css style sheet refers to Cascading Style Sheets (CSS), a computer language used to express file styles such as HTML or XML, and a programming language used to express HTML styles. Language is a style language that can separate web pages and content.
The operating environment of this tutorial: Windows 7 system, CSS3 version, Dell G3 computer.
css style sheet generally refers to CSS (cascading style sheet).
Cascading Style Sheets (English full name: Cascading Style Sheets) are files used to express HTML (an application of Standard Generalized Markup Language) or XML (a subset of Standard Generalized Markup Language). The computer language of styles is a programming language used to express HTML styles. It is a style language that can separate web pages and content.
CSS is mainly used to design the style of web pages and beautify web pages; it can not only statically modify web pages, but also dynamically format various elements of web pages in conjunction with various scripting languages.
CSS can perform pixel-level precise control over the layout of element positions in web pages, supports almost all font size styles, and has the ability to edit web page objects and model styles.
Composition of css
css definition consists of three parts: selector, attribute, attribute value
選擇符{屬性:屬性值;}
1. Selector: also known as Selectors, all tags in HTML language are controlled through different css selectors.
2. Attributes: mainly include font attributes, text attributes, background attributes, layout attributes, border attributes, list item attributes, table attributes, etc. Some of these attributes are only supported by some browsers, which makes the use of CSS attributes more complicated
3. Attribute value: is the valid value of a certain attribute. Attributes and attribute values ??are separated by ":" semicolons. When there are multiple attributes, use ";" to separate them.
Note: h2 is the selector; font-family is the attribute; "宋體" is the attribute value
css selector
Commonly used ones include tag selector, category selector, id selector, etc.
1) Tag selector (also called element selector, type selector)
what: HTML page is composed of many tags, such as image tag , hyperlink tag , table tag
, etc. The css tag selector declares which tags on the page adopt css styles.
Example:
<style>
a{
font-size:9px;
color:#F93;
}
<style>
2) Category selector
Format: Dot (.) Category name
There are limitations to using tag selectors. If you declare a tag selector, all content of that tag in the page will change. Suppose there are 3
tags on the page. If you want each
to display differently, you can use the category tagger.
The HTML tag of the category selector only needs to be declared using the class attribute.
In HTML tags, you can apply multiple category selectors, which allows HTML to load the styles of multiple category selectors at the same time. Use spaces to separate multiple category selectors, for example:
.
3) id selector
The id selector selects and adds styles through the id attribute in the HTML page, which is basically the same as the category selector.
Format: "#" id attribute value
The named id selector should start with "#", followed by the "#" in the HTML tag id attribute value.
For more programming related knowledge, please visit: Programming Video! !
The above is the detailed content of what is css style sheet. For more information, please follow other related articles on the PHP Chinese website!
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Choosing the correct display value in CSS is crucial because it controls the behavior of elements in the layout. 1.inline: Make elements flow like text, without occupying a single line, and cannot directly set width and height, suitable for elements in text, such as; 2.block: Make elements exclusively occupy one line and occupy all width, can set width and height and inner and outer margins, suitable for structured elements, such as; 3.inline-block: has both block characteristics and inline layout, can set size but still display in the same line, suitable for horizontal layouts that require consistent spacing; 4.flex: Modern layout mode, suitable for containers, easy to achieve alignment and distribution through justify-content, align-items and other attributes, yes
CSSHoudini is a set of APIs that allow developers to directly manipulate and extend the browser's style processing flow through JavaScript. 1. PaintWorklet controls element drawing; 2. LayoutWorklet custom layout logic; 3. AnimationWorklet implements high-performance animation; 4. Parser&TypedOM efficiently operates CSS properties; 5. Properties&ValuesAPI registers custom properties; 6. FontMetricsAPI obtains font information. It allows developers to expand CSS in unprecedented ways, achieve effects such as wave backgrounds, and have good performance and flexibility
In Vue, provide and inject are features for directly passing data across hierarchical components. The parent component provides data or methods through provide, and descendant components directly inject and use these data or methods through inject, without passing props layer by layer; 2. It is suitable for avoiding "propdrilling", such as passing global or shared data such as topics, user status, API services, etc.; 3. Note when using: non-responsive original values ??must be wrapped into responsive objects to achieve responsive updates, and should not be abused to avoid affecting maintainability.
