#intro {
    background-image: url(../img/sub/customer/bg.jpg);
}

#content {
    overflow: hidden;
}

#content li {
    width: 24%;
    float: left;
    color: #1c1c1c;
    margin-left: 1%;
    margin-bottom: 30px;
}

#content li img {
    width: 90%;
    object-fit: contain;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

#content .logo_box {
    border: 1px solid #ccc;
    height: 120px;
    position: relative;
}

#content li p {
    font-size: 2rem;
    text-align: center;
    line-height: 3rem;
    font-weight: 700;
}

@media screen and (max-width:1400px) {
    #content li {
        width: 32.33%;
    }
}

@media screen and (max-width:720px) {
    #content li {
        width: 49%;
    }
}

@media screen and (max-width:520px) {
    #content li {
        width: 70%;
        margin: auto;
        float: none;
        margin-bottom: 30px;
    }

    #content .logo_box {
        height: 100px;
    }
}

@media screen and (max-width:460px) {
    #content li {
        width: 80%;
        margin-bottom: 20px;
    }

    #content .logo_box {
        height: 80px;
    }

    #content li p {
        font-size: 1.8rem;
    }
}