JavaScript - - By James Edwards

Creating Beveled Images with CSS

Recently, I wanted a simple CSS method for adding a beveled effect to images. It’s easy enough to create a sense of depth with normal outset borders (below left), but I was after an effect that would actually look like part of the image, as though it were a bevel on the image itself (below right).

Demo 2: The borders look like bevelling on the image itself.Demo 1: The image has gray outset borders around it.

In the end I found four different ways of doing it, each with different levels of support: from the cleanest approach that only worked in one browser, to the most robust that works in everything back to IE6.

All of them work on the same core principal; black borders for shade and white borders for highlighting are overlaid on top of an image, and then blended with some form of opacity. In each case, browsers without support for that technique will simply show the image as normal.

Technique 1: Using Generated Content on the Image (Demo)

  • Pros: Ultra-clean technique requires no additional markup
  • Cons: Only works in Opera

With this first technique we create a pseudo-element using :after, then style it to be perfectly overlaid on top of the image. Then we add borders to the overlaid element, and use RGBA to define each border color: the top and left borders are rgba(255,255,255,0.4), white with 40% opacity; and the bottom and right borders are rgba(0,0,0,0.4), black with 40% opacity:

img.beveled{    position:relative;}img.beveled:after{    position:absolute;    left:0;    top:0;    display:block;    content:"0a0";    box-sizing:border-box;    width:100%;    height:100%;    border:5px solid;    border-color:rgba(255,255,255,0.4)                 rgba(0,0,0,0.4)                 rgba(0,0,0,0.4)                 rgba(255,255,255,0.4);}
<img class="beveled" src="stormtroopers.jpg"     alt="A legion of Lego Stormtroopers, standing in formation." />

This technique only works in Opera because no other browser supports generated content on multimedia replacement elements like <img> and <object>. But since we’re only addressing Opera, we have the freedom to use box-sizing and 100% dimensions, rather than having to define the dimensions explicitly.(Note: the value of the content property in all these examples is a unicode non-breaking space. This is added because pseudo-elements have to contain something or they’re not rendered.)

Technique 2: Using Generated Content on a Wrapper Element (Demo)

  • Pros: Wider range of supported browsers
  • Cons: Requires additional markup and explicit dimensions

The second technique is essentially the same as the first, but this time we create the overlay element using generated content on a wrapper <span> for browsers that don’t support generated content on the <img> itself. For this technique we also need to begin defining explicit dimensions on the wrapper element and the generated content (although we could use vendor-specific versions of box-sizing on the generated content, we’d still have to define the dimensions of the wrapper, so we may as well do the same for both):

span.beveled{    position:relative;    width:200px;    height:200px;    display:block;}span.beveled:after{    position:absolute;    left:0;    top:0;    display:block;    content:"0a0";    width:190px;    height:190px;    border:5px solid;    border-color:rgba(255,255,255,0.4)                 rgba(0,0,0,0.4)                 rgba(0,0,0,0.4)                 rgba(255,255,255,0.4);}
<span class="beveled">    <img src="stormtroopers.jpg"         alt="A legion of Lego Stormtroopers, standing in formation." /></span>

Technique 3: Using Shadows instead of Borders (Demo)

  • Pros: The most visually attractive technique
  • Cons: Only works in Firefox 3.5 or later

The third technique is a diversion from the second, where instead of using RGBA borders we’re using -moz-box-shadow:inset to create the beveling effect. Since box shadow effects have an alpha gradient (rather than the same opacity at all points), the overall effect is much prettier and more rounded; and the spread radius parameter can be subtly used to blend away the corner sharpness.This effect is only supported in Firefox 3.5 or later; although Safari does implement box-shadow (as -webkit-box-shadow), there’s no support for inset:

span.beveled{    position:relative;    width:200px;    height:200px;    display:block;}span.beveled:after{    position:absolute;    left:0;    top:0;    display:block;    content:"0a0";    width:200px;    height:200px;    -moz-box-shadow:-5px -5px 2px rgba(0,0,0,0.4) inset,                    5px 5px 2px rgba(255,255,255,0.4) inset;}
<span class="beveled">    <img src="stormtroopers.jpg"         alt="A legion of Lego Stormtroopers, standing in formation." /></span>

I suppose we could have added a -webkit version anyway, in the hope of forward compatibility, but that would be a risk since we can’t know what any future implementation will be like — it might be worse than nothing!

Technique 4: Everybody’s Happy (Demo)

  • Pros: Works in all modern browsers
  • Cons: Requires more additional markup and explicit dimensions

The fourth and final technique is the most cross-browser compatible, but also requires the most HTML modification. It’s essentially the same as the second technique, but with two important differences: firstly, it uses a second physical <span> rather than generated content; and secondly, it uses ordinary hex border colors rather than RGBA, and then blends the whole element with opacity. Even Internet Explorer can handle this:

span.beveled{    position:relative;    width:200px;    height:200px;    display:block;}span.beveled span{    position:absolute;    left:0;    top:0;    display:block;    width:190px;    height:190px;    border:5px solid;    border-color:#fff #000 #000 #fff;    filter:alpha(opacity=40);    opacity:0.4;}
<span class="beveled">    <img src="stormtroopers.jpg"         alt="A legion of Lego Stormtroopers, standing in formation." />    <span></span></span>

Further Development

You could take this further by using colorful borders for a gel-like effect, or even multiple staggered overlays to create effects that are more subtle or intricate.But the basic idea is here, and I hope you find it useful. It’s certainly been great fun to play with!

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