actually, this is what I tried in the first place, but as this is rendered somehow within the component, I cannot find out which css definition does apply.
You can have a look at the site:
www.265.dic.at/
(go to "Kirchturmrenovierung / Referenzen" in the top menu):
The relevant HTML (rendered) is:
<div id="hotspots-categories-inner" style="width: 210px;">
<div id="hotspots-category-items">
<span id="cat1" class="hotspots-category-item hasTip " title="" data-id="1">
<img border="0" src="
www.265.dic.at/media/com_hotspots/images...R_turm-allgemein.png
" alt="Tooltip">
</span>
<span id="cat6" class="hotspots-category-item hasTip " title="" data-id="6">
<img border="0" src="
www.265.dic.at/media/com_hotspots/images...trich-unsichtbar.png
" alt="Tooltip">
</span>
<span id="cat5" class="hotspots-category-item hasTip " title="" data-id="5">
<img border="0" src="
www.265.dic.at/media/com_hotspots/images...6_R_turm-fassade.png
" alt="Tooltip">
</span>
<span id="cat2" class="hotspots-category-item hasTip " title="" data-id="2">
<img border="0" src="
www.265.dic.at/media/com_hotspots/images...9664_R_turm-helm.png
" alt="Tooltip">
</span>
<span id="cat3" class="hotspots-category-item hasTip " title="" data-id="3">
<img border="0" src="
www.265.dic.at/media/com_hotspots/images...1_R_turm-schmuck.png
" alt="Tooltip">
</span>
</div>
**********************************************
So in fact, the "title" of the category is not rendered in the relevant SPAN area, but comes from somewhere else...
and this is where I am stuck.