One-time setup needed — this page reads live data from Google Analytics, which requires two IDs to be filled in at the top of the script in stats.html:
1. GA_PROPERTY_ID — GA4 numeric property ID (Analytics → Admin → Property settings).
2. OAUTH_CLIENT_ID — Google Cloud Console → APIs & Services → Credentials → Create OAuth client ID (Web application), with https://emmaruyiyang.github.io and http://localhost:8000 as authorized JavaScript origins. Also enable the Google Analytics Data API for the project.