@keyframes coin_rotation {
  0% {
    transform: rotateY(0deg);
  }
  100% {
    transform: rotateY(360deg);
  }
}

.coin {
  position: relative;
  width: 100px;
  height: 100px;
  transform-style: preserve-3d;
  animation: coin_rotation 3s linear infinite;
}

.parts {
  position: absolute;
  top: 0;
  left: 0;
}

.front,
.back {
  width: 100px;
  height: 100px;
  border-radius: 100%;
 /* background: #ffd400;*/
}

.inner {
  margin: 10px 0 0 10px;
  width: 80px;
  height: 80px;
  border-radius: 100%;
 /* background: #e5c10b; 
  box-shadow: inset 0 0 0 2px #cca83d;
  color: #ffd400;  */
  text-align: center;
  text-shadow: 2px 2px 0 #cca83d;
  font-weight: bold;
  font-size: 50px;
  line-height: 80px;
}
 .front.inner img{
-webkit-filter: drop-shadow(0px 3px 0px rgba(0, 0, 0, 1)); /* SafariなどのWebkitブラウザ用 */
filter: drop-shadow(0px 3px 0px rgba(0, 0, 0, 1)); 
 }



.front {
  transform: translateZ(5px);
}

.front.inner {
  transform: translateZ(6px);
}

.back {
  transform: translateZ(-5px);
}

.back.inner {
  transform: translateZ(-6px);
}

.side {
  left: 50px;
  width: 10px;
  height: 100px;
  background: #000000;
  transform: rotateY(90deg);
}