Breakpoints in CSS - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Breakpoint Usage

Which CSS media query correctly applies styles only when the screen width is between 600px and 900px?

A @media screen and (min-width: 600px) or (max-width: 900px) { /* styles */ }

B @media (max-width: 600px) and (min-width: 900px) { /* styles */ }

C @media (min-width: 600px) and (max-width: 900px) { /* styles */ }

D @media (min-width: 600px), (max-width: 900px) { /* styles */ }

💡 Hint

Think about how to combine conditions so both must be true at the same time.

The correct syntax uses and to combine conditions that must both be true. Option C applies styles only when the screen width is between 600px and 900px.

Option C has the min and max reversed, so it never matches. Option C uses a comma which means 'or', so it applies styles outside the range too. Option C uses 'or' which applies styles if either condition is true, not both.

📝 Syntax

intermediate

Identify the Syntax Error in Media Query

What error does this CSS media query produce?

@media screen min-width: 500px) { body { background: blue; } }

CSS

@media screen min-width: 500px) { body { background: blue; } }

A SyntaxError: Missing opening parenthesis before 'min-width'

B SyntaxError: Missing colon after 'screen'

C SyntaxError: Missing opening parenthesis after 'screen'

D No error, valid syntax

💡 Hint

Check the parentheses around the condition.

Media queries require conditions to be inside parentheses. The correct syntax is @media screen and (min-width: 500px). Here, the opening parenthesis before min-width is missing, causing a syntax error.

❓ rendering

advanced

What background color will the box have on a 700px wide screen?

Given this CSS, what background color will the box have if the screen width is exactly 700px?

.box { background: yellow; }
@media (max-width: 600px) { .box { background: red; } }
@media (min-width: 601px) and (max-width: 800px) { .box { background: green; } }
@media (min-width: 801px) { .box { background: blue; } }

CSS

.box { background: yellow; }
@media (max-width: 600px) { .box { background: red; } }
@media (min-width: 601px) and (max-width: 800px) { .box { background: green; } }
@media (min-width: 801px) { .box { background: blue; } }

A red

B green

C blue

D yellow

💡 Hint

Check which media query matches 700px width.

The base background is yellow. The first media query applies red only up to 600px. The second media query applies green between 601px and 800px, which includes 700px. The last applies blue above 800px. So at 700px, the background is green.

❓ selector

advanced

Which media query targets only portrait orientation on screens wider than 480px?

Select the correct media query that applies styles only when the device is in portrait mode and the screen width is greater than 480px.

A @media (orientation: portrait) and (min-width: 481px) { /* styles */ }

B @media (min-width: 481px), (orientation: portrait) { /* styles */ }

C @media (orientation: portrait) or (min-width: 481px) { /* styles */ }

D @media screen and (orientation: portrait) or (min-width: 481px) { /* styles */ }

💡 Hint

Use 'and' to combine conditions that must both be true.

Option A correctly uses and to require both portrait orientation and minimum width greater than 480px.

Options A and C use commas or 'or', which apply styles if either condition is true, not both. Option A mixes 'and' and 'or' without parentheses, causing unexpected behavior.

❓ accessibility

expert

How to ensure accessible breakpoint changes for screen readers?

When using CSS breakpoints to change layout, which practice best supports screen reader users?

A Use JavaScript to remove hidden content from the DOM at breakpoints to improve screen reader experience.

B Use CSS to visually hide content but keep it accessible by using <code>visibility: hidden</code>.

C Use <code>display: none</code> on content at breakpoints to hide it visually and from screen readers.

D Use only CSS to hide content visually at breakpoints without removing it from the accessibility tree.

💡 Hint

Think about how screen readers interpret hidden content.

Option D is best because visually hiding content (e.g., with clip-path or position: absolute; left: -9999px;) keeps it in the accessibility tree for screen readers.

Option D removes content from the DOM, which can confuse users. Option D hides content from both visual and screen readers, which may remove important information. Option D hides content visually but visibility: hidden also hides it from screen readers.