Inset Border-Radius with CSS3
In CSS3, achieving inset border-radius, where the corners are curved inward rather than outward, can be challenging without using images. However, there's a clever solution that utilizes CSS3 gradients.
Lea Verou's ingenious approach involves creating a series of transparent gradients with curves, creating the illusion of inset border-radius. By positioning these gradients precisely, you can achieve the desired rounded corners effect.
Her CSS code, as seen below, defines a custom class for an element with the desired inset border-radius:
div.round {
background:
-moz-radial-gradient(0 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
-moz-radial-gradient(100% 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
-moz-radial-gradient(100% 0, circle, rgba(204,0,0,0) 14px, #c00 15px),
-moz-radial-gradient(0 0, circle, rgba(204,0,0,0) 14px, #c00 15px);
background:
-o-radial-gradient(0 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
-o-radial-gradient(100% 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
-o-radial-gradient(100% 0, circle, rgba(204,0,0,0) 14px, #c00 15px),
-o-radial-gradient(0 0, circle, rgba(204,0,0,0) 14px, #c00 15px);
background:
-webkit-radial-gradient(0 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
-webkit-radial-gradient(100% 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
-webkit-radial-gradient(100% 0, circle, rgba(204,0,0,0) 14px, #c00 15px),
-webkit-radial-gradient(0 0, circle, rgba(204,0,0,0) 14px, #c00 15px);
background-position: bottom left, bottom right, top right, top left;
-moz-background-size: 50% 50%;
-webkit-background-size: 50% 50%;
background-size: 50% 50%;
background-repeat: no-repeat;
}
Applying this class to an element will result in an element with inset border-radius. It's important to note that this technique relies on support for rgba and gradients, making it a progressive enhancement strategy. For older browsers or browsers that don't support gradients, an image-based fallback is recommended for providing support.
The above is the detailed content of How Can I Create Inset Border-Radius Using Only CSS3?. 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
How can I include CSS only on some pages?
Jun 11, 2025 am 12:01 AM
There are three ways to selectively include CSS on a specific page: 1. Inline CSS, suitable for pages that are not frequently accessed or require unique styles; 2. Load external CSS files using JavaScript conditions, suitable for situations where flexibility is required; 3. Containment on the server side, suitable for scenarios using server-side languages. This approach can optimize website performance and maintainability, but requires balance of modularity and performance.
Flexbox vs Grid: Understanding the Key Differences in CSS Layout
Jun 10, 2025 am 12:03 AM
Flexboxisidealforone-dimensionallayouts,whileGridsuitstwo-dimensional,complexlayouts.UseFlexboxforaligningitemsinasingleaxisandGridforprecisecontroloverrowsandcolumnsinintricatedesigns.
Creating an Auto-Closing Notification With an HTML Popover
Jun 10, 2025 am 09:45 AM
The HTML popover attribute transforms elements into top-layer elements that can be opened and closed with a button or JavaScript. Popovers can be dismissed a number of ways, but there is no option to auto-close them. Preethi has a technique you can u
What is 'render-blocking CSS'?
Jun 24, 2025 am 12:42 AM
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.
How to use Lotties in Figma
Jun 14, 2025 am 10:17 AM
In the following tutorial, I will show you how to create Lottie animations in Figma. We'll use two colorful designs to exmplify how you can animate in Figma, and then I'll show you how to go from Figma to Lottie animations. All you need is a free Fig
Breaking Boundaries: Building a Tangram Puzzle With (S)CSS
Jun 13, 2025 am 11:33 AM
We put it to the test and it turns out Sass can replace JavaScript, at least when it comes to low-level logic and puzzle behavior. With nothing but maps, mixins, functions, and a whole lot of math, we managed to bring our Tangram puzzle to life, no J
External vs. Internal CSS: What's the Best Approach?
Jun 20, 2025 am 12:45 AM
ThebestapproachforCSSdependsontheproject'sspecificneeds.Forlargerprojects,externalCSSisbetterduetomaintainabilityandreusability;forsmallerprojectsorsingle-pageapplications,internalCSSmightbemoresuitable.It'scrucialtobalanceprojectsize,performanceneed
Does my CSS must be on lower case?
Jun 19, 2025 am 12:29 AM
No,CSSdoesnothavetobeinlowercase.However,usinglowercaseisrecommendedfor:1)Consistencyandreadability,2)Avoidingerrorsinrelatedtechnologies,3)Potentialperformancebenefits,and4)Improvedcollaborationwithinteams.
