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Apparently /templates/rt_quasar_j15/css/template.css overrides /templates/rt_quasar_j15/css/style2.cs. This override doesn't seem to be documented....
So I just changed the #rt-logo params in that file, and changed the float param (below) to 'left'
LINE NUMBER ON/OFF | EXPAND/CONTRACT | SELECT ALL
#rt-header ul {margin: 0;padding: 0;float: left;position: relative;z-index: 1000;}