body {
  margin: 0;
  font-family: sans-serif;
}

.main-content {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 10px;
  box-sizing: border-box;
}

.page-title {
  text-align: center;
  margin-top: 0;
}

input {
  width: 100%;
  max-width: 500px;
  display: block;
  margin: 0 auto 20px auto;
  padding: 10px;
  font-size: 16px;
  box-sizing: border-box;
}

/* Grid cho danh sách video */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.video {
  margin-bottom: 10px;
}

.video img {
  width: 100%;
  border-radius: 10px;
  display: block;
}

.video-title {
  font-weight: bold;
  margin: 5px 0;
  text-align: center;
}
.video-frame {
  position: relative;
  width: 100%;
  height: 0;
  padding-bottom: 56.25%; /* tỉ lệ 16:9 */
}
.video-frame iframe {
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: 10px;
}

/* Mobile: 1 cột video */
@media (max-width: 768px) {
  .video-grid {
    grid-template-columns: 1fr;
    gap: 15px;
  }
  input {
    max-width: 100%;
  }
}