* {
        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: 1000px;
        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;
      }

      input[type="text"],
      input[type="url"],
      textarea {
        width: 100%;
        padding: 12px 14px;
        border: 1px solid #d1d5db;
        border-radius: 8px;
        font-size: 0.95rem;
        font-family: inherit;
        transition: all 0.2s;
      }

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

      textarea {
        resize: vertical;
        min-height: 80px;
      }

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

      .image-upload-wrapper {
        position: relative;
      }

      .image-upload {
        display: none;
      }

      .image-upload-label {
        display: inline-block;
        padding: 10px 20px;
        background: #f3f4f6;
        border: 2px dashed #d1d5db;
        border-radius: 8px;
        cursor: pointer;
        font-size: 0.9rem;
        transition: all 0.2s;
      }

      .image-upload-label:hover {
        background: #e5e7eb;
      }

      .image-preview {
        margin-top: 12px;
        max-width: 200px;
        border-radius: 8px;
        display: none;
      }

      .preview-tabs {
        display: flex;
        gap: 8px;
        margin-bottom: 20px;
        border-bottom: 2px solid #e5e7eb;
      }

      .tab {
        padding: 10px 16px;
        background: none;
        border: none;
        border-bottom: 2px solid transparent;
        cursor: pointer;
        font-size: 0.9rem;
        font-weight: 500;
        color: #6b7280;
        transition: all 0.2s;
      }

      .tab.active {
        color: #2563eb;
        border-bottom-color: #2563eb;
      }

      .preview-content {
        display: none;
      }

      .preview-content.active {
        display: block;
      }

      /* Facebook Preview */
      .facebook-preview {
        background: #f0f2f5;
        border-radius: 12px;
        padding: 16px;
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          Helvetica, Arial, sans-serif;
      }

      .facebook-card {
        background: #ffffff;
        border: 1px solid #dddfe2;
        border-radius: 8px;
        overflow: hidden;
      }

      .facebook-image {
        width: 100%;
        aspect-ratio: 1.91/1;
        background: #e4e6eb;
        display: flex;
        align-items: center;
        justify-content: center;
        color: #65676b;
      }

      .facebook-image img {
        width: 100%;
        height: 100%;
        object-fit: cover;
      }

      .facebook-content {
        padding: 12px;
      }

      .facebook-domain {
        font-size: 12px;
        color: #65676b;
        text-transform: uppercase;
        margin-bottom: 4px;
      }

      .facebook-title {
        font-size: 16px;
        font-weight: 600;
        color: #050505;
        margin-bottom: 4px;
        line-height: 1.3;
      }

      .facebook-description {
        font-size: 14px;
        color: #65676b;
        line-height: 1.4;
      }

      /* LinkedIn Preview */
      .linkedin-preview {
        background: #f3f2ef;
        border-radius: 12px;
        padding: 16px;
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          Helvetica, Arial, sans-serif;
      }

      .linkedin-card {
        background: #ffffff;
        border: 1px solid #e0dfdc;
        border-radius: 8px;
        overflow: hidden;
      }

      .linkedin-image {
        width: 100%;
        aspect-ratio: 1.91/1;
        background: #f3f2ef;
        display: flex;
        align-items: center;
        justify-content: center;
        color: #666;
      }

      .linkedin-image img {
        width: 100%;
        height: 100%;
        object-fit: cover;
      }

      .linkedin-content {
        padding: 12px 16px;
      }

      .linkedin-title {
        font-size: 15px;
        font-weight: 600;
        color: #000000;
        margin-bottom: 4px;
        line-height: 1.3;
      }

      .linkedin-domain {
        font-size: 12px;
        color: #666;
      }

      /* Twitter Preview */
      .twitter-preview {
        background: #f7f9f9;
        border-radius: 12px;
        padding: 16px;
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          Helvetica, Arial, sans-serif;
      }

      .twitter-card {
        background: #ffffff;
        border: 1px solid #cfd9de;
        border-radius: 16px;
        overflow: hidden;
      }

      .twitter-image {
        width: 100%;
        aspect-ratio: 2/1;
        background: #e1e8ed;
        display: flex;
        align-items: center;
        justify-content: center;
        color: #657786;
      }

      .twitter-image img {
        width: 100%;
        height: 100%;
        object-fit: cover;
      }

      .twitter-content {
        padding: 12px;
      }

      .twitter-title {
        font-size: 15px;
        font-weight: 700;
        color: #0f1419;
        margin-bottom: 2px;
        line-height: 1.3;
      }

      .twitter-description {
        font-size: 14px;
        color: #536471;
        line-height: 1.4;
        margin-bottom: 4px;
      }

      .twitter-domain {
        font-size: 13px;
        color: #536471;
      }

      .code-section {
        margin-top: 20px;
        background: #f9fafb;
        border: 1px solid #e5e7eb;
        border-radius: 8px;
        padding: 16px;
      }

      .code-section h3 {
        font-size: 0.95rem;
        font-weight: 600;
        margin-bottom: 12px;
        color: #111827;
      }

      .code-block {
        background: #1f2937;
        color: #e5e7eb;
        padding: 16px;
        border-radius: 8px;
        font-family: "Courier New", monospace;
        font-size: 0.85rem;
        overflow-x: auto;
        line-height: 1.6;
      }

      .copy-btn {
        float: right;
        padding: 6px 12px;
        background: #111827;
        color: #ffffff;
        border: none;
        border-radius: 6px;
        font-size: 0.85rem;
        cursor: pointer;
        transition: all 0.2s;
      }

      .copy-btn:hover {
        background: #374151;
      }

      .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;
        }
      }