Learn common CSS selectors

To understand commonly used CSS selectors, you need specific code examples

CSS selectors are a way to select HTML elements. It allows us to match elements by Specific attributes, tag names, or other criteria to select elements to be styled. A deep understanding of commonly used CSS selectors is very important for writing efficient CSS style sheets and managing web page structure. Below are some commonly used CSS selectors and their specific code examples.

1. Element Selector:

The element selector is the most basic selector, selecting elements by tag name.

Code example:

p {
  color: red;
}

The above code will set the text color of all <p></p> elements to red.

2. Class Selector:

The class selector selects elements through their class attribute.

Code example:

.header {
  font-size: 20px;
}

The above code will set the font size of all elements with class "header" to 20 pixels.

3. ID Selector:

The ID selector selects elements through their id attribute.

Code example:

#container {
  width: 500px;
}

The above code will set the width of the element with id "container" to 500 pixels.

4. Descendant Selector:

The descendant selector selects elements through their hierarchical relationship.

Code example:

.container p {
  color: blue;
}

The above code will set the text color of all <p></p> elements inside elements with class "container" to blue.

5. Child Selector:

The child selector selects elements through their direct child element relationship.

Code example:

.container > p {
  font-weight: bold;
}

The above code will make the font bold of all <p></p> elements directly located inside elements with class "container".

6. Adjacent Sibling Selector:

The Adjacent Sibling Selector selects elements through their adjacent sibling relationship.

Code example:

h1 + p {
  margin-top: 10px;
}

The above code will add the top outer edge of the <p></p> element immediately following the <h1></h1> element Set the distance to 10 pixels.

7. Pseudo-class Selector:

Pseudo-class selector selects elements through the specific state of the element, such as mouse hover, specified position, etc. .

Code example:

a:hover {
  color: purple;
}

The above code will set the text color when the mouse is hovering over the link to purple.

8. Pseudo-element Selector:

The pseudo-element selector is used to select a specific part of the element, such as the first letter and the last letter of the element. child elements etc.

Code Example:

p::first-letter {
  font-size: 24px;
}

The above code will set the font size of the first letter of each <p></p> element to 24 pixels.

The above are some commonly used CSS selectors and their code examples. By understanding and flexibly using these selectors, we can more easily control the style and structure of web page elements. Hope this article is helpful to you!

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