.item-l{
    height: 480px;
    width: 100%;
    background-image: url("../pic/entegras.jpg");
    float: left;
    margin-bottom: 0;
}

.sec-ltext{
    width: 30%;
}

@media only screen and (max-width: 900px) {
    .item-l{
        height: 770px;
        background-position: bottom;
    }

    .sec-ltext{
        width: 80%;
    }
}

@media only screen and (max-width: 688px) {
    .item-l{
        height: 820px;
    }
}