.st-skew-right-up {
	position: relative;
	z-index: 0;
}

	.st-skew-right-up::after {
		content: '';
		position: absolute;
		left: 0;
		top: 0;
		/*四角形を傾けます*/
		transform: skewY(-5deg);
		transform-origin: bottom left;
		z-index: -1;
		width: 100%;
		height: 100%;
		background-color: #EFE9E3;
	}