Hi @diegosomar ,
Yes, it certainly is! ??
Click on the Heading block and in the Style tab > Typography, you will see the setting Size. Next, click on the responsive toggle icon and select the Tablet or Mobile icon. From there, you can adjust the sizes accordingly.
Here’s a screenshot that can help: https://app.screencast.com/Ut3T2ZITlibrv
Alternatively, you may also set fixed responsive font sizes for the different Headings in Stackable’s Global Typography settings. For this, click on the Stackable logo on the top right of the Editor, then under Global Typography, select the Heading you want to edit. Again, click the responsive toggle icon next to Size and choose the device you want to edit: https://app.screencast.com/CkmEFzLwS9QxE
Please let us know if this helps! ??