Column Sizing - Where to find?

Hi - I’m quite new on Wappler and the latest version is my first I tried.
I have a question about the column sizing: Is there any posibility to change it in the Properties-Field or can I just edit it in CSS?
I found a tutorial from a older Wappler-version where you can see an extra “column sizing” option, but I can’t find it in the latest version…

Thanks in advance

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