@charset "utf-8";

.bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: transpaint;
}

/* 丸いオブジェクト共通 */
.bg span {
  position: absolute;
  bottom: -100px;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  filter: blur(8px);
  animation: floatUp linear infinite;
}

@keyframes gradientBg {
 0% {
  background-position: 0% 50%;
 }

 50% {
  background-position: 100% 50%;
 }

 100% {
  background-position: 0% 50%;
 }
}

/* 上へ流れるアニメーション */
@keyframes floatUp {
  from {
    transform: translateY(0);
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  to {
    transform: translateY(-120vh);
    opacity: 0;
  }
}

/* 個別に位置・サイズ・速度を変更 */
.bg span:nth-child(1) {
  left: 5%;
  width: 76px;
  height: 76px;
  animation-duration: 8s;
}

.bg span:nth-child(2) {
  left: 15%;
  width: 55px;
  height: 55px;
  animation-duration: 12s;
  animation-delay: 2s;
}

.bg span:nth-child(3) {
  left: 30%;
  width: 100px;
  height: 100px;
  animation-duration: 10s;
}

.bg span:nth-child(4) {
  left: 45%;
  width: 80px;
  height: 80px;
  animation-duration: 14s;
  animation-delay: 3s;
}

.bg span:nth-child(5) {
  left: 60%;
  width: 90px;
  height: 90px;
  animation-duration: 9s;
}

.bg span:nth-child(6) {
  left: 70%;
  width: 120px;
  height: 120px;
  animation-duration: 11s;
  animation-delay: 1s;
}

.bg span:nth-child(7) {
  left: 80%;
  width: 35px;
  height: 35px;
  animation-duration: 13s;
}

.bg span:nth-child(8) {
  left: 90%;
  width: 60px;
  height: 60px;
  animation-duration: 7s;
}

.bg span:nth-child(9) {
  left: 25%;
  width: 55px;
  height: 55px;
  animation-duration: 15s;
}

.bg span:nth-child(10) {
  left: 55%;
  width: 28px;
  height: 28px;
  animation-duration: 10s;
}

.bg span:nth-child(11) {
  left: 90%;
  width: 35px;
  height: 35px;
  animation-duration: 10s;
}

.bg span:nth-child(12) {
  left: 8%;
  width: 70px;
  height: 70px;
  animation-duration: 10s;
}