Friday, March 19, 2010

Drop Shadow With CSS For IE

One of the most common CSS effects is using shadows in various ways. Before, we needed to resort to images, but now we can offer this to all major web browser with CSS!

Web browser support

Believe me or not, but all of these web browsers we can offer shadows with CSS:
  • Firefox 3.5+
  • Safari 3+
  • Google Chrome
  • Opera 10.50
  • Internet Explorer 5.5

The standards way

As we all know, a majority of the web browsers implement features in a standardized way, while others don’t (although they are getting better at it). Previously, in the W3C specification CSS Backgrounds and Borders Module Level 3 box-shadow was described, although at the moment, it’s not in there for some things to be discussed further. Anyway, this is how the implementation looks:
1: .shadow {    
2:     box-shadow: 3px 3px 4px #000; 
3: }

The first value describes the x-offset (could be a negative value as well), the second the y-offset, the third the radius of the shadow and the fourth the color of it. Opera 10.50 (currently only available on Windows) is the first web browser to have an implementation without a vendor-prefix, whereas Firefox, Safari and Google Chrome all need it for now. So, this code makes it work in all those web browsers:
1: .shadow {
2:  -moz-box-shadow: 3px 3px 4px #000;
3:  -webkit-box-shadow: 3px 3px 4px #000;
4:  box-shadow: 3px 3px 4px #000;
5: }

What about Internet Explorer?

Luckily enough for us, there are a couple of filters we can use to make this work: The DropShadow filter and the Shadow filter. The problem with the DropShadow filter is that the shadow is solid, and not fluffy as desired, although it offers easy values for X and Y. The Shadow filter on the other hand offers a nice shadow, but instead of x and y offset, we need to specify direction and strength the set the length of the shadow.
So, this is how we make it work in Internet Explorer:
1: .shadow {
2:  /* For IE 8 */
3:  -ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=135, Color='#000000')";
4:  /* For IE 5.5 - 7 */
5:  filter: progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=135, Color='#000000');
6: }

The combined styles

This all the CSS for various web browser collected in one rule:

1: .shadow {
2:  -moz-box-shadow: 3px 3px 4px #000;
3:  -webkit-box-shadow: 3px 3px 4px #000;
4:  box-shadow: 3px 3px 4px #000;
5:  /* For IE 8 */
6:  -ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=135, Color='#000000')";
7:  /* For IE 5.5 - 7 */
8:  filter: progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=135, Color='#000000');
9: }

Honorable mention: CSS3 Please!

An easy way to automatically generate these styles and others, cross-browser, is available in the excellent service CSS3 Please! by Paul Irish and Jonathan Neal. Just enter your value, watch its rendering, copy the code and you’re good to go!
A little caveat is that they are currently using the DropShadow filter for IE, but I’m sure that will be updated soon.

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