When working with scoped CSS in Vue, applying styles from a parent to a child component can be tricky. Vue offers two powerful tools to help with this: the deep selector (>>>) and the :deep() pseudo-class. Both allow you to penetrate scoped CSS boundaries, but which one should you use? Let’s explore both with examples and compare them!
🛠 1. Using the Deep Selector (>>>)
As we discussed earlier, the deep selector is a special way to apply styles from a parent component to a child component while keeping the scoped attribute in place.
Example:
<!-- ParentComponent.vue -->
<template>
<div class="parent-container">
<ChildComponent />
</div>
</template>
<script>
import ChildComponent from './ChildComponent.vue'
export default {
components: {
ChildComponent
}
}
</script>
<style scoped>
/* Scoped styles apply only to the parent */
.parent-container {
background-color: lightblue;
}
/* Deep selector to apply styles to a child component */
>>> .child-text {
color: red;
}
</style>
In this example, the deep selector (>>>) allows us to style the .child-text class inside the child component, even though both components have scoped styles.
🛠 2. Using the :deep() Pseudo-Class
Vue 3 introduced a new and more semantic way of applying deep styles using the :deep() pseudo-class. This is the recommended way moving forward.
Example:
<!-- ParentComponent.vue -->
<template>
<div class="parent-container">
<ChildComponent />
</div>
</template>
<script>
import ChildComponent from './ChildComponent.vue'
export default {
components: {
ChildComponent
}
}
</script>
<style scoped>
/* Scoped styles apply only to the parent */
.parent-container {
background-color: lightblue;
}
/* :deep() to apply styles to a child component */
:deep(.child-text) {
color: red;
}
</style>
With :deep(), you get the same result as using >>>, but the syntax is more future-proof and aligns with modern CSS practices.
🔍 Which Is Better: >>> or :deep()?
Vue 3 Compatibility:
In Vue 3, the:deep()pseudo-class is the preferred method and will likely become the standard. It’s more semantic and readable than the>>>operator, which may feel a bit hacky.Vue 2 Compatibility:
If you’re using Vue 2, you’ll need to stick with>>>, as:deep()is not supported in Vue 2 by default. However, withVue-loaderupdates,:deep()can also be used in Vue 2 if configured properly.
💡 Recommendation
- If you're working in Vue 3, it's best to use
:deep()as it’s more readable, modern, and future-compatible. - If you're using Vue 2, the deep selector (
>>>) is a reliable option. However, if your project will upgrade to Vue 3, start using:deep()to future-proof your styles.
🔧 Bonus: Combining :deep() with Inline Styles
You can also use :deep() for inline styles if necessary:
<style scoped>
/* :deep() with dynamic style binding */
:deep(.child-text) {
font-size: 20px;
color: v-bind('textColor'); /* Example of using Vue dynamic styling */
}
</style>
This ensures the child component gets the style, even when you bind data to the CSS dynamically!
🎯 Conclusion
Both >>> and :deep() selectors allow you to control the styles of child components while maintaining scoped styles. If you're using Vue 3, it's better to adopt the :deep() pseudo-class for a more modern, clean, and future-proof approach. However, >>> remains effective and reliable, especially in older Vue 2 projects.
Happy styling! 🎨
Top comments (2)
This is out of date. It is recommended to use
:deep(Thank you for pointing that out! 🙌 I’ve updated the documentation to reflect the latest recommendation of using
:deep()instead of the older>>>syntax. Your feedback helps keep the content accurate and up-to-date. If you have any more suggestions or questions, feel free to let me know! 😊