.video-wrapper {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
background-color: #404040;
}

#myVideo {
  width: 50%;
  max-width: 800px;
  height: auto;
  display: block;
}

.play-button {
  position: absolute;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: 0.3s;
}

.play-button:hover {
  background: rgba(0, 0, 0, 0.7);
}

.play-button::before {
  content: "";
  display: block;
  width: 0;
  height: 0;
  border-left: 24px solid white;
  border-top: 14px solid transparent;
  border-bottom: 14px solid transparent;
  margin-left: 6px;
}

/* スマホ時*/
@media screen and (max-width: 768px) {
  #myVideo {
    width: 80%;
  }
}