Custom Button is too small

I'm very new to the dashboard and try to create a custom button using a ui template with this code:

<button
	class="md-raised md-button md-ink-ripple" type="button"
	ng-transclude="" ng-click="send({payload:'play_mysonos',topic:'SRF 1'});"
	ng-style="{'background-color':me.item.getText(), 'color':me.item.getColor(), 'z-index':1, 'padding':'0px'}"
	style="z-index: 1; padding: 0px; background-image: url('http://cdn-radiotime-logos.tunein.com/s17465q.png');
		background-size: 90% 90%; background-repeat: no-repeat;background-position: center;">
</button>

Everything works well except of the fact, that the button is to small ! See this screenshot: Screenshot

Can somebody explain me the reason? Thank you!

Probably what affects the size is the outer div with class nr-dashboard-template

.nr-dashboard-template {
  padding: 3px 6px;
}

Try to override this and see if it helps

Thank you very much. That solved the problem!