Global vs scoped style strategies in Svelte - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to apply a scoped style to the paragraph.

Svelte

<style>
p [1] {
  color: blue;
}
</style>

<p>This text should be blue only inside this component.</p>

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

Ap

B:global(p)

C:local(p)

D:scoped(p)

Attempts:

3 left

💡 Hint

Common Mistakes

Using :global() when you want scoped styles

Trying to add :scoped() which is not a valid Svelte selector

In Svelte, styles inside the <style> tag are scoped by default. So just using p applies styles only to this component.

2fill in blank

medium

Complete the code to apply a global style to all paragraphs.

Svelte

<style>
[1] {
  font-weight: bold;
}
</style>

<p>This text should be bold everywhere.</p>

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

Ap

B:scoped(p)

C:local(p)

D:global(p)

Attempts:

3 left

💡 Hint

Common Mistakes

Using just 'p' which scopes styles locally

Using :local() which is not needed for global styles

Using :global(p) applies the style to all <p> elements globally, not just inside this component.

3fill in blank

hard

Fix the error in the style to make the button color red globally.

Svelte

<style>
button [1] {
  color: red;
}
</style>

<button>Click me</button>

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

A:local()

B:scoped()

C:global()

D:scope()

Attempts:

3 left

💡 Hint

Common Mistakes

Using :local() which scopes styles locally

Using :scoped() which is not a valid Svelte selector

To make the button style global, wrap the selector with :global(). Other options are invalid or scope styles locally.

4fill in blank

hard

Complete the code to create a global style for links and a scoped style for headings.

Svelte

<style>
a[1] {
  text-decoration: none;
}
h1 {
  color: green;
}
</style>

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

A:global()

B:local()

D:scoped()

Attempts:

3 left

💡 Hint

Common Mistakes

Adding :local() unnecessarily for scoped styles

Using :scoped() which is invalid

Use :global() for the link style to apply globally. For the heading, no special selector is needed because styles are scoped by default.

5fill in blank

hard

Fill both blanks to style a global class, a scoped id, and a global element.

Svelte

<style>
.[1] {
  background: yellow;
}
#[2] {
  border: 1px solid black;
}
button {
  padding: 0.5rem;
}
</style>

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

Ahighlight

B:global()

Dmain

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the dot before class name

Using :scoped() which is invalid

Putting :global() on the class selector instead of the id

The class highlight is styled globally by default with the dot. The id uses :global() to apply globally. The empty string means no extra selector for the id, so it is scoped by default.

Practice

1. In Svelte, what does it mean when styles are scoped by default?

easy

A. Styles apply globally to all components in the app.

B. Styles apply only to the current component, not affecting others.

C. Styles are ignored unless marked as global.

D. Styles must be written in a separate CSS file.

Solution

1. Step 1: Understand Svelte's default style behavior

   Svelte automatically scopes styles to the component they are written in, preventing them from affecting other components.

2. Step 2: Compare with global styles

   Global styles affect the entire app, but Svelte requires explicit marking for global styles, so default is scoped.

3. Final Answer:

   Styles apply only to the current component, not affecting others. -> Option B

4. Quick Check:

   Scoped styles = component-only styles [OK]

Hint: Remember: Svelte isolates styles by default [OK]

Common Mistakes:

• Thinking styles apply globally without marking
• Confusing scoped with global styles
• Assuming styles must be external

2. Which of the following is the correct way to write a global style inside a Svelte component's <style> block?

easy

A.

B.

C.

D.

Solution

1. Step 1: Identify how to mark global styles in Svelte

   Svelte uses the :global() pseudo selector inside the style block to mark styles as global.

2. Step 2: Check each option

   is scoped by default. uses an invalid attribute. mixes scoped attribute (not valid) with :global(). Only correctly uses :global().

3. Final Answer:

   <style> :global(.btn) { color: red; } </style> -> Option A

4. Quick Check:

   Use :global() for global styles inside <style> [OK]

Hint: Use :global() inside style block for global CSS [OK]

Common Mistakes:

• Using invalid <style> attributes like global or scoped
• Forgetting to wrap selectors in :global()
• Assuming all styles are global by default

3. Given this Svelte component code, what color will the <h1> text be?

<script>
  let active = true;
</script>

<style>
  h1 { color: blue; }
  :global(h1) { color: red; }
</style>

<h1>Hello</h1>

medium

A. Red

B. Black (default)

C. Blue

D. Both blue and red, causing a gradient

Solution

1. Step 1: Understand style precedence in Svelte

   The scoped style h1 { color: blue; } compiles to something like h1.svelte-abc { color: blue; } which has higher specificity. The :global(h1) { color: red; } compiles to h1 { color: red; }.

2. Step 2: Determine final color

   Both rules apply to the component's h1, but the scoped rule has higher specificity (element + class vs element only), so the text will be blue.

3. Final Answer:

   Blue -> Option C

4. Quick Check:

   Scoped styles have higher specificity than plain global styles [OK]

Hint: Scoped styles have higher specificity than global styles [OK]

Common Mistakes:

• Thinking global styles override scoped styles
• Assuming global styles have higher specificity
• Ignoring the unique class added by Svelte scoping

4. You wrote this Svelte style block but the global style is not applying:

<style>
  global(.title) { font-weight: bold; }
</style>

What is the error and how to fix it?

medium

A. Wrap the style block in a <global> tag instead of <style>.

B. Add the attribute global to the style tag like <style global>.

C. No error; the style will apply globally as written.

D. Use :global(.title) instead of global(.title) to apply global styles.

Solution

1. Step 1: Identify the syntax for global styles in Svelte

   Svelte requires the :global() pseudo selector inside the style block to mark styles as global, not just global().

2. Step 2: Correct the syntax

   Replace global(.title) with :global(.title) to apply the style globally.

3. Final Answer:

   Use :global(.title) instead of global(.title) to apply global styles. -> Option D

4. Quick Check:

   Global styles need :global() syntax [OK]

Hint: Use :global() not global() inside style block [OK]

Common Mistakes:

• Using global() instead of :global()
• Trying to add global attribute to style tag incorrectly
• Assuming styles are global by default

5. You want to apply a global font style to all paragraphs in your Svelte app but keep button styles scoped. Which approach is correct?

hard

A.

B.

C.

D.

Solution

1. Step 1: Identify how to apply global styles selectively

   To make paragraph styles global, wrap the selector in :global(). Button styles remain scoped by default.

2. Step 2: Evaluate each option

   applies both styles scoped (not global). correctly applies global to paragraphs only. uses invalid global attribute. incorrectly makes button styles global.

3. Final Answer:

   <style> :global(p) { font-family: Arial; } button { color: blue; } </style> -> Option A

4. Quick Check:

   Use :global() only on selectors needing global scope [OK]

Hint: Wrap only global selectors with :global() [OK]

Common Mistakes:

• Making all styles global unintentionally
• Using invalid style tag attributes
• Forgetting :global() for global styles