.app_timer {
    text-align: center;
    max-width: 380px;
    margin: 0 auto;
}

@media (max-width: 425px) {
    .app_timer {
        font-size: 13px;
    }
}

.app_timer__container {
    display: flex;
}

.app_timer__heading {
    margin: 0;
}

.app_timer__days,
.app_timer__hours,
.app_timer__minutes,
.app_timer__seconds {
    color: #3d404c;
    font-size: 47px;
    flex-basis: 25%;
    line-height: 1.3;
}

.app_timer__days__title,
.app_timer__hours__title,
.app_timer__minutes__title,
.app_timer__seconds__title {
    color: #989898;
    font-size: 14px;
}

.app_timer__days__value,
.app_timer__hours__value,
.app_timer__minutes__value,
.app_timer__seconds__value {
    position: relative;
}

.app_timer__hours__value:before,
.app_timer__minutes__value:before {
    content: ":";
    position: absolute;
    right: -2px;
    top: 0;
    bottom: 0;
    margin: auto;
    font-size: 18px;
    line-height: 1;
    height: 21px;
    transition: opacity .1s;
}

.app_timer__hours__value.tick:before,
.app_timer__minutes__value.tick:before {
    opacity: 0;
}

@media (max-width: 425px) {
    .app_timer__days,
    .app_timer__hours,
    .app_timer__minutes,
    .app_timer__seconds {
        font-size: 40px;
    }
}