Is it possible to replace the hinges despite the laptop's current situation? I plan on buying new hinges when I can...

Try an External Monitor to check that at least the Laptop is POSTING. Try the VGA Port, if nothing shows up, try to switch the output to the external monitor using the keyboard key. Let’s just hope that the screen is dead no damage to the Internal Motherboard. :)

Sorry Sophie, about what you have said but, the battery might have short circuited due to being in the water (even under Apple's recommendations) and then not have enough “peak" power to the motherboard. Always don't purposely take your iPhone X to a dip in the pool. Even though Apple says the iPhone X can hold up 30 minutes underwater for 1 meter (3ft.) Apple did this because if you accidentally dropped your iPhone X in the pool the iPhone X would most likely survive. I hope you understand that you should get your iPhone X serviced by Apple itself or an Authorized Apple Officials like iCracked. DO NOT ATTEMPT TO FIX THE IPHONE X YOURSELF. Thank You, Prajwal Rajashekar