body {
  padding-top: 10px;
}
div.calc_wrap {
  width: 50%;
  height: 50%;
  background-color: #ffffff;
  border-radius: 4px;
  font-size: 10pt;
  margin: 0 auto;
  border: 1px solid #333;
}
h4.calc_title {
  padding: 10px;
  text-align: center;
  border-bottom: 1px solid #333;
  background-color: #2D5064;
  color: #ffffff;
  margin-top: 0;
}
div.calc_wrap ul {
  list-style-type: none;
}

div.calc_wrap .solution {
  margin-top: 10px;
}
div.calc_wrap input {
  margin: 5px 5px;
}

#article {
  padding: 3% 10% 1%;
}