css code meaning

CSS code is a language used for web design and layout that controls the style and visual presentation of HTML documents. The full name of CSS is Cascading Style Sheets, which is used to describe the layout, fonts, colors, backgrounds, borders and other appearance features of web pages.

CSS code consists of selectors and declaration blocks. Selectors are used to specify which HTML elements should be styled, while declaration blocks contain a series of CSS properties and values ​​that define the style of the element.

For example, the following CSS code will change the font color of all paragraph elements to red:

p {
    color: red;
}

In this code snippet, p is the selector, which means to apply the style for all paragraph elements. color is the attribute, red is the attribute value, used to specify the color.

In addition to applying styles to an element individually, CSS also supports nested selectors, which can select sub-elements within an element for style setting, for example:

ul li {
    font-size: 14px;
}

In this code snippet , ul li is a nested selector, which means that the style is applied to all li elements within the ul element. font-size is the attribute, 14px is the attribute value.

CSS also supports the use of class selectors and ID selectors. The class selector starts with a period and is used to select a specific class in the HTML element, for example:

.button {
    background-color: blue;
    color: white;
}

In this code snippet, .button is a class selector, which means to apply the style to All HTML elements whose class attribute is button. background-color and color are attributes, blue and white are attribute values.

The ID selector starts with a pound sign and is used to select a specific id in the HTML document, for example:

#header {
    border-bottom: 1px solid gray;
}

In this code snippet, #header is the ID selection Device, indicating that the style is applied to the HTML element with id being header. border-bottom is the attribute, 1px solid gray is the attribute value.

In general, CSS code is a powerful web design tool that allows developers to control the style of various elements in a web page and create beautiful web page layouts.

The above is the detailed content of css code meaning. For more information, please follow other related articles on the PHP Chinese website!