Vue Scoped Styling

🎨 Vue Scoped Styling

It is one of the most important features of Vue Single File Components (SFCs).

 What is Scoped Styling?

Scoped styling ensures that CSS written inside a component applies only to that component, not globally.

You enable it by adding the scoped attribute to the <style> tag:

 Basic Example

✔ .box styles apply only to this component
✔ Other .box classes elsewhere remain unaffected

 How Scoped Styling Works (Behind the Scenes)

Vue adds a unique attribute to the component’s HTML and CSS.

Example output:

👉 This is how Vue isolates styles automatically.

 Scoped vs Global Styles

✔ Default choice → Scoped
✔ Use global styles sparingly

 Styling Child Components (Deep Selector)

Scoped styles do not apply to child components by default.

✅ Use :deep()

✔ Styles elements inside child components
✔ Recommended way in Vue 3

 Styling Slot Content

Slot content comes from the parent, so scoped styles won’t apply directly.

✅ Use :slotted()

 Multiple Style Blocks

You can mix scoped and global styles.

✔ Scoped → component
✔ Non-scoped → global

 Scoped Styling with Preprocessors

Works with preprocessors too:

✔ SCSS / LESS / Stylus supported

 Common Use Cases

• Buttons

• Cards

• Forms

• Modals

• UI library components

 Common Mistakes ❌

❌ Forgetting scoped
❌ Overusing :deep()
❌ Writing layout CSS in scoped styles
❌ Expecting scoped CSS to affect child components automatically

 Best Practices ✅

✔ Use scoped styles by default
✔ Keep global styles minimal
✔ Use :deep() only when necessary
✔ Use meaningful class names
✔ Prefer component-level styling

 Summary Table

🏁 Conclusion

Vue scoped styling keeps your CSS safe, modular, and maintainable, especially in large applications.
It is a must-use feature for professional Vue development.