/* Floating action button (History / Review) */
.fab {
    position: fixed;
    right: 16px;
    bottom: 18px;
    background: var(--accent);
    color: #fff;
    font-weight: 700;
    padding: 10px 14px;
    border-radius: 999px;
    border: none;
    box-shadow: 0 10px 22px rgba(0,0,0,.22);
    cursor: pointer;
    display: none;    /* shown/hidden by JS */
    z-index: 45;
  }