原文地址：https://segmentfault.com/a/1190000014680999
吃鸡倍镜，哈哈哈
HTML代码：
<div class="box">
<span>BUTTON</span>
<span class="left"></span>
<span class="right"></span>
<span class="top"></span>
<span class="bottom"></span>
</div>
CSS代码：
html, body {
margin:;
padding:;
height: 100%;
display: flex;
align-items: center;
justify-content: center;
color: black;
}
.box{
width:9em;
height:3em;
text-align: center;
line-height: 3em;
font-size: 30px;
/* 字母间距 */
letter-spacing: 0.2em;
position: relative;
filter: blur(2px);
transition: 1s;
}
.box:hover {
filter: blur(0.2px);
}
.box::after {
content: '';
position: absolute;
width: 3em;
height: 3em;
border: 1px solid red;
border-radius: 50%;
left: 3em;
filter: opacity(0);
}
.box span:not(:first-child) {
position: absolute;
background-color: red;
filter: opacity(0);
}
.box:hover::after,
.box:hover span:not(:first-child) {
animation: aim 1s linear infinite alternate;
}
.box span.top,
.box span.bottom {
width: 1px;
height: 3em;
left: 50%;
}
.box span.top {
top: -3em;
}
.box span.bottom {
bottom: -3em;
}
.box span.left,
.box span.right {
width: 3em;
height: 1px;
top: 50%;
}
.box span.left {
left:;
}
.box span.right {
right:;
}
@keyframes aim {
from {
filter: opacity(0.2);
}
to {
filter: opacity(0.8);
}
}