[html] How to make CSS3 rounded corners hide overflow in Chrome/Opera

I need round corners on a parent div to mask content from its childen. overflow: hidden works in simple situations, but breaks in webkit based browsers and Opera when the parent is positioned relatively or absolutely.

This works in Firefox and IE9:

CSS

#wrapper {
  width: 300px;
  height: 300px;
  border-radius: 100px;
  overflow: hidden;
  position: absolute;
}

#box {
  width: 300px;
  height: 300px;
  background-color: #cde;
}

HTML

<div id="wrapper">
  <div id="box"></div>
</div>

Example on JSFiddle

Thanks for the help!

UPDATE: The bug causing this issue has been since fixed in Chrome. I have not re-tested Opera or Safari however.

Seems this one works:

.wrap {
    -webkit-transform: translateZ(0);
    -webkit-mask-image: -webkit-radial-gradient(circle, white 100%, black 100%);
}

http://jsfiddle.net/qWdf6/82/

Supported in latest chrome, opera and safari, you can do this:

-webkit-clip-path: inset(0 0 0 0 round 100px);
clip-path: inset(0 0 0 0 round 100px);

You should definitely check out the tool http://bennettfeely.com/clippy/!

Not an answer, but this is a filed bug under the Chromium source: http://code.google.com/p/chromium/issues/detail?id=62363

Unfortunately, doesn't look like there's anyone working on it. :(

based on graycrow's excellent answer...

Here's a more real world example that has two cicular divs with some filler content. I replaced the hard-coded png background with just a hex value, i.e.

-=-webkit-mask-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAA5JREFUeNpiYGBgAAgwAAAEAAGbA+oJAAAAAElFTkSuQmCC);

is replaced with

-webkit-mask-image:#fff;

See this JSFiddle... http://jsfiddle.net/hqLkA/

opacity: 0.99; on wrapper solve webkit bug

As for me none of the solutions worked well, only using:

-webkit-mask-image: -webkit-radial-gradient(circle, white, black);

on the wrapper element did the job.

Here the example: http://jsfiddle.net/gpawlik/qWdf6/74/

Add a z-index to your border-radius'd item, and it will mask the things inside of it.

change the opacity of the parent element with the border and this will re organize the stacked elements. This worked miraculously for me after hours of research and failed attempts. It was as simple as adding an opacity of 0.99 to re organize this paint process of browsers. Check out http://philipwalton.com/articles/what-no-one-told-you-about-z-index/

Here look at how I done it; Jsfiddle

With the Code I put in, I managed to get it working on Webkit (Chrome/Safari) and Firefox. I don't know if it works with the latest version of Opera. Yes it does work under the latest version of Opera.

#wrapper {
  width: 300px; height: 300px;
  border-radius: 100px;
  overflow: hidden;
  position: absolute; /* this breaks the overflow:hidden in Chrome/Opera */
}

#box {
  width: 300px; height: 300px;
  background-color: #cde;
  border-radius: 100px;
  -webkit-border-radius: 100px;
  -moz-border-radius: 100px;
  -o-border-radius: 100px;
}

I found another solution for this problem. This looks like another bug in WebKit (or probably Chrome), but it works. All you need to do - is to add a WebKit CSS Mask to the #wrapper element. You can use a single pixel png image and even include it to the CSS to save a HTTP request.

#wrapper {
width: 300px; height: 300px;
border-radius: 100px;
overflow: hidden;
position: absolute; /* this breaks the overflow:hidden in Chrome/Opera */

/* this fixes the overflow:hidden in Chrome */
-webkit-mask-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAA5JREFUeNpiYGBgAAgwAAAEAAGbA+oJAAAAAElFTkSuQmCC);
}

#box {
width: 300px; height: 300px;
background-color: #cde;
}?

JSFiddle Example

If you are looking to create a mask for an image and position the image inside the container don't set the 'position: absolute' attribute. All you have to do is change the margin-left and margin-right. Chrome/Opera will adhere to the overflow: hidden and border-radius rules.

// Breaks in Chrome/Opera.
    .container {
        overflow: hidden;
        border-radius: 50%;
        img {
            position: absolute;
            left: 20px;
            right: 20px;
        }
    }

// Works in Chrome/Opera.
    .container {
        overflow: hidden;
        border-radius: 50%;
        img {
            margin-left: 20px;
            margin-right: 20px;
        }
    }