function initMap() {
        // Styles a map in night mode.
        var map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: 40.674, lng: -73.945},
          zoom: 12,
          styles: [
            {elementType: 'geometry', stylers: [{color: '#242f3e'}]},
            {elementType: 'labels.text.stroke', stylers: [{color: '#242f3e'}]},
            {elementType: 'labels.text.fill', stylers: [{color: '#746855'}]},
            {
              featureType: 'administrative.locality',
              elementType: 'labels.text.fill',
              stylers: [{color: '#d59563'}]
            },
            {
              featureType: 'poi',
              elementType: 'labels.text.fill',
              stylers: [{color: '#d59563'}]
            },
            {
              featureType: 'poi.park',
              elementType: 'geometry',
              stylers: [{color: '#263c3f'}]
            },
            {
              featureType: 'poi.park',
              elementType: 'labels.text.fill',
              stylers: [{color: '#6b9a76'}]
            },
            {
              featureType: 'road',
              elementType: 'geometry',
              stylers: [{color: '#38414e'}]
            },
            {
              featureType: 'road',
              elementType: 'geometry.stroke',
              stylers: [{color: '#212a37'}]
            },
            {
              featureType: 'road',
              elementType: 'labels.text.fill',
              stylers: [{color: '#9ca5b3'}]
            },
            {
              featureType: 'road.highway',
              elementType: 'geometry',
              stylers: [{color: '#746855'}]
            },
            {
              featureType: 'road.highway',
              elementType: 'geometry.stroke',
              stylers: [{color: '#1f2835'}]
            },
            {
              featureType: 'road.highway',
              elementType: 'labels.text.fill',
              stylers: [{color: '#f3d19c'}]
            },
            {
              featureType: 'transit',
              elementType: 'geometry',
              stylers: [{color: '#2f3948'}]
            },
            {
              featureType: 'transit.station',
              elementType: 'labels.text.fill',
              stylers: [{color: '#d59563'}]
            },
            {
              featureType: 'water',
              elementType: 'geometry',
              stylers: [{color: '#17263c'}]
            },
            {
              featureType: 'water',
              elementType: 'labels.text.fill',
              stylers: [{color: '#515c6d'}]
            },
            {
              featureType: 'water',
              elementType: 'labels.text.stroke',
              stylers: [{color: '#17263c'}]
            }
          ]
        });
      }