.input-group {
  position: relative;
  border: 0;
  display: inline-block;
  padding: 0;
}

.input-group > .input-group {
  position: relative;
  border: solid gray 0.3px;
  display: inline-block;
  padding: 3px;
}

.input-group > input{
  border: 0;
  padding: 0;
  border-bottom: dotted gray 1px;
  outline: none;
  text-align: center
}

span:hover{
  cursor: default;
}

h1 {
  font-family: Arial, Helvetica, sans-serif;
opacity: 0.5;
}

body {
  padding: 30px;
}

.article {
  padding: 3% 20% 0 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}