test CSS3

<style>
#div1 {
    width: 250px;
    height: 250px;
    border: 1px solid;
    color: red;
    padding: 8px;
    border-radius: 8px;
    box-shadow: 6px 6px 6px 0 #888;
    resize: both;
    overflow: auto;

    box-sizing: border-box;
    -moz-box-sizing: border-box;
    /* Firefox */
    
    -webkit-box-sizing: border-box;
    /* Safari */
}
#div1:hover {
    /*width: 300px;
    height: 300px;*/
    
    padding: 28px;
    -webkit-transform: translate(200px, 80px) rotate(0deg);
    /* Safari and Chrome */
}
#div1 {
    transform: rotate(-20deg);
    -ms-transform: rotate(-20deg);
    /*IE9*/
    
    -moz-transform: rotate(-20deg);
    /* Firefox */
    
    -webkit-transform: translate(200px, 80px) rotate(-20deg);
    /* Safari and Chrome */
    
    -o-transform: rotate(-20deg);
    /* Opera */
}
#div1 {//把鼠标指针放到 div 元素上，其宽度会从
    transition: width 1s, height 1s;
    -moz-transition: width 1s, height 1s;
    /* Firefox 4 */
    
    -webkit-transition: width 1s, height 1s, padding 1s, -webkit-transform 1s;
    /* Safari 和 Chrome */
    
    -o-transition: width 1s, height 1s;
    /* Opera */
}
#div1 {
    animation: myfirst 5s;
    -moz-animation: myfirst 5s;
    /* Firefox */
    
    -webkit-animation: myfirst 5s;
    /* Safari 和 Chrome */
    
    -o-animation: myfirst 5s;
    /* Opera */
    
    animation-iteration-count: infinite;
    -webkit-animation-iteration-count: infinite;
}
@keyframes myfirst {
    from {
        background: red;
    }
    to {
        background: yellow;
    }
}
@-moz-keyframes myfirst
/* Firefox */

{
    from {
        background: red;
    }
    to {
        background: yellow;
    }
}
@-webkit-keyframes myfirst
/* Safari 和 Chrome */

{
    0% {
        background: red;
    }
    25% {
        background: yellow;
    }
    50% {
        background: blue;
    }
    100% {
        background: green;
    }
}
@-o-keyframes myfirst
/* Opera */

{
    from {
        background: red;
    }
    to {
        background: yellow;
    }
}
</style>
11111111
<br> 22222222222
<br> 33333333333
<br>
<div id="div1">
    <img src="a.jpg" alt="aaaaa">
</div>