body {
  font-family: "Helvetica Neue", Arial, sans-serif;
  margin: 0;
  padding: 0;
  color: #222;
  background: #fff;
}

header.hero {
  position: relative;
}

.cover-img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  filter: brightness(0.6);
  display: block;
}

.overlay-text {
  position: absolute;
  top: 25%;
  left: 8%;
  color: white;
  z-index: 10;
  font-weight: bold;
  text-shadow: 0 0 8px rgba(0,0,0,0.8);
}

main {
  padding: 20px;
}

footer {
  background: #f8f8f8;
  text-align: center;
  padding: 10px;
  font-size: 14px;
}

/* 文章页面封面图 */
.article-header img {
  width: 100%;
  max-height: 300px;
  object-fit: cover;
  border-radius: 12px;
  display: block;
  margin: 0 auto 20px auto;
}

/* 文章副标题 */
.subtitle {
  font-size: 16px;
  color: #555;
  margin-top: -10px;
  text-align: center;
}

/* 视频 iframe 样式容器 */
.video-container {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  margin-bottom: 30px;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* 响应式优化 */
@media (max-width: 768px) {
  .overlay-text {
    top: 15%;
    font-size: 16px;
    left: 5%;
  }

  .article-header img {
    max-height: 200px;
  }
}