Wow, this looks really professional! I love the design, I love how clean the UI is, I love how you can even edit the markdown using the mind map. Everything is really nicely made and intuitive. As a first time user, I wasn't sure what the 3 options on the top right slider did until I clicked them. I would add tool tips on the buttons in the slider saying something along the lines of "markdown", "split view", and "mindmap." If possible, I would add the ability to zoom out on the mind map using CTRL and the scroll wheel. Even the verification email was decorated nicely, that surprised me! I'm really curious what stack you're using for the project! I would love to hear more about it