I am using NG-ZORRO library and would like to customize it's DatePicker.
For example, I would like to highlight some of the days with different color like screenshot below, and the days that I would like to highlight are dynamic (based on a date list get from database):

My idea was create a directive, bind the host element with ElementRef and add custom class to the element with Renderer2. Here is what I have so far:
html
<nz-date-picker nzInline customDatePicker></nz-date-picker>
ts
@Directive({
selector: `[customDatePicker]`
})
export class CustomDatePickerDirective {
constructor(@Host() @Self() @Optional() public hostDatePicker: NzDatePickerComponent, renderer: Renderer2, hostElement: ElementRef) {
console.log(this.hostDatePicker);
renderer.addClass(hostElement.nativeElement, 'custom-color');
}
}
The problem is renderer.addClass will only add the custom class at top element (<nz-date-picker> element), but the element I need to inject the custom class is within this element, I am thinking if there is any way I can look for the child/nested elements? I inspect the <nz-date-picker> element with devtools, the element that I will need to add the custom class is pretty deep inside (within the red box of the screenshot below):