/* YouTubeプレースホルダーのスタイル */
.video-placeholder {
  position: relative;
  width: 100%;
  max-width: 100%;
  aspect-ratio: 16 / 9;
  background-color: #000;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  margin-bottom: 20px;
  border-radius: 4px;
}

/* サムネイル画像 */
.video-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.9;
  transition: opacity 0.3s;
}

.video-placeholder:hover img {
  opacity: 1.0;
}

/* 中央の再生ボタン */
.play-button {
  position: absolute;
  width: 68px;
  height: 48px;
  background-color: rgba(255, 64, 64, 0.8);
  border-radius: 12%;
  transition: background-color 0.2s;
}

.play-button::after {
  content: "";
  display: block;
  border-left: 18px solid #fff;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  margin: 14px 0 0 26px;
}

/* ホバー時にYouTube風の赤色にする */
.video-placeholder:hover .play-button {
  background-color: #ff0000;
}