How to use css in html

HTML and CSS are the two core technologies of modern web design. HTML is used to create the content of web pages, while CSS is used for style and layout. In this article, we will learn how to apply CSS to HTML pages so that you can start adding a beautiful and personalized touch to your website.

1. Introduce CSS files

The first step in using CSS in HTML pages is to introduce CSS files into your HTML files. This can be achieved by adding a link element to the HTML header. This element needs to point to the location of your CSS file, like this:

<link rel="stylesheet" type="text/css" href="style.css">

2. Applying CSS to HTML Elements

Once your CSS file is properly brought in Within your HTML page, you can start applying CSS styles to your HTML elements. You can use a variety of selectors to select elements and then apply style attributes to them, for example:

h1 {
  color: red;
  text-align: center;
  font-size: 36px;
}

This CSS style selector applies to all h1 elements on the page. It changes the element's text color to red, centers the text, and changes the element's font size.

3. Nested Styles

You can add styles to any element by nesting the style declaration of one element within the style declaration of another element. For example, you can italicize all the emphasized text in a paragraph and change their color to blue:

p em {
  font-style: italic;
  color: blue;
}

Now, all in the <p> tag The text in the <em> tags will appear in italics and will be blue.

4. Category Selector

The category selector is a selector that can be used to style multiple elements of the same type. With a class-named CSS style selector, you can apply the same style to all elements in a category. Here is an example of a category selector:

.blue-text {
  color: blue;
}

This style selector defines a class called "blue-text". To apply this type of style, you just need to grant this class to the required element:

<p class="blue-text">这段文字会变成蓝色的。</p>

Note: By using the class attribute, you can set multiple different classes in the same page, and Assign them to different HTML elements when needed. You can even combine multiple classes together to set more complex styles, so be sure to use them well.

5. Other selectors

CSS has many other selectors, including ID selectors, descendant selectors, child selectors, pseudo-class selectors, etc. These selectors are useful when you need to style a specific element. The following is an introduction to other selectors:

• ID selector: By defining an ID, you can style a specific element on the page.
• Descendant selector: used to select descendant elements of the specified element.
• Child selector: Similar to the descendant selector, but it only selects direct child elements.
• Pseudo-class selector: used to select elements in a specific state, such as hover, access or selected states.

6. CSS Box Model

The CSS box model is a basic concept for laying out and positioning web page elements. This model describes the box around an HTML element, which includes different parts such as content area, padding, borders, and margins.

You can precisely control the layout of HTML elements by setting the size and position of each box. The following are several common properties in the CSS box model:

• box-sizing: Set the box model of the element.
• width: Set the width of the element.
• height: Set the height of the element.
• margin: Set the margin of the element.
• padding: Set the padding of the element.
• border: Set the border of the element.

You can use these properties to position and adjust various elements on your web page to achieve the desired style and layout.

Summary

In this article, we have introduced how to style HTML elements using CSS. You can use CSS by creating a CSS file and linking it to an HTML page. You can then use selectors to apply different styles to each element. You can also use the CSS box model to lay out and control elements on the page. Mastering these skills will allow you to create web pages that you can be proud of with a beautiful and personalized website design.

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