Pseudo Classes CSS , Pseudo Elements, ::before and ::after in CSS | Web Development Course #31

Summary

In this video, Anuj introduces key concepts in web development, focusing on pseudo-classes and pseudo-elements. He explains how pseudo-classes define special states of elements, like hover or visited, and demonstrates their use with examples in HTML and CSS. Anuj also covers pseudo-elements, which allow styling specific parts of an element, such as the first letter or line. The tutorial includes practical demonstrations in VS Code, helping viewers understand how to effectively use these techniques in their web projects.

Takeaways

• 📘 Pseudo classes and pseudo elements are essential for adding special styles to elements in different states or selecting specific parts of an element.
• 🔗 Pseudo classes are used to style elements based on their state, such as ':hover', ':active', ':visited', and ':focus'.
• 🔑 The 'link' state is the default appearance of a link before it has been interacted with, and can be styled using pseudo classes.
• 🔴 The 'hover' state changes the style of an element when the user hovers over it with the cursor, allowing for interactive feedback.
• 🔄 The 'visited' state indicates that a user has clicked on a link before, and can be styled to reflect this interaction.
• 🎯 The 'active' state is used to style an element when it is being activated or clicked on by the user.
• 👶 The 'first-child' pseudo class is used to select and style the first child element within a parent.
• 👧 The 'last-child' pseudo class targets the last child element within a parent for specific styling.
• 🔢 The 'nth-child' pseudo class allows for styling elements based on their position in a sequence using a formula like 'an+b'.
• 📝 Pseudo elements like ':first-letter' and ':first-line' enable styling of specific parts of an element, such as the first letter or line of text.
• ✨ The '::before' and '::after' pseudo elements can be used to insert content before or after an element, without altering the HTML structure.

Q & A

What are pseudo-classes in CSS?

Pseudo-classes in CSS are used to define a special state of an element, such as when a user hovers over a link or clicks on a button. They allow you to apply styles to these different states without altering the actual HTML structure.

Can you give an example of a pseudo-class used on a link?

Yes, an example of a pseudo-class used on a link is `:hover`. When applied, it changes the appearance of the link when a user hovers over it. For instance, you can change the color of the link to red when hovered.

What is the difference between `:hover` and `:active` pseudo-classes?

`:hover` is used to style an element when the user hovers over it, whereas `:active` applies styles when the element is being clicked or activated by the user.

What is a visited pseudo-class, and how does it work?

The `:visited` pseudo-class targets links that have been clicked on and visited by the user. For example, a link might appear in a different color, like purple, after it has been visited.

How can you style the first child of a list using a pseudo-class?

You can style the first child of a list using the `:first-child` pseudo-class. For example, applying `ul li:first-child { background-color: violet; }` will change the background color of the first list item to violet.

What is the purpose of the `:nth-child()` pseudo-class?

The `:nth-child()` pseudo-class allows you to select one or more elements based on their position in a parent element. You can specify a formula like `2n+1` to select elements at specific intervals.

What are pseudo-elements in CSS, and how do they differ from pseudo-classes?

Pseudo-elements in CSS allow you to style specific parts of an element, such as the first letter or first line of a paragraph, while pseudo-classes style an element based on its state. Pseudo-elements use double colons (`::`) in their syntax.

Can you give an example of a pseudo-element?

An example of a pseudo-element is `::first-letter`, which targets and styles the first letter of a text block. For instance, you can make the first letter of a paragraph larger or change its color.

How do the `::before` and `::after` pseudo-elements work?

The `::before` and `::after` pseudo-elements allow you to insert content before or after an element's actual content. They are often used to add decorative elements, such as icons or labels, without adding extra HTML elements.

What is a practical use of the `::before` pseudo-element?

A practical use of the `::before` pseudo-element is to indicate required fields in a form. For example, you can add a red asterisk before the label of a required input field using `::before`.