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CSS CSS Foundations Values and Units Relative Length Units

Question about rem?

Select the link with the class more. Using the rem unit, set its font size back to the base font size of the root HTML element.

I have the following code

html { font-size: 100% }

.more a{ font-size: 1.0rem; }

I thought rem clears the previous css formatting and adjust the formating based on the highest attribute which in this case was html. By putting html at 100% i am asking to keep the fonts 100% of normal size. By putting the link font-size at 1.0 rem I thought i was telling CSS to match the normal font-size for the HTML. What I am I missing?

2 Answers

Dave McFarland
Dave McFarland
Treehouse Teacher

You don't need to set the HTML element's font-size to pass the challenge. Just leave that out. The main problem is your selector: .more a. This translates to "select an <a> tag inside another element with the class more. The challenge is asking you to select an <a> tag WITH the class more:

.more {
  font-size: 1rem;


a.more {
  font-size: 1rem;

Thanks for the input. It really helps. I just completed the challenge.

I think you have illuminated a bigger issue I was a bit confused on. When to use "a.more" versus "more a"

So if the HTML would have read:

<div class="more"> <a href="#top">Top Page</a> </div>

Then the following CSS would work

.more a{ font-size: 1rem; }

But because the HTML was:

<a class="more" href="#top"> Top Page</a>

The a.more{ font-size: 1 rem;} is used in these situations.