body {
  padding: 0;
  margin: 0;
  background-color: salmon;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  height: 100vh;
  font-family: "Courier New", Courier, monospace;
}

h2 {
  font-size: 2rem;
  color: aliceblue;
}

.section {
  text-align: center;
}

.btn {
  font-size: 5rem;
  border: none;
  background: rgb(255, 255, 255, 0.2);
  border-radius: 10px;
  padding: 15px;
  filter: grayscale(); /* 灰色 */
  transition: filter 0.2s ease-in-out;
  cursor: pointer;
  height: 200px;
  width: 200px;
}

.btn:hover {
  filter: grayscale(0); /*原始的色彩*/
}

.emoji-name {
  font-weight: 600;
  color: darkblue;
}