bem-example.scss

// Block
.scenery {
   //Elements
  &__sky {
    fill: screen;
  }
  &__ground {
    float: bottom; 
  }
  &__people {
    float: center;
  }
}

//Block
.sky {
  background: dusk;
  
  // Elements
  
  &__clouds {
    type: distant;
  }
  
  &__sun {
    strength: .025;
  }
  
  // Modifiers
  &--dusk {
    background: dusk;
    .sky__clouds {
      type: distant;
    }
    .sky__sun {
      strength: .025;
    }
  }
  
  &--daytime {
    background: daylight;
    .sky__clouds {
      type: fluffy;
      float: center;
    }
    .sky__sun {
      strength: .7;
      align: center;
      float: top;
    }
  }
}