how to grow columns to be the same height of content of either column using css flexbox?

Question

Demo: https://jsfiddle.net/chovy/7vgLpm9h/7/

I'm having a hard time getting the nav to be as tall as the content (or if you remove content having the content be as tall as the nav).

Both should be 100% of height of the tallest column.

I also need to position last nav item at bottom of navigation bar.

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

html,
body,
main {
  height: 100%;
  min-height: 100vh;
  width: 100vw;
}

main {
  display: flex;
  justify-content: flex-start;
  align-items: flex-start;
}

aside {
  width: 100rem;
  border: 1px solid red;
  align-self: stretch;
  flex-grow: 1;
}

section {
  flex-grow: 1;
  border: 1px solid green;
}

nav li {
  margin-bottom: 1rem;
}

nav li:last-child {
  margin-top: auto;
  margin-bottom: 0;
  color: blue;
  font-weight: 700;
}

<main>
  <aside>
    <header>header</header>
    <nav>
      <ul>
        <li>link 1</li>
        <li>link 1</li>
        <li>link 1</li>
        <li>link 1</li>
        <li>link 1</li>
        <li>link 1</li>
        <li>link 1</li>
        <li>link 1</li>
      </ul>
    </nav>
  </aside>
  <section>
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  </section>
</main>