@charset "UTF-8";
.c-under__fv {
	aspect-ratio: 1500/750;
  width: min(90%, 150rem, 100vw);
	margin-inline: auto;
  height: auto;
  position: relative;
  overflow-y: hidden;
	overflow-x: visible;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
  will-change: width;
}
.c-under__fv-bg {
  position: absolute;
  top: -250px;
  left: 50%;
  transform: translateX(-50%);   /* ← これだけ固定。YはGSAPで加算される */
  width: 100%;                   /* 初期値はJSで“vw”に上書きします */
  max-width: none;               /* 100vw まで広げたいので制限なし */
  height: calc(100% + 500px);
  background-size: cover;        /* お好みで cover / 110% など */
  background-position: center top;
  will-change: transform, width;
  z-index: 0;
}
@media (max-width: 834px) {
  .c-under__fv {
    aspect-ratio: 4/3;
  }
	.c-under__fv-bg {
		background-size: cover;
	}
}