I learned how to style components where one element defines the width of the whole component using 'max-content' and 'min-content'.
Articles – Page 107
I learned that there is more than pressing the UP arrow to works with the shell history. There are also handy little shorthands.
I learned that code that doesn't look valid can be valid... sometimes.
I learned that caniuse.com can be enriched with your very own Google Analytics data. This can help making the right decisions.