Get rid of white space around Angular Material modal dialog

import {ViewEncapsulation} from '@angular/core';
    
@Component({
  .....,
  encapsulation: ViewEncapsulation.None 
})

.mat-dialog-container {
    padding: 0px !important;
}

this.dialog.open(MyDialogComponent, { panelClass: 'custom-dialog-container' })

.custom-dialog-container .mat-dialog-container {
    /* add your styles */
}