This time I will bring you common CSS styles. What are the precautions for using common CSS styles? Here are practical cases, let’s take a look.
What does CSS Sprite (Sprite) refer to? What is its function
CSS Sprite is CSS Sprite, some people also call it CSS Sprite. It is a CSS image merging technology. The method is Merge the small icon and background image into one image, and then use CSS background positioning to display the part of the image that needs to be displayed.
What are the differences in usage scenarios between img tags and CSS background images?
img is used as an html tag, and the images used by img are generally used as content.
The CSS background image is generally used for decoration.
In a more detailed direction, during the loading process of the web page, the images that exist as css background images will not start loading until the structure is loaded (after all the content of the web page is displayed), and the img tag in html is the web page structure. Part of (the content) is loaded during the loading of the structure. The image is used as the background. When the image is not loaded or fails to load, there will be no placeholder mark for the image and no red cross will appear.
What are the functions of title and alt attributes?
The title attribute specifies additional information about the element. This information usually displays a ToolTip text when the mouse is moved over the element. The alt attribute specifies alternative text when the image cannot be displayed.
background:url(abc.png) 0 0 no-repeat;What does this sentence mean?
This sentence is the abbreviation of background, and url represents background- imageInsert the address of the background image. 0 0 represents the value of background-position, which indicates the positioning of the background image. The two before and after are horizontal positioning and vertical positioning respectively. The upper left corner is 0 0, and no-repeat represents the value of background-repeat. Available values are repeat, no-repeat, repeat-x, repeat-y, and inherit. Indicates respectively horizontal and vertical repetition, no repetition, only horizontal repetition, only vertical repetition, and inheritance from parent elements.
background-sizeWhat is the function? How is the compatibility? Commonly used values are?
background-size compatibility
Commonly used values are auto |length|cover|contain|initial|inherit;
How to center a div horizontally? How to center the picture horizontally
Center the div horizontally:
1. Margin method: by setting the margin on the div, margin: 0 auto;
2. display: inline-block method: parent element Set text-align:center. You need to set display:inline-block on the div in the play.
3. Floating method: For div and its parent element, float:left, relative positioning, parent element left50%, div right 50%.
Horizontally center the image: Put the image into a block-level element, using the above method.
How to set an element to be transparent? Compatibility?
You can set the speech rate transparency through rgba and opcity. For browsers of ie8 and worse versions, you need to add filter:alpha(opacity=x).
opacity and rgba can be set to be transparent, what is the difference?
opacity will inherit the opacity attribute of the parent element, while the descendant elements of the element set by RGBA will not inherit the opacity attribute.
<html> <head> <meta charset="UTF-8"> <title>Document</title> <style type="text/css"> .rgba,.opacity{ margin:0 auto; width:200px; height: 200px; text-align: center; line-height: 200px; font-size: 20px; border:1px solid black; } .rgba{ background: rgba(255,0,0,0.5); } .opacity{ background: red; opacity: 0.5; } </style> </head> <body> <div class="rgba"> 这是RGBA不透明度 </div> <div class="opacity"> 这是opacity不透明度 </div> </body> </html>
, it can be proved that opacity can inherit the attributes of the parent element. In addition, opacity can also set the transparency of the image.
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!
Related reading:
Time objects and reference types in JS
Use the simplest front-end technology to create a simple music player
The above is the detailed content of CSS common styles. For more information, please follow other related articles on the PHP Chinese website!

The function of HTML is to define the structure and content of a web page, and its purpose is to provide a standardized way to display information. 1) HTML organizes various parts of the web page through tags and attributes, such as titles and paragraphs. 2) It supports the separation of content and performance and improves maintenance efficiency. 3) HTML is extensible, allowing custom tags to enhance SEO.

The future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.

The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

The roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.

HTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.

HTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

HTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Atom editor mac version download
The most popular open source editor

SublimeText3 Linux new version
SublimeText3 Linux latest version

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

Zend Studio 13.0.1
Powerful PHP integrated development environment

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.