body {
  padding-top: 40px;
  padding-bottom: 40px;
  padding-left: 5px;
  padding-right: 5px;
}

hr {
  border-top: solid black;
}

div #error-message {
  color: red;
  font-size: 15px;
  font-weight: bold;
}

div #success-message, #results-message {
  color: green;
  font-size: 15px;
  font-weight: bold;
}

.form-calculator {
  max-width: 530px;
  padding: 15px;
  margin: 0 auto;
}

.form-calculator .form-calculator-heading {
  margin-bottom: 10px;
}

.form-calculator .form-control {
  position: relative;
  height: auto;
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
  padding: 10px;
  font-size: 16px;
}

.form-calculator .form-control:focus {
  z-index: 2;
}

.form-calculator input[type="text"] {
  margin-bottom: 10px;
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.diagram {
  text-align: center;
  width: 100%;
}