discourse/app/assets/stylesheets/mobile/admin_report_table.scss

.admin-report-table {
  .table {
    font-size: $font-down-1;
  }

  .table .admin-report-table-header {
    font-weight: 500;
    border-right: 1px solid $primary-low;
    padding: auto;

    .title {
      writing-mode: vertical-rl;
      text-orientation: mixed;
      text-align: right;
      transform: rotate(180deg);
    }

    .sort-btn {
      display: none;
    }
  }

  .table tbody tr td {
    &.user .username {
      display: none;
    }
  }
}