视频缩略图悬停播放几秒钟，然后显示缩略图。- Javascript

// HTML代码
<div class="video-container">
  <video class="video" src="video.mp4" poster="thumbnail.jpg"></video>
  <img class="thumbnail" src="thumbnail.jpg" alt="Thumbnail">
</div>

// CSS代码
.video-container {
  position: relative;
  width: 300px;
  height: 200px;
}

.video {
  width: 100%;
  height: 100%;
}

.thumbnail {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  cursor: pointer;
}

// JavaScript代码
var video = document.querySelector('.video');
var thumbnail = document.querySelector('.thumbnail');

thumbnail.addEventListener('mouseover', function() {
  video.play();
});

thumbnail.addEventListener('mouseout', function() {
  video.pause();
});