7个CSS Background Image小技巧

1. 背景图片根据窗口大小自适应

body {
  background-image: url('https://images.unsplash.com/photo-1573480813647-552e9b7b5394?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2253&q=80');
  background-repeat: no-repeat;
  background-position: center;
  background-attachment: fixed;
  background-size: cover;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
}

效果:

2. 同时叠加显示多张背景图

body {
  background-image: url(https://image.flaticon.com/icons/svg/748/748122.svg), url(https://images.unsplash.com/photo-1478719059408-592965723cbc?ixlib=rb-1.2.1&auto=format&fit=crop&w=2212&q=80);
  background-position: center, top;
  background-repeat: repeat, no-repeat;
  background-size: contain, cover;
}

效果:

3. 创建三角形背景图

body {
  margin: 0;
  padding: 0;
}

div {
  position: absolute;
  height: 100vh;
  width: 100vw;
}

.day {
  background-image: url("https://images.unsplash.com/photo-1477959858617-67f85cf4f1df?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2613&q=80");
  background-size: cover;
  background-repeat: no-repeat;
}

.night {
  background-image: url("https://images.unsplash.com/photo-1493540447904-49763eecf55f?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  background-size: cover;
  background-repeat: no-repeat;
  clip-path: polygon(100vw 0, 0% 0vh, 100vw 100vh);
}

效果:

4. 背景图添加渐变效果

body {
  background-image: 
    linear-gradient(4deg, rgba(38,8,31,0.75) 30%, rgba(213,49,127,0.3) 45%, rgba(232,120,12,0.3) 100%),
    url("https://images.unsplash.com/photo-1503803548695-c2a7b4a5b875?ixlib=rb-1.2.1&auto=format&fit=crop&w=2250&q=80");
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position: center
}

效果:

5. 颜色渐变背景图动画

@keyframes background-overlay-animation {
  0% {
    background-image:
      linear-gradient(4deg, rgba(255, 78, 36, 0.3) 50%, rgba(255, 78, 36, 0.3) 100%), url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }

  25% {
    background-image:
      linear-gradient(4deg, rgba(213, 49, 127, 0.3) 50%, rgba(213, 49, 127, 0.3) 100%), url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }

  50% {
    background-image:
      linear-gradient(4deg, rgba(36, 182, 255, 0.3) 50%, rgba(36, 182, 255, 1) 100%),
      url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }

  100% {
    background-image:
      linear-gradient(4deg, rgba(0, 255, 254, 0.3) 50%, rgba(0, 255, 254, 0.3) 100%),
      url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }
}

@-webkit-keyframes background-overlay-animation {
  0% {
    background-image:
      linear-gradient(4deg, rgba(255, 78, 36, 0.3) 50%, rgba(255, 78, 36, 0.3) 100%) url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }

  25% {
    background-image:
      linear-gradient(4deg, rgba(213, 49, 127, 0.3) 50%, rgba(213, 49, 127, 0.3) 100%),
      url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }

  50% {
    background-image:
      linear-gradient(4deg, rgba(36, 182, 255, 0.3) 50%, rgba(36, 182, 255, 1) 100%),
      url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }

  100% {
    background-image:
      linear-gradient(4deg, rgba(0, 255, 254, 0.3) 50%, rgba(0, 255, 254, 0.3) 100%),
      url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  }
}

body {
  background-image: url("https://images.unsplash.com/photo-1559310589-2673bfe16970?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2250&q=80");
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position: center;
  animation-name: background-overlay-animation;
  animation-duration: 5s;
  animation-iteration-count: infinite;
  animation-direction: alternate;
  animation-timing-function: linear;
}

效果:

6. 网格背景图

body {
 margin: 0;
  padding: 0;
}

.container {
  position: absolute;
  width: 100%;
  height: 100%;
  background: black;
  display: grid;
  grid-template-columns: 25fr 30fr 40fr 15fr;
  grid-template-rows: 20fr 45fr 5fr 30fr;
  grid-gap: 20px;
  .item_img {
    background-image: url('https://images.unsplash.com/photo-1499856871958-5b9627545d1a?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2207&q=80');
  background-repeat: no-repeat;
  background-position: center;
  background-attachment: fixed;
  background-size: cover;
}
}

效果:

7. 背景图作为文本颜色

body {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  width: 100%;
  text-align: center;
  min-height: 100vh;
  font-size: 120px;
  font-family:Arial, Helvetica, sans-serif;
}

h1 {
   background-image: url("https://images.unsplash.com/photo-1462275646964-a0e3386b89fa?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2600&q=80");
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
}

效果:

原文链接：CSS Background Image Tutorial With Examples