<a:skin xmlns:a="http://ajax.org/2005/aml"><a:chart name="chart">
    <a:style><![CDATA[
    .chart {
        background-color:transparent;
    }
    ]]></a:style>

    <a:presentation>
        <a:main container=".">
            <div class="chart" style="position:relative; overflow:hidden;"/>
        </a:main>
    </a:presentation>
</a:chart></a:skin>