Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

CSS CSS Basics Understanding Values and Units Em and Rem Units

Posted by Jessica Perry
Jessica Perry
1,417 Points

I want to make sure I'm understanding the math Correctly:

HTML 16px X Header 1.5em = 24pixels.right?so would be 1.5? Do i divide by the header? cause then i get 4.8 em.....@.@

style.css 
/* Complete the challenge by writing CSS below */

html {
  font-size: 16px;
}

header {
  font-size: 1.5em;
}

.heading {
  font-size: 5rem;
}
h2{
font-size:3em
}
h3{
font-size:5em
}
index.html 
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Developer Diane: Resume</title>
  <link rel="stylesheet" href="page.css">
  <link rel="stylesheet" href="style.css">
</head>
<body>
  <main>
    <header>
      <div id="header-box">
        <h1 class="heading">Developer Diane: Resume</h1>
        <address>
          <p>website: developerdiane.com</p>
          <p>email: diane@developerdiane.com</p>
        </address>
        <img src="developer-diane.jpg" alt="Developer Diane coding on her laptop.">
      </div>
    </header>          
    <section id="education">
      <h2>Education</h2>          
      <ul>
        <li>
          <h3><a href="https://teamtreehouse.com">Treehouse</a></h3>
          <p>Front End <em>Web Development</em> Techdegree</p>
          <p class="date special">Graduated January 2020</p>
        </li>
      </ul>
    </section>
    <section id="experience">
      <h2>Experience</h2>
      <ul>
        <li>
          <h3>Super Web Design Shop</h3>
          <p>Junior Developer</p>
          <p class="date special">February 2020-present</p>
        </li>
        <li>
          <h3>Pretty Good Websites, Inc.</h3>
          <p>Web Development Intern</p>
          <p class="date">July 2019-January 2020</p>
        </li>
      </ul>
    </section>
    <section>
      <h2>Skills</h2>
      <ul id="skills-list">
        <li class="top-skill">HTML</li>
        <li>CSS</li>
        <li class="top-skill" id="proud">JavaScript</li>
        <li>Git</li>
        <li>Bootstrap</li>
        <li class="top-skill">Mobile Web Development</li>
        <li>Accessibility</li>
      </ul>
    </section>
    <section>
      <h2>Awards and Achievements</h2>
      <ol>
        <li>Dev Ninja Award, November 2020</li>
        <li>Developer of the Month, October 2019</li>
        <li>Achieved rating of 6 kyu on <a href="https://www.codewars.com/">Codewars</a></li>
        <li>Certified Accessibility Specialist</li>
      </ol>
    </section>
    <footer>Ā©2020 Developer Diane.</footer>
  </main>
</body>
</html>

1 Answer

Ismael Liriano
Ismael Liriano
11,490 Points
Ismael Liriano
Ismael Liriano
11,490 Points

Hi! The header's font-size will be 24px. You don't have to divide anything. The difference between 'em' and 'rem' is that rem is relative to the main parent (in this case, the html element), and em takes into account every parent. For example, let's say the .heading class uses the em unit rather than the rem unit. The .heading's parent is the header element, and the header's parent ,in this case, is the html element, so the operations for .heading would be 16 x 1.5 x 5