html - slider 背景图像不显示在 ios 移动设备上？

Question

网站背景图像显示在笔记本电脑和安卓手机等所有其他设备上。但不仅限于 iOS 移动版。我什至将图像调整为 768 px * 365 px 但无法正常工作。

.bg-img {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
    background-position: center;
    background-size: cover;
    background-attachment: fixed;
}

.bg-img .overlay {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    opacity: .8;
    background: #1C1D21;
}

<!-- Background Image -->
		<!-- large device only -->
		<div class="visible-xl visible-lg visible-md hidden-sm hidden-xs">
			<div class="bg-img" style="background-image: url('./img/team/background-clouds-dark-957002.jpg');">
			<div class="overlay"></div>
			</div>
		</div>
		<!-- mobile only -->
		<div class="visible-xs visible-sm hidden-md hidden-lg hidden-xl">
			<div class="bg-img" style="background-image: url('./img/team/Smallsize.jpg');">
				<div class="overlay"></div>
			</div>
		</div>
		<!-- /Background Image -->

Answer 1

css 取决于浏览器而不是 os 请安装chrome进行测试。或为单独的浏览器使用 css

 #urID{
        background:url("../images/bg.jpg") no-repeat scroll right top #000000;
        -o-background-size: cover;
        -moz-background-size: cover;
        -webkit-background-size:cover;
        background-size: cover;
    }