* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
      background: linear-gradient(135deg, #0d1117 0%, #161b22 100%);
      color: #e6edf3;
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      line-height: 1.6;
    }

    .header {
      background: rgba(22, 27, 34, 0.95);
      backdrop-filter: blur(10px);
      padding: 20px 30px;
      border-bottom: 1px solid rgba(48, 54, 61, 0.5);
      display: flex;
      align-items: center;
      gap: 16px;
      position: sticky;
      top: 0;
      z-index: 100;
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    }

    .header img {
      width: 36px;
      height: 36px;
      border-radius: 8px;
      transition: transform 0.2s ease;
    }

    .header img:hover {
      transform: scale(1.05);
    }

    .header h1 {
      font-size: 24px;
      font-weight: 600;
      background: linear-gradient(135deg, #58a6ff, #79c0ff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .container {
      flex: 1;
      display: flex;
      min-height: 0;
      gap: 1px;
      background: #30363d;
    }

    .sidebar {
      width: 280px;
      background: rgba(22, 27, 34, 0.95);
      padding: 24px;
      display: flex;
      flex-direction: column;
      overflow-y: auto;
      min-width: 200px;
    }

    .sidebar h2 {
      font-size: 14px;
      font-weight: 600;
      margin: 20px 0 12px;
      color: #8b949e;
      text-transform: uppercase;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .sidebar h2:first-child {
      margin-top: 0;
    }

    .tab {
      padding: 14px 16px;
      margin-bottom: 6px;
      border-radius: 12px;
      cursor: pointer;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 15px;
      font-weight: 500;
      border: 1px solid transparent;
      position: relative;
      overflow: hidden;
    }

    .tab::before {
      content: '';
      position: absolute;
      top: 0;
      left: -100%;
      width: 100%;
      height: 100%;
      background: linear-gradient(90deg, transparent, rgba(88, 166, 255, 0.1), transparent);
      transition: left 0.5s ease;
    }

    .tab:hover::before {
      left: 100%;
    }

    .tab:hover {
      background: rgba(88, 166, 255, 0.1);
      border-color: rgba(88, 166, 255, 0.3);
      transform: translateX(4px);
    }

    .tab.active {
      background: linear-gradient(135deg, #238636, #2ea043);
      color: white;
      box-shadow: 0 4px 12px rgba(35, 134, 54, 0.3);
      transform: translateX(4px);
    }

    .tab.active::before {
      display: none;
    }

    .main {
      flex: 1;
      display: flex;
      flex-direction: column;
      min-width: 0;
      background: #0d1117;
    }

    .options {
      padding: 24px;
      border-bottom: 1px solid rgba(48, 54, 61, 0.5);
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 20px;
      background: rgba(22, 27, 34, 0.5);
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .form-group label {
      font-size: 14px;
      font-weight: 500;
      color: #f0f6fc;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .form-group input,
    .form-group select {
      padding: 12px 16px;
      border-radius: 10px;
      border: 1px solid #30363d;
      background: rgba(13, 17, 23, 0.8);
      color: #e6edf3;
      font-size: 14px;
      font-family: inherit;
      transition: all 0.3s ease;
      backdrop-filter: blur(10px);
    }

    .form-group input:focus,
    .form-group select:focus {
      outline: none;
      border-color: #58a6ff;
      box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.1);
      background: rgba(13, 17, 23, 0.95);
    }

    .preview {
      flex: 1;
      padding: 32px;
      display: flex;
      align-items: flex-start;
      justify-content: center;
      overflow: auto;
      gap: 24px;
      min-height: 300px;
      position: relative;
      flex-wrap: wrap;
    }

    .preview img {
      border-radius: 12px;
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
      background: #161b22;
      min-width: 320px;
      min-height: 120px;
      object-fit: contain;
      transition: all 0.3s ease;
      border: 1px solid rgba(48, 54, 61, 0.3);
    }

    .preview img:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
    }

    .spinner {
      width: 48px;
      height: 48px;
      border: 4px solid rgba(48, 54, 61, 0.3);
      border-top: 4px solid #58a6ff;
      border-radius: 50%;
      animation: spin 1s linear infinite;
      margin: 60px auto;
    }

