article {
  position: relative;
  flex: 1;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  grid-template-areas:
    "header"
    "nav   "
    "main  "
    "footer";
}

article>header {
  grid-area: header;
}

article>nav {
  grid-area: nav;
  display: flex;
}

article>main {
  padding: 1rem;
  grid-area: main;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

article>footer {
  grid-area: footer;
}

.page {
  grid-gap: var(--page-gap);
  font-family: var(--page-font);
}

.page>menu {
  grid-area: menu;
  display: none;
  margin: 0;
  padding: 0;
  overflow-y: scroll !important; /* has to be scroll, not auto */
  -webkit-overflow-scrolling: touch;
}

.page>menu.active {
  position: absolute;
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100%;
  z-index: 10;
}

.page>aside {
  grid-area: aside;
  display: none;
}

@media (min-width: 1024px) {

  .page {
    flex: 1;
    display: grid;
    grid-template-columns: auto 1fr auto;
    grid-template-rows: auto auto 1fr auto;
    grid-template-areas:
    "header header header"
    "menu   nav    aside"
    "menu   main   aside"
    "menu   footer aside";
  }

  .page>menu {
    display: flex;
    flex-direction: column;
    position: relative;
    min-width: 30rem;
  }

  .page>menu.active {
    position: relative;
    min-width: 30rem;
  }

  .page>main.center {
    max-width: var(--page-max-width, 1024px);
  }

  .page>aside {
    display: flex;
    flex-direction: column;
    width: 0;
  }

  .page>aside.active {
    width: 25rem;
  }
}

@media (min-width: 1284px) {
  .page:not(.fullscreen) {
    max-width: 1284px;
    margin: 0 auto;
  }
}