:root {
	--aspect: 0.46095126247798;		// 縦/横
}
#sx {
	position: relative;
	  height: calc(98vw * var(--aspect));
	   width: 98vw;
	         background: url(/img/isca_top_back.jpg);
	background-position: center center;
	    background-size: 98vw calc(98vw * var(--aspect));
	  background-repeat: no-repeat;
	             border: solid 1px #000;
  transition: 0.5s;
}
.slider {
	position: relative;
	   width: 4000px;
  transition: 0.5s;
}
.slider1 {
	float:left;
	height: calc(98vw * var(--aspect));
	 width: 98vw;
	  background-size: 98vw calc(98vw * var(--aspect));
	background-repeat:  no-repeat;
	       transition: 2s;
}