CSS code to change site title font size

I need the CSS code that will make my WordPress site title a lot smaller. It's on the left top of every page, and on desktops, it covers over important parts of my menus. I DO NOT know much about CSS, so I won't be able to make any changes to the code later on. I'll preserve it in a text file and add it again manually if I have to change themes. I do know how to paste code into the "Additional CSS" field in the "Customizer". This project is to give me the code that will allow me to control the size of the Site Title using a snippet of code that I can paste into "additional CSS" fieldm, under "Customizing" in word press. This code did NOT work: #site-title { font-size: 3rem; } It may be that you will only have to make a small change to the code above. That's fine. It may call for a completely different code. I need to be able to make changes to my site (like a new theme, for example) wihout having to create anotehr project here. Send me the code via the Freelancer messaging system, and I'll test it ASAP. Sorry, I'm not allowed to let others log in. One alternative solution may be to suppress the site title for all pages. There don't seem to be any plugins that do that, except Yoast, but I will lose my SEO throughout the site if I do that.