body {
      font-family: 'Roboto', sans-serif;
      max-width: 800px;
      margin: 20px auto;
      padding: 20px;
      background-color: #f8f9fa;
      color: #343a40;
      transition: background-color 0.3s ease;
    }
    
    h1 {
      text-align: center;
      margin-bottom: 30px;
      color: #212529;
    }
    
    .container {
      display: grid;
      grid-template-columns: auto 1fr;
      gap: 20px;
      background-color: #fff;
      padding: 20px;
      border-radius: 8px;
      box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
      transition: box-shadow 0.3s ease;
    }
    
    .qr-code-container {
      display: flex;
      justify-content: center;
      align-items: center;
    }
    
    .options-container {
      display: grid;
      grid-template-columns: 1fr;
      gap: 10px;
    }
    
    .options-group {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
      gap: 10px;
      margin-bottom: 10px;
    }
    
    .data-input-container {
      grid-column: 1 / -1;
      margin-top: 20px;
    }
    
    .form-group {
      margin-bottom: 10px;
    }
    
    label {
      display: block;
      margin-bottom: 5px;
      font-weight: 500;
      color: #495057;
    }
    
    input, select, textarea {
      width: 100%;
      padding: 8px;
      box-sizing: border-box;
      font-size: 14px;
      border: 1px solid #ced4da;
      border-radius: 4px;
      transition: border-color 0.3s ease;
    }
    
    input:focus, select:focus, textarea:focus {
      outline: none;
      border-color: #007bff;
      box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
    }
    
    #qrcode {
      text-align: center;
      padding: 10px;
      border: 1px solid #ddd;
      border-radius: 8px;
      min-height: 150px;
      display: flex;
      align-items: center;
      justify-content: center;
      background-color: #fff;
      box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
      transition: box-shadow 0.3s ease;
    }
    
    /* Modern Button Styles */
    button {
      padding: 10px 15px;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 14px;
      transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
      font-weight: 500;
      display: inline-block;
      text-align: center;
      white-space: nowrap;
    }
    
    #generateBtn {
      background-color: #28a745;
      color: white;
    }
    
    #generateBtn:hover {
      background-color: #218838;
      transform: translateY(-2px);
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    }
    
    /* Icon Buttons - Minimal Dark Style */
    .button-group {
      display: flex;
      gap: 8px;
      margin-top: 12px;
      justify-content: center;
    }

    .icon-btn {
      width: 44px;
      height: 44px;
      padding: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      background-color: #24292e;
      color: #ffffff;
      border: none;
      border-radius: 8px;
      cursor: pointer;
      transition: all 0.2s ease;
      position: relative;
    }

    .icon-btn:hover {
      background-color: #3a4149;
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    }

    .icon-btn:active {
      transform: translateY(0);
      background-color: #1a1e22;
    }

    .icon-btn svg {
      width: 20px;
      height: 20px;
      stroke: currentColor;
      transition: stroke 0.2s ease;
    }

    /* Tooltip on hover */
    .icon-btn::after {
      content: attr(title);
      position: absolute;
      bottom: -32px;
      left: 50%;
      transform: translateX(-50%) translateY(4px);
      background-color: #24292e;
      color: #fff;
      padding: 4px 10px;
      border-radius: 4px;
      font-size: 12px;
      font-weight: 500;
      white-space: nowrap;
      opacity: 0;
      visibility: hidden;
      transition: all 0.2s ease;
      pointer-events: none;
      z-index: 10;
    }

    .icon-btn:hover::after {
      opacity: 1;
      visibility: visible;
      transform: translateX(-50%) translateY(0);
    }

    /* Individual button colors on hover */
    #downloadBtn:hover {
      background-color: #238636;
    }

    #copyBtn:hover {
      background-color: #1f6feb;
    }

    #shareBtn:hover {
      background-color: #8957e5;
    }

    /* Success state */
    .icon-btn.success {
      background-color: #238636 !important;
    }

    .icon-btn:disabled {
      opacity: 0.5;
      cursor: not-allowed;
      transform: none;
    }

    .icon-btn:disabled:hover {
      transform: none;
      box-shadow: none;
    }

    .secondary-btn {
      background-color: #6c757d;
      color: white;
      width: 100%;
    }

    .secondary-btn:hover {
      background-color: #545b62;
      transform: translateY(-2px);
    }

    .secondary-btn:disabled {
      background-color: #adb5bd;
      cursor: not-allowed;
      transform: none;
    }
    
    /* Color Picker Styles */
    .color-picker-container {
      display: flex;
      align-items: center;
      gap: 5px;
    }
    
    .color-preview {
      width: 25px;
      height: 25px;
      border: 1px solid #ced4da;
      border-radius: 4px;
      cursor: pointer;
      transition: border-color 0.3s ease, box-shadow 0.3s ease;
    }
    
    .color-preview:hover {
      border-color: #007bff;
      box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
    }
    
    .color-picker-container input[type="color"] {
      opacity: 0;
      position: absolute;
      width: 0;
      height: 0;
      pointer-events: none;
    }
    
    /* Responsive Styles */
    @media (max-width: 768px) {
      body {
        padding: 10px;
      }
    
      .container {
        grid-template-columns: 1fr;
        gap: 15px;
        padding: 15px;
      }
    
