/* 首页关于区：边框装饰 + 封面/视频播放器
 * 整图 border: 850×596（含底部 36px 装饰）
 * 有效边框区: 850×560 — 视频/封面/按钮按此区域居中
 * poster/video: 821×534
 */
.cts-about-video {
  width: 100%;
  max-width: 850px;
  margin: 0 auto;
  box-sizing: border-box;
  background: transparent;
}
.cts-about-video-stage {
  position: relative;
  width: 100%;
  aspect-ratio: 850 / 596;
  background: transparent;
  overflow: visible;
}
/* 有效边框区（不含底部 36px 装饰） */
.cts-about-video-frame {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: calc(560 / 596 * 100%);
  background: transparent;
  z-index: 1;
}
.cts-about-video-media {
  position: absolute;
  left: 50%;
  top: 50%;
  width: calc(821 / 850 * 100%);
  height: calc(534 / 560 * 100%);
  transform: translate(-50%, -50%);
  overflow: hidden;
  background: transparent;
}
.cts-about-video-media video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  background: transparent;
  vertical-align: middle;
}
.cts-about-video-border {
  position: absolute;
  inset: 0;
  z-index: 2;
  background: url(/static/cts/img/video-border.png) center center / 100% 100% no-repeat;
  pointer-events: none;
}
.cts-about-video-toggle {
  position: absolute;
  left: 50%;
  top: 50%;
  z-index: 3;
  width: 72px;
  height: 72px;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  background: transparent;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform .2s ease, opacity .2s ease;
}
.cts-about-video-toggle:hover {
  transform: translate(-50%, -50%) scale(1.06);
}
.cts-about-video-toggle:focus {
  outline: none;
}
.cts-about-video-toggle:focus-visible {
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.55);
}
.cts-about-video-toggle svg {
  display: block;
  width: 72px;
  height: 72px;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.35));
}
.cts-about-video-toggle .cts-av-pause {
  display: none;
}
.cts-about-video.is-playing .cts-about-video-toggle .cts-av-play {
  display: none;
}
.cts-about-video.is-playing .cts-about-video-toggle .cts-av-pause {
  display: block;
}
.cts-about-video.is-playing .cts-about-video-toggle {
  opacity: 0;
}
.cts-about-video.is-playing .cts-about-video-frame:hover .cts-about-video-toggle,
.cts-about-video.is-playing .cts-about-video-toggle:focus-visible {
  opacity: 1;
}

@media (max-width: 768px) {
  .cts-about-video-toggle,
  .cts-about-video-toggle svg {
    width: 56px;
    height: 56px;
  }
}