Use the html5 doctype
March 11, 2019 · View on GitHub
Be sure that you have specified the html5 doctype (Document Type Definition - DTD) for your html page:
<!DOCTYPE html>
A doctype impacts browser layout and measurement apis. Not specifying a doctype is a world of pain 🔥. Browsers will use some other doctype such as "Quirks mode" which can drastically change layout and measurement (more information). The html5 doctype is our only supported doctype.
For non production builds we will log a warning to the console if a html5 doctype is not found. You can disable the warning if you like.