* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
}

.counter_div {
  display: flex;
  flex-direction: row;
}

.minus,
.plus,
.number_div {
  font-size: 50px;
}

.number_div {
  padding-left: 30px;
  padding-right: 30px;
  border: 1px solid black;
}

.minus,
.plus {
  padding-left: 20px;
  padding-right: 20px;
}

.positive {
  color: green;
}

.negative {
  color: red;
}