.main_sec {
  min-height: auto;
  padding-bottom: 80px;
  background: url("../images/main_bg.jpg") top center repeat-x;
  background-size: cover;
  overflow: hidden;
}
.main_sec .inr {
  position: relative;
  z-index: 2;
  display: flex;
}
.main_sec .inr .txt {
  order: 2;
  width: 40%;
  padding-top: 10%;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  line-height: 1.8;
  letter-spacing: 0.1em;
  line-break: strict;
  word-break: keep-all;
  overflow: hidden;
  animation: revealMask 2.5s ease-out forwards;
}
.main_sec .inr .txt h2 {
  letter-spacing: 0.2em;
  line-height: 1.7;
  color: #fff;
  font-size: min(3.3vw, 34px);
  margin-left: 1em;
}
.main_sec .inr .txt h2 span {
  background-color: #332a2a;
}
.main_sec .inr .txt h2 div:nth-child(2) {
  text-indent: 1.5em;
}
.main_sec .inr .txt h2 div:nth-child(3) {
  text-indent: 3em;
}
.main_sec .inr .txt p {
  font-size: min(1.8vw, 18px);
  line-height: 2.2;
  font-weight: 600;
  padding-top: 60px;
}
@keyframes revealMask {
  0% {
    clip-path: polygon(100% 0, 100% 0, 100% 100%, 100% 100%);
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    opacity: 1;
  }
}
.main_sec .inr .img {
  order: 1;
  width: 50%;
}
.main_sec .inr .img img {
  display: block;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 1.5s ease-out forwards;
}
.main_sec .inr .img img:nth-child(1) {
  width: 80%;
  animation-delay: 0.3s;
}
.main_sec .inr .img img:nth-child(2) {
  width: 30%;
  animation-delay: 0.8s;
}
.main_sec .inr .img img:nth-child(3) {
  width: 100%;
  margin-top: -30%;
  margin-left: 10%;
  animation-delay: 1.3s;
}
@keyframes fadeInUp {
  0% {
    opacity: 0;
    transform: translateY(20px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}
.main_sec .cloud {
  z-index: -1;
}
.main_sec .cloud img {
  position: absolute;
  display: block;
  animation: sway 20s ease-in-out infinite;
}
.main_sec .cloud img:nth-child(1) {
  width: 30%;
  top: 20%;
  left: -10%;
  animation-duration: 25s;
  animation-delay: 0s;
}
.main_sec .cloud img:nth-child(2) {
  width: 35%;
  top: 15%;
  right: -10%;
  animation-duration: 30s;
  animation-delay: 1s;
}
.main_sec .cloud img:nth-child(3) {
  width: 25%;
  bottom: 3%;
  right: 0;
  animation-duration: 22s;
  animation-delay: 1s;
}
.main_sec .cloud img:nth-child(4) {
  width: 25%;
  bottom: 5%;
  left: -5%;
  animation-duration: 28s;
  animation-delay: 1s;
}
@keyframes sway {
  0% {
    transform: translate(0, 0);
  }
  25% {
    transform: translate(60px, -10px);
  }
  50% {
    transform: translate(0, 0);
  }
  75% {
    transform: translate(-60px, 10px);
  }
  100% {
    transform: translate(0, 0);
  }
}

@media screen and (max-width: 780px) {
  .main_sec {
    margin-top: 40px;
  }
  .main_sec .inr {
    justify-content: space-between;
  }
  .main_sec .inr .txt {
    width: 50%;
    padding-top: 8%;
    line-height: 1.6;
  }
  .main_sec .inr .txt h2 {
    letter-spacing: 0.2em;
    line-height: 1.7;
    font-size: min(4.3vw, 34px);
    margin-left: 10px;
  }
  .main_sec .inr .txt p {
    font-size: min(2.5vw, 18px);
    line-height: 2;
    padding-top: 30px;
  }
  .main_sec .inr .img {
    order: 1;
    width: 50%;
  }
  .main_sec .inr .img img {
    display: block;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 1.5s ease-out forwards;
  }
  .main_sec .inr .img img:nth-child(1) {
    margin-top: 10%;
    width: 85%;
  }
  .main_sec .inr .img img:nth-child(2) {
    width: 35%;
  }
  .main_sec .inr .img img:nth-child(3) {
    margin-top: -30%;
    margin-left: 8%;
  }
}