This is a tricky question and the answer for your particular website may differ from that of another business.
The content, logo and other materials absolutely belong to you. You domain name belongs to you as long as you continue to keep it registered in your name through the registrar.
The arrangement and technique of code placement such as that used in styling and other features belong to me. The reason for this is because there are only so many ways to perform certain tasks when developing a website. Transferring ownership of the result of those techniques would, for a lack of a better explanation, be foolish.
You do, however, have a non-exclusive non-expiring right to any of these styles as provided to you by me.
Also, there will likely be third party assets such as WordPress, themes, stock photography and so on and so forth. While you will have rights to use those third party assets the ownership of them belongs to the originating party.
Your website will be unique among other websites that I have created or will create. There will be certain features of it that will guarantee its uniqueness. So, while technically you do now own “all” of it, it is yours to call your own.