A mobile compatible template IS in the works, however out of the box the default template for SMF is
NOT phone friendly.
Also, whoever keeps e-mailing me about it, it would help if you called yourself something other than "guest" and used an actual working e-mail instead of made up ones so I could interact with you on the topic.
For the time being, I would suggest the very stripped down WAP2 version of the site on smaller displays.
https://forums.cutcodedown.com/index.php?wap2It sucks since it was made for the age before smartphones were really a thing, but it works.