.grid-msg-overlay {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.4);
}

    .grid-msg-overlay .msg {
        opacity: 1;
        position: absolute;
        top: 30%;
        left: 35%;
        width: 250px;
        height: 50px;
        background-color: #eee;
        border-radius: 4px;
        border: 1px solid #555;
        text-align: center;
        font-size: 24px;
        display: table;
    }

        .grid-msg-overlay .msg span {
            display: table-cell;
            vertical-align: middle;
        }