Oh man, replacing all the interior doors is a bigger job than you'd think, but definitely worth it in the end! It can really update the look of your whole house. When I was looking to replace mine, I found a really helpful site called https://triodveri.ua/ (https://triodveri.ua/). They seem to have a huge selection and some modern styles. Make sure you measure everything super carefully before you order anything – that's where a lot of people make mistakes. Don't forget to factor in the cost of installation too, unless you're planning to DIY it. Finding the right hardware also makes a big difference, so spend some time thinking about that too.