CSS is not software, but a language. css refers to cascading style sheets, which is a computer language used to express file styles such as HTML or XML; it is mainly used to design the style of web pages and beautify web pages. It can not only statically modify web pages, but also cooperate with various script languages Dynamically format various web page elements.
The operating environment of this tutorial: Windows 7 system, CSS3 version, Dell G3 computer.
CSS refers to Cascading Style Sheets (Cascading Style Sheets)
is a style used to represent HTML (Standard Common Markup Language) Application) or XML (a subset of Standard Universal Markup Language) or XML (a subset of Standard Generalized Markup Language) or other file styles
Styles are usually stored in style sheets
Styles are added to HTML 4.0 to solve the problem of separation of content and presentation
External style sheets can greatly improve work efficiency
External style sheets are usually stored in CSS files
Multiple style definitions can be cascaded as A
style provides pixel-precise control over the layout of element positions within a web page
CSS helps achieve responsible web design. CSS has a huge impact on how developers build Web sites, and the impact is likely to be endless. Moving most or even all of the presentation information of a web page out of (X)HTML files and keeping them in a style sheet has many advantages, such as reducing file size, saving network bandwidth, and ease of maintenance. In addition, the separation of the site's performance information and core content allows site designers to make various modifications to the entire site in a short period of time.
1. Rich style definitions
CSS provides rich document style appearance, as well as the ability to set text and background attributes. Ability; allows you to create a border for any element, as well as the distance between the element border and other elements, as well as the distance between the element border and the element content; allows you to change the capitalization, decoration, and other page effects of text at will.
2. Easy to use and modifyCSS can define the style in the style attribute of the HTML element, or in the header part of the HTML document, or you can declare the style in a Special CSS files for reference in HTML pages. In short, CSS style sheets can store and manage all style declarations in a unified manner.
In addition, elements of the same style can be classified and defined using the same style, you can also apply a certain style to all HTML tags with the same name, or you can assign a CSS style to a certain in page elements. If we want to modify the style, we only need to find the corresponding style statement in the style list and modify it.
3. Multi-page application
CSS style sheet can be stored in a separate CSS file, so that we can use the same CSS style sheet in multiple pages. Theoretically, CSS style sheets do not belong to any page file and can be referenced in any page file. In this way, the styles of multiple pages can be unified.
4. Cascading
Simply put, cascading is to set the same style multiple times on an element, which will use the last attribute value set. For example, if you use the same set of CSS style sheets for multiple pages in a site, and if you want to use other styles for some elements in some pages, you can define a separate style sheet for these styles and apply them to the page.
5. Page compression
In websites that use HTML to define page effects, a large number or repeated tables and font elements are often required to form text styles of various specifications. The consequence of this is that Generates a large number of HTML tags, thereby increasing the page file size.
(Learning video sharing:
css video tutorial)
The above is the detailed content of css what software. For more information, please follow other related articles on the PHP Chinese website!