body {
  margin: 0;
} .mainImg {
  background-color: black;
  position: fixed; 
  top: -50%; 
  left: -50%; 
  width: 200%; 
  height: 200%;
} .mainImg svg {
  position: absolute; 
  top: 0; 
  left: 0; 
  right: 0; 
  bottom: 0; 
  margin: auto; 
  min-width: 50%;
  min-height: 50%;
}

#c_sech, #c_minh, #c_hrh, #secondhand, #minutehand, #hourhand, #datumkerek{
  transform-box: fill-box;
  transform-origin: center;
}

@media (max-width: 768px) {
  .mainImg{
    background-color: black;
  }
   .mainImg svg{
   width: 155%; 
   height: 155%;
   transform: translateX(-26.8%);
  }
}