:root {
      --primary-color: #1a9837;
      --primary-hover: #147a2d;
      --danger-color: #b71c1c;
      --danger-hover: #8e0000;
      --text-color: #333;
      --light-gray: #f5f5f5;
      --medium-gray: #e0e0e0;
      --dark-gray: #666;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      font-family: 'Roboto', Arial, sans-serif;
      margin: 0;
      padding: 20px;
      background-color: var(--light-gray);
      color: var(--text-color);
      line-height: 1.6;
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
      display: grid;
      grid-template-columns: 1fr 350px;
      gap: 20px;
    }
    
    .main-content, .sidebar {
      background-color: white;
      border-radius: 8px;
      padding: 20px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.1);
      border: 1px solid var(--medium-gray);
    }
    
    h1, h2, h3 {
      color: var(--primary-color);
      margin-bottom: 15px;
    }
    
    .input-container {
      display: flex;
      gap: 10px;
      margin-bottom: 20px;
    }
    
    input[type="text"], input[type="range"], select {
      width: 100%;
      padding: 10px;
      border: 1px solid var(--medium-gray);
      border-radius: 4px;
      font-size: 16px;
    }
    
    button {
      background-color: var(--primary-color);
      color: white;
      border: none;
      padding: 10px 15px;
      border-radius: 4px;
      cursor: pointer;
      font-size: 16px;
      transition: background-color 0.3s;
      white-space: nowrap;
    }
    
    button:hover {
      background-color: var(--primary-hover);
    }
    
    .delete-btn, #clearPlaylist {
      background-color: var(--danger-color);
    }
    
    .delete-btn:hover, #clearPlaylist:hover {
      background-color: var(--danger-hover);
    }
    
    #player {
      width: 100%;
      aspect-ratio: 16/9;
      background-color: black;
      margin-bottom: 20px;
      border-radius: 4px;
    }
    
    #controls {
      display: flex;
      justify-content: center;
      gap: 10px;
      margin-bottom: 20px;
      flex-wrap: wrap;
    }
    
    .control-group {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 20px;
    }
    
    .volume-percentage {
      width: 40px;
      text-align: right;
      color: var(--dark-gray);
    }
    
    #playlistItems {
      max-height: 400px;
      overflow-y: auto;
      border: 1px solid var(--medium-gray);
      border-radius: 4px;
    }
    
    .playlist-item {
      padding: 10px;
      border-bottom: 1px solid var(--medium-gray);
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 10px;
      transition: background-color 0.2s;
    }
    
    .playlist-item:hover {
      background-color: #f0f0f0;
    }
    
    .playlist-item.active {
      background-color: #e8f5e9;
      font-weight: bold;
    }
    
    .playlist-item.dragging {
      opacity: 0.5;
      background-color: var(--light-gray);
    }
    
    .thumbnail-container {
      width: 80px;
      height: 45px;
      flex-shrink: 0;
    }
    
    .thumbnail-container img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      border-radius: 2px;
    }
    
    .video-info {
      flex-grow: 1;
      overflow: hidden;
    }
    
    .video-position {
      margin-right: 5px;
      color: var(--dark-gray);
    }
    
    .video-url {
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      display: block;
    }
    
    .delete-btn {
      padding: 5px 10px;
      font-size: 14px;
      border-radius: 50%;
      width: 25px;
      height: 25px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .action-buttons {
      display: flex;
      gap: 10px;
      margin-bottom: 20px;
    }
    
  
    
    .tooltip {
      position: relative;
      display: inline-block;
    }
    
    .tooltip .tooltiptext {
      visibility: hidden;
      width: 120px;
      background-color: #555;
      color: #fff;
      text-align: center;
      border-radius: 6px;
      padding: 5px;
      position: absolute;
      z-index: 1;
      bottom: 125%;
      left: 50%;
      margin-left: -60px;
      opacity: 0;
      transition: opacity 0.3s;
    }
    
    .tooltip:hover .tooltiptext {
      visibility: visible;
      opacity: 1;
    }
    
    #about {
      margin-top: 20px;
      padding: 15px;
      background-color: var(--light-gray);
      border-radius: 4px;
    }
    
    #about ul {
      list-style-type: disc;
      margin-left: 20px;
      font-size: 14px;
    }
    
    #about li {
      margin-bottom: 10px;
    }
    
    #about h2 {
      cursor: pointer;
    }
    
    @media (max-width: 768px) {
      .container {
        grid-template-columns: 1fr;
      }
      
      #controls {
        flex-direction: column;
        align-items: center;
      }
      
      #about {
        margin: 10px 0;
      }
      
      #about ul {
        margin-left: 15px;
      }
    }