.orologio_center {
    display: grid;
    place-items: center;
}

.orologio{
  width: 82vmin;
  height: 82vmin;
  display:flex;
  justify-content:center;
  align-items:center; 
  background:url(
    https://www.byte-post.com/wp-content/uploads/2020/03/clock-number-only.png
  );
  background-size:cover;
  border:10px solid #000000;
  border-radius:50%;
  box-shadow: 0 15px 15px rgba(0,0,0,0.3);
}

.orologio:before{
    content:'';
    position:absolute;
    width:3.2vmin;
    height:3.2vmin;
    background: red;
    border:1px solid rgb(166,0,0);
    border-radius:50%;
    z-index:100;
}
        
.orologio .ora, .orologio .min,  .orologio .sec {
    position:absolute;
}
        
.o {
    width: 32vmin;
    height: 32vmin;
}
        
.m {
    width: 38vmin;
    height: 38vmin;
}
        
.s {
    width: 46vmin;
    height: 46vmin;
}
        
.o, .m, .s {
    display:flex;
    justify-content:center;
    border-radius:50%;
}
        
.o:before {
    content:'';
    position:absolute;
    width: 1.6vmin;
    height: 18vmin;
    background:black;
    border:1px solid rgb(0, 0, 0);
    z-index:8;
}
        
.m:before {
    content:'';
    position:absolute;
    width: 1vmin;
    height: 21vmin;
    background:black;
    border:1px solid rgb(0, 0, 0);
    z-index:9;
}
        
.s:before {
    content:'';
    position:absolute;
    width: 0.4vmin;
    height: 30vmin;
    border:1px solid rgb(166,0,0);
    background:red;
    z-index:10;
}
        
.o:before, .m:before, .s:before{
  box-shadow: 3px  3px 4px  rgba(0,0,0,0.24);
}