* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

img {
    display: block;
}
main .container {
    margin: 3ex auto;
}

#clock {
    width: 800px;
    height: 852px;
    position: relative;
    background: url('img/img_52.png');
    background-size: cover;
}

#clock img {
    position: absolute;
    top: 78px;
    left: 252px;
}