a.sm2_button {
 position:relative;
 display:inline-block; /* If you worry old browser bugs, Firefox 2 might not like this and may need -moz-inline-box instead. :D */
 width:18px;
 height:16px;
 text-indent:-9999px; /* don't show link text */
 overflow:hidden; /* don't draw inner link text */
 vertical-align:middle;
 /* and, a bit of round-ness for the cool browsers. */
 -moz-border-radius:6px;
 -webkit-border-radius:6px;
 -opera-border-radius:6px;
 border-radius:6px;
 margin-top:-1px; /* vertical align tweak */
 /* safari 3.1+ fun (/W3 working draft extension, TBD.) */
 -webkit-transition-property: hover;
 -webkit-transition: background-color 0.15s ease-in-out;
}

a.sm2_button:focus {
 outline:none; /* maybe evil, but don't show the slight border outline on focus. */
}

a.sm2_button,
a.sm2_button.sm2_paused:hover {
 background-color:#fff;
 background-image:url(/static/arrow-right-black.png);
 /* where possible, use data: and skip the HTTP request. Fancy-pants. Would use short-hand background: for above, but IE 8 doesn't override background-image. */
/* background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAKCAYAAABmBXS+AAAAbklEQVQY02NgQAL//v1jZMAF/v//vwuIs9HEUBUBTbj4HwIeA3EGVsVAxtn/qOAVUGM8uknIiv4hsV8A5ZKxKfoLVvnvHwifAzLtMKwDSQLBVSBti27dJajkcSD2RJODO3wtkOOMz/tMSJJYAxMA5dmsL0IfubQAAAAASUVORK5CYII=); */
 *background-image:url(/static/arrow-right-black.gif); /* IE 6+7 don't do DATA: URIs */
 background-repeat:no-repeat;
 background-position:5px 50%;
}

a.sm2_button:hover,
a.sm2_button.sm2_playing,
a.sm2_button.sm2_playing:hover {
 background-color:#00ffff;
}

a.sm2_button.sm2_paused,
a.sm2_button.sm2_paused:hover {
 background-color:#ccc;
}