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

      body {
        background: #f3f4f6;
        color: #111827;
        font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont,
          "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
        line-height: 1.6;
      }

      .ad-banner-top {
        background: #ffffff;
        border-bottom: 1px solid #e5e7eb;
        padding: 15px;
        text-align: center;
        min-height: 80px;
        display: flex;
        align-items: center;
        justify-content: center;
        width: 100%;
      }

      .ad-placeholder {
        background: #f9fafb;
        border: 2px dashed #d1d5db;
        color: #9ca3af;
        display: inline-flex;
        align-items: center;
        justify-content: center;
        font-size: 14px;
        padding: 12px 20px;
        border-radius: 999px;
      }

      .page {
        max-width: 900px;
        margin: 0 auto;
        padding: 40px 24px;
      }

      .nav {
        margin-bottom: 24px;
      }

      .nav a {
        color: #6b7280;
        text-decoration: none;
        font-size: 0.9rem;
        display: inline-flex;
        align-items: center;
        gap: 6px;
        transition: color 0.2s;
      }

      .nav a:hover {
        color: #111827;
      }

      .header {
        margin-bottom: 32px;
      }

      .badge {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        padding: 4px 10px;
        border-radius: 999px;
        background: #e5f2ff;
        color: #1d4ed8;
        font-size: 0.75rem;
        text-transform: uppercase;
        letter-spacing: 0.06em;
        margin-bottom: 12px;
      }

      .header h1 {
        font-size: 2rem;
        font-weight: 600;
        letter-spacing: -0.03em;
        margin-bottom: 8px;
      }

      .header p {
        color: #4b5563;
        font-size: 1rem;
      }

      .tool-section {
        background: #ffffff;
        border-radius: 14px;
        border: 1px solid #e5e7eb;
        padding: 24px;
        margin-bottom: 20px;
        box-shadow: 0 10px 28px rgba(15, 23, 42, 0.05);
      }

      .form-group {
        margin-bottom: 20px;
      }

      .form-group label {
        display: block;
        font-weight: 500;
        margin-bottom: 8px;
        font-size: 0.95rem;
      }

      textarea {
        width: 100%;
        padding: 12px 14px;
        border: 1px solid #d1d5db;
        border-radius: 8px;
        font-size: 0.85rem;
        font-family: "Courier New", monospace;
        transition: all 0.2s;
        resize: vertical;
        min-height: 250px;
      }

      textarea:focus {
        outline: none;
        border-color: #2563eb;
        box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
      }

      .help-text {
        font-size: 0.85rem;
        color: #6b7280;
        margin-top: 6px;
      }

      .button-group {
        display: flex;
        gap: 12px;
        margin-top: 20px;
      }

      .btn {
        padding: 10px 20px;
        border: none;
        border-radius: 8px;
        font-size: 0.95rem;
        font-weight: 500;
        cursor: pointer;
        transition: all 0.2s;
      }

      .btn-primary {
        background: #111827;
        color: #ffffff;
      }

      .btn-primary:hover {
        background: #1f2937;
        transform: translateY(-1px);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
      }

      .btn-secondary {
        background: #ffffff;
        color: #111827;
        border: 1px solid #d1d5db;
      }

      .btn-secondary:hover {
        background: #f3f4f6;
      }

      .results-section {
        display: none;
      }

      .results-section.show {
        display: block;
      }

      .summary-box {
        background: #ffffff;
        border-radius: 14px;
        border: 1px solid #e5e7eb;
        padding: 24px;
        margin-bottom: 20px;
        box-shadow: 0 10px 28px rgba(15, 23, 42, 0.05);
      }

      .summary-box.success {
        background: #f0fdf4;
        border-color: #10b981;
      }

      .summary-box.error {
        background: #fef2f2;
        border-color: #ef4444;
      }

      .summary-title {
        font-size: 1.2rem;
        font-weight: 600;
        margin-bottom: 12px;
        display: flex;
        align-items: center;
        gap: 8px;
      }

      .summary-title.success {
        color: #059669;
      }

      .summary-title.error {
        color: #dc2626;
      }

      .summary-stats {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 16px;
        margin-top: 16px;
      }

      .stat-item {
        text-align: center;
      }

      .stat-value {
        font-size: 2rem;
        font-weight: 700;
        color: #111827;
      }

      .stat-label {
        font-size: 0.85rem;
        color: #6b7280;
        margin-top: 4px;
      }

      .issues-list {
        background: #ffffff;
        border-radius: 14px;
        border: 1px solid #e5e7eb;
        padding: 24px;
        box-shadow: 0 10px 28px rgba(15, 23, 42, 0.05);
      }

      .issues-title {
        font-size: 1.1rem;
        font-weight: 600;
        margin-bottom: 16px;
        color: #111827;
      }

      .issue-item {
        background: #fef2f2;
        border-left: 3px solid #ef4444;
        padding: 12px 16px;
        margin-bottom: 12px;
        border-radius: 6px;
      }

      .issue-type {
        font-weight: 600;
        color: #dc2626;
        font-size: 0.9rem;
      }

      .issue-detail {
        font-size: 0.9rem;
        color: #4b5563;
        margin-top: 4px;
      }

      .example-link {
        color: #2563eb;
        text-decoration: none;
        font-size: 0.85rem;
        display: inline-flex;
        align-items: center;
        gap: 4px;
      }

      .example-link:hover {
        text-decoration: underline;
      }

      .ad-banner-bottom {
        background: #ffffff;
        border-top: 1px solid #e5e7eb;
        padding: 20px;
        text-align: center;
        min-height: 80px;
        display: flex;
        align-items: center;
        justify-content: center;
        margin-top: 32px;
        width: 100%;
      }

      .footer {
        margin-top: 12px;
        font-size: 0.78rem;
        color: #9ca3af;
        text-align: center;
      }

      @media (max-width: 768px) {
        .page {
          padding: 24px 16px;
        }

        .header h1 {
          font-size: 1.6rem;
        }

        .tool-section {
          padding: 20px;
        }

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