简单实现 opera 的 log

代码如下：
html:

<div class="wrap">
   <div class="opera">
       <div class="opera-top"></div>
    </div>
</div>

css:

* {
    margin: 0;
    padding: 0;
}
.wrap {
    width: 258px;
    height: 275px;
    padding: 100px;
    margin: 20px auto;
    background-color: #eee;
}
.opera {
    width: 258px;
    height: 275px;
    background-color: #f22629;
    box-sizing: border-box;
    padding-top: 22.5px;
    border-radius: 258px/275px;
}

.opera-top {
    height: 230px;
    width: 112px;
    background-color: #fff;
    margin-left: 73px;
    border-radius: 112px/230px;
}