* {
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  padding: 0;
  margin: 0
}

img {
  width: 100%;
  display: block
}

.app {
  width: 100%;
  height: 100vh;
  position: relative;
  background-image: url(../image/bg.jpg);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat
}

.notice {
  position: absolute;
  top: 5%;
  left: 33%;
  width: 40%
}

.logo {
  position: absolute;
  width: 14%;
  left: 26%;
  top: 3.3%
}

.cards {
  width: 70%;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  position: absolute;
  top: 20%;
  left: 15%;
  -webkit-box-pack: justify;
  -ms-flex-pack: justify;
  justify-content: space-between
}

.cards .card {
  -ms-flex-preferred-size: 24%;
  flex-basis: 24%;
  position: relative;
  -webkit-filter: grayscale(100%);
  filter: grayscale(100%);
  -webkit-transition: all ease .5s;
  transition: all ease .5s
}

.cards .card .card-name {
  position: absolute;
  width: 50%;
  bottom: 0;
  left: -5%;
  opacity: 0;
  -webkit-transform: translateX(-20%) rotate(-30deg);
  transform: translateX(-20%) rotate(-30deg);
  -webkit-transition: all ease-in .4s;
  transition: all ease-in .4s
}

.cards .card:hover {
  -webkit-filter: grayscale(0);
  filter: grayscale(0);
  -webkit-transform: scale(1.02);
  transform: scale(1.02)
}

.cards .card:hover .card-name {
  opacity: 1;
  -webkit-transform: translateX(0) rotate(0);
  transform: translateX(0) rotate(0)
}

.cards .card .cn3,
.cards .card .cn4 {
  width: 65%;
}

.cards .card_color {
  -webkit-filter: grayscale(0);
  filter: grayscale(0);
  -webkit-transform: scale(1.02);
  transform: scale(1.02)
}

.button {
  position: absolute;
  width: 20%;
  left: 40%;
  top: 80%;
  -webkit-animation: button 1s ease;
  animation: button 1s ease;
  -webkit-animation-iteration-count: infinite;
  animation-iteration-count: infinite
}

@-webkit-keyframes button {
  from {
      -webkit-transform: scale(1);
      transform: scale(1)
  }
  50% {
      -webkit-transform: scale(1.1);
      transform: scale(1.1)
  }
  to {
      -webkit-transform: scale(1);
      transform: scale(1)
  }
}

@keyframes button {
  from {
      -webkit-transform: scale(1);
      transform: scale(1)
  }
  50% {
      -webkit-transform: scale(1.1);
      transform: scale(1.1)
  }
  to {
      -webkit-transform: scale(1);
      transform: scale(1)
  }
}