function initMap() {
  // Create a map object and specify the DOM element for display.
  var map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: 33.972536, lng: -118.426561},
    scrollwheel: false,
    zoom: 14
  });
}

function initMap() {
  // Map style from https://snazzymaps.com/style/27/shift-worker
  var styledMapType = new google.maps.StyledMapType(
    [
      {
        "stylers": [
          {
            "saturation": -100
          },
          {
            "gamma": 1
          }
        ]
      },
      {
        "elementType": "labels.text.stroke",
        "stylers": [
          {
            "visibility": "off"
          }
        ]
      },
      {
        "featureType": "poi.business",
        "elementType": "labels.text",
        "stylers": [
          {
            "visibility": "off"
          }
        ]
      },
      {
        "featureType": "poi.business",
        "elementType": "labels.icon",
        "stylers": [
          {
            "visibility": "off"
          }
        ]
      },
      {
        "featureType": "poi.place_of_worship",
        "elementType": "labels.text",
        "stylers": [
          {
            "visibility": "off"
          }
        ]
      },
      {
        "featureType": "poi.place_of_worship",
        "elementType": "labels.icon",
        "stylers": [
          {
            "visibility": "off"
          }
        ]
      },
      {
        "featureType": "road",
        "elementType": "geometry",
        "stylers": [
          {
            "visibility": "simplified"
          }
        ]
      },
      {
        "featureType": "water",
        "stylers": [
          {
            "visibility": "on"
          },
          {
            "saturation": 50
          },
          {
            "gamma": 0
          },
          {
            "hue": "#50a5d1"
          }
        ]
      },
      {
        "featureType": "administrative.neighborhood",
        "elementType": "labels.text.fill",
        "stylers": [
          {
            "color": "#333333"
          }
        ]
      },
      {
        "featureType": "road.local",
        "elementType": "labels.text",
        "stylers": [
          {
            "weight": 0.5
          },
          {
            "color": "#333333"
          }
        ]
      },
      {
        "featureType": "transit.station",
        "elementType": "labels.icon",
        "stylers": [
          {
            "gamma": 1
          },
          {
            "saturation": 50
          }
        ]
      }
    ], {name: 'Styled Map'});

  // Create a map object and specify the DOM element for display.
  var map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: 33.972536, lng: -118.426561},
    scrollwheel: false,
    zoom: 14,
    mapTypeControlOptions: {
        mapTypeIds: ['roadmap', 'satellite', 'hybrid', 'terrain',
                     'styled_map']
      }
  });

  // Associate the styled map with the MapTypeId and set it to display.
  map.mapTypes.set('styled_map', styledMapType);
  map.setMapTypeId('styled_map');
}

Add custom styling to map