html, body {
    height: 100%;
}

html {
    display: table;
    margin: auto;
}

body {
    display: table-cell;
    vertical-align: middle;
}
h1 {
    text-align: center;
      background-color: #398AD7;
      color: white;
      width: 100%;
      height: 50px;
      margin: 0px 0px 10px 0px;
    }
#input-number{

}
section#calculator{
  text-align: center;
}
#calculator{
  text-align: center;
  border: 2px solid #398AD7;
  border-radius: 5px;
  width: 30em;
  padding: 0.2em  0em  0.2em  0em ;
}
#calc-actions{
  margin-top: 10px;
}
#calc-actions button{
  font-size : 1.5em;
  background-color: #398AD7;
  height: 4em;
  width: 4em;
}
#results{
  text-align: center;
}