anchor.diff:    }
   }
   
  -String? _renderFilterButtons({
  -  required SearchForm searchForm,
  -  required List<_FilterOption>? options,
  -}) {
  -  if (options == null || options.isEmpty) return null;
  -  final tp = searchForm.tagsPredicate;
  -  String searchWithTagsLink(TagsPredicate tagsPredicate) {
  -    return searchForm.change(tagsPredicate: tagsPredicate).toSearchLink();
  -  }
  -
  -  return renderSearchTabs(
  -    options.map((option) => SearchTab(
  -          title: option.title,
  -          text: option.label,
  -          href: searchWithTagsLink(
  -            tp.isRequiredTag(option.tag)
  -                ? tp.withoutTag(option.tag)
  -                : tp.appendPredicate(TagsPredicate(
  -                    requiredTags: [option.tag],
  -                  )),
  -          ),
  -          active: option.isActive,
  -        )),
  -  ).toString();
  -}
  -
   /// `Linux`, `macOS`, `Windows` platforms are not yet stable, and we want
   /// to display them only when the user has already opted-in to get them
   /// displayed.
  -_SubSdkLayout _calculateLayout(SearchForm searchForm) {
  -  List<_FilterOption>? options;
  -
  -  _FilterOption option({
  +List<SearchTab> _calculateSearchTabs(SearchForm searchForm) {
  +  SearchTab searchTab({
       required String label,
       required String tag,
       required String title,
     }) {
  -    return _FilterOption(
  -      label: label,
  -      tag: tag,
  +    final tp = searchForm.tagsPredicate;
  +    return SearchTab(
  +      text: label,
  +      href: searchForm
  +          .change(
  +            tagsPredicate: tp.isRequiredTag(tag)
  +                ? tp.withoutTag(tag)
  +                : tp.appendPredicate(TagsPredicate(requiredTags: [tag])),
  +          )
  +          .toSearchLink(),
         title: title,
  -      isActive: searchForm.tagsPredicate.isRequiredTag(tag),
  +      active: searchForm.tagsPredicate.isRequiredTag(tag),
       );
     }
   
     final sdk = searchForm.sdk;
     if (sdk == SdkTagValue.dart) {
  -    options = [
  -      option(
  +    return <SearchTab>[
  +      searchTab(
           label: 'native',
           tag: DartSdkTag.runtimeNativeJit,
           title:
               'Packages compatible with Dart running on a native platform (JIT/AOT)',
         ),
  -      option(
  +      searchTab(
           label: 'JS',
           tag: DartSdkTag.runtimeWeb,
           title: 'Packages compatible with Dart compiled for the web',
  
positive.code:     ];
    }
    if (sdk == SdkTagValue.flutter) {
      options = [
        option(
          label: 'Android',
          tag: FlutterSdkTag.platformAndroid,
          title: 'Packages compatible with Flutter on the Android platform',
        ),
        option(
          label: 'iOS',
          tag: FlutterSdkTag.platformIos,
          title: 'Packages compatible with Flutter on the iOS platform',
        ),
        option(
          label: 'Web',
          tag: FlutterSdkTag.platformWeb,
          title: 'Packages compatible with Flutter on the Web platform',
        ),
        option(
          label: 'Linux',
          tag: FlutterSdkTag.platformLinux,
          title: 'Packages compatible with Flutter on the Linux platform',
        ),
        option(
          label: 'macOS',
          tag: FlutterSdkTag.platformMacos,
          title: 'Packages compatible with Flutter on the macOS platform',
        ),
        option(
          label: 'Windows',
          tag: FlutterSdkTag.platformWindows,
          title: 'Packages compatible with Flutter on the Windows platform',
        ),
      ];
    }
    return _SubSdkLayout(options: options);
  }
  
  class _SubSdkLayout {
    final List<_FilterOption>? options;
  
    _SubSdkLayout({
      required this.options,
    });
  
    bool get hasOptions => options != null && options!.isNotEmpty;
  }
  
  class _FilterOption {
    final String label;
    final String tag;
    final String title;
    final bool isActive;
  
    _FilterOption({
      required this.label,
      required this.tag,
      required this.title,
      required this.isActive,
    });
  }
  
negative.code:   final includeDiscontinued = searchForm.includeDiscontinued ?? false;
    final includeUnlisted = searchForm.includeUnlisted ?? false;
    final nullSafe = searchForm.nullSafe ?? false;
    final searchTabs = _calculateSearchTabs(searchForm);
    final hasActiveAdvanced = includeDiscontinued || includeUnlisted || nullSafe;
    final values = {
      'has_active_advanced': hasActiveAdvanced,
      'sdk_tabs_html': renderSdkTabs(searchForm: searchForm),
      'has_subsdk_options': searchTabs.isNotEmpty,
      'subsdk_label': _subSdkLabel(searchForm),
      'subsdk_filter_buttons_html':
          searchTabs.isNotEmpty ? renderSearchTabs(searchTabs).toString() : null,
      'is_search': isSearch,
      'listing_info_html': renderListingInfo(
        searchForm: searchForm,
  