Header sizes on computer vs. tablet vs. phone

Site URL: https://synthesizer-broccoli-5mar.squarespace.com/

Hi there,

I'm on SS 7.1 and am trying to have my site heading show up the same way on my tablet as it does on my computer (i.e., with links going horizontally across the page rather than under the hamburger). Right now the computer view looks good; the mobile phone view looks good; but the tablet looks basically the same as the mobile phone -- it has the hamburger (I changed it to say "Menu"), small logo (almost as small as on the phone view!), and cart. Worse, there is way too much space between the header and the banner photo. I don't understand why SS doesn't have site heading customization options for each of the three devices. Or does it, and I just can't find it? Please help, it's making me insane. Thanks!