I was thinking stuff like robotic dragons and little nano robots that let you act like you're doing magic, but do you have any ideas?
One of my favorite quotes is Clarke's third law, and fits in pretty well here:
Any sufficiently advanced technology is indistinguishable from magic.
If you've got nanobots in your blood igniting fire in your palm directed outward in such a way that you can just throw fireballs like a wizard… is it fantasy or is it sci-fi?
that depends on how hard you want your sci fi. do you want to bring psychic powers in? want kind of feel do you want, and what are your intentions?
I'm working on a similar project. I'm the GM for a tabletop game where I'm combining magic and technology to coexist. Thankfully, the game I'm using (Stars Without Number) has a system in place for psychic powers, so I decided to build upon that and add fantasy spells to the psychic powers. Precognition powers let you use Divination spells, Telekinesis powers let you use spells like fireballs and lightning storms, and so on, so forth. I think that however you decide to do it is fine, as long as the tech and fantasy fit together well. Tech Elementals, steam engine dragons, etc.
I'm kind of dealing with a similar thing when it comes to a sci-fi/futuristic but also kind of fantasy type story. Mine is based in a semi-dystopian futuristic world where mainly the government, the rich, and the sponsored have access to all this technology that commoners don't have. A group of underground scientists in this world create a humanoid weapon that they can research, and later mass produce in order to sell it to warring countries for a lot of money. The weapon has several abilities that stems from her psychic mind. So even though her powers seem kind of like magic at times, I made sure to list my reasonings for her abilities and even did a little research in different fields to see if I could tie some scientific elements in with it all to make it seem less like pure magic and fantasy and what not. Not sure if this helps at all, but good luck.