@media only screen and (max-width: 40rem) {
  .sign-in-form {
    max-width: 100%;
    margin: 1rem auto;
  }

  .flash-message {
    width: calc(100vw - 1rem);
  }

  .article-container {
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
  }

  .right-sidebar {
    display: none;
  }

  .left-content {
    max-width: 100%;
  }

  header .nav-links a,
  header .nav-links form {
    display: none;
  }

  .hamburger-btn {
    display: flex;
  }

  .admin-dropdown {
    display: none;
  }
}