body {
  height: 100vh;
  background-color: antiquewhite;
  display: flex;
  align-items: center;
  justify-content: center;
}

main {
  padding: 0;
  min-width: 200px;
  border: 3px solid #2F2F2F;
}

#display {
  background-color: rgb(125, 179, 225);
  min-height: 120px;
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  border: 3.5px solid #2F2F2F;
  border-radius: 5px;
  font-size: x-large;
}

#number {
  background-color: rgb(34, 24, 26);
  display: flex;
  flex-direction: column;
  border: 3px solid #2F2F2F;
  width: 100%;
}

#number div {
  display: flex;
  justify-content: baseline;
  justify-content: space-evenly;
  padding: 1px;
}



#number button {
  text-align: center;
  background-color: #217C7E;
  border-radius: 4px;
  border: none;
  font-size: 2em;
  font-family: monospace;
  color: black;
  width: 100px;
  height: 100px;
}

#number .btn-blue {
  background-color: #1E90FF;
}

button#zero {
  flex-basis: 200px;
}

#number button:last-child {
  background-color: #FF8F1F;
}

#number button:hover {
  opacity: 0.9;
}