JSFiddle - React, Tailwind, and code Playground

HTML

<header>
  Header
</header>

<main>
  <div class="container">

    <div class="sidebar-nav">
      Sidebar Navigation
    </div>
    <div class="sidebar-content">
      Sidebar Content
    </div>
    <div class="sidebar-right">
      Right Sidebar
    </div>
    <div class="main-content">
      Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content<br> Main Content
    </div>

  </div>
</main>

<footer>
  Footer
</footer>

CSS

body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  margin: 0;
}

main {
  flex-grow: 1;
  min-height: 0; /* new */
}

.container {
  display: flex;
  flex-direction: column;
  flex-wrap: wrap;
  height: 100%;
}

header,
footer,
[class^="sidebar-"],
.main-content {
  box-sizing: border-box;
  padding: 1rem;
}

header,
footer {
  background-color: lightgreen;
}

.sidebar-nav {
  background-color: lightblue;
}

.sidebar-content {
  background-color: lightyellow;
}

.sidebar-right {
  background-color: lightpink;
}

.main-content {
  background-color: lightgray;
}

@media(min-width: 48em) {

  .sidebar-nav,
  .sidebar-content {
    width: 26%;
    margin-right: 8%;
  }

  .main-content,
  .sidebar-right {
    flex-basis: 100%;
  }

  .main-content {
    width: 66%;
  }

  .sidebar-right {
    margin-left: 2rem;
    width: 20%;
  }

  .sidebar-right+.main-content {
    width: calc(66% - (20% + 2rem));
  }
}


/* Ordering of Page Layout */

.sidebar-nav {
  order: 1;
}

.main-content {
  order: 2;
  overflow: auto; /* new */
}

.sidebar-content {
  order: 3;
}

.sidebar-right {
  order: 4;
}

@media(min-width: 48em) {
  .sidebar-content {
    order: 2;
  }

  .main-content {
    order: 3;
  }
}