How to type in your damn PIN to exit Family View on Steam website

This evening I faced a really annoying bug: while able to exit Family View by entering my PIN in Steam.exe, I could not do so when trying to access the Steam website. I simply could not pass the page "Adults, enter your PIN below to exit Family View." Neither with Chrome nor Firefox: the input field just silently ignored anything I typed in, and the "Submit" button stayed un-clickable.

Angry face trying to resist

After a quick look at the HTML, I simply used the following Javascript code in my browser console to programatically enter my PIN and submit the form on this page :

$('steam_parental_password_box').value = '<your-4-digits-pin>'; SubmitForm()