.tile {
  background-size: cover;
  height: 350px;
  position: relative;
}
    
    #pool1 {
    background-image: url("../assets/images/pool/Mojo\ Construction\ -\ Pine\ Street\ Greenslopes5095.jpg");

    }
    
    #pool2 {
    background-image: url("../assets/images/pool/Mojo\ Construction\ -\ Pine\ Street\ Greenslopes5106.jpg");

    }
    
    #pool3 {
    background-image: url("../assets/images/pool/Mojo\ Construction\ -\ Pine\ Street\ Greenslopes5182.jpg");

    }
    
    #pool4 {
    background-image: url("../assets/images/pool/Mojo\ Construction\ -\ Pine\ Street\ Greenslopes5197.jpg");

    }

    @media only screen and (max-width: 350px) {
        .cover-heading {
            font-size: 3em;
        }
      
        .navbar-brand {
          width:50%;
        }
      
        .masthead-brand {
          width:50%;
          height:50%;
        }
      
        .inner img {
          width: 120px;
        }
      }