CSS vertical centering method to organize_html/css_WEB-ITnose
Vertical centering is often used in CSS positioning, such as pop-ups on overlays.
Method with better compatibility:
<!DOCTYPE html PUBliC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><style type="text/css">#box{ width:200px; height:100px; text-align:center; position: absolute; left: 50%; top: 50%; margin-top: -50px; /* 高度的一半 */ margin-left: -100px; /* 宽度的一半 */ background-color:#ffff99;}</style></head><body><div id="box">Hello World!</div></body></html>This method is only applicable to blocks with known width and height, because negative margins need to be set to correct it.
If it is a block of unknown size, you can use the following method:
<!DOCTYPE html PUBliC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><style type="text/css">#box{ width:200px; height:100px; text-align:center; position: absolute; left: 0; top: 0; right:0; bottom:0; margin:auto; background-color:#ffff99;}</style></head><body><div id="box">Hello World!</div></body></html>The reason is that absolutely positioned layout depends on three factors, one is the position of the element, one is the size of the element, and one is the margin value of the element. Elements without set size and margin will adapt to the remaining space. If the position is fixed, the size will be assigned. If the size is fixed, margin will be assigned. All are adaptive.
IE7- has different rendering methods and different rendering rules. It will not allow positioning elements to adapt.
Now with CSS3, there are new tricks:
<!DOCTYPE html PUBliC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><style type="text/css">#box{ width:200px; height:100px; text-align:center; position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); background-color:#ffff99;}</style></head><body><div id="box">Hello World!</div></body></html>That is to use transform instead of margin. Translate offset in transform The percentage value is relative to its own size, which is similar to the first method.
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
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1386
52
What is the purpose of the <progress> element?
Mar 21, 2025 pm 12:34 PM
The article discusses the HTML <progress> element, its purpose, styling, and differences from the <meter> element. The main focus is on using <progress> for task completion and <meter> for stati
Is HTML easy to learn for beginners?
Apr 07, 2025 am 12:11 AM
HTML is suitable for beginners because it is simple and easy to learn and can quickly see results. 1) The learning curve of HTML is smooth and easy to get started. 2) Just master the basic tags to start creating web pages. 3) High flexibility and can be used in combination with CSS and JavaScript. 4) Rich learning resources and modern tools support the learning process.
What is the purpose of the <datalist> element?
Mar 21, 2025 pm 12:33 PM
The article discusses the HTML <datalist> element, which enhances forms by providing autocomplete suggestions, improving user experience and reducing errors.Character count: 159
What is the viewport meta tag? Why is it important for responsive design?
Mar 20, 2025 pm 05:56 PM
The article discusses the viewport meta tag, essential for responsive web design on mobile devices. It explains how proper use ensures optimal content scaling and user interaction, while misuse can lead to design and accessibility issues.
What is the purpose of the <iframe> tag? What are the security considerations when using it?
Mar 20, 2025 pm 06:05 PM
The article discusses the <iframe> tag's purpose in embedding external content into webpages, its common uses, security risks, and alternatives like object tags and APIs.
The Roles of HTML, CSS, and JavaScript: Core Responsibilities
Apr 08, 2025 pm 07:05 PM
HTML defines the web structure, CSS is responsible for style and layout, and JavaScript gives dynamic interaction. The three perform their duties in web development and jointly build a colorful website.
What is the purpose of the <meter> element?
Mar 21, 2025 pm 12:35 PM
The article discusses the HTML <meter> element, used for displaying scalar or fractional values within a range, and its common applications in web development. It differentiates <meter> from <progress> and ex
Understanding HTML, CSS, and JavaScript: A Beginner's Guide
Apr 12, 2025 am 12:02 AM
WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.
