:root {
      --primary: #4361ee;
      --primary-dark: #3a56d4;
      --secondary: #7209b7;
      --accent: #f72585;
      --light: #f8f9fa;
      --dark: #212529;
      --gray: #6c757d;
      --light-gray: #e9ecef;
      --border-radius: 12px;
      --box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
      --transition: all 0.3s ease;
    }

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

    body {
      font-family: 'Poppins', sans-serif;
      background: linear-gradient(135deg, #f5f7ff 0%, #f0f4ff 100%);
      color: var(--dark);
      line-height: 1.6;
      min-height: 100vh;
      padding: 20px;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
    }

    header {
      text-align: center;
      padding: 30px 0 20px;
      margin-bottom: 30px;
    }

    .logo {
      font-size: 2.8rem;
      margin-bottom: 15px;
      color: var(--primary);
      display: inline-block;
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% { transform: scale(1); }
      50% { transform: scale(1.05); }
      100% { transform: scale(1); }
    }

    h1 {
      font-size: 2.5rem;
      margin-bottom: 10px;
      font-weight: 700;
      color: var(--dark);
      background: linear-gradient(90deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .tagline {
      font-size: 1.2rem;
      color: var(--gray);
      max-width: 700px;
      margin: 0 auto 25px;
    }

    .card {
      background: white;
      border-radius: var(--border-radius);
      box-shadow: var(--box-shadow);
      padding: 30px;
      margin-bottom: 30px;
      transition: var(--transition);
    }

    .card:hover {
      transform: translateY(-5px);
      box-shadow: 0 12px 35px rgba(0, 0, 0, 0.1);
    }

    h2 {
      font-size: 1.8rem;
      margin-bottom: 25px;
      color: var(--dark);
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    h2 i {
      color: var(--primary);
    }

    h3 {
      font-size: 1.4rem;
      margin-bottom: 15px;
      color: var(--dark);
      font-weight: 600;
    }

    .drag-drop-area {
      width: 100%;
      max-width: 500px;
      margin: 2em auto;
      padding: 2em;
      border: 2px dashed var(--light-gray);
      border-radius: var(--border-radius);
      background: white;
      color: var(--gray);
      cursor: pointer;
      transition: var(--transition);
      text-align: center;
      font-size: 1rem;
    }

    .drag-drop-area.drag-over {
      background: #e6f0fa;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
    }

    .file-info {
      width: 100%;
      max-width: 500px;
      margin: 1em auto;
      padding: 15px;
      background: var(--light);
      border-radius: var(--border-radius);
      text-align: left;
    }

    .file-detail {
      display: flex;
      justify-content: space-between;
      margin: 0.3rem 0;
      font-size: 0.9rem;
    }

    .settings-grid {
      width: 100%;
      max-width: 500px;
      margin: 1em auto;
    }

    .setting-group {
      margin-bottom: 1.5rem;
      background: #f8f9ff;
      padding: 15px;
      border-radius: 8px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    }

    .description {
      font-size: 0.9em;
      color: var(--gray);
      margin-bottom: 0.5em;
    }

    .toggle-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin: 0.5em 0;
    }

    .toggle-switch {
      position: relative;
      display: inline-block;
      width: 50px;
      height: 24px;
    }

    .toggle-switch input {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      opacity: 0;
      cursor: pointer;
      z-index: 1;
    }

    .slider {
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background-color: var(--gray);
      transition: background-color 0.3s ease;
      -webkit-transition: background-color 0.3s ease;
      -moz-transition: background-color 0.3s ease;
      border-radius: 24px;
    }

    .slider:before {
      position: absolute;
      content: "";
      height: 16px;
      width: 16px;
      left: 4px;
      bottom: 4px;
      background-color: white;
      transition: transform 0.3s ease;
      -webkit-transition: transform 0.3s ease;
      -moz-transition: transform 0.3s ease;
      border-radius: 50%;
    }

    .toggle-switch input:checked + .slider {
      background-color: var(--primary);
    }

    .toggle-switch input:checked + .slider:before {
      transform: translateX(26px);
      -webkit-transform: translateX(26px);
      -moz-transform: translateX(26px);
    }

