how to change font size of a specific widget text

hey there,
i just don t get it! ??

i m a beginner! i got my first actions with css and i ve changed a lot of (small) things on my page.
now i want to change the font size of the texts of two specific widgets on the “about us”-page.
with the siteOrigin page builder i ve put (from above):
– a text
– an image
– two colums with texts (CV) -> these i want to customize!
Take a look: https://www.korn-wiese.de/ueber-uns/

i ve been tryin “everything”:
– i tried it with the siteOrigin css but in the view mode i didn t manage to navigate to the two wigdets
– i tried to find the selector/id-name/or whatever of the widget texts
– i ve also installed the firefox firebug plug in

so i ve found this but

<div id="panel-278-1-0-0" class="so-panel widget widget_sow-editor panel-first-child panel-last-child" data-index="2">
<div class="panel-widget-style" style="font-size: 10px;">
<div class="so-widget-sow-editor so-widget-sow-editor-base">
<h3 class="widget-title">Simon Korn</h3>
<div class="siteorigin-widget-tinymce textwidget">

and i ve tried this in my css:
.panel-278-1-0-0 {font-size: 8px !important;}

can someone please help me with that? i d be too cool! ??