* {
  -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: 2%;
  left: 0;
  width: 100%;
}
.logo {
  position: absolute;
  width: 14%;
  left: 20%;
  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 0.5s;
  transition: all ease 0.5s;
}
.cards .card .card-name {
  position: absolute;
  width: 60%;
  bottom: 0;
  left: -5%;
  opacity: 0;
  -webkit-transform: translateX(-20%) rotate(-30deg);
  transform: translateX(-20%) rotate(-30deg);
  -webkit-transition: all ease-in 0.4s;
  transition: all ease-in 0.4s;
}
.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 .cn1 {
  width: 50%;
}
.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: 82%;
  -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);
  }
}