html, body {
    height: 100%;
}
#container {
    width: 100%;
    height: 100%;
}

.info {
    color: #fff;
    background: #000!important;
    opacity: 0.8;
  }

  .info h4, .info p {
      margin: .75rem 0;
  }
  .input-item input[type=number], .input-item button {
      flex: 1 1 1;
      width: 80%;
      -webkit-appearance: none;
      border: 1px solid #ced4da;
      color: #495057;
      line-height: 1.5;
      border-radius: .25rem;
      padding: .375rem .75rem;
      height: calc(2.2rem + 2px);
      appearance: none;
      /* height: 30px; */
  }
 #rangeBtn {
    background: #275739;
    border: none;
    color: #fff;
    width: 20%;
  }
  .input-item input[type=number]:focus {
    border-color: #80bdff;
    outline: 0;
    box-shadow: 0 0 0 .1rem rgba(128, 189, 255, .1)
  }