SOURCE

<header>
  <h2>Header Section</h2>
</header>

<main>
  <article>
    <h2>Main Section</h2>
  </article>

  <nav>
    <h2>Nav Section</h2>
  </nav>

  <aside>
    <h2>Aside Section</h2>
  </aside>
</main>

<footer>
  <h2>Footer Section</h2>
</footer>

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  width: 100vw;
  min-height: 100vh;
  margin: 0;
  background-color: #291642;
  font-family: "Gochi Hand", sans-serif;
  font-size: 100%;
  letter-spacing: 0.1rem;
  color: #fff;

  display: flex;
  flex-direction: column;
}

header,
main,
footer {
  display: flex;
  justify-content: center;
  align-items: center;
}

header {
  background-color: #2196f3;
  min-height: 15vh;
}

main h2 {
  text-align: center;
  margin: 2vh 0;
}

footer {
  min-height: 20vh;
  background-color: #222;
  margin-top: auto;
}



main {
  background-color: #f4f4f4;
  color: #444;
  flex: 1;
  display: flex;
  align-items: stretch;
  width: 100%;
}
nav {
  background-color: #ff9800;
  color: #fff;
  width: 220px;
  order: -1;
}

article {
  background-color: #795548;
  color: #fff;
  flex: 1;
}

aside {
  background-color: #607d8b;
  color: #fff;
  width: 220px;
}