Mouseover animation button implemented in pure css3_html/css_WEB-ITnose

Today I bring you a mouseover animation button implemented purely in CSS3. This button takes the form of a square before the mouse passes over it, and animates into a circle when the mouse passes over it. The renderings are as follows:

Online preview Source code download

Implemented code.

html code:

<div>        <span></span>    </div>

css3 code:

 body        {            background-color: #333;        }        div        {            width: 200px;            height: 200px;            margin: 0 auto;        }        span        {            position: relative;            width: 180px;            height: 180px;            display: block;            margin: auto;            top: 25px;            border: 20px solid rgba(255, 255, 0, .25);            background-color: rgba(124,155,13,1);            -webkit-transition: .5s;            -moz-transition: .5s;            -ms-transition: .5s;            transition: .5s;            border-radius: 30px 0px 30px 0px;        }        span:before, span:after        {            position: absolute;            display: block;            background-color: #fff;            border-radius: 10px;            margin: auto;            top: 0px;            bottom: 0px;            left: 0px;            right: 0px;        }        span:before        {            width: 100px;            height: 10px;            content: "";        }                span:after        {            width: 10px;            height: 100px;            content: "";        }                div:hover span        {            -webkit-transform: scale(.5) rotate(45deg);            -moz-transform: scale(.5) rotate(45deg);            -ms-transform: scale(.5) rotate(45deg);            transform: scale(.5) rotate(45deg);            border-radius: 110px;            background-color: rgba(112,18,255,1);        }