Master the secrets and practical skills of CSS advanced selectors

Understand the secrets and application skills of CSS advanced selectors

CSS (Cascading Style Sheets) is a markup language used to describe page styles. It can control the style and layout of web page elements, so that the web page has a more beautiful and reasonable appearance. However, in actual applications, we often need to set different styles for different elements, which requires the use of CSS selectors.

CSS selectors refer to different ways to select and position elements in web pages to set their styles. In addition to basic selectors (such as tag selectors, class selectors, ID selectors), there are also some advanced selectors that can help us achieve more flexible and powerful style settings. So, how to correctly understand and apply CSS advanced selectors, let us explore the mysteries and techniques together!

1. Attribute selector

Attribute selector is used to select elements with specific attributes or attribute values. Its syntax is to write square brackets in the selector, and then specify the attribute or attribute value in the square brackets, for example:

[type="text"] {
background-color: pink;
}

The above code will select all elements whose type attribute value is "text" and set their background color to pink. Use attribute selectors to conveniently select and style a group of elements with the same attribute or attribute value.

2. Pseudo-class selector

Pseudo-class selector is used to select the special state or specific position of the element. Commonly used pseudo-classes include: hover, :focus and :first-child, etc. For example:

a:hover {
color: red;
}

The above code means that when the user hovers the mouse over the link, the text color of the link will change to red. Pseudo-class selectors can help us respond to user behavior and make web pages more interactive and friendly.

3. Pseudo-element selector

Pseudo-element selector is used to insert specific content at a specific position of the element and set its style. Commonly used pseudo-element selectors include ::before and ::after, etc. For example:

h1::before {
content: "Title:";
font-weight: bold;
}

The above code will be inserted before the h1 title Text "Title:" and style it to bold. Pseudo-element selectors allow us to insert additional content or decorations into web pages to improve the beauty and readability of the page.

4. Structural pseudo-class selector

The structural pseudo-class selector is used to select elements based on their position or relationship in their parent elements. Commonly used structural pseudo-class selectors include: first-child, :last-child and :nth-child(n), etc. For example:

li:nth-child(odd) {
background-color: #f2f2f2;
}

The above code will select all odd-numbered positions in its parent element li element and set its background color to light gray. Structural pseudo-class selectors can help us set regular styles for elements in web pages.

Summary:

CSS advanced selectors are powerful tools for achieving refined style settings. Proper use of them can improve the beauty and readability of web pages. Although sometimes the syntax, memory, and understanding are a bit complicated, as long as we understand their principles and master some common techniques, we can use these advanced selectors to easily meet various style needs.

Of course, this article is just a brief introduction to CSS advanced selectors. In fact, CSS selectors are widely used, and there are more diverse selectors waiting for us to explore and use. If you are more interested in a certain selector, you can further consult relevant information to learn more so that it can be better applied in actual development.

In short, as long as we have a sufficient understanding of CSS selectors and are good at applying its advanced selectors, we can easily implement complex web page style settings and make our web pages even better!

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