JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="absolute-menu">
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
    <div>5</div>
    <div>6</div>
    <div>7</div>
  </div>
  <div class="column course-column">
    Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula     eget dolor. Aenean massa. 
    Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula     eget dolor. Aenean massa. 
  </div>
</div>
<div id="footer"></div>

CSS

.container {
  position: relative;
  display: block;
  background: red; /* This will serve as a background for a menu. */
}

.absolute-menu {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  overflow-y: auto;
  width: 25%; /* You'll have to sync this... */
}

.course-column {
  margin-left: 25%; /* ... and this. */
  background-color: blue;
}

#footer {
  width:100%;
  height:20px;
  background-color:white;
  border: 1px solid black;
}