iOS doesn't swap vh and vw like you would expect in landscape view, so we have to set these manually

ios_vh_fix.css

/* fix iOS bug not displaying 100vh correctly */

/* iPad Pro */
@media only screen and (min-device-width : 1024px) and (max-device-width : 1366px) and (orientation : landscape) {
	.fullheight {
		height: 1024px;
	}
}
@media only screen and (min-device-width : 1024px) and (max-device-width : 1366px) and (orientation : portrait) {
	.fullheight {
		height: 1366px;
	}
}

/* iPad */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : landscape) {
	.fullheight {
		height: 768px;
	}
}
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : portrait) {
	.fullheight {
		height: 1024px;
	}
}

/* iPhone 6/7 plus */
@media only screen and (min-device-width: 414px) and (max-device-height: 736px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2) {
	.fullheight {
		height: 414px;
	}
}
@media only screen and (min-device-width: 414px) and (max-device-height: 736px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2) {
	.fullheight {
		height: 736px;
	}
}

/* iPhone 6/7 */
@media only screen and (min-device-width: 375px) and (max-device-height: 667px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2) {
	.fullheight {
		height: 375px;
	}
}
@media only screen and (min-device-width: 375px) and (max-device-height: 667px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2) {
	.fullheight {
		height: 667px;
	}
}


/* iPhone5 */
@media only screen and (min-device-width: 320px) and (max-device-height: 568px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2) {
	.fullheight {
		height: 320px;
	}
}
@media only screen and (min-device-width: 320px) and (max-device-height: 568px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2) {
	.fullheight {
		height: 568px;
	}
}

/* iPhone 4 */
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) and (orientation : landscape) and (-webkit-min-device-pixel-ratio : 2) {
	.fullheight {
		height: 320px;
	}
}
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) and (orientation : portrait) and (-webkit-min-device-pixel-ratio : 2) {
	.fullheight {
		height: 480px;
	}
}