@media all and (max-width: 1000px) {
  .sidebar {
    display: none;
  }

  .page {
    display: block;
  }

  .mobile-navigation {
    display: flex;
  }
}

@media all and (max-width: 840px) {
  html {
    font-size: 14px;
  }

  .header {
    padding: 0;
    margin-bottom: 1rem;
  }

  .mobile-navigation {
    display: block;
    padding: 0.5rem 0;
  }

  .mobile-navigation > a {
    display: block;
    text-align: center;
    line-height: 2rem;
  }

  h1 {
    font-size: 2rem;
    line-height: 3rem;
  }
}