style.css

@import url('https://fonts.googleapis.com/css2?family=Freeman&display=swap');

* {
    font-family: "Freeman", sans-serif;
    user-select: none;
}

body {
    background-image: url("images/background.png");
    background-size: cover;
    background-position: center center;
    height: 100vh;
    display: flex;
    flex-direction: column; 
    align-items: center;
    justify-content: center;
    text-align: center;
    margin: 0;
    padding: 0;
    overflow: hidden
}

.countdown {
    display: flex;
    transform: scale(2);
    font-family: fantasy;
}

.time {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin: 15px;
    color: green
}

.time h2 {
    font-weight: bold;
    font-size: 36px;
    line-height: 1;
    margin: 0 0 5px
}

#text {
    font-size: 80px;
    position: absolute;
    top: 0;
    margin-top: 300px;
    color: yellow;
}

@media only screen and (max-width: 600px) {
    .time {
        margin: 5px;
    }
    .time h2 {
        font-size: 12px;
    }
    .time small {
        font-size: 10px;
    }
    #text {
        font-size: 150%;
        margin-top: 300px;
    }
}