.bgextend{
	animation-name:bgextendAnimeBase;
	animation-duration:1s;
	animation-fill-mode:forwards;
	position: relative;
	overflow: hidden;/*　はみ出た色要素を隠す　*/
    display: inline-block; /* ブロックにしてもOK */
	opacity:0;
}

@keyframes bgextendAnimeBase{
  from {
    opacity:0;
  }

  to {
    opacity:1;  
}
}

/*中の要素*/
.bgappear{
	animation-name:bgextendAnimeSecond;
	animation-duration:2s;
	animation-delay: 0.8s;
	animation-fill-mode:forwards;
	opacity: 0;
}

@keyframes bgextendAnimeSecond{
	0% {
	opacity: 0;
	}
	100% {
	opacity: 1;
}
}

/*左から右*/
.bgLRextend::before{
	animation-name:bgLRextendAnime;
	animation-duration:2s;
	animation-fill-mode:forwards;
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: #505050;/*伸びる背景色の設定*/
}
@keyframes bgLRextendAnime{
	0% {
		transform-origin:left;
		transform:scaleX(0);
	}
	50% {
		transform-origin:left;
		transform:scaleX(1);
	}
	50.001% {
		transform-origin:right;
	}
	100% {
		transform-origin:right;
		transform:scaleX(0);
	}
}

/* スクロールをしたら出現する要素にはじめに透過0を指定　*/
.bgappearTrigger,
.bgLRextendTrigger{
    opacity: 0;
}