style.css

.calculator {
  background: #f6f7f8;
  border: 1px solid #e9eaed;
  padding: 10px 10px 20px 20px;
  font-family: roboto-h, sans-serif;
}
.calculator .row {
  line-height: 50px;
}
.caption {
  font-weight: 400;
  min-width: 120px;
  display: inline-block;
  font-size: 16px;
}
.calculator input,
.calculator select {
  width: auto;
  line-height: 18px;
  padding: 3px;
  height: auto;
  margin-top: 0;
  text-align: center;
  background-color: #fff;
  border: 1px solid #ddd;
  color: #333;
  font-size: 14px;
  font-weight: 400;
}
.rbtn label {
  font-size: 14px;
  font-weight: 400;
  margin-right: 10px;
}
.calculator button {
  padding: 10px 20px;
  color: #fff;
  cursor: pointer;
  width: 160px;
  text-transform: uppercase;
  margin-top: 10px;
  background-color: #a2cc41;
  border: 0;
  font-size: 16px;
  font-weight: 700;
}
.rst {
  border: 1px solid #ddd;
  margin-top: 20px;
  padding: 10px;
  font-weight: 400;
  font-size: 16px;
  font-family: roboto-h, sans-serif;
  display: none;
}