.ch{
    width: 2.5rem;
    margin: 0 0.25rem;
    text-align: center;
    padding-left: 0;
    display: inline-block;
}
.butspan{
    background-color: #2d8cf0;
    border: 1px solid #2d8cf0;
    display: inline-block;
    height: 1.6rem;
    line-height: 1.6rem;
    font-size: 0.65rem;
    width: 3rem;
    border-radius: 6px;
    margin: 0 0.25rem;
    cursor: pointer;
    color: #fff;
}
.butlis{
    background-color: #fff;
    border: 1px solid #eee;
    color: #666;
}
.night .butlis{
    background-color: #222;
    border: 1px solid #444;
    color: #aaa;
}
.chengyus{
    text-align: center;
    background-color: #f6f7fa;
    padding: 1rem 0;
}
.night .chengyus{
    background-color: #333;
}
em{
    font-style: normal;
    color: #ff7503;
}