How does the CSS flexbox layout work for creating responsive navigation bars?

<!-- BEGIN COPY / PASTE -->
    .navbar {
      display: flex;
      justify-content: space-between; /* Distributes space between items */
      align-items: center; /* Aligns items vertically in the center */
      padding: 1rem;
    }

    .navbar-item {
      margin: 0 0.5rem; /* Adds spacing between items */
    }

    .navbar-logo {
      flex: 1; /* Allows the logo to grow and take available space */
    }

    .navbar-menu {
      display: flex;
      list-style: none;
    }

    .navbar-menu-item {
      margin: 0 1rem;
    }
    <!-- END COPY / PASTE -->