@geoext/geoext/resources/css/gx-popup.css

GeoExt is Open Source and enables building desktop-like GIS applications through the web. It is a JavaScript framework that combines the GIS functionality of OpenLayers with the user interface savvy of the ExtJS library provided by Sencha.

.gx-popup {
    position: absolute;
    background-color: transparent;
    padding: 0 0 15px 0;
    bottom: 0;
    left: -50px;
    background-image: url(../../resources/images/anchor.png);
    background-repeat: no-repeat;
    background-position: 34px 100%;
}