Sleepy phone

My iPhone wouldn’t wake up.
I pressed the home key, but it didn’t respond.
It didn’t respond when I pressed the lock key, either.
When I plugged the phone in, it didn’t respond.
I panicked.
Is the Apple Store open? Is it still under warranty? How much will this cost?
So, I Googled “iphone doesn’t respond” on my laptop.
The Apple website told me to press and hold the home and lock keys at the same time for ten seconds.
And I did that.
The Apple logo appeared on the screen, and thirty seconds later, thankfully, the home screen appeared.