    .toggle-switch input:focus + .slider {
      box-shadow: 0 0 0 2px var(--primary-dark);
    }

    .toggle-switch input:disabled + .slider {
      background-color: var(--light-gray);
      opacity: 0.5;
      cursor: not-allowed;
    }

    .toggle-switch input:disabled + .slider:before {
      background-color: #ddd;
    }

    .progress-container {
      width: 100%;
      max-width: 500px;
      margin: 1.5em auto;
      padding: 15px;
      background: var(--light);
      border-radius: var(--border-radius);
      display: none;
    }

    .progress-header {
      display: flex;
      justify-content: space-between;
      margin-bottom: 0.5rem;
      font-size: 0.95rem;
    }

    .progress-bar {
      height: 10px;
      background: var(--light-gray);
      border-radius: 5px;
      overflow: hidden;
    }

    .progress-fill {
      height: 100%;
      width: 0;
      background: linear-gradient(90deg, var(--primary), var(--secondary));
      border-radius: 5px;
      transition: width 0.4s ease;
    }

    .result-container {
      width: 100%;
      max-width: 500px;
      margin: 1.5em auto;
      padding: 1.2rem;
      background: rgba(39, 174, 96, 0.08);
      border: 1px dashed #27ae60;
      border-radius: var(--border-radius);
      display: none;
    }

    .download-btn {
      background: #27ae60;
      color: white;
      padding: 15px;
      border-radius: 10px;
      text-decoration: none;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 10px;
      transition: var(--transition);
    }

    .download-btn:hover {
      background: #219653;
      transform: translateY(-2px);
      box-shadow: 0 4px 15px rgba(39, 174, 96, 0.3);
    }

    .error {
      color: #e74c3c;
      padding: 15px;
      background: rgba(231, 76, 60, 0.1);
      border-radius: var(--border-radius);
      margin: 20px 0;
      border-left: 4px solid #e74c3c;
      display: none;
    }

    .success {
      color: #27ae60;
      padding: 15px;
      background: rgba(39, 174, 96, 0.1);
      border-radius: var(--border-radius);
      margin: 20px 0;
      border-left: 4px solid #27ae60;
      display: none;
    }

    .loading {
      display: none;
      text-align: center;
      padding: 30px;
    }

    .spinner {
      border: 4px solid rgba(0, 0, 0, 0.1);
      border-left-color: var(--primary);
      border-radius: 50%;
      width: 50px;
      height: 50px;
      animation: spin 1s linear infinite;
      margin: 0 auto 20px;
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    label {
      display: block;
      margin-bottom: 8px;
      font-weight: 500;
      color: var(--dark);
    }

    input, select, button {
      margin: 0.5em auto;
      padding: 15px;
      width: 100%;
      font-size: 1rem;
      border-radius: 10px;
      border: 1px solid var(--light-gray);
      background: white;
      display: block;
      transition: var(--transition);
      font-family: 'Poppins', sans-serif;
    }

    input:focus, select:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
    }

    button {
      background: var(--primary);
      color: white;
      border: none;
      cursor: pointer;
      font-weight: 600;
      padding: 15px 20px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
    }

    button:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 4px 15px rgba(67, 97, 238, 0.3);
    }

    button:disabled {
      background: var(--gray);
      cursor: not-allowed;
      transform: none;
      box-shadow: none;
    }

    .features-section {
      margin: 40px auto;
    }

    .features-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
      margin-top: 25px;
    }

    .feature-card {
      background: white;
      border-radius: var(--border-radius);
      padding: 25px;
      text-align: center;
      box-shadow: var(--box-shadow);
      transition: var(--transition);
      font-size: 1.1rem;
    }

    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    }

    .feature-card i {
      font-size: 3rem;
      color: var(--primary);
      margin-bottom: 20px;
      background: #f0f4ff;
      width: 90px;
      height: 90px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      margin: 0 auto 20px;
    }

    .feature-card h3 {
      font-size: 1.6rem;
      margin-bottom: 15px;
      color: var(--dark);
    }

    .feature-card p {
      margin-bottom: 20px;
      color: var(--gray);
      font-size: 1.1rem;
    }

    .guide-section {
      background: white;
      border-radius: var(--border-radius);
      padding: 40px;
      margin: 40px auto;
      box-shadow: var(--box-shadow);
    }

