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HTML

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About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

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Insecure Resource

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CSS

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CSS Base

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                <header>
  <div class="row">
    <div class="small-12 col">
      <h1>Cake Shop</h1>
    </div>
  </div>
</header>
<div class="row">
  <nav class="small-12 medium-shrink xxlarge-2 col">
    <ul class="block-grid medium-vertical">
      <li><a href="#">Home</a></li>
      <li><a href="#">About</a></li>
      <li><a href="#">Clients</a></li>
      <li><a href="#">Contact Us</a></li>
    </ul>
  </nav>  
  <aside class="small-hidden large-shrink xxlarge-2 col">
    <p>Sections</p>
    <ol>
      <li><strong>Section 1</strong>
        <ol>
          <li>Section 1.1</li>
        </ol>
      </li>      
      <li>Section 2</li>
      <li>Section 3</li>
    </ol>  
  </aside>
  <main class="small-12 medium-auto col">
    <article>
      <h1>Main Heading of the article</h1>
      <p>Introducing of the essay goes here.</p>
      <h2>Section 1—Photos</h2>
      <p>You’ll find a couple of images in the following that shows the flexbox-based block-grid system.</p>
      <div class="block-grid small-up-to-2 medium-up-to-3">
        <figure>
          <img src="//via.placeholder.com/300x300" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/350x300" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/700x400" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/500x300" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/500x600" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/300x300" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/300x300" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
        <figure>
          <img src="//via.placeholder.com/300x300" alt="placeholder image" />
          <figcaption>This is a placeholder.</figcaption>
        </figure>
      </div>
      <h3>1.1 Sub section</h3> 
      <p>This is a paragraph of section 1.1. It’s the sub-section that conclude the section 1.</p>
      <h2>2. Section 2</h2>
      <p>We create more sections. An essay usually contains more than 1 section. This is the reason we put section 2 here.</p>
      <h2>3. Summary</h2>
      <p>This section summerize the entire article.</p>
    </article>
  </main>
  <div class="advertisement row">
    <div class="small-hidden xlarge-shrink col">
      <img src="//via.placeholder.com/160x600&text=ad." alt="Advertisement" />
    </div>
  </div>
</div>  
<footer>
  <div class="row">
    <div class="small-12 col">
      CC0 Do anything license.
    </div>
  </div>
</footer>
!

CSS 

              
                /* Border box */
* {
  box-sizing: border-box;
}

img {
  max-width: 100%;
}

/* Grid */
.row {
  /* if you need a largest width */
  width: 1920px;
  max-width: 100%;
  margin: 0 auto;

  display: flex;
  flex-wrap: wrap;
}
.row .row {
  margin-left: -10px;
  margin-right: -10px;
  width: auto;
  max-width: none;
}

.col {
  padding: 0 10px;
  min-width: 0;
  
  border: 1px dashed LIGHTGRAY;
}

$columns-count: 12;
$screen-sizes: small medium large xlarge xxlarge;
$breakpoints: 0 500px 1000px 1200px 1600px;
@for $i from 1 through length($screen-sizes) {
  @media screen and (min-width: nth($breakpoints, $i)){
    .#{nth($screen-sizes, $i)}-vertical { flex-direction:column; }
    .#{nth($screen-sizes, $i)}-horizontal { flex-direction:row; }
    .#{nth($screen-sizes, $i)}-hidden { display: none; }
    .#{nth($screen-sizes, $i)}-auto   { display: block; flex: 1}
    .#{nth($screen-sizes, $i)}-shrink { display: block; flex: 0 1 auto}
    @for $j from 1 through $columns-count {
      .#{nth($screen-sizes, $i)}-#{$j} {
        display: block; 
        flex: 0 1 calc( 100% / #{$columns-count} * #{$j} );
      }
    }    
  }  
}

/* Block grid */
.block-grid {
  display: flex;
  flex-wrap: wrap;
}
.block-grid > * { flex: 1; }
@for $i from 1 through length($screen-sizes) {
  @media screen and (min-width: nth($breakpoints, $i)){   
    @for $j from 2 through 10 {
      .block-grid.#{nth($screen-sizes, $i)}-up-to-#{$j} > * {
        flex: 0 1 calc( 100% / #{$j} );
      }
    }
  }
}

/* Individual element’s style */
figure {
  padding: 5px;
  
  img {
    width: 100%;
    height: 200px;
    object-fit: cover;
  }
  
  figcaption {
    text-align: center;
  }
}

/* Visual styles */
body {
  background: LIGHTYELLOW;
  font-size: 14pt;
  line-height: 1.2em;
  font-family: Gill Sans, sans-serif;
  font-weight: 300;
}
h1, h2, h3 {
  font-weight: 600;
}
h2 {
  margin: 1em 0 0.5em;
}
strong{
  font-weight: bold;
}
p {
  margin: 0.5em 0;
}
header {
  line-height: 3em;
  background: MOCCASIN;
}
article {
  padding-top: 1em;
}
nav {
  width: 150px;
}
nav li {
  
  a {
    text-decoration: none;
    color: CRIMSON ;
    padding: 5px 15px 5px 5px;
    margin-left: -5px;
    display: block;
    
    &:hover {
      background: CRIMSON;
      color: WHITE;
    }
  }
}
footer {
  font-size: 0.7em;
  padding: 2em 0;
}
!

JS
!
999px

Console