div#fondo-cabecera{
    width: 100%;
    height: 400px;
    background-image: url("../piezas/gb02.jpg");
    background-size: 100% auto;
    background-attachment: fixed;
    box-shadow: inset 0px 0px 10px rgba(0,0,0,0.3);
}

div#quienes-somos{
    display: inline-block;
    margin: 20px 0px 10px 0px;
    width: calc(70% - 8px);
    vertical-align: top;
    text-align: justify;
}

 ul#logos-somos{
        display: inline-block;
        margin: 50px 0px 20px 0px;
        padding: 0px;
        width: 90%;
        vertical-align: top;
    }

        ul#logos-somos > li{
            display: inline-block;
            margin:0px;
            padding: 10px 30px 30px 30px;
            width: calc(25% - 65px);
            text-align: center;
            vertical-align: top;
        }

        ul#logos-somos > li > img{
            margin: 0px auto;
            width: 90%;
            vertical-align: middle;
        }