title: Overlay Canvas on Entire Page (not just window)
body: <p><strong>Background</strong></p>
  
  <p>We are presenting some lessons in a long page format, with each section being the full height of the window... there many different sections in each lesson.</p>
  
  <p><a href="https://i.stack.imgur.com/Y4zNw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y4zNw.png" alt="enter image description here"></a></p>
  
  <p><strong>What I am trying to do</strong>
  I want people to be able to scribble all over the page. As you can see there are some options for highlighting and erasing canvas content.</p>
  
  <p>The goal here is to get a canvas to cover the entire page so that users can draw everywhere.</p>
  
  <p><strong>What I've Tried</strong></p>
  
  <p>I have added <code>position:absolute</code> to my canvas (<code>#theCanvas</code>) and that put the canvas on top of my content but when I scroll down I cant draw on anything under the initial window viewport.</p>
  
  <p><strong>My Code</strong></p>
  
  <p>Markup</p>
  
  <pre><code>&lt;canvas id="theCanvas"&gt;&lt;/canvas&gt;
  
  &lt;div class="right-menu"&gt;
  
      &lt;div class="right-menu-section"&gt;
          &lt;div class="right-menu-section-circle"&gt;
              &lt;svg height="32" width="32"&gt;
                  &lt;circle cx="16" cy="16" r="16" fill="#eeeeee"&gt;
              &lt;/svg&gt;
          &lt;/div&gt;
          &lt;div class="right-menu-section-circle"&gt;
              &lt;svg height="16" width="16"&gt;
                  &lt;circle cx="8" cy="8" r="8" fill="#eeeeee"&gt;
              &lt;/svg&gt;
          &lt;/div&gt;
          &lt;div class="right-menu-section-circle"&gt;
              &lt;svg height="8" width="8"&gt;
                  &lt;circle cx="4" cy="4" r="4" fill="#eeeeee"&gt;
              &lt;/svg&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  
      &lt;div class="right-menu-section"&gt;
          &lt;div class="right-menu-section-icon"&gt;
              &lt;i class="fa fa-eraser" aria-hidden="true"&gt;&lt;/i&gt;
          &lt;/div&gt;
          &lt;div class="right-menu-section-icon"&gt;
              &lt;i class="fa fa-pencil" aria-hidden="true"&gt;&lt;/i&gt;
          &lt;/div&gt;
          &lt;div class="right-menu-section-icon"&gt;
              &lt;i class="fa fa-hand-pointer-o" aria-hidden="true"&gt;&lt;/i&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  
      &lt;div class="right-menu-section"&gt;
          &lt;div id="colors"&gt;&lt;/div&gt;
      &lt;/div&gt;
  
      &lt;div class="right-menu-section"&gt;
          &lt;div class="right-menu-section-icon"&gt;
              &lt;i class="fa fa-hand-paper-o" aria-hidden="true"&gt;&lt;/i&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  
  &lt;/div&gt;
  
  &lt;div class="" style="display:block;position:absolute;float:right;margin-left:40px;margin-top:20px"&gt;
      &lt;h4&gt;Estimated Time to complete:&lt;h4&gt;
      &lt;h2&gt;
          &lt;i class="fa fa-clock-o"&gt;&lt;/i&gt;
          25m
      &lt;/h2&gt;
  &lt;/div&gt;
  
  &lt;!-- intro --&gt;
  &lt;div class="container-fluid card" style="background:#e8e6e1"&gt;
      &lt;div class="container card-content"&gt;
          &lt;h1 class="text-center"&gt;Welcome...&lt;/h1&gt;
          &lt;h4 class="text-center"&gt;
              Today's Lesson Focus:
              &lt;?php echo $focus-&gt;lesson_focus; ?&gt;
          &lt;/h4&gt;
          &lt;p class="text-center"&gt;&lt;b&gt;Details:&lt;/b&gt; &lt;?php echo $focus-&gt;details; ?&gt;&lt;/p&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  &lt;!-- end intro --&gt;
  
  &lt;!-- lesson --&gt;
  &lt;?php foreach ($cards as $card) : ?&gt;
  &lt;div class="container-fluid card" style="background:#eaeaec"&gt;
      &lt;div class="container card-content"&gt;
          &lt;div class="col-md-6"&gt;
              &lt;h2&gt;
                  &lt;?php echo $card-&gt;card_title; ?&gt;
                  &lt;i class="fa fa-volume-up"&gt;&lt;/i&gt;
              &lt;/h2&gt;
              &lt;p&gt;&lt;?php echo $card-&gt;card_content; ?&gt;&lt;/p&gt;
          &lt;/div&gt;
          &lt;div class="col-md-6"&gt;
              &lt;img src="&lt;?php echo $card-&gt;card_file_path; ?&gt;" alt=""&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  &lt;?php endforeach; ?&gt;
  &lt;!-- end lesson --&gt;
  
  &lt;!-- outtro --&gt;
  &lt;div class="container-fluid card" style="background:#E7E1E8"&gt;
      &lt;h1 class="text-center"&gt;Thanks!&lt;/h1&gt;
  &lt;/div&gt;
  &lt;!-- end outtro --&gt;
  </code></pre>
  
  <p>CSS</p>
  
  <pre><code>.card {
          height: 100vh;
          display: flex;
          justify-content: center;
          align-items: center;
          margin-right:50px;
      }
  
      .card-content {
  
      }
  
      .card-content img {
          width:100% !important;
          -webkit-box-shadow: 0px 0px 71px -11px rgba(0,0,0,0.75);
          -moz-box-shadow: 0px 0px 71px -11px rgba(0,0,0,0.75);
          box-shadow: 0px 0px 71px -11px rgba(0,0,0,0.75);
          border-radius: 20px;
      }
  
      .right-menu {
          position:fixed;
          float:right;
          height:100vh;
          right: 0;
          top: 0;
          width:50px;
          background:#222222;
          -webkit-box-shadow: -4px 0px 10px 0px rgba(153,153,153,1);
          -moz-box-shadow: -4px 0px 10px 0px rgba(153,153,153,1);
          box-shadow: -4px 0px 10px 0px rgba(153,153,153,1);
          border-top:1px solid #444444;
      }
  
      .right-menu-section {
          border-top:1px solid #444444;
          padding-top:20px;
          padding-bottom:20px;
      }
  
      .right-menu-section-icon {
          color: #eeeeee;
          margin-top:10px;
          font-size:24px;
          display:block;
          text-align:center;
      }
  
      .right-menu-section-circle {
          color: #eeeeee;
          margin-top:10px;
          display:block;
          text-align:center;
      }
  
      .swatch {
          width:30px;
          height:30px;
          border-radius:15px;
          box-shadow: inset 0px 1px 0px rgba(255, 255, 255, 0.5), 0px 2px 2px rgba(0, 0, 0, 0.5);
          display: block;
          margin-top: 10px;
          margin-left:10px;
      }
  
      #theCanvas {
          position: absolute;
      }
  </code></pre>
  
  <p><strong>My Question</strong></p>
  
  <p>How can I get the canvas to span the entire page not just the window.</p>