css这样实现
html如下
.download-block{
width:90%
height:100px
background:#0b0e32
/*margin: 100px auto 0*/
margin:0 auto
position:absolute
left:0
right:0
transition-duration:2s
opacity:0.7
}
.download-block1{
background:transparent
height:100px
overflow:hidden
position:relative
left:0
top:-100px
right:0
padding-top:100px
transition-duration:2s
opacity:0.7
cursor:pointer
}
.download-block1:hover{
padding-top:0
transition-duration:2s
opacity:0.7
}
HTML代码
<html xmlns="http://www.w3.org/1999/xhtml"><head>
<title>用CSS3动画给一个小球创建跳跃的动画效果</title>
<link rel="stylesheet" type="text/css" href="index.css" />
</head>
<body>
<section class="main">
<div id="ballWrapper">
<div id="ball"></div>
<div id="ballShadow"></div>
</div>
</section>
</body>
</html>
CSS代码（创建一个与html同目录的index.css文件）
#ballWrapper{position:fixedtop:35%left:50%z-index:100margin-left:-70pxwidth:140pxheight:300pxcursor:pointer-webkit-transition:all 5s linear 0s-moz-transition:all 5s linear 0stransition:all 5s linear 0s-webkit-transform:scale(1)-moz-transform:scale(1)-o-transform:scale(1)transform:scale(1)-ms-transform:scale(1)}#ballWrapper:active{cursor:pointer-webkit-transform:scale(0)-moz-transform:scale(0)-o-transform:scale(0)transform:scale(0)-ms-transform:scale(0)}
#ball{position:absolutetop:0z-index:11width:140pxheight:140pxborder-radius:70pxbackground:#bbbbackground:url(data:image/svg+xml background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(187,187,187,1)), color-stop(99%,rgba(119,119,119,1))) background: -webkit-linear-gradient(top, rgba(187,187,187,1) 0%,rgba(119,119,119,1) 99%) background: -o-linear-gradient(top, rgba(187,187,187,1) 0%,rgba(119,119,119,1) 99%) background: -ms-linear-gradient(top, rgba(187,187,187,1) 0%,rgba(119,119,119,1) 99%) background: linear-gradient(top, rgba(187,187,187,1) 0%,rgba(119,119,119,1) 99%) box-shadow: inset 0 -5px 15px rgba(255,255,255,0.4), inset -2px -1px 40px rgba(0,0,0,0.4), 0 0 1px #000 cursor: pointer base64,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)background:-moz-linear-gradient(top,rgba(187,187,187,1) 0,rgba(119,119,119,1) 99%)filter:progid:DXImageTransform.Microsoft.gradient( startColorstr='#bbbbbb', endColorstr='#777777', GradientType=0 )-webkit-animation:jump 1s infinite-moz-animation:jump 1s infinite-o-animation:jump 1s infinite-ms-animation:jump 1s infiniteanimation:jump 1s infinite}
#ball::after{position:absolutetop:10pxleft:30pxz-index:10width:80pxheight:40pxborder-radius:40px/20pxbackground:url(data:image/svg+xml background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(232,232,232,1)), color-stop(1%,rgba(232,232,232,1)), color-stop(100%,rgba(255,255,255,0))) background: -webkit-linear-gradient(top, rgba(232,232,232,1) 0%,rgba(232,232,232,1) 1%,rgba(255,255,255,0) 100%) background: -o-linear-gradient(top, rgba(232,232,232,1) 0%,rgba(232,232,232,1) 1%,rgba(255,255,255,0) 100%) background: -ms-linear-gradient(top, rgba(232,232,232,1) 0%,rgba(232,232,232,1) 1%,rgba(255,255,255,0) 100%) background: linear-gradient(top, rgba(232,232,232,1) 0%,rgba(232,232,232,1) 1%,rgba(255,255,255,0) 100%) content: "" base64,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)background:-moz-linear-gradient(top,rgba(232,232,232,1) 0,rgba(232,232,232,1) 1%,rgba(255,255,255,0) 100%)filter:progid:DXImageTransform.Microsoft.gradient( startColorstr='#e8e8e8', endColorstr='#00ffffff', GradientType=0 )}
#ballShadow{position:absolutebottom:0left:50%z-index:10margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-webkit-transform:scaleY(.3)-moz-transform:scaleY(.3)-o-transform:scaleY(.3)transform:scaleY(.3)-ms-transform:scaleY(.3)-webkit-animation:shrink 1s infinite-moz-animation:shrink 1s infinite-o-animation:shrink 1s infinite-ms-animation:shrink 1s infiniteanimation:shrink 1s infinite}
@-webkit-keyframes jump{0%{top:0-webkit-animation-timing-function:ease-in}
50%{top:140pxheight:140px-webkit-animation-timing-function:ease-out}
55%{top:160pxheight:120pxborder-radius:70px/60px-webkit-animation-timing-function:ease-in}
65%{top:120pxheight:140pxborder-radius:70px-webkit-animation-timing-function:ease-out}
