CSS basics · Lesson 8 of 12 · 10 minutes

CSS basics: Background surfaces

A background should keep foreground content readable rather than carry meaning alone.

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Your objectives

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1
Build background surfaces
Build this first target: main with background-color: #f4f7f5. Keep the selector relationships intact and inspect the preview.
Hint & worked example
A background should keep foreground content readable rather than carry meaning alone.
The requested selectors and declarations exist outside comments.
```
main { background-color: #f4f7f5; }
```
Common mistake to avoid: If the page fits one desktop viewport, no narrower viewport needs checking.
2
Extend the background surfaces example
Extend your file to include: main with background-color: #f4f7f5; main with color: #182b2a. Keep the selector relationships intact and inspect the preview.
Hint & worked example
A background should keep foreground content readable rather than carry meaning alone.
The requested selectors and declarations exist outside comments.
```
main { background-color: #f4f7f5; }
main { color: #182b2a; }
```
Common mistake to avoid: Hiding all overflow always makes content accessible.
3
Verify the complete background surfaces pattern
Finish the pattern with: main with background-color: #f4f7f5; main with color: #182b2a; .notice with background-color: #ffffff. Keep the selector relationships intact and inspect the preview.
Hint & worked example
A background should keep foreground content readable rather than carry meaning alone.
The requested selectors and declarations exist outside comments.
```
main { background-color: #f4f7f5; }
main { color: #182b2a; }
.notice { background-color: #ffffff; }
```
Common mistake to avoid: If the page fits one desktop viewport, no narrower viewport needs checking.

Understand the pattern

A background should keep foreground content readable rather than carry meaning alone.

Misconceptions to reject

If the page fits one desktop viewport, no narrower viewport needs checking.
Hiding all overflow always makes content accessible.

The preview is a sanitized subset, not a full browser compatibility test.

Worked example and expected result

main { background-color: #f4f7f5; }
main { color: #182b2a; }
.notice { background-color: #ffffff; }

A background should keep foreground content readable rather than carry meaning alone.

Try a variation

Adapt the final example to a different project name while retaining its structure and relationships. A different context still needs a real browser and accessibility check.

Explain it

Which statement correctly explains background surfaces?A background should keep foreground content readable rather than carry meaning alone.If the page fits one desktop viewport, no narrower viewport needs checking.Hiding all overflow always makes content accessible.

Apply it elsewhere

You reuse background surfaces in a different project. What must still be verified?Nothing; passing a single exercise guarantees every future use.Only whether the source code has the same number of lines.The resulting layout, focus behavior, and readability at the target viewport sizes.

Keep the momentum.

Complete the lab, then explain and apply the pattern.

Next: CSS basics: Reusable utility classes Try an incident drill

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