角材料组件什么都不显示

Question

当我使用组件时，Angular Material不会显示任何内容。

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MatSliderModule } from '@angular/material/slider';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    BrowserAnimationsModule,
    MatSliderModule],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app.component.html

<mat-slider min="1" max="100" step="1" value="1"></mat-slider>