视频在标题中，容器的比例是可变的，宽度为100%，高度为65VH，视频必须覆盖整个容器，从上到下或从左到右剪切。
我可以使用:object-Fit:Cover通过本地视频来实现，但这不能用于YouTube iframe。
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.wp-custom-header {
position: relative;
overflow: hidden;
width: 100vw;
height: 65vh;
}
.wp-custom-header video,
.wp-custom-header iframe {
/* may be video or iframe depends if the user uploads a video, or insert YouTube */
position: absolute;
top: 0;
left: 0;
height: 100%;
width: 100%;
object-fit: cover;
}<div id="wp-custom-header" class="wp-custom-header">
<iframe id="wp-custom-header-video" allowfullscreen="1" title="YouTube video player" src="https://www.youtube.com/embed/rzfmZC3kg3M?autoplay=1&controls=0&disablekb=1&fs=0&iv_load_policy=3&loop=1&modestbranding=1&playsinline=1&rel=0&showinfo=0&enablejsapi=1&origin=http%3A%2F%2Flocalhost&widgetid=1" allow="accelerometer; encrypted-media; gyroscope; picture-in-picture" width="1920" height="677" frameborder="0"></iframe><button type="button" id="wp-custom-header-video-button" class="wp-custom-header-video-button wp-custom-header-video-pause" style="z-index: 9999999;position: relative;">Play</button>
</div>null
看看这个。 有帮助吗？ 顺便说一句，请分享一些我更能理解这个问题的东西。
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* { box-sizing: border-box; }
.video-background {
background: #000;
position: fixed;
top: 0; right: 0; bottom: 0; left: 0;
z-index: -99;
}
.video-foreground,
.video-background iframe {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
pointer-events: none;
}
#vidtop-content {
top: 0;
color: #fff;
}
.vid-info { position: absolute; top: 0; right: 0; width: 33%; background: rgba(0,0,0,0.3); color: #fff; padding: 1rem; font-family: Avenir, Helvetica, sans-serif; }
.vid-info h1 { font-size: 2rem; font-weight: 700; margin-top: 0; line-height: 1.2; }
.vid-info a { display: block; color: #fff; text-decoration: none; background: rgba(0,0,0,0.5); transition: .6s background; border-bottom: none; margin: 1rem auto; text-align: center; }
@media (min-aspect-ratio: 16/9) {
.video-foreground { height: 300%; top: -100%; }
}
@media (max-aspect-ratio: 16/9) {
.video-foreground { width: 300%; left: -100%; }
}
@media all and (max-width: 600px) {
.vid-info { width: 50%; padding: .5rem; }
.vid-info h1 { margin-bottom: .2rem; }
}
@media all and (max-width: 500px) {
.vid-info .acronym { display: none; }
}<div class="video-background">
<div class="video-foreground">
<iframe src="https://www.youtube.com/embed/W0LHTWG-UmQ?controls=0&showinfo=0&rel=0&autoplay=1&loop=1&playlist=W0LHTWG-UmQ" frameborder="0" allowfullscreen></iframe>
</div>
</div>
<div id="vidtop-content">
<div class="vid-info">
<h1>YouTube Fullscreen Background Demo</h1>
<p>The International Space Station orbits the Earth every 92 minutes, with its crew seeing a sunrise 15 times a day. It exists as a scientific, educational, and engineering platform in low orbit, 330 to 435 kilometres above the Earth.
<p>Original timelapse by Riccardo Rossi (ISAA), used under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Raw photos courtesy of http://eol.jsc.nasa.gov/
<a href="/500/Use-YouTube-Videos-as-Fullscreen-Web-Page-Backgrounds">Full article</a>
</div>
</div>