CSS style clearing style is a technology to clear the browser's default style. Since different browsers have different implementations of the default style of HTML elements, when developing web pages, you need to consider clearing the browser's default style, otherwise it will cause Inconsistency in web page styles affects user experience.
In order to solve this problem, developers generally use CSS style clearing technology to ensure the uniformity and standardization of web page styles. This article will introduce the basic concepts and implementation methods of CSS style clearing styles.
1. Inheritance of CSS styles
Before introducing CSS style clearing styles, we need to understand the inheritance of CSS styles. CSS styles can be set through selectors such as tags, classes, and IDs. At the same time, CSS styles are inheritable, and child elements can inherit the style attributes of parent elements.
For example, the following code snippet defines a div element with the class name .container, which contains a p element:
<div class="container">
<p>这是段落文本</p>
</div>We can set styles for the p element:
.container p {
font-size:16px;
color:#333;
line-height:1.5;
}This means that all p elements under the .container class will inherit the style of the parent element .container.
2. Clear browser default styles
By default, the browser will set some default CSS styles for HTML elements, and these styles may affect the layout and design of the page. For example, hyperlink elements have underlined and blue text colors by default, which may conflict with our custom styles.
To solve this problem, we need to clear the browser's default style. Normally, we need to clear the default style for each HTML element separately. The following are some common ways to clear the default styles of HTML elements:
1. Clear the default styles of all HTML elements
The following CSS code can clear the default styles of all HTML elements:
*{
margin:0;
padding:0;
border:0;
font-size:100%;
font:inherit;
vertical-align:baseline;
}Among them, * means selecting all HTML elements. This CSS style sets the margin, padding, and border of all elements to 0, the font size to 100%, the font to default inheritance, and the vertical alignment to baseline.
2. Clear hyperlink underline
Hyperlink elements have underline and blue text color by default. The following CSS code can clear hyperlink underlines and text colors:
a{
text-decoration:none;
color:#333;
}Among them, text-decoration:none; can eliminate hyperlink underlines, and color:#333; can set the text color to black or other colors.
3. Clear the list item default style
The list item elements (
ul,ol{
list-style:none;
margin:0;
padding:0;
}Among them, list-style:none; can eliminate the default style of list items, margin:0; and padding:0; can cancel the margin and padding of elements.
4. Clear the default style of form elements
Form elements (,