@nebular/theme/components/tree-grid/tree-grid.component.css

:host{table-layout:fixed;border-spacing:0;border-collapse:collapse;width:100%;max-width:100%;overflow:auto}::ng-deep .nb-tree-grid-cell,::ng-deep .nb-tree-grid-header-cell,::ng-deep .nb-tree-grid-footer-cell{overflow:hidden}