一个Banner, 背景添加一个图片:

HTML:

<div class="banner">
  <div class="banner-bg"></div>
  Other Content
</div>

CSS:

.banner {
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.banner-bg {
  background-image: url('/demo.png');
  position: absolute;
  width: 100%;
  height: 100%;
  background-size: cover;
  z-index: -1;
  opacity: 0.4;
  transform: rotate(-5deg);
  left: 0;
  top: 0;
}

说明:

参考: