.clock {
  display: block;
  margin: 0 auto;
  max-width: 100%;
}
.clock div {
  background-color: rgba(255, 255, 255, 0.25);
  color: #fff;
  display: inline-block;
  padding: 0.65rem 1rem;
  margin: 0 0.05rem;
  font-size: 1.2rem;
  width: calc (10% - 1.25rem);
  text-align: center; 
  font-weight: bold;
  border-radius: 10%
}

.clock div[data-value*=days]:after, .clock div[data-value*=hours]:after, .clock div[data-value*=minutes]:after, .clock div[data-value*=seconds]:after {
  display: block;
  font-size: 0.60rem;
  margin-top: 0.15rem;
  font-weight: 300;
  text-align: center; 
}
.clock div[data-value*=days]:after {
  content: "Tage";
}
.clock div[data-value*=hours]:after {
  content: "Std.";
}
.clock div[data-value*=minutes]:after {
  content: "Min.";
}
.clock div[data-value*=seconds]:after {
  content: "Sek.";
}