      .qr-code-container {
        order: -1;
        margin-bottom: 15px;
      }
    
      #qrcode {
        min-height: 120px;
      }
    
      .options-container {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
        gap: 8px;
      }
    
      .data-input-container {
        margin-top: 15px;
      }
    
      input, select, textarea {
        font-size: 13px;
        padding: 8px;
      }
    
      button {
        width: 100%;
        padding: 10px;
        font-size: 14px;
      }
    
      h1 {
        font-size: 22px;
        text-align: center;
      }
    }
    
    @media (max-width: 480px) {
      body {
        padding: 5px;
      }

      .container {
        gap: 10px;
      }

      #qrcode {
        min-height: 100px;
        padding: 8px;
      }

      .form-group {
        margin-bottom: 8px;
      }

      .icon-btn {
        width: 40px;
        height: 40px;
      }

      .icon-btn svg {
        width: 18px;
        height: 18px;
      }

      .icon-btn::after {
        display: none;
      }
    }

    /* History Button */
    #historyBtn:hover {
      background-color: #f9826c;
    }

    /* History Modal */
    .history-modal {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-color: rgba(0, 0, 0, 0.6);
      z-index: 1000;
      opacity: 0;
      transition: opacity 0.2s ease;
    }

    .history-modal.show {
      display: flex;
      justify-content: center;
      align-items: center;
      opacity: 1;
    }

    .history-modal-content {
      background-color: #1a1e22;
      border-radius: 12px;
      width: 90%;
      max-width: 420px;
      max-height: 80vh;
      display: flex;
      flex-direction: column;
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
      animation: modalSlideIn 0.2s ease;
    }

    @keyframes modalSlideIn {
      from {
        transform: translateY(-20px);
        opacity: 0;
      }
      to {
        transform: translateY(0);
        opacity: 1;
      }
    }

    .history-modal-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 16px 20px;
      border-bottom: 1px solid #30363d;
    }

    .history-modal-header h3 {
      margin: 0;
      color: #ffffff;
      font-size: 16px;
      font-weight: 500;
    }

    .history-close-btn {
      background: none;
      border: none;
      color: #8b949e;
      font-size: 24px;
      cursor: pointer;
      padding: 0;
      width: 32px;
      height: 32px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 6px;
      transition: all 0.2s ease;
      box-shadow: none;
    }

    .history-close-btn:hover {
      background-color: #30363d;
      color: #ffffff;
      transform: none;
    }

    .history-list {
      flex: 1;
      overflow-y: auto;
      padding: 8px;
      min-height: 200px;
      max-height: 400px;
    }

    .history-empty {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      height: 200px;
      color: #8b949e;
      font-size: 14px;
    }

    .history-empty-icon {
      font-size: 48px;
      margin-bottom: 12px;
      opacity: 0.5;
    }

    .history-item {
      display: flex;
      align-items: center;
      padding: 12px;
      background-color: #24292e;
      border-radius: 8px;
      margin-bottom: 8px;
      cursor: pointer;
      transition: all 0.2s ease;
      gap: 12px;
    }

    .history-item:last-child {
      margin-bottom: 0;
    }

    .history-item:hover {
      background-color: #30363d;
      transform: translateX(4px);
    }

    .history-item-icon {
      font-size: 20px;
      flex-shrink: 0;
      width: 28px;
      text-align: center;
    }

    .history-item-content {
      flex: 1;
      min-width: 0;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    .history-item-type {
      color: #8b949e;
      font-size: 11px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      margin-bottom: 2px;
      display: block;
    }

    .history-item-preview {
      color: #ffffff;
      font-size: 14px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      margin-bottom: 2px;
      display: block;
    }

    .history-item-time {
      color: #8b949e;
      font-size: 12px;
      display: block;
    }

    .history-item-thumbnail {
      width: 50px;
      height: 50px;
      border-radius: 6px;
      background-color: #ffffff;
      flex-shrink: 0;
      object-fit: contain;
      padding: 4px;
    }

    .history-item-delete {
      background: none;
      border: none;
      color: #8b949e;
      font-size: 18px;
      cursor: pointer;
      padding: 4px 8px;
      border-radius: 4px;
      transition: all 0.2s ease;
      flex-shrink: 0;
      opacity: 0;
      box-shadow: none;
    }

    .history-item:hover .history-item-delete {
      opacity: 1;
    }

    .history-item-delete:hover {
      background-color: #f85149;
      color: #ffffff;
      transform: none;
    }

    .history-modal-footer {
      padding: 12px 20px;
      border-top: 1px solid #30363d;
      display: flex;
      justify-content: center;
    }

    .history-clear-btn {
      background-color: transparent;
      border: 1px solid #f85149;
      color: #f85149;
      padding: 8px 20px;
      border-radius: 6px;
      font-size: 13px;
      cursor: pointer;
      transition: all 0.2s ease;
      box-shadow: none;
    }

    .history-clear-btn:hover {
      background-color: #f85149;
      color: #ffffff;
      transform: none;
    }

    .history-clear-btn:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }

    /* Responsive History Modal */
    @media (max-width: 480px) {
      .history-modal-content {
        width: 95%;
        max-height: 85vh;
      }

      .history-item {
        padding: 10px;
        gap: 10px;
      }

      .history-item-thumbnail {
        width: 44px;
        height: 44px;
      }

      .history-item-delete {
        opacity: 1;
        padding: 4px 6px;
      }
    }