How to inherit css

CSS (Cascading Style Sheets) is a language used for web design that allows us to change the appearance of text, the layout and overall style of the website. Among them, inheritance is an important feature of CSS, which allows child elements to inherit properties from parent elements. In this article, we’ll take a deep dive into the inheritance feature in CSS, including how to use it, as well as its pros, cons, and considerations.

1. Inheritance characteristics of CSS

In CSS, each element has its own unique style rules, which can be set through CSS selectors. However, for nested elements, some style rules from the parent element are inherited to the child elements. These style rules include fonts, colors, line heights, text alignment, list styles, etc. Inheritance in CSS follows the following rules:

1. Child elements will inherit the style of the parent element.

2. Inherited styles will be passed down the document hierarchy.

3. If an element has multiple parent elements, it will inherit the style from the nearest parent element.

4. Child elements can also modify inherited styles by overriding them.

For developers who use CSS, the characteristics of inherited styles can reduce the burden of writing styles. By defining some global style rules, we can avoid writing the same style code on every element. At the same time, it can also increase the flexibility and maintainability of styled code. If we need to globally modify a certain style in a web page, by modifying the global style rule, all elements that use the rule can be automatically modified.

2. How to use the inheritance feature of CSS

In CSS, you can use the following methods to take advantage of the inheritance feature.

1. Use global style rules

In CSS, we can use the "*" general selector to define global style rules. These rules apply to all elements throughout the document.

For example, we can use the following code to define the text color and font of all paragraph elements:

*{
    color: #333;
    font-family: Arial, Helvetica, sans-serif;
}

2. Using class and ID selectors

We can use the Add class or ID selectors to define style rules. These selectors can be applied to individual elements or to multiple elements.

For example, we can define the same font size and color for all heading elements as follows:

h1, h2, h3, h4, h5, h6{
    color: #333;
    font-size: 24px;
    font-weight: bold;
}

3. Use different CSS rules

We can use different CSS rules to define different properties of elements. For example, we can define a font color for the paragraph element, while defining different text alignments for individual paragraph elements:

p{
    color: #333;
}
.align-left{
    text-align: left;
}
.align-right{
    text-align: right;
}

In HTML, we can define a paragraph element and add a class selector on the element , to define text alignment:

<p class="align-left">这是一个左对齐的段落。</p>
<p class="align-right">这是一个右对齐的段落。</p>

3. Advantages, Disadvantages and Precautions of CSS Inheritance Features

Although the inheritance feature of CSS can allow developers to reduce the burden of writing styles, improper use can also cause Will bring some problems.

First of all, inheriting styles may reduce the performance of the website. In a web page, all style rules need to be calculated and applied to elements. If there are a large number of inherited style rules in a web page, it will increase the rendering time and burden of the web page. Furthermore, improper use of inheritance can make CSS less readable.

Secondly, when using inheritance features, be careful to avoid the problem of "style pollution". If an element inherits too many style rules, its style and layout may suffer. At this point, we should use the override function of style rules to correct the style of the element.

Finally, it should be noted that not all style rules can be inherited. For example, background images, borders, and positioning properties are not inherited by child elements. When writing styles, we need to use inheritance attributes carefully to ensure style correctness and compatibility.

To sum up, the inheritance feature of CSS is an important style feature that can help us reduce the burden of writing styles and improve the maintainability and readability of the code. But we need to use inheritance features carefully to avoid affecting the performance and usability of the website, and be careful about style pollution and non-inheritable style rules.

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