HTML
CSS
JavaScript
HTML
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>IT书包</title>
</head>
<body>

<div class="demo_box origin_1">在中心点旋转45度</div>
<div class="demo_box origin_2">在左上角旋转45度</div>
<div class="demo_box origin_3">用百分百值来来设置旋转点旋转45度</div>
<div class="demo_box origin_4">用长度值来设置旋转点旋转45度</div>

</body>
</html>
CSS
.demo_box {
    border: 1px solid #3DA5DC;
    background: #a4dcf9;
    height: 100px;
    width: 200px;
    text-align: center;
    color: #fff;
}
.origin_1{
    -webkit-transform-origin:center center;
    -moz-transform-origin:center center;
    -webkit-transition:0.5s ease all;
    -moz-transition:0.5s ease all;
    position:absolute;
    left:10px;
    top:50px;
}
.origin_2{
    -webkit-transform-origin:left top;
    -moz-transform-origin:left top;
    -webkit-transition:0.5s ease all;
    -moz-transition:0.5s ease all;
    position:absolute;
    left:250px;
    top:50px;
}
.origin_3{
    -webkit-transform-origin:100% 100%;
    -moz-transform-origin:100% 100%;
    -webkit-transition:0.5s ease all;
    -moz-transition:0.5s ease all;
    position:absolute;
    left:480px;
    top:50px;
}
.origin_4{
    -webkit-transform-origin:20px 60px;
    -moz-transform-origin:20px 60px;
    -webkit-transition:0.5s ease all;
    -moz-transition:0.5s ease all;
    position:absolute;
    left:250px;
    top:160px;
}
.origin_1:hover,
.origin_2:hover,
.origin_3:hover,
.origin_4:hover{
    -webkit-transform:rotate(45deg);
    -moz-transform:rotate(45deg);
}
JavaScript