@media all and (min-width: 1000px) {
    .caixa {
        width: 1120px;
        float: left;
        margin: 0 calc(50% - 560px) 50px;
    }

    h2 {
        color: #999;
        padding: 80px 0;
        font-size: 86px;
        text-align: center;
        margin: 0 auto;
    }

    h2 span {
        font-size: 30px;
        display: block;
    }
}

@media all and (max-width: 999px) {
    .caixa {
        /*width: 1120px;*/
        float: left;
        margin: 0 20px;
    }

    h2 {
        color: #999;
        padding: 40px 0;
        font-size: 60px;
        text-align: center;
        margin: 0 auto;
    }

    h2 span {
        font-size: 30px;
        display: block;
    }
}