Multistep form made with SolidJS and TailwindCSS

Hello! Alright, I think I chose this project a bit too quickly, I think it was a bit out of my league. But I could manage to come with something functional enough, maybe. I wanted to try SolidJS and practice some Tailwind.

I'm honestly not sure if my Solid code is good or bad practice, so any advice would be welcome! I had troubles trying to use the form validation example on the Solid docs (https://www.solidjs.com/examples/forms), I couldn't manage to make it work with my project, so I used solid-form-handler (https://solid-form-handler.com/docs/), which I'm very grateful for. I have to admit that I only used it on the first form, personal information. I didn't find the courage to do it on the other pages. I also met another issue with this: the first click on the Next step button of the Personal information form wasn't triggering any display of the "Invalid email" (for example) error, only the native one (which I didn't know how to remove), so I had to disable the Next step button. I also allowed myself to disable the last step button until the form isn't fully filled.

There is also something that I'm not proud of, it's the fact that the data is immediately stored in the store, even if you don't press the Next Step button (for example if you fill the first form and then you go to the "Select plan" form, even if you don't "save" your choice by clicking on Next step, it's still saved and you can directly go to the summary). I'm not sure whether that's a good thing or not, I actually don't think so, I think I know how to fix it but I'm being lazy.

Another issue, is that I couldn't find how to get the "tick" back on my checkboxes. They just turn purple, and I don't know how to fix this, if anyone knows I'd gladly take any lead.

And I'm sure there are some more things I forgot to tell you about, but that's it. I feel so excited to submit my very first FrontendMentor project solution! Again, any feedback would be appreciated! Thank you, and have a nice weekend!