/* Style the header: fixed position (always stay at the top) */
        .header {
          position: fixed;
          top: 0;
          z-index: 1;
          width: 100%;
          background-color: #f1f1f1;
        }

        /* The progress container (grey background) */
        .progress-container {
          width: 100%;
          height: 3px;
          background: #ccc;
        }

        /* The progress bar (scroll indicator) */
        .progress-bar {
          height: 3px;
          background: #343a40;
          width: 0%;
        }