见下图：
http://i.imgur.com/3vTrB.png
在后台查看那些透明圆圈？我想要做的是让它们从下往上动画,然后手动跳下(屏幕外)并重新开始动画.圆圈很简单< span>具有border-radius的元素可以产生圆形效果.
这可能与CSS3有关,还是我需要javascript？如果可能的话,我也希望在向上移动的同时在X范围内随机移动圆圈.我会想象随机性需要javascript吗？
如果可能的话,我会很感激有关如何制作它的一些建议/想法.如果不能用CSS,Javascript库也是受欢迎的！
解决方法
这是一个纯粹的CSS
demonstration(改编自
tutorial),它依赖于动画属性.更新：感谢TonioElGringo,现在气泡也会向侧面移动,虽然运动是有节奏的,而不是随机的：
html,body,#bubbles { height: 100% }
body { overflow: hidden }
#bubbles { padding: 100px 0 }
.bubble {
width: 60px;
height: 60px;
background: #ffb200;
border-radius: 200px;
-moz-border-radius: 200px;
-webkit-border-radius: 200px;
position: absolute;
}
.x1 {
-webkit-transform: scale(0.9);
-moz-transform: scale(0.9);
transform: scale(0.9);
opacity: 0.2;
-webkit-animation: moveclouds 15s linear infinite,sideWays 4s ease-in-out infinite alternate;
-moz-animation: moveclouds 15s linear infinite,sideWays 4s ease-in-out infinite alternate;
-o-animation: moveclouds 15s linear infinite,sideWays 4s ease-in-out infinite alternate;
}
.x2 {
left: 200px;
-webkit-transform: scale(0.6);
-moz-transform: scale(0.6);
transform: scale(0.6);
opacity: 0.5;
-webkit-animation: moveclouds 25s linear infinite,sideWays 5s ease-in-out infinite alternate;
-moz-animation: moveclouds 25s linear infinite,sideWays 5s ease-in-out infinite alternate;
-o-animation: moveclouds 25s linear infinite,sideWays 5s ease-in-out infinite alternate;
}
.x3 {
left: 350px;
-webkit-transform: scale(0.8);
-moz-transform: scale(0.8);
transform: scale(0.8);
opacity: 0.3;
-webkit-animation: moveclouds 20s linear infinite,sideWays 4s ease-in-out infinite alternate;
-moz-animation: moveclouds 20s linear infinite,sideWays 4s ease-in-out infinite alternate;
-o-animation: moveclouds 20s linear infinite,sideWays 4s ease-in-out infinite alternate;
}
.x4 {
left: 470px;
-webkit-transform: scale(0.75);
-moz-transform: scale(0.75);
transform: scale(0.75);
opacity: 0.35;
-webkit-animation: moveclouds 18s linear infinite,sideWays 2s ease-in-out infinite alternate;
-moz-animation: moveclouds 18s linear infinite,sideWays 2s ease-in-out infinite alternate;
-o-animation: moveclouds 18s linear infinite,sideWays 2s ease-in-out infinite alternate;
}
.x5 {
left: 150px;
-webkit-transform: scale(0.8);
-moz-transform: scale(0.8);
transform: scale(0.8);
opacity: 0.3;
-webkit-animation: moveclouds 7s linear infinite,sideWays 1s ease-in-out infinite alternate;
-moz-animation: moveclouds 7s linear infinite,sideWays 1s ease-in-out infinite alternate;
-o-animation: moveclouds 7s linear infinite,sideWays 1s ease-in-out infinite alternate;
}
@-webkit-keyframes moveclouds {
0% {
top: 500px;
}
100% {
top: -500px;
}
}
@-webkit-keyframes sideWays {
0% {
margin-left:0px;
}
100% {
margin-left:50px;
}
}
@-moz-keyframes moveclouds {
0% {
top: 500px;
}
100% {
top: -500px;
}
}
@-moz-keyframes sideWays {
0% {
margin-left:0px;
}
100% {
margin-left:50px;
}
}
@-o-keyframes moveclouds {
0% {
top: 500px;
}
100% {
top: -500px;
}
}
@-o-keyframes sideWays {
0% {
margin-left:0px;
}
100% {
margin-left:50px;
}
}