95%{top:0-webkit-animation-timing-function:ease-in}
100%{top:0-webkit-animation-timing-function:ease-in}
}
@-moz-keyframes jump{0%{top:0-moz-animation-timing-function:ease-in}
50%{top:140pxheight:140px-moz-animation-timing-function:ease-out}
55%{top:160pxheight:120pxborder-radius:70px/60px-moz-animation-timing-function:ease-in}
65%{top:120pxheight:140pxborder-radius:70px-moz-animation-timing-function:ease-out}
95%{top:0-moz-animation-timing-function:ease-in}
100%{top:0-moz-animation-timing-function:ease-in}
}
@-o-keyframes jump{0%{top:0-o-animation-timing-function:ease-in}
50%{top:140pxheight:140px-o-animation-timing-function:ease-out}
55%{top:160pxheight:120pxborder-radius:70px/60px-o-animation-timing-function:ease-in}
65%{top:120pxheight:140pxborder-radius:70px-o-animation-timing-function:ease-out}
95%{top:0-o-animation-timing-function:ease-in}
100%{top:0-o-animation-timing-function:ease-in}
}
@-ms-keyframes jump{0%{top:0-ms-animation-timing-function:ease-in}
50%{top:140pxheight:140px-ms-animation-timing-function:ease-out}
55%{top:160pxheight:120pxborder-radius:70px/60px-ms-animation-timing-function:ease-in}
65%{top:120pxheight:140pxborder-radius:70px-ms-animation-timing-function:ease-out}
95%{top:0-ms-animation-timing-function:ease-in}
100%{top:0-ms-animation-timing-function:ease-in}
}
@keyframes jump{0%{top:0animation-timing-function:ease-in}
50%{top:140pxheight:140pxanimation-timing-function:ease-out}
55%{top:160pxheight:120pxborder-radius:70px/60pxanimation-timing-function:ease-in}
65%{top:120pxheight:140pxborder-radius:70pxanimation-timing-function:ease-out}
95%{top:0animation-timing-function:ease-in}
100%{top:0animation-timing-function:ease-in}
}
@-webkit-keyframes shrink{0%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-webkit-animation-timing-function:ease-in}
50%{bottom:30pxmargin-left:-10pxwidth:20pxheight:5pxborder-radius:20pxbackground:rgba(20,20,20,.3)box-shadow:0 0 20px 35px rgba(20,20,20,.3)-webkit-animation-timing-function:ease-out}
100%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-webkit-animation-timing-function:ease-in}
}
@-moz-keyframes shrink{0%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-moz-animation-timing-function:ease-in}
50%{bottom:30pxmargin-left:-10pxwidth:20pxheight:5pxborder-radius:20pxbackground:rgba(20,20,20,.3)box-shadow:0 0 20px 35px rgba(20,20,20,.3)-moz-animation-timing-function:ease-out}
100%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-moz-animation-timing-function:ease-in}
}
@-o-keyframes shrink{0%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-o-animation-timing-function:ease-in}
50%{bottom:30pxmargin-left:-10pxwidth:20pxheight:5pxborder-radius:20pxbackground:rgba(20,20,20,.3)box-shadow:0 0 20px 35px rgba(20,20,20,.3)-o-animation-timing-function:ease-out}
100%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-o-animation-timing-function:ease-in}
}
@-ms-keyframes shrink{0%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-ms-animation-timing-function:ease-in}
50%{bottom:30pxmargin-left:-10pxwidth:20pxheight:5pxborder-radius:20pxbackground:rgba(20,20,20,.3)box-shadow:0 0 20px 35px rgba(20,20,20,.3)-ms-animation-timing-function:ease-out}
100%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)-ms-animation-timing-function:ease-in}
}
@keyframes shrink{0%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)animation-timing-function:ease-in}
50%{bottom:30pxmargin-left:-10pxwidth:20pxheight:5pxborder-radius:20pxbackground:rgba(20,20,20,.3)box-shadow:0 0 20px 35px rgba(20,20,20,.3)animation-timing-function:ease-out}
100%{bottom:0margin-left:-30pxwidth:60pxheight:75pxborder-radius:30px/40pxbackground:rgba(20,20,20,.1)box-shadow:0 0 20px 35px rgba(20,20,20,.1)animation-timing-function:ease-in}
}
看你需要什么样的动画吧，css本身一些也能满足一些动画效果的要求。例如
.ss {
width:200px
height:200x
display:none
transtion: transform 2s
transform:scale(0)
}
.ss-active{
display:block
transform:scale(1)
}
当标签被赋上ss-active的类名是，是一个两秒逐渐放大的效果。示例仅供参考，transform还有其他效果平移，旋转，扭曲之类的。
(手机盲写的，感觉没问题，如有错误欢迎指正。)
