HTML & CSS · The Box Model · Lesson 9 of 25
Backgrounds and Borders
Concept
Backgrounds and Borders
background-color, background-image, and border-radius let you style a box's fill and corners.
border-radius can take a single value for uniform corners, or up to four values to round each corner independently — a value of 50% on a square element makes it a perfect circle.
- Explain the core idea behind Backgrounds and Borders.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Backgrounds and Borders. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Style a card with a soft background color and rounded corners.
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
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