Gravatar without <img> tag

dabblet.css

/**
 * Gravatar without <img> tag
 * 
 * @memo https://secure.gravatar.com/avatar/36d07341931078d5125fa99397a34ed8?s=140&d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-140.png
 * 
 * @todo make this doable with a javascript
 * @link http://darcyclarke.me/development/quick-tip-get-gravatar-images-from-emails-with-javascript/
 */

[data-gravatar-uri]::after
{
    content: url(attr(data-gravatar-uri)); /* impossible */
}

[data-email-md5]::after
{
    content: url("http://www.gravatar.com/avatar/" attr(data-email-md5) "?s=100"); /* more impossible */
}


[data-email-md5][data-gravatar-size]::after
{
    content: url("http://www.gravatar.com/avatar/" attr(data-email-md5) "?s=" attr(data-gravatar-size) ); /* more & more impossible */
}

dabblet.html

<div data-gravatar-uri="http://www.gravatar.com/avatar/36d07341931078d5125fa99397a34ed8?s=100"></div>

<div data-email-md5="36d07341931078d5125fa99397a34ed8"></div>

<div data-email-md5="36d07341931078d5125fa99397ddddda34ed8" data-gravatar-size="200"></div>

settings.json

{"view":"split","seethrough":"","prefixfree":"1","page":"html"}