#learn-widget {
      position: fixed;
      bottom: 16px;
      right: 16px;
      width: 360px;
      max-width: 95vw;
      height: 480px;
      background: #fff;
      border-radius: 10px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.15);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.4s ease, transform 0.4s ease;
      z-index: 10000;
      pointer-events: none;
      color: #1f2937;
      font-size: 14px;
      user-select: none;
    }
    #learn-widget.active {
      opacity: 1;
      transform: translateY(0);
      pointer-events: auto;
    }
    #learn-widget header {
      padding: 12px 20px;
      font-weight: 700;
      font-size: 18px;
      color: #111827;
      display: flex;
      justify-content: space-between;
      align-items: center;
      border-bottom: 1px solid #e5e7eb;
      background: #f9fafb;
      user-select: none;
    }
    #learn-widget header button.close-btn {
      background: #e0e7ff;
      border-radius: 50%;
      width: 34px;
      height: 34px;
      display: flex;
      justify-content: center;
      align-items: center;
      font-weight: 700;
      color: #2563eb;
      border: none;
      cursor: pointer;
      transition: background-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease, transform 0.15s ease;
      padding: 0;
      font-size: 22px;
      line-height: 1;
    }
    #learn-widget header button.close-btn:hover {
      background-color: #3b82f6;
      color: white;
      box-shadow: 0 0 8px 2px rgba(59,130,246,0.6);
      transform: scale(1.1);
    }
    #learn-widget header button.close-btn:active {
      transform: scale(0.95);
      box-shadow: 0 0 6px 1px rgba(37, 99, 235, 0.8);
    }

    #learn-list {
      flex-grow: 1;
      overflow-y: auto;
      margin: 0;
      padding: 0;
      list-style: none;
      background: #fff;
    }
    #learn-list::-webkit-scrollbar { width: 6px; }
    #learn-list::-webkit-scrollbar-thumb { background-color: #9ca3af; border-radius: 6px; }
    #learn-list::-webkit-scrollbar-track { background-color: transparent; }
    .learn-item {
      display: flex;
      align-items: center;
      padding: 10px 20px;
      cursor: pointer;
      border-bottom: 1px solid #e5e7eb;
      transition: background-color 0.25s ease, transform 0.2s ease;
      color: #111827;
      font-weight: 600;
      font-size: 14px;
      user-select: none;
    }
    .learn-item:hover, .learn-item:focus-visible {
      background-color: #e0e7ff;
      transform: translateX(6px);
      outline: none;
    }
    .learn-avatar {
      flex-shrink: 0;
      width: 40px;
      height: 40px;
      border-radius: 8px;
      background: #c7d2fe;
      color: #3730a3;
      font-weight: 700;
      font-size: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-right: 14px;
      user-select: none;
      transition: background-color 0.3s ease;
    }
    .learn-item:hover .learn-avatar {
      background-color: #6366f1;
      color: white;
    }
    .learn-info {
      flex-grow: 1;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .learn-title {
      margin-bottom: 3px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .learn-description {
      font-weight: 400;
      font-size: 12px;
      color: #6b7280;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .learn-badge {
      flex-shrink: 0;
      background: #3b82f6;
      color: white;
      font-size: 10px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 12px;
      margin-left: 10px;
      user-select: none;
      transition: background-color 0.3s ease;
    }
    .learn-item:hover .learn-badge {
      background-color: #2563eb;
    }

