


How Does Overflow Affect Sticky Positioning in CSS Positioned Layout Module Level 3?
Nov 17, 2024 pm 10:37 PMScrolling Boxes in CSS Positioned Layout Module Level 3
The CSS Positioned Layout Module Level 3 defines sticky positioning, which is similar to the behavior of a relatively positioned box. However, the offset is calculated with regard to the nearest ancestor with a scrolling box, or the viewport if no ancestor has a scrolling box.
What Qualifies as a Scrolling Box?
A scrolling box is a box where the value of overflow is set to a value other than visible (the default). This is based on previous documentation where issues with sticky elements arose due to overflow.
Effect of Overflow on Sticky Positioning
If an element with overflow: hidden is an ancestor of a position: sticky element, the latter's offset will be calculated based on the ancestor box with hidden overflow. As a result, scrolling behavior will be restricted, preventing the sticky element from being visible.
Code Example
.wrapper { height:200vh; border:2px solid; } .wrapper >div { position:sticky; top:0; height:20px; background:red; }
<div class="wrapper"> <div></div> </div>
The above is the detailed content of How Does Overflow Affect Sticky Positioning in CSS Positioned Layout Module Level 3?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

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

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

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

CSS blocks page rendering because browsers view inline and external CSS as key resources by default, especially with imported stylesheets, header large amounts of inline CSS, and unoptimized media query styles. 1. Extract critical CSS and embed it into HTML; 2. Delay loading non-critical CSS through JavaScript; 3. Use media attributes to optimize loading such as print styles; 4. Compress and merge CSS to reduce requests. It is recommended to use tools to extract key CSS, combine rel="preload" asynchronous loading, and use media delayed loading reasonably to avoid excessive splitting and complex script control.

ThebestapproachforCSSdependsontheproject'sspecificneeds.Forlargerprojects,externalCSSisbetterduetomaintainabilityandreusability;forsmallerprojectsorsingle-pageapplications,internalCSSmightbemoresuitable.It'scrucialtobalanceprojectsize,performanceneed

No,CSSdoesnothavetobeinlowercase.However,usinglowercaseisrecommendedfor:1)Consistencyandreadability,2)Avoidingerrorsinrelatedtechnologies,3)Potentialperformancebenefits,and4)Improvedcollaborationwithinteams.

CSSismostlycase-insensitive,butURLsandfontfamilynamesarecase-sensitive.1)Propertiesandvalueslikecolor:red;arenotcase-sensitive.2)URLsmustmatchtheserver'scase,e.g.,/images/Logo.png.3)Fontfamilynameslike'OpenSans'mustbeexact.

Autoprefixer is a tool that automatically adds vendor prefixes to CSS attributes based on the target browser scope. 1. It solves the problem of manually maintaining prefixes with errors; 2. Work through the PostCSS plug-in form, parse CSS, analyze attributes that need to be prefixed, and generate code according to configuration; 3. The usage steps include installing plug-ins, setting browserslist, and enabling them in the build process; 4. Notes include not manually adding prefixes, keeping configuration updates, prefixes not all attributes, and it is recommended to use them with the preprocessor.

CSScounterscanautomaticallynumbersectionsandlists.1)Usecounter-resettoinitialize,counter-incrementtoincrease,andcounter()orcounters()todisplayvalues.2)CombinewithJavaScriptfordynamiccontenttoensureaccurateupdates.

In CSS, selector and attribute names are case-sensitive, while values, named colors, URLs, and custom attributes are case-sensitive. 1. The selector and attribute names are case-insensitive, such as background-color and background-Color are the same. 2. The hexadecimal color in the value is case-sensitive, but the named color is case-sensitive, such as red and Red is invalid. 3. URLs are case sensitive and may cause file loading problems. 4. Custom properties (variables) are case sensitive, and you need to pay attention to the consistency of case when using them.

CSSselectorsandpropertynamesarecase-insensitive,whilevaluescanbecase-sensitivedependingoncontext.1)Selectorslike'div'and'DIV'areequivalent.2)Propertiessuchas'background-color'and'BACKGROUND-COLOR'aretreatedthesame.3)Valueslikecolornamesarecase-insens
