body {
  width: 100%;
  margin: 0;
  background-color: bisque;
}
main {
  margin: 5rem auto 0;
  width: 60%;
  align-content: center;
}
.input-div {
  display: flex;
  justify-content: space-between;
  margin-bottom: 20px;
}

input {
  width: 70%;
  padding: 1rem;
}
#output {
  border: 5px solid gray;
  height: 20px;
  text-align: center;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1.3rem;
  padding: 1rem;
}

button {
  color: white;
  padding: 1rem;
  background-color: black;
  transition: background-color ease-in 1s;
}
button:hover {
  background-color: red;
  border: none;
}