使用CSS3动画扩展圆圈

Question

我试图这样做,当页面加载圆圈出现,这很好,但我需要它们向外生长,从中心到小到大,而不是从左上角:

你可以看到我目前在这里:http://thomasbritton.co.uk/projects/ebrd/

理想情况下,希望这可以在CSS中完成,但如果它更容易/更稳定,可以使用JS.

有任何想法吗？

这是我的动画部分的css:

.circle a {
  border-radius: 150px;
  color: #fff;
  height: 0;
  position: absolute;
  text-decoration: none;
  width: 0;
}

.circle a.grow {
  -webkit-animation-name: grow;
  -webkit-animation-duration: 2.2s;
  -webkit-animation-timing-function: ease;
  -webkit-animation-iteration-count: 1;
  -webkit-animation-direction: normal;
  -webkit-animation-delay: 0;
  -webkit-animation-play-state: running;
  -webkit-animation-fill-mode: forwards;

  -moz-animation-name: grow;
  -moz-animation-duration: 2.2s;
  -moz-animation-timing-function: ease;
  -moz-animation-iteration-count: 1;    
  -moz-animation-direction: normal;
  -moz-animation-delay: 0;
  -moz-animation-play-state: running;
  -moz-animation-fill-mode: forwards;

  animation-name: grow;
  animation-duration: 2.2s;
  animation-timing-function: ease;
  animation-iteration-count: 1; 
  animation-direction: normal;
  animation-delay: 0;
  animation-play-state: running;
  animation-fill-mode: forwards;
}

@-webkit-keyframes grow {
  0% { -moz-transform: scale(0); }
  100% { -moz-transform: scale(1); }
}

@-moz-keyframes grow {
  0% { -moz-transform: scale(0); }
  100% { -moz-transform: scale(1); height: 168px; width: 168px; }
}

@keyframes grow {
  0% { -moz-transform: scale(0); }
  100% { -moz-transform: scale(1); }
}

Answer 1

以下是您需要做的一个粗略示例:jsfiddle.net/UxtJV/.它使用一些JS来添加一个类来为圆圈设置动画.这是width,height,top和left属性的动画和它被赋予position: relative.

div.circle {
    position: relative;

    width: 0px;
    height: 0px;
    top: 50px;
    left: 50px;

    -webkit-transition-duration: 2s;
    -webkit-transition-property: all;
    -webkit-transition-timing-function: ease-in-out;

    text-align: center;
    background: red;
    color: white;
    border-radius: 100%;
    padding: 20px;
    overflow: hidden;
}

div.circle.open {
    top: 0px;
    left: 0px;
    width: 100px;
    height: 100px;
}?