After pseudo-element in CSS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add content after a paragraph using the after pseudo-element.

CSS

p::after { content: [1]; }

Drag options to blanks, or click blank then click option'

Ablock

Bnone

C"!"

Dafter

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to put quotes around the content value.

Using invalid values like 'none' or 'block' for content.

The content property inside the ::after pseudo-element must be a string, so "!" adds an exclamation mark after the paragraph.

2fill in blank

medium

Complete the code to make the after content display as a block element.

CSS

p::after { content: "!"; display: [1]; }

Drag options to blanks, or click blank then click option'

Ainline

Bblock

Cnone

Dflex

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'inline' which is the default and won't change layout.

Using 'none' which hides the content.

Setting display to block makes the after content appear on its own line below the paragraph.

3fill in blank

hard

Fix the error in the code to correctly add a red asterisk after labels.

CSS

label::after { content: [1]; color: red; }

Drag options to blanks, or click blank then click option'

A'*'

B*

Cstar

D"*"

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving the asterisk unquoted causing syntax errors.

Using words like 'star' which are not valid content values.

The content property requires a string in quotes. "*" correctly adds a red asterisk after labels.

4fill in blank

hard

Fill both blanks to add a blue dash after headings and make it inline-block.

CSS

h2::after { content: [1]; display: [2]; color: blue; }

Drag options to blanks, or click blank then click option'

A"-"

Binline

Cinline-block

Dblock

Attempts:

3 left

💡 Hint

Common Mistakes

Using display 'inline' which limits styling options.

Forgetting quotes around the dash.

The content is a dash "-" and display is inline-block to allow styling and spacing after the heading.

5fill in blank

hard

Fill all three blanks to add a green checkmark after list items, make it inline, and add margin-left.

CSS

li::after { content: [1]; display: [2]; margin-left: [3]; color: green; }

Drag options to blanks, or click blank then click option'

A"✔"

Binline

C0.5rem

Dblock

Attempts:

3 left

💡 Hint

Common Mistakes

Using display block which moves the checkmark to a new line.

Not adding margin-left so the checkmark is too close to text.

The content is a checkmark "✔", display is inline so it flows with text, and margin-left adds space after the list item.

Practice

1. What does the CSS ::after pseudo-element do?

easy

A. Adds content after an element without changing the HTML

B. Removes the element from the page

C. Changes the background color of an element

D. Makes the element invisible

Solution

1. Step 1: Understand the purpose of ::after

   The ::after pseudo-element inserts content after the selected element in the page layout without modifying the HTML structure.

2. Step 2: Compare with other options

   Options A, C, and D describe different CSS effects unrelated to ::after.

3. Final Answer:

   Adds content after an element without changing the HTML -> Option A

4. Quick Check:

   ::after adds content after element [OK]

Hint: Remember ::after adds content visually, not in HTML [OK]

Common Mistakes:

• Thinking it changes the HTML structure
• Confusing it with visibility or color changes
• Forgetting it needs content property to show

2. Which CSS rule correctly uses ::after to add a red asterisk after a paragraph?

easy

A. p::after { content: '*'; color: red; }

B. p:after { content: '*'; color: red; }

C. p::after { text: '*'; color: red; }

D. p::after { content: '*'; font-color: red; }

Solution

1. Step 1: Check correct pseudo-element syntax

   The modern and correct syntax for the after pseudo-element is ::after, not :after.

2. Step 2: Verify property names

   The property to add text is content, and color is set with color. Options C and D use incorrect properties (text and font-color).

3. Final Answer:

   p::after { content: '*'; color: red; } -> Option A

4. Quick Check:

   Use ::after with content and color [OK]

Hint: Use double colons and 'content' property for ::after [OK]

Common Mistakes:

• Using single colon instead of double (::after vs :after)
• Using wrong property like 'text' instead of 'content'
• Using 'font-color' instead of 'color'

3. What will be the visual output of this CSS?

h1::after { content: ' [check]'; color: green; }

Given HTML: <h1>Task Complete</h1>

medium

A. [check] Task Complete (green check mark before text)

B. Task Complete [check] (green check mark after text)

C. Task Complete (no change visible)

D. Task Complete [check] (check mark in default color)

Solution

1. Step 1: Understand ::after content insertion

   The ::after adds the string ' [check]' after the h1 text, so the check mark appears after "Task Complete".

2. Step 2: Check color styling

   The color property applies to the inserted content, so the check mark will be green.

3. Final Answer:

   Task Complete [check] (green check mark after text) -> Option B

4. Quick Check:

   ::after adds green check after text [OK]

Hint: Content appears after element text with given styles [OK]

Common Mistakes:

• Thinking content appears before text
• Ignoring color styling on inserted content
• Expecting no visible change without HTML change

4. Identify the error in this CSS code:

div::after { content: foo; }

medium

A. content: foo; is valid and will not show anything

B. Missing semicolon after content property

C. ::after cannot be used on div elements

D. content must be a string or url, not 'foo'

Solution

1. Step 1: Check valid values for content

   The content property requires a string (in quotes), url(), or special keywords like '' (empty string). The value foo is invalid here.

2. Step 2: Verify usage of ::after on div

   The ::after pseudo-element can be used on any element, including div.

3. Final Answer:

   content must be a string or url, not 'foo' -> Option D

4. Quick Check:

   content needs string or url, not 'foo' [OK]

Hint: Use quotes for content, 'foo' is invalid [OK]

Common Mistakes:

• Using 'foo' instead of empty string or valid content
• Thinking ::after can't be on div
• Missing semicolon (not the main error here)

5. You want to add a decorative quote mark after every blockquote without changing HTML. Which CSS snippet correctly does this and ensures accessibility?

hard

A. blockquote::after { content: '"'; font-size: 2rem; color: gray; aria-hidden: true; }

B. blockquote::after { content: '"'; font-size: 2rem; color: gray; display: none; }

C. blockquote::after { content: '"'; font-size: 2rem; color: gray; }

D. blockquote::after { content: '"'; font-size: 2rem; color: gray; role: presentation; }

Solution

1. Step 1: Add decorative content with ::after

   Using content: '"' adds the quote mark after blockquote text visually.

2. Step 2: Accessibility for pseudo-elements

   Generated content from ::after is not part of the DOM accessibility tree and is ignored by screen readers, so no additional CSS properties are needed.

3. Step 3: Check other options

   blockquote::after { content: '"'; font-size: 2rem; color: gray; aria-hidden: true; } uses invalid CSS property aria-hidden (ARIA attributes belong on HTML elements). blockquote::after { content: '"'; font-size: 2rem; color: gray; display: none; } uses display: none; which hides the quote visually. blockquote::after { content: '"'; font-size: 2rem; color: gray; role: presentation; } uses invalid CSS property role.

4. Final Answer:

   blockquote::after { content: '"'; font-size: 2rem; color: gray; } -> Option C

5. Quick Check:

   ::after content ignored by screen readers [OK]

Hint: Pseudo ::after content doesn't need special accessibility handling [OK]

Common Mistakes:

• Using invalid CSS properties like aria-hidden or role
• Using invalid CSS properties like role
• Hiding content visually instead of from screen readers