CSS basics · Lesson 7 of 12 · 7 minutes

CSS basics: Borders

A visible border needs a style as well as a width and color; it participates in box sizing.

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Your objectives

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1
Build borders
Build this first target: .notice with border-style: solid. Keep the selector relationships intact and inspect the preview.
Hint & worked example
A visible border needs a style as well as a width and color; it participates in box sizing.
The requested selectors and declarations exist outside comments.
```
.notice { border-style: solid; }
```
Common mistake to avoid: If the page fits one desktop viewport, no narrower viewport needs checking.
2
Extend the borders example
Extend your file to include: .notice with border-style: solid; .notice with border-width: 1px. Keep the selector relationships intact and inspect the preview.
Hint & worked example
A visible border needs a style as well as a width and color; it participates in box sizing.
The requested selectors and declarations exist outside comments.
```
.notice { border-style: solid; }
.notice { border-width: 1px; }
```
Common mistake to avoid: Hiding all overflow always makes content accessible.
3
Verify the complete borders pattern
Finish the pattern with: .notice with border-style: solid; .notice with border-width: 1px; .notice with border-color: #658b84. Keep the selector relationships intact and inspect the preview.
Hint & worked example
A visible border needs a style as well as a width and color; it participates in box sizing.
The requested selectors and declarations exist outside comments.
```
.notice { border-style: solid; }
.notice { border-width: 1px; }
.notice { border-color: #658b84; }
```
Common mistake to avoid: If the page fits one desktop viewport, no narrower viewport needs checking.

Understand the pattern

A visible border needs a style as well as a width and color; it participates in box sizing.

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

.notice { border-style: solid; }
.notice { border-width: 1px; }
.notice { border-color: #658b84; }

A visible border needs a style as well as a width and color; it participates in box sizing.

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 borders?Hiding all overflow always makes content accessible.A visible border needs a style as well as a width and color; it participates in box sizing.If the page fits one desktop viewport, no narrower viewport needs checking.

Apply it elsewhere

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

Keep the momentum.

Complete the lab, then explain and apply the pattern.

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MDN: CSS styling