Hi Bucky and the NewBoston team:
I've just finished the first 20 tutorials on HTML5 & CSS3. Thank you very much for your excellent work.
I have two problems so far about the coding.
My first problem is the browser - chrome - doesn't display the header "Welcome to the newboston!" in yellow background color. It only displays plain black text on white background color. The other effects that I have are the same like the tutorial.
I paste the codes of the first one below here and could you please check it for me. How could I make the header in "yellow"?
Thank you very much for your help.

html file:

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