<div class="bootstrap container-fluid">
  <header>Header</header>
  <section class="row">
    <aside class="column sidebar-left">whatever left</aside>
    <article id="main-section" class="column">Main</article>
    <aside class="column sidebar-right">whatever right</aside>
  </section>
  <footer>Footer</footer>
</div>
.bootstrap {
  min-height: 100vh;
}
header, footer {
  min-height: 50px;
  min-width: 100vw;
}
section {
  display: flex;
  min-height: calc(100vh - 100px);
  min-width: 100vw;
  margin: 1em 0;
}

aside {
  width: 100px;
}

article {
  background-color: #f8cecc;
  margin: 0 1em;
  flex-grow: 1;
}

header {
  background-color: #ffe6cc;
}
.sidebar-left {
  background-color: #e1d5e7;
}
.sidebar-right {
  background-color: #dae8fc;
}
footer {
  background-color: #d5e7d4;
}

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.4.1/css/bootstrap.min.css

External JavaScript

This Pen doesn't use any external JavaScript resources.