.container {
  max-width: 545px;
  border: 1px solid black;
  border-radius: 10px;
  margin: auto;
  padding: 50px 20px;
  background-color: darkblue;
}

.output {
  background-color: grey;
  border-radius: 5px;
  padding: 30px 50px;
  margin-bottom: 20px;
}

.output p {
  font-size: 38px;
  margin: 0;
  text-align: right;
}

button {
  font-size: 30px;
  border-radius: 5px;
  background-color: white;
}

.row {
  display: flex;
}

.column-1 {
  display: flex;
  width: 75%;
  overflow: hidden;
  flex-wrap: wrap;
  justify-content: space-between;
}

.column-2 {
  display: flex;
  width: 25%;
  flex-flow: column;
  overflow: hidden;
  flex-wrap: wrap;
}

.number {
  width: calc(100% * (1/3) - 10px - 1px);
  margin: 10px 0 0 10px;
  flex-grow: 1;
  height: 100px;
}

.operator,
.equals,
.reset {
  width: calc(100% - 10px - 1px);
  margin: 10px 0 0 10px;
  flex-grow: 1;
}