It’s working now. Apparently I had somehow forgotten to install WordPress before installing the theme. I deleted everything and re-installed it in the proper order (WordPress first, theme later), and everything seems to be working fine now.
Thanks for your help!
I deleted the theme and reinstalled it. Now the WordPress bar format has gone all wonky, but the responsive menu seems to be working. Thanks for your help!
Yes. I also tried switching the template to Illyria (which is a child theme of Lawyeria), and the same thing happens.
Here: inplanta.com.
Interestingly, the responsive menu does work in the subdomain en.inplanta.com.