html, body {
      height: 100%;
      margin: 0;
    }
    body {
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }
    main.content {
      flex: 1 0 auto;
      display: flex;
      flex-direction: column;
    }
    footer {
      flex-shrink: 0;
    }