解决iOS不支持background-attachment: fixed

iOS不支持background-attachment: fixed 背景图片固定，造成背景图片放大并模糊不清。

解决办法：文章源自知更鸟-https://zmingcx.com/fixed-background-image-with-ios.html

@supports (-webkit-touch-callout: inherit) {
	.bg {
		background-attachment: scroll !important;
	}
}

但该方法只解决了图像放大并模糊不清问题，并无固定视差效果。文章源自知更鸟-https://zmingcx.com/fixed-background-image-with-ios.html

经测试安卓上很多国产浏览器也同样不支持background-attachment: fixed，手机版火狐和Chrome支持。文章源自知更鸟-https://zmingcx.com/fixed-background-image-with-ios.html

出处：https://stackoverflow.com/questions/20443574/fixed-background-image-with-ios7文章源自知更鸟-https://zmingcx.com/fixed-background-image-with-ios.html 文章源自知更鸟-https://zmingcx.com/fixed-background-image-with-ios.html