?

CSS Published 03 Oct 2026 Updated 03 Oct 2026 0 Views Verified

Problem: A semi-transparent overlay should cover the viewport behind a modal. Context: This CSS troubleshooting question uses a site header example. Correct approach: Use fixed positioning and full viewport insets. Working CSS: .overlay { position:fixed; inset:0; background:rgb(0 0 0 / .5); }

Looking for the latest Sarkari Result 2026 updates? Check the latest government exam results, merit lists and result updates on Sarkari Resultess.

Answer & Explanation

4 Answers

Verified

A. Common but incorrect approach

Use width:50%; height:50%

Additional Explanation

This approach does not directly implement the required CSS behavior.

Verified

B. Incorrect CSS alternative

Use float:cover

Additional Explanation

This is not a valid CSS property or does not solve the stated problem.

Verified Correct Answer

C. Correct CSS solution

.overlay { position:fixed; inset:0; background:rgb(0 0 0 / .5); }

Additional Explanation

Use fixed positioning and full viewport insets.

Verified

D. Another incorrect approach

Use display:overlay

Additional Explanation

This does not address the underlying CSS layout or styling issue.