CSS如何显示一个从左上角开始展开的弹窗，最终是显示在屏幕中间，思路是什么，请大神指导下。

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CSS如何显示一个从左上角开始展开的弹窗，最终是显示在屏幕中间，思路是什么，请大神指导下。,第1张

思路应该是一个从0%到100%的动画展开的效果，大概需要写0%，50%，100%三个样式。 弹窗的css代码大概是:position: fixedz-index: 2000left: 0top: 0这样弹窗的左上角原点在页面最左上角，如果要调整位置要用CSS变换特效(transform)的平移translate函数达到目的: translate(x, y)（长度值或者百分比）：在水平方向、垂直方向平移元素。    translateX(value)：水平方向平移。    translateY(value)：垂直方向平移。    scale(x, y)、scaleX(value)、scaleY(value)：在水平方向、垂直方向或者两个方向上缩放元素。    rotate()、rotateX()、rotateY()、rotateZ()：rotate支持3D效果，可在x、y、z轴上旋转元素。    skew()、skewX()、skewY()：在水平方向、垂直方向或者两个方向倾斜一定的角度。  另外弹窗展开的动画要用到css3的动画属性:    animation-delay：设置动画开始前的延迟时间。    animation-direction：设置动画循环播放的时候是否方向播放，包含normal和alternate两个值。    animation-duration：设置动画播放持续的时间。    animation-interacion-count：设置动画的播放次数，可以为具体数据或者无限循环关键字infinite。    animation-name：指定动画名称。    animation-play-state：允许动画暂停和重新播放，包含running、paused。    animation-timing-function：指定如何计算中间动画值，

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}

}

要创建 CSS3 动画，你需要了解 @keyframes 规则。

@keyframes 规则是创建动画。

@keyframes 规则内指定一个 CSS 样式和动画将逐步从目前的样式更改为新的样式。