A basic theme is mostly CSS though, so you can probably reuse many of your rules (though you will have to change the selectors to the ones Wordpress uses.)
Wordpress uses a custom HTML structure that is created by its PHP core. A theme has to be built on top of the existing "lattice". You won't find a converter since there is no standard for the lattice you happened to use.
One good way to start your design from scratch is to go for a theme generator. All it need to work with is your creativity. You will be able to produce your design from the very fist point without doing html/CSS coding.
http://templatetoaster.com/showcase/word...
Yes, you have to start over from scratch. If you want to change your style multiple times, you might want to try out ultimatewb. It has a styles manager and cms where you can modify/add styles very easily, and you won't have to start from scratch each time.
I have looked up tutorials on how to build WP custom themes from scratch, but I have not found one where you can set up your already finished website (HTML/CSS) on Wordpress theme. Is there a way where I can set up my HTML/css design on wordpress or do I have to start from scratch?
