*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  background-color: lightgray;
}

h1 {
  text-align: center;
  font-family: "Courier New", Courier, monospace;
}

.button-container {
  width: fit-content;
  margin: auto;
}

button {
  padding: 8px 16px;
  border-radius: 4px;
  border: none;
  font-size: 16px;
  cursor: pointer;
  margin: 0.5rem;
}

.container {
  width: 60vw;
  height: 55vw;
  margin: auto;
  margin-top: 2rem;
  display: flex;
  flex-wrap: wrap;
}

.div {
  margin: 0;
  padding: 0;
  background-color: white;
  transition: background-color 0.5s ease;
}