    #learn-detail {
      position: absolute;
      top: 0; left: 0; bottom: 0; right: 0;
      background: #f9fafb;
      border-radius: 10px;
      padding: 20px 24px;
      overflow-y: auto;
      opacity: 0;
      pointer-events: none;
      transform: translateX(30px);
      transition: opacity 0.4s ease, transform 0.4s ease;
      z-index: 10;
      color: #1f2937;
      box-shadow: none;
    }
    #learn-detail.active {
      opacity: 1;
      pointer-events: auto;
      transform: translateX(0);
      animation: slideRightFadeIn 0.4s ease forwards;
    }
    #learn-detail header {
      display: flex;
      align-items: center;
      margin-bottom: 16px;
      gap: 12px;
      user-select: none;
    }
    #learn-detail header .back-btn {
      background: #e0e7ff;
      border-radius: 50%;
      width: 34px;
      height: 34px;
      display: flex;
      justify-content: center;
      align-items: center;
      border: none;
      cursor: pointer;
      padding: 0;
      transition: background-color 0.3s ease, box-shadow 0.3s ease, transform 0.15s ease;
      font-size: 22px;
      line-height: 1;
      margin-left: 0;
      margin-right: 6px;
    }
    #learn-detail header .back-btn:hover {
      background-color: #3b82f6;
      box-shadow: 0 0 8px 2px rgba(59,130,246,0.6);
      transform: scale(1.1) translateX(-3px);
    }
    #learn-detail header .back-btn:active {
      transform: scale(0.95) translateX(-2px);
      box-shadow: 0 0 6px 1px rgba(37, 99, 235, 0.8);
    }
    #learn-detail header .back-btn img {
      width: 18px;
      height: 18px;
      user-select: none;
      pointer-events: none;
    }
    #learn-detail header h3 {
      font-weight: 700;
      font-size: 20px;
      margin: 0;
      line-height: 1.2;
      flex-grow: 1;
    }
    #learn-content {
      font-size: 14px;
      line-height: 1.5;
      color: #374151;
      user-select: text;
    }
    #learn-content p {
      margin-bottom: 12px;
    }
    #learn-content p:last-child {
      margin-bottom: 0;
    }

    #learn-toggle-btn {
      position: fixed;
      bottom: 16px;
      right: 16px;
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: #3b82f6;
      border: none;
      cursor: pointer;
      box-shadow: 0 6px 18px rgba(59,130,246,0.5);
      display: flex;
      justify-content: center;
      align-items: center;
      z-index: 11000;
      transition: background-color 0.3s ease, box-shadow 0.3s ease, transform 0.2s ease;
      user-select: none;
      padding: 0;
    }
    #learn-toggle-btn:hover {
      background: #2563eb;
      box-shadow: 0 10px 28px rgba(37,99,235,0.7);
      transform: scale(1.1);
    }
    #learn-toggle-btn:active {
      transform: scale(0.95);
      box-shadow: 0 5px 15px rgba(37,99,235,0.6);
    }
    #learn-toggle-btn img {
      display: block;
      pointer-events: none;
      user-select: none;
      width: 36px;
      height: 36px;
      transition: filter 0.3s ease;
    }
    #learn-toggle-btn:hover img {
      filter: drop-shadow(0 0 2px rgba(255,255,255,0.7));
    }

    @media (max-width: 768px) {
      #learn-widget {
        width: 100vw;
        height: 92%;
        bottom: 48px;
        right: 0;
        border-radius: 0;
        max-width: 100vw;
        overflow-y: auto;
      }

      #learn-list {
        overflow-y: auto;
      }

      #learn-detail {
        padding: 12px 16px;
        border-radius: 0;
        overflow-y: auto;
      }

      #learn-toggle-btn {
        width: 50px;
        height: 50px;
        bottom: 10px;
        right: 10px;
      }

      #learn-toggle-btn img {
        width: 28px;
        height: 28px;
      }

      #learn-widget header {
        padding: 10px 16px;
        font-size: 16px;
      }

      .learn-item {
        padding: 8px 16px;
        font-size: 13px;
      }

      .learn-avatar {
        width: 36px;
        height: 36px;
        font-size: 18px;
      }

      .learn-title {
        font-size: 13px;
      }

      .learn-description {
        font-size: 11px;
      }

      .learn-badge {
        font-size: 9px;
        padding: 2px 6px;
      }

      #learn-detail header h3 {
        font-size: 18px;
      }

      #learn-content {
        font-size: 13px;
        line-height: 1.4;
      }
    }