.wbk {
        display: block;
        width: 400px;
        margin: 0 auto;}

    .bk {
    border: 1px solid #c3c3c3;
    line-height: 35px;
    text-indent: 10px;}

    .size {
        font-size: 18px;
        width: 120px;
        line-height: 35px;}

    .cx {
        padding: 10px 20px;
        background-color: #0873b8;
        color: #fff;
        border-radius: 5px;
        font-size: 16px;}