iPhone 7 Plus Won't Turn On? So I recently got a new iPhone 7 Plus a week ago. Tonight, I got onto this website which kept on putting up pop-ups on the page. I went to the lock screen, and it instantly froze. I couldn't even unlock the phone. Then, it went into a black screen with the loading icon. I tried to shut it off several times, but no use. I tried to connect it to iTunes via my MacBook Pro, but since the phone has a password, iTunes sent a verification text to my phone. Of course, I can't access anything in my phone now. There's literally nothing I can do with the phone. (The battery was at 70%, if that helps.)

Sorry for the long post, but what do I do? I'm very worried that it might've gotten hacked or something. Please help!
If a device seems like it's not responding to any input, often a hard reset, which is Sleep + Volume Down (for iPhone 7 and above; for iPhone 6s and below, use Sleep + Home) held until the Apple logo appears, is needed.

Powering off an iOS device isn't like powering off a computer. It doesn't reset everything, flush RAM, etc as a computer does when powered down. It's more akin to hibernation mode on a computer, as it's designed to come back on quickly. The hard reset is more like turning the computer off and back on - it dumps RAM and does any housekeeping that might be preventing the device from responding. It does NOT reset any data, preferences, apps, content, or so on.