@media all and (max-width: 599px){
    .dong-ho{
        text-align: center;
        margin: 30px auto;
        width: 100%;
    }
    .dong-ho .top p{
        margin: 0 auto;
        width: 100%;
        text-align: center;
        margin: 0 auto;
        width: 100%;
        text-align: center;
        font-weight: bold;
        font-size: 24px;
    }

    .timer-area ul li{
        display: inline-block;
        padding: 5px;
        fon-weight: bold;
    }
    .timer-area ul li span{
        display: block;
        margin: 5px;
    }
    .timer-area ul li span.days,
    .timer-area ul li span.hours,
    .timer-area ul li span.minutes,
    .timer-area ul li span.seconds
    {
        font-weight: bold;
        font-size: 50px;
    }

}