Css3的动画效果给我们的网站增加不少乐趣特色，你如果喜欢个性动感的效果，学学CSS的动画过渡很有帮助。

一、Html布局

<a rel="hover-shadow" class="button hover-shadow">Hover Shadow</a>

二、Css代码
1、给button添加样式

.button {
  margin: .4em;
  padding: 1em;
  cursor: pointer;
  background: #e1e1e1;
  text-decoration: none;
  color: #666666;
  /* Prevent highlight colour when element is tapped */
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

2、给Hover Shadow添加动画效果和兼容

/* Hover Shadow */
@keyframes hover {
  50% {
    -webkit-transform: translateY(-3px);
    -ms-transform: translateY(-3px);
    transform: translateY(-3px);
  }
  100% {
    -webkit-transform: translateY(-6px);
    -ms-transform: translateY(-6px);
    transform: translateY(-6px);
  }
}
@-webkit-keyframes hover-shadow {
  0% {
    -webkit-transform: translateY(6px);
    transform: translateY(6px);
    opacity: .4;
  }
  50% {
    -webkit-transform: translateY(3px);
    transform: translateY(3px);
    opacity: 1;
  }
  100% {
    -webkit-transform: translateY(6px);
    transform: translateY(6px);
    opacity: .4;
  }
}
@keyframes hover-shadow {
  0% {
    -webkit-transform: translateY(6px);
    -ms-transform: translateY(6px);
    transform: translateY(6px);
    opacity: .4;
  }
  50% {
    -webkit-transform: translateY(3px);
    -ms-transform: translateY(3px);
    transform: translateY(3px);
    opacity: 1;
  }
  100% {
    -webkit-transform: translateY(6px);
    -ms-transform: translateY(6px);
    transform: translateY(6px);
    opacity: .4;
  }
}
.hover-shadow {
  display: inline-block;
  position: relative;
  -webkit-transition-duration: 0.3s;
  transition-duration: 0.3s;
  -webkit-transition-property: -webkit-transform;
  transition-property: transform;
  -webkit-transform: translateZ(0);
  -ms-transform: translateZ(0);
  transform: translateZ(0);
  box-shadow: 0 0 1px rgba(0, 0, 0, 0);
}
.hover-shadow:before {
  pointer-events: none;
  position: absolute;
  z-index: -1;
  content: '';
  top: 100%;
  left: 5%;
  height: 10px;
  width: 90%;
  opacity: 0;
  background: -webkit-radial-gradient(center, ellipse, rgba(0, 0, 0, 0.35) 0%, rgba(0, 0, 0, 0) 80%);
  background: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.35) 0%, rgba(0, 0, 0, 0) 80%);
  /* W3C */
  -webkit-transition-duration: 0.3s;
  transition-duration: 0.3s;
  -webkit-transition-property: -webkit-transform, opacity;
  transition-property: transform, opacity;
}
.hover-shadow:hover {
  -webkit-transform: translateY(-6px);
  -ms-transform: translateY(-6px);
  transform: translateY(-6px);
  -webkit-animation-name: hover;
  animation-name: hover;
  -webkit-animation-duration: 1.5s;
  animation-duration: 1.5s;
  -webkit-animation-delay: 0.3s;
  animation-delay: 0.3s;
  -webkit-animation-timing-function: linear;
  animation-timing-function: linear;
  -webkit-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
  -webkit-animation-direction: alternate;
  animation-direction: alternate;
}
.hover-shadow:hover:before {
  opacity: .4;
  -webkit-transform: translateY(6px);
  -ms-transform: translateY(6px);
  transform: translateY(6px);
  -webkit-animation-name: hover-shadow;
  animation-name: hover-shadow;
  -webkit-animation-duration: 1.5s;
  animation-duration: 1.5s;
  -webkit-animation-delay: .3s;
  animation-delay: .3s;
  -webkit-animation-timing-function: linear;
  animation-timing-function: linear;
  -webkit-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
  -webkit-animation-direction: alternate;
  animation-direction: alternate;
}

三、兼容性

适用浏览器：360、FireFox、Chrome、Safari、Opera、傲游、搜狗、世界之窗. 不支持IE8及以下浏览器。