@media (max-width: 1023px) {
    .m_title {
        font-size: 17px;
        line-height: 40px;
        position: relative;
        background: #fff;
        text-align: center;
        border-bottom: 1px solid #e0e0e0;
        color:#333;
    }

    .m_title .back {
        font-size: 20px;
        position: absolute;
        left: 10px;
        top: 2px;
    }
}

@media (min-width: 1200px) {
    .m_title {
        display: none;
    }
}