* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Roboto, sans-serif;
}

body {
  background: #f4f6f9;
  color: #222;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
}

.wrapper {
  width: 90vw;
  height: 90vh;
  display: flex;
  gap: 20px;
}

.video-area {
  position: relative;
  flex: 1;
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0, 0, 0, .08);
}

.video-area iframe {
  width: 100%;
  height: 100%;
  border: 0;
  background: #000;
}

.sidebar {
  width: 300px;
  background: #fff;
  border-radius: 12px;
  padding: 15px;
  overflow-y: auto;
  border: 1px solid #e5e7eb;
  box-shadow: 0 4px 16px rgba(0, 0, 0, .08);
}

.sidebar h3 {
  text-align: center;
  margin-bottom: 15px;
}

.tabs {
  display: flex;
  margin-bottom: 15px;
}

.tab {
  flex: 1;
  padding: 12px;
  border: none;
  background: #343a40;
  color: #fff;
  cursor: pointer;
  font-weight: bold;
  transition: .2s;
}

.tab + .tab {
  margin-left: 0;
}

.tab:hover {
  background: #495057;
}

.tab.active {
  background: #ff9800;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

.channel-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.channel {
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 8px;
  background: #f8f9fa;
  cursor: pointer;
  color: #333;
  font-size: 15px;
  transition: .2s;
}

.channel:hover {
  background: #0d6efd;
  color: #fff;
  border-color: #0d6efd;
}

.channel.active {
  background: #0d6efd;
  color: #fff;
  border-color: #0d6efd;
}

@media (max-width:768px) {

  body {
    align-items: flex-start;
    padding: 10px;
  }

  .wrapper {
    flex-direction: column;
    width: 100vw;
    height: auto;
    margin-top: 0;
  }

  .video-area {
    width: 100%;
    aspect-ratio: 16 / 9;
  }

  .sidebar {
    width: 100%;
  }

  .channel-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
  }

  .channel {
    padding: 10px;
    font-size: 14px;
  }

}