/**
 * Flexbox is a one-dimensional layout method for laying out items in rows or columns.
 *
 * @see https://developer.mozilla.org/en-US/docs/Learn/CSS/CSS_layout/Flexbox
 *
 * @see https://google.github.io/styleguide/htmlcssguide.html
 * @see https://github.com/google/closure-stylesheets
 */

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

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

#main,
#main > article {
  flex: 1;
}

@media only screen and (min-width: 768px) {
  #main {
    display: flex;
  }

  #main > aside {
    flex: 0 0 20%;
  }

  #main > aside:first-of-type {
    order: -1;
  }
}

aside,
footer,
header,
#main > article {
  padding: 1em;
}