Tip calculator built in React

Hey, the responsiveness is not bad, I like it tbh! The visual end really isn't that bad and the functionality is perfect! The only thing I can help with is the HTML and Accessibility validations. You can't have two "main" tags, it should be one and you also can't have a main landmark within another landmark. That's the only problem, you could opt to use a div to replace the nested main landmark. This will pretty much fix everything. I like your HTML template too! I will use it too😎. Otherwise, I think your solution is really great, I appreciate the hard work! Kudos! Keep on coding!