Calculator App in NodeJS & Material-UI

Hi, I developed this app using NextJS and Material-UI. I used themes and JSS/TSS for CSS. I got stuck on some issues when developing this. For the first two I found solutions. The last one is unsolved.

1. When implementing JSS/TSS I stumbled on this error: In order to get SSR working with tss-react you need to explicitly provide an Emotion cache. MUI users be aware: This is not an error strictly related to tss-react, with or without tss-react, MUI needs an Emotion cache to be provided for SSR to work. Here is the MUI documentation related to SSR setup: https://mui.com/material-ui/guides/server-rendering/ TSS provides helper that makes the process of setting up SSR easier: https://docs.tss-react.dev/ssr
2. When I serialized some synchronous methods on a string (e.g. split, join) and then applying an asynchronous filter on the resulted array, I was getting this error: Uncaught (in promise) Error: A listener indicated an asynchronous response by returning true, but the message channel closed before a response was received
3. I don’t know how to override some default behavior in MaterialUI theme classes (i.e. when clicking the div element, it blinks light blue. It should blink with a lighter palette color from the theme). Thank you!