Prevent page rotation

I think this is a new topic…

Landscape views on iPhones and iPads can look horrible, so I’ve been looking for a means of ‘locking’ orientation to portrait mode.

I found this, but I don’t understand coding… does it make sense to people who do?

(I tried the meta example by pasting into the header but in Solis nothing changed - and I’ve no idea how to use the second CSS suggestion.)