动态渐变背景

案例一、

span>Meditation</span>

@import url("https://fonts.googleapis.com/css2?family=Quicksand&display=swap");

:root {
  font-size: 15px;
}

body {
  font-family: "Quicksand", sans-serif;
  margin: 0;
  min-height: 100vh;
  background-color: #e493d0;
  background-image: radial-gradient(
      closest-side,
      rgba(235, 105, 78, 1),
      rgba(235, 105, 78, 0)
    ),
    radial-gradient(closest-side, rgba(243, 11, 164, 1), rgba(243, 11, 164, 0)),
    radial-gradient(
      closest-side,
      rgba(254, 234, 131, 1),
      rgba(254, 234, 131, 0)
    ),
    radial-gradient(
      closest-side,
      rgba(170, 142, 245, 1),
      rgba(170, 142, 245, 0)
    ),
    radial-gradient(
      closest-side,
      rgba(248, 192, 147, 1),
      rgba(248, 192, 147, 0)
    );
  background-size: 130vmax 130vmax, 80vmax 80vmax, 90vmax 90vmax,
    110vmax 110vmax, 90vmax 90vmax;
  background-position: -80vmax -80vmax, 60vmax -30vmax, 10vmax 10vmax,
    -30vmax -10vmax, 50vmax 50vmax;
  background-repeat: no-repeat;
  animation: 10s movement linear infinite;
}

body::after {
  content: "";
  display: block;
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

span {
  position: relative;
  z-index: 10;
  display: flex;
  min-height: 100vh;
  width: 100%;
  justify-content: center;
  align-items: center;
  font-size: 5rem;
  color: transparent;
  text-shadow: 0px 0px 1px rgba(255, 255, 255, 0.6),
    0px 4px 4px rgba(0, 0, 0, 0.05);
  letter-spacing: 0.2rem;
}

@keyframes movement {
  0%,
  100% {
    background-size: 130vmax 130vmax, 80vmax 80vmax, 90vmax 90vmax,
      110vmax 110vmax, 90vmax 90vmax;
    background-position: -80vmax -80vmax, 60vmax -30vmax, 10vmax 10vmax,
      -30vmax -10vmax, 50vmax 50vmax;
  }
  25% {
    background-size: 100vmax 100vmax, 90vmax 90vmax, 100vmax 100vmax,
      90vmax 90vmax, 60vmax 60vmax;
    background-position: -60vmax -90vmax, 50vmax -40vmax, 0vmax -20vmax,
      -40vmax -20vmax, 40vmax 60vmax;
  }
  50% {
    background-size: 80vmax 80vmax, 110vmax 110vmax, 80vmax 80vmax,
      60vmax 60vmax, 80vmax 80vmax;
    background-position: -50vmax -70vmax, 40vmax -30vmax, 10vmax 0vmax,
      20vmax 10vmax, 30vmax 70vmax;
  }
  75% {
    background-size: 90vmax 90vmax, 90vmax 90vmax, 100vmax 100vmax,
      90vmax 90vmax, 70vmax 70vmax;
    background-position: -50vmax -40vmax, 50vmax -30vmax, 20vmax 0vmax,
      -10vmax 10vmax, 40vmax 60vmax;
  }
}

案例二、

<div class="text">渐变背景动画</div>

body {
  /* 初始化 取消内外边距 */
  margin: 0;
  padding: 0;
  /* 100%窗口高度 */
  height: 100vh;
  /* 弹性布局 水平垂直居中 */
  display: flex;
  justify-content: center;
  align-items: center;
  /* 渐变背景 */
  background: linear-gradient(
    125deg,
    #2c3e50,
    #27ae60,
    #2980b9,
    #e74c3c,
    #8e44ad
  );
  /* 指定背景图像的大小 */
  background-size: 500%;
  /* 执行动画：动画名 时长 线性的 无限次播放 */
  animation: bgAnimation 20s linear infinite;
}
.text {
  color: #fff;
  font-size: 30px;
  /* 字间距 */
  letter-spacing: 15px;
}

/* 定义动画 */
@keyframes bgAnimation {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}