div.container {
    display: flex;
    flex-direction: row;

    /* prevents wrapping of flex items; default value */
    flex-wrap: nowrap;

    border: 5px solid black;
    background-color: purple;
}

div.box {
    width: 1000px;
    height: 60px;
    text-align: center;
    border: 1px solid black;
    background-color: orange;
    margin: 4px;
}