body,
html {
  margin: 0;
  padding: 0;
}

body {
  height: 200vh;
}

#app {
  /* background-color: #000; */
  height: 80vh;
  display: flex;
  box-sizing: border-box;
  flex-wrap: wrap;
}

.box {
  width: 400px;
  height: 600px;
  display: flex;
  justify-content: center;
  align-items: center;
}