body{
  margin: 0;
  height: 100vh;
  width: 100%;
  display: grid;
  place-items: center;
}
.app{
  width: 650px;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  perspective: 1000px;
}
.card{
  height: 150px;
  width: 150px;
  border: 1px solid #ccc;
  transform-style: preserve-3d;
  transition: .7s;
}

.sides{
  position: absolute;
  height: 100%;
  width: 100%;
  font-size: 2em;
  display: grid;
  place-items: center;
  backface-visibility: hidden;
}
.front{
  background-color: rgb(18, 168, 238);
}
.back{
  background-color: rgb(222, 79, 251);
  transform: rotateY(180deg);
}

.btn{
  padding: 1em 1.5em;
  color: #222;
  background-color: rgb(240, 240, 14);
  outline: none;
  border: none;
}

.rotate{
  transform: rotateY(180deg);
}

@media (max-width: 900px) and (min-width: 600px) {
  .app {
      width: 80%;
  }

  .card {
      height: 120px;
      width: 120px;
  }

  .fruit-piece {
      font-size: 1.8rem;
  }
}

@media (max-width: 600px) and (min-width: 250px) {
  .app {
      width: 85%;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
  }

  .card {
      height: 90px;
      width: 90px;
  }

  .fruit-piece {
      font-size: 1.5rem;
  }
}