新增UI样式

实际应用：旋转的风车

<style>
        .box{
            width:400px;
            height:400px;
            margin:50px auto;
            transition:6s;
        }
        .box div{
           width:180px;
            height:180px;
            margin:10px;
            border:1px solid #000;
            box-sizing:border-box;
            float:left;
            background-color: #8ec63f;
        }
        .box div:nth-child(1),.box div:nth-child(4){
            border-radius:0 70%;
        }
        .box div:nth-child(2),.box div:nth-child(3){
            border-radius:70% 0;
        }

        .box:hover{
            -webkit-transform: rotate(720deg);
        }
    </style>
</head>
<body>
<div class="box">
    <div></div>
    <div></div>
    <div></div>
    <div></div>
</div>

线性渐变

新增UI样式

纯css实现进度条效果