title: Keeping content inside modal box
body: <p>I'm attempting to create a month calendar pop-up inside my app using a material UI Modal where you can select the day. I'm running into an issue where the modal does not fit the size of my calendar. how can I fix this? (Open calendar modal by clicking the date in top right between the two arrows) thank you! all code below.</p>
  <p><a href="https://codesandbox.io/s/unruffled-pine-owsxg1?file=/src/index.js" rel="nofollow noreferrer">https://codesandbox.io/s/unruffled-pine-owsxg1?file=/src/index.js</a></p>