title: why does my my css styling not applied to the html elements
body: <p>I copied a html code from codepen. When i run the code, it runs fine except that some of the css styling is not applied.When i inspect elements, i notice that some css stylings are crossed ( have a horizontal on them) . when i hover over it, it says &quot;invalid property value&quot;.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>html {
    box-sizing: border-box;
  }
  *, *:before, *:after {
    box-sizing: inherit;
  }
  
  body {
    font-family: 'Roboto', Arial, sans-serif;
    font-size: 18px;
    font-weight: 300;
    line-height: 1.6;
  }
  
  a {
    text-decoration: none;
    color: #212121;
  
    &amp;:visited {
      color: #212121;
    }
  }
  
  h1, h2 {
    font-family: 'Montserrat', Arial, sans-serif;
    font-weight: bold;
  }
  
  h1 {
    font-size: 38px;
    margin-bottom: 40px;
  }
  
  h2 {
    font-size: 22px;
    margin-bottom: 10px;
  }
  
  img {
    max-width: 100%;
  }
  
  .text-center {
    text-align: center;
  }
  
  .container {
    max-width: 1200px;
    margin: auto;
  }
  header {
    background: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/195612/cssgrid_triangles.svg');
    background-size: cover;
    color: white;
  
    .top-nav {
      display: flex;
      justify-content: space-between;
      padding: 40px 0;
      
    }
  }
  .button {
    border: 1px solid #212121;
    padding: 12px 40px;
  
    &amp;:hover {
      color: #e9e9e9;
      background: #212121;
    }
  }
  
  .button-white {
    border: 1px solid #e9e9e9;
    color: #e9e9e9 !important;
  
    &amp;:hover {
      color: #212121 !important;
      background: #e9e9e9;
    }
  }
  
  .section-description {
    width: 80%;
    margin: auto;
  }
  
  .button-container {
    margin: 80px 0;
  }
  
  
  
  .hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-gap: 30px;
    padding-top: 20px;
    padding-bottom: 84px;
  
    .hero-image {
      padding-left: 60px;
    }
  
    h1 {
      font-size: 52px;
      margin-top: 50px;
    }
  
    p {
      margin: 40px 0 68px;
    }
  
    .button {
      margin-right: 14px;
    }
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;header&gt;
      &lt;div class="top-nav container"&gt;
          &lt;div class="logo"&gt;CSS Grid Example&lt;/div&gt;
          &lt;ul&gt;
              &lt;li&gt;&lt;a href="#"&gt;Shop&lt;/a&gt;&lt;/li&gt;
              &lt;li&gt;&lt;a href="#"&gt;About&lt;/a&gt;&lt;/li&gt;
              &lt;li&gt;&lt;a href="#"&gt;Blog&lt;/a&gt;&lt;/li&gt;
              &lt;li&gt;&lt;a href="#"&gt;Cart&lt;/a&gt;&lt;/li&gt;
          &lt;/ul&gt;
      &lt;/div&gt; &lt;!-- end top-nav --&gt;
  
      &lt;div class="hero container"&gt;
          &lt;div class="hero-copy"&gt;
              &lt;h1&gt;CSS Grid Example&lt;/h1&gt;
              &lt;p&gt;A practical example of using CSS Grid for a typical website layout.&lt;/p&gt;
              &lt;div class="hero-buttons"&gt;
                  &lt;a href="#" class="button button-white"&gt;Button 1&lt;/a&gt;
                  &lt;a href="#" class="button button-white"&gt;Button 2&lt;/a&gt;
              &lt;/div&gt;
          &lt;/div&gt; &lt;!-- end hero-copy --&gt;
  
          &lt;div class="hero-image"&gt;
              &lt;img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/195612/cssgrid_macbook-pro-laravel.png" alt="hero image"&gt;
          &lt;/div&gt;
      &lt;/div&gt; &lt;!-- end hero --&gt;
  &lt;/header&gt;</code></pre>
  </div>
  </div>
  
  Here, im trying to get the nav-bar elements (shop, cart,about etc) to the right side. for that, justify-content: space-between is used. But when i run it in browser, the css for navbar is crossed. Can someone kindly tell whats wrong here.
  link to the codepen: <a href="https://codepen.io/drehimself/pen/GyVPgb?editors=1100" rel="nofollow noreferrer">https://codepen.io/drehimself/pen/GyVPgb?editors=1100</a></p>