body {

    color: #f7f7f7;
  }

  .jumbotron {
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url("../images/MethaneSources3.png");
    background-size: 100% 100%;
    text-align: center;
  }

  .legend span, .legend label {
    display: block;
    width: 50px;
    height: 18px;
    float: left;
    opacity: 0.7;
    text-align: center;
    font-size: 80%
  }