.custom-flex-grid {
            height: 350px;
        }
.custom-flex-grid .wj-header.wj-cell {
  color: #fff;
  background-color: #424040;
  border-bottom: solid 1px #404040;
  border-right: solid 1px #404040;
  font-weight: bold;
}

.custom-flex-grid .wj-cell {
  background-color: #fff;
  border: none;
}

.custom-flex-grid .wj-alt:not(.wj-state-selected):not(.wj-state-multi-selected) {
  background-color: #fff;
}

.custom-flex-grid .wj-state-selected {
  background: #424040;
  color: #fff;
}

.custom-flex-grid .wj-state-multi-selected {
  background: #424040;
  color: #fff;
}