    @keyframes spin {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }

    .error-message {
      color: #ff7b72;
      background: rgba(248, 81, 73, 0.1);
      border: 1px solid rgba(248, 81, 73, 0.3);
      border-radius: 12px;
      padding: 20px 24px;
      margin: 40px auto;
      font-size: 16px;
      max-width: 480px;
      text-align: center;
      backdrop-filter: blur(10px);
      display: flex;
      align-items: center;
      gap: 12px;
      justify-content: center;
    }

    .error-message::before {
      content: '⚠️';
      font-size: 20px;
    }

    .markdown {
      padding: 24px;
      border-top: 1px solid rgba(48, 54, 61, 0.5);
      background: rgba(22, 27, 34, 0.5);
    }

    .markdown-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 16px;
    }

    .markdown-header h3 {
      font-size: 16px;
      font-weight: 600;
      color: #f0f6fc;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    textarea {
      width: 100%;
      height: 120px;
      border: 1px solid #30363d;
      border-radius: 10px;
      padding: 16px;
      background: rgba(13, 17, 23, 0.8);
      color: #e6edf3;
      font-size: 14px;
      font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
      resize: vertical;
      transition: all 0.3s ease;
      backdrop-filter: blur(10px);
      line-height: 1.5;
    }

    textarea:focus {
      outline: none;
      border-color: #58a6ff;
      box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.1);
      background: rgba(13, 17, 23, 0.95);
    }

    .button-group {
      display: flex;
      gap: 12px;
      margin-top: 16px;
    }

    button {
      padding: 12px 20px;
      border: none;
      border-radius: 10px;
      font-size: 14px;
      font-weight: 500;
      font-family: inherit;
      cursor: pointer;
      transition: all 0.3s ease;
      display: flex;
      align-items: center;
      gap: 8px;
      position: relative;
      overflow: hidden;
    }

    .btn-primary {
      background: linear-gradient(135deg, #238636, #2ea043);
      color: white;
      box-shadow: 0 4px 12px rgba(35, 134, 54, 0.3);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(35, 134, 54, 0.4);
    }

    .btn-secondary {
      background: rgba(48, 54, 61, 0.5);
      color: #e6edf3;
      border: 1px solid #30363d;
    }

    .btn-secondary:hover {
      background: rgba(48, 54, 61, 0.8);
      border-color: #58a6ff;
    }

    .footer {
      background: rgba(22, 27, 34, 0.95);
      color: #8b949e;
      text-align: center;
      padding: 20px;
      font-size: 14px;
      border-top: 1px solid rgba(48, 54, 61, 0.5);
      backdrop-filter: blur(10px);
    }

    .footer a {
      color: #58a6ff;
      text-decoration: none;
      transition: color 0.3s ease;
    }

    .footer a:hover {
      color: #79c0ff;
    }

    .success-toast {
      position: fixed;
      top: 20px;
      right: 20px;
      background: linear-gradient(135deg, #238636, #2ea043);
      color: white;
      padding: 16px 20px;
      border-radius: 10px;
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
      transform: translateX(400px);
      transition: transform 0.3s ease;
      z-index: 1000;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .success-toast.show {
      transform: translateX(0);
    }

    .loading-overlay {
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background: rgba(13, 17, 23, 0.8);
      backdrop-filter: blur(4px);
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      visibility: hidden;
      transition: all 0.3s ease;
    }

    .loading-overlay.show {
      opacity: 1;
      visibility: visible;
    }

    @media (max-width: 1024px) {
      .container {
        flex-direction: column;
      }
      
      .sidebar {
        width: 100%;
        padding: 16px;
        border-bottom: 1px solid rgba(48, 54, 61, 0.5);
        flex-direction: row;
        overflow-x: auto;
        gap: 12px;
      }

      .sidebar h2 {
        display: none;
      }

      .tab {
        white-space: nowrap;
        min-width: fit-content;
      }

      .options {
        grid-template-columns: 1fr;
        gap: 16px;
      }

      .preview {
        flex-direction: column;
        align-items: center;
        padding: 24px 16px;
      }

      .preview img {
        max-width: 100%;
        min-width: auto;
      }
    }

    @media (max-width: 640px) {
      .header {
        padding: 16px 20px;
      }

      .header h1 {
        font-size: 20px;
      }

      .sidebar {
        padding: 12px;
      }

      .options {
        padding: 16px;
      }

      .markdown {
        padding: 16px;
      }

      .button-group {
        flex-direction: column;
      }
    }