How can you create a CSS3 gradient in Opera?

Question

I can create CSS gradients in IE6/7/8/9/FF3.6+ and Chrome (see below).

My question is:

How would one create a gradient in Opera?

.gradient{
        /*Mozilla Firefox 3.6*/
        background-image: -moz-linear-gradient(top, #dcdcdc, #c6c6c6);

        /*Webkit aka Google Chrome*/
        background-image: -webkit-gradient(linear,left bottom,left top,color-stop(0, #c6c6c6),color-stop(1, #dcdcdc));

        /*Internet Explorer 6,7 and 8*/
        filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#dcdcdc', endColorstr='#c6c6c6');

        /*Internet Explorer 8 only*/
        -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr='#dcdcdc', endColorstr='#c6c6c6')";

        /* Opera */
        /* ??? */
}

Answer 1

Opera 10.x supports SVG in background images, and SVG lets you do gradients in much the same way Firefox and Safari’s CSS extensions do.

Opera’s SVG background support seems to have some nasty bugs when your element also has borders in 10.0 and below, but as of 10.5 it seems reasonably solid (in my limited experience).

CSS

/* Opera */
background-image: url(gradient.svg);

gradient.svg

<svg xmlns="http://www.w3.org/2000/svg" version="1.0">
    <defs>
        <linearGradient id="gradient" x1="0" y1="0" x2="0" y2="100%">
            <stop offset="0%" style="stop-color: #c6c6c6;"/>
            <stop offset="100%" style="stop-color: #dcdcdc;"/>
        </linearGradient>
    </defs>

    <rect x="0" y="0" fill="url(#gradient)" width="100%" height="100%" />
</svg>

You can also include the SVG directly in the CSS file, using a data url, if you url encode the SVG. (In e.g. Python, you can do this by removing newlines and unnecessary spaces, and then passing the file’s contents to urllib.quote).

It’s a bit unreadable, but it saves an HTTP request, and if you’ve got more than one SVG gradient embedded in your CSS file, you should see some bandwidth savings over individual files (assuming your CSS file is gzipped).

/* Opera */
background-image: url(data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20version%3D%221.0%22%3E%3Cdefs%3E%3ClinearGradient%20id%3D%22gradient%22%20x1%3D%220%22%20y1%3D%220%22%20x2%3D%220%22%20y2%3D%22100%25%22%3E%3Cstop%20offset%3D%220%25%22%20style%3D%22stop-color%3A%20%23c6c6c6%3B%22/%3E%3Cstop%20offset%3D%22100%25%22%20style%3D%22stop-color%3A%20%23dcdcdc%3B%22/%3E%3C/linearGradient%3E%3C/defs%3E%3Crect%20x%3D%220%22%20y%3D%220%22%20fill%3D%22url%28%23gradient%29%22%20width%3D%22100%25%22%20height%3D%22100%25%22%20/%3E%3C/svg%3E);