body {
  /* image ratio is 16:9 */
  background-image: url(../images/outdoors_railroad_tracks_foliage_hd-wallpaper-936158.JPG);
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;
  overflow-x: hidden;
}

.jumbotron {
  text-align: center;
  background-color: #272b30;
}

h1 {
  float: center;
}

#image1,
#image4 {
  height: 100px;
  width: 175px;
  float: left;
  border-style: solid;
  border-color: grey;
  border-width: 1px;
}

#image3,
#image6 {
  height: 100px;
  width: 175px;
  float: right;
  border-style: solid;
  border-color: grey;
  border-width: 1px;
}

#image2,
#image5 {
  height: 100px;
  width: 100px;
  border-style: solid;
  border-color: grey;
  border-width: 1px;
}

/* Alerts */
#message {
  position: fixed;
  top: -100px; /* start hidden above screen */
  left: 0;
  width: 100%;
  z-index: 1050; /* higher than Bootstrap navbars etc */
  text-align: center;
  padding: 15px;
  font-weight: bold;
  font-size: 16px;
  transition: top 0.5s ease-in-out;
  display: none;
}

/* When shown */
#message.show {
  top: 0;
}

#resetAdd,
#resetExisting {
  float: right;
}

@media screen and (max-width: 452px) {
  #image1,
  #image3,
  #image4,
  #image6 {
    width: 80px;
    height: 60px;
    margin: 4px;
  }

  #image2,
  #image5 {
    width: 80px;
    height: 80px;
  }
  #traintable {
    table-layout: fixed;
    font-size: 10px;
  }
  td {
    text-align: center;
  }

  tr {
    text-align: center;
  }
}