    .guide-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
      margin-top: 25px;
    }

    .guide-card {
      padding: 25px;
      background: #f8f9ff;
      border-radius: var(--border-radius);
      text-align: center;
      font-size: 1.1rem;
    }

    .guide-card h3 {
      font-size: 1.5rem;
      margin-bottom: 15px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 10px;
      justify-content: center;
    }

    .guide-card h3 i {
      font-size: 1.8rem;
    }

    .guide-card p {
      font-size: 1.1rem;
      color: var(--gray);
    }

    .sister-tools-section {
      margin: 40px auto;
    }

    .sister-tools-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 25px;
      margin-top: 25px;
    }

    .sister-tool {
      background: white;
      border-radius: var(--border-radius);
      padding: 25px;
      text-align: center;
      box-shadow: var(--box-shadow);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      min-height: 320px;
    }

    .sister-tool:hover {
      transform: translateY(-5px);
      box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    }

    .sister-tool i {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 20px;
      background: #f0f4ff;
      width: 80px;
      height: 80px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      margin: 0 auto 20px;
    }

    .sister-tool h3 {
      font-size: 1.4rem;
      margin-bottom: 15px;
      color: var(--dark);
    }

    .sister-tool p {
      margin-bottom: 20px;
      color: var(--gray);
      flex-grow: 1;
    }

    .sister-tool-btn {
      display: inline-block;
      background: var(--primary);
      color: white;
      padding: 12px 25px;
      border-radius: 50px;
      text-decoration: none;
      font-weight: 600;
      transition: var(--transition);
      margin-top: auto;
    }

    .sister-tool-btn:hover {
      background: var(--primary-dark);
      transform: translateY(-3px);
      box-shadow: 0 4px 15px rgba(67, 97, 238, 0.3);
    }

    .everytool-card {
      grid-column: 1 / -1;
      display: flex;
      flex-direction: row;
      align-items: center;
      gap: 25px;
      padding: 30px;
      text-align: left;
      background: linear-gradient(135deg, #4361ee, #7209b7);
      color: white;
    }

    .everytool-card i {
      font-size: 4rem;
      color: white;
      background: rgba(255, 255, 255, 0.15);
      width: 100px;
      height: 100px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      margin: 0;
    }

    .everytool-content {
      flex: 1;
    }

    .everytool-card h3 {
      font-size: 1.8rem;
      color: white;
      margin-bottom: 10px;
      justify-content: flex-start;
    }

    .everytool-card p {
      margin-bottom: 20px;
      font-size: 1.1rem;
      opacity: 0.9;
      font-weight: bold;
      color: white;
    }

    .everytool-btn {
      display: inline-block;
      background: white;
      color: var(--primary);
      padding: 12px 25px;
      border-radius: 50px;
      text-decoration: none;
      font-weight: 600;
      transition: var(--transition);
    }

    .everytool-btn:hover {
      background: rgba(255, 255, 255, 0.9);
      transform: translateY(-3px);
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    }

    .creator-credit {
      font-weight: 500;
      color: var(--dark);
      font-size: 1rem;
    }

    @media (max-width: 768px) {
      .features-grid, .guide-grid {
        grid-template-columns: 1fr;
      }

      .card {
        padding: 20px;
      }

      h1 {
        font-size: 2rem;
      }

      h2 {
        font-size: 1.5rem;
      }

      .guide-section {
        padding: 25px;
      }

      .everytool-card {
        flex-direction: column;
        text-align: center;
      }

      .everytool-card h3 {
        justify-content: center;
      }
    }

    @media (max-width: 480px) {
      body {
        padding: 15px;
      }

      header {
        padding: 20px 0 10px;
      }

      .logo {
        font-size: 2.2rem;
      }

      h1 {
        font-size: 1.8rem;
      }

      .feature-card i, .guide-card h3 i {
        font-size: 2.5rem;
        width: 70px;
        height: 70px;
      }

      .feature-card h3, .guide-card h3 {
        font-size: 1.4rem;
      }

      .feature-card p, .guide-card p {
        font-size: 1rem;
      }

      .sister-tool {
        min-height: 280px;
      }
    }