I think someone last year forgot page numbers or to double space, something like that. I'm sure plenty of people do it, and I'm sure at the end of the day, it won't be the thing that dings you. Yes, small details matter, but I think Stanford can look past missing page numbers for an excellent candidate! Stay positive!
But yes, don't look at your application after it's submitted

I learned that lesson after submitting my first application and realized I had two periods after a sentence instead of one. Whatever!