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CSS CSS Basics (2014) Understanding Values and Units Em and Rem Units

Tim Cope
Tim Cope
2,280 Points

Im having a hard time understanding EM and REM. I dont totally understand the ? or how to approach it

The original question is as follows:

The em-based font-size values for .title and h1 are relative to their parent header's font-size value. This causes a compounding issue that makes their font size values larger than the desired values.

Replace the em units of .title and h1 with a unit that is relative to the root element of the page.

/* Complete the challenge by writing CSS below */

header {
  font-size: 1.8em; /* 16Base or 28.8 */

.title {
  font-size: 1.625em;

h1 {
  font-size: 5.625em;
<!DOCTYPE html>
    <title>Lake Tahoe</title>
    <link rel="stylesheet" href="page.css">
    <link rel="stylesheet" href="style.css">
      <span class="title">Journey through the Sierra Nevada Mountains</span>
      <h1>Lake Tahoe, California</h1>
    <div class="main-content">
        Lake Tahoe is one of the most breathtaking attractions located in California. It's home to a number of ski resorts, summer outdoor recreation, and tourist attractions. Snow and skiing are a significant part of the area's reputation.
      <a href="#">Find out more</a>
      <h2>Check out all the Wildlife</h2>
        As spawning season approaches, the fish acquire a humpback and protuberant jaw. After spawning, they die and their carcasses provide a feast for gatherings of mink, bears, and Bald eagles.
      <a href="#">See the Wildlife</a>
      <h3>From Tents to Resorts</h3>
        Lake Tahoe is full of wonderful places to stay. You have the ability to sleep in the outdoors in a tent, or relax like a king at a five star resort. Here are our top three resorts:
      <p>All rights reserved to the state of <a href="#">California</a>.</p>
      <a href="#top">Back to top &raquo;</a>

2 Answers

Steven Parker
Steven Parker
225,652 Points

From the question itself, we know that "em-based font-size values ... are relative to their parent's font-size", so it seems logical that the "unit that is relative to the root element" must be rem. ("rem" actually stands for "root em").

:point_right: For task 1 of this challenge, just replace "em" with "rem" in the named elements.

Kyle Johnson
Kyle Johnson
33,528 Points

You can learn more about em and rem here: https://developer.mozilla.org/en-US/docs/Web/CSS/font-size#Ems

I recommend using this site for everything HTML, CSS, and JavaScript. You can google search what you need help with followed by the keyword mdn and the first result should be this site. (ex: font-size mdn)