当悬停在圆圈（黄色）内时，边界外（高度和宽度）需要从中心增加（动画）并在同一位置圆圈？答案

【问题标题】：When hover inside circle(yellow) outside border (height and width) need to be increased (animate) from center and circle in same position?当悬停在圆圈（黄色）内时，边界外（高度和宽度）需要从中心增加（动画）并在同一位置圆圈？
【发布时间】：2017-07-19 08:55:45
【问题描述】：

当鼠标悬停在圆形（黄色）内时，边框（高度和宽度）需要从中心增加（动画），圆形（黄色）在边框内的中心位置

{
  background-color: yellow;
  border-radius: 50%;
  border: 1px solid grey;
  padding: 10px;
}

.circle {
  position: absolute;
  border: 5px solid #000;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  transition: width 0.5s, height 0.5s;
}

.circle:hover {
  width: 60px;
  height: 60px;
}

<div class="circle">
  <span><a><i class="icon_social fa fa-facebook-square"></i></a></span>
</div>

【问题讨论】：

标签： javascript html css jquery-ui css-transitions

【解决方案1】：

你可以写 css 即

 

html {
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
}
*, *:before, *:after {
  -moz-box-sizing: inherit;
  -webkit-box-sizing: inherit;
  box-sizing: inherit;
}
.circle {
  border-radius: 50%;
  height: 40px;
  margin-top: 20px;
  position: relative;
  transition: all 0.5s ease 0s;
  width: 40px;
}
.circle::before {
  border: 4px solid #000;
  border-radius: 50%;
  bottom: 0;  
  content: "";
  height: 100%;
  left: 0;
  margin: auto;
  position: absolute;
  right: 0;
  top: 0;
  -webkit-transition: all 0.5s ease 0s;
  transition: all 0.5s ease 0s;
  width: 100%;
}
.circle:hover::before {
  -webkit-transform: scale(1.2);
  transform: scale(1.2);
}
.circle span {
  display: block;
  height: 100%;
  text-align: center;
  vertical-align: middle;
  width: 100%;
}
.circle a {
  left: 50%;
  margin: auto;
  position: absolute;
  text-align: center;
  top: 50%;
  transform: translate(-50%, -50%);
}
i {
  background-color: yellow;
  border: 1px solid grey;
  border-radius: 50%;  
  display: block;
  padding: 10px;
  text-align: center;
  vertical-align: middle;
}

<div class="circle">
  <span><a><i class="icon_social fa fa-facebook-square"></i></a></span>
</div>

【讨论】：

【解决方案2】：

它可以帮助你..！

* {box-sizing: border-box;}
.holder {position: relative; display: inline-block; padding: 10px; border-radius: 50%; margin: 100px;}
.circle {position: absolute; top: 0px; left: 0px; border: solid 5px #000; width: 100%; height: 100%; border-radius: 50%; transition: all 0.3s ease;}
i {background: yellow; padding: 10px; border-radius: 50%;}
.circle:hover {transform: scale(1.2);}

<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet"/>
<div class="holder">
	<i class="fa fa-facebook-square"></i>
	<div class="circle"></div>
</div>

【讨论】：