There was a bug that confused me a little bit, that is, there was a box-like symbol in front of the SPAN label. When I looked at the code I had written, there was no mistake in the text, but the box appeared inexplicably, and it was invisible on the Mac, only Windows could see it.
Here is the code on the Mac:
Then the window looks like this, with a symbol in front of it:
Do you know what this symbol is?
