极限高度header-background-video？

Question

我正在制作放在中和 header 中的背景视频。 header 的高度仅为 100%-257 像素，因此页面的其余部分在加载页面时可见。但是，我无法让视频成为 header 内的完整背景。它总是在 full-size 中溢出 header 容器。我错过了一些 css 吗？非常感谢您的帮助！

Html:

<header id="home">
        <div id="videoBackground">
            <video loop="loop" playsinline="playsinline" autoplay="autoplay" muted="muted" poster="Images/posterImg.png" id="videoBackgroundVideo">
                <source type="video/mp4" src="Images/BillVid.mp4">
            </video>    
        </div>
        <h1> This is a title</h1>
        <h2> This is a subtitle</h2>
        <div id="welcomeMessage">
            <h3> Welcome at <span>My Page</span></h3>
            <img src="Images/LogoRoundWhite.png" id="homeLogoWhite" style="border-style:none;" />
        </div>
    </header>

CSS:

header{
    padding-top: 100px;
    padding-bottom: 30px;
    margin-top: 0px;
    min-height: 400px;
    text-align: center;
    height: calc(100% - 257px);
    justify-content: center;
    overflow: hidden;
}

#videoBackground {
    position: absolute;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    z-index: -10;
}

#videoBackgroundVideo {
    position: absolute;
    top: 50%;
    left: 50%;
    width: auto;
    height: auto;
    min-width: 100%;
    min-height: 100%;
    -webkit-transform: translate(-50%, -50%);
        -moz-transform: translate(-50%, -50%);
            -ms-transform: translate(-50%, -50%);
               transform: translate(-50%, -50%);
}

Answer 1

尝试添加

header {
    position:relative;
}

绝对定位的元素将根据最近的父元素定位自己 position:relative;

如果它不存在，它只会根据我认为的 body 标签定位自己，这也是为什么 overflow:hidden 可能没有效果的原因。

Answer 2

这很好用。从 #videoBackgroundVideo 元素中删除 min-height: 100%;。

header{
    padding-top: 100px;
    padding-bottom: 30px;
    margin-top: 0px;
    min-height: 400px;
    text-align: center;
    height: calc(100% - 257px);
    justify-content: center;
    overflow: hidden;
}

#videoBackground {
    position: absolute;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    z-index: -10;
}

#videoBackgroundVideo {
    position: absolute;
    top: 50%;
    left: 50%;
    width: auto;
    height: auto;
    min-width: 100%;
    /* min-height: 100%; */
    -webkit-transform: translate(-50%, -50%);
        -moz-transform: translate(-50%, -50%);
            -ms-transform: translate(-50%, -50%);
               transform: translate(-50%, -50%);
}

<header id="home">
        <div id="videoBackground">
            <video loop="loop" playsinline="playsinline" autoplay="autoplay" muted="muted" poster="Images/posterImg.png" id="videoBackgroundVideo">
                <source type="video/mp4" src="Images/BillVid.mp4">
            </video>    
        </div>
        <h1> This is a title</h1>
        <h2> This is a subtitle</h2>
        <div id="welcomeMessage">
            <h3> Welcome at <span>My Page</span></h3>
            <img src="Images/LogoRoundWhite.png" id="homeLogoWhite" style="border-style:none;" />
        </div>
    </header>

https://jsfiddle.net/Sampath_Madhuranga/xk8henbo/1/

极限高度header-background-video？

Limit height of header-background-video?

css

video

background

fullscreen