diff --git a/lib/src/services/country_query_service.dart b/lib/src/services/country_query_service.dart
index 1af081c..9dc2ba7 100644
--- a/lib/src/services/country_query_service.dart
+++ b/lib/src/services/country_query_service.dart
@@ -115,12 +115,12 @@ class CountryQueryService {
 }
 
 /// Builds the MongoDB aggregation pipeline based on the provided filters.
- List<ul class="image_map">> _buildAggregationPipeline(
+ List<ul class="image_map">> _buildAggregationPipeline(
 Map<string, dynamic> filter,
 PaginationOptions? pagination,
 List<sortoption>? sort,
 ) {
- final pipeline = <ul class="image_map">>[];
+ final pipeline = <ul class="image_map">>[];
 final compoundMatchStages = <ul class="image_map">>[];
 
 // --- Stage 1: Initial Match for active status, text search, and other filters ---
@@ -131,7 +131,10 @@ class CountryQueryService {
 final qValue = filter['q'];
 if (qValue is String && qValue.isNotEmpty) {
 compoundMatchStages.add({
- r'$text': {r'$search': qValue},
+ 'name': {
+ r'$regex': qValue,
+ r'$options': 'i', // Case-insensitive
+ },
 });
 }
 
@@ -163,7 +166,10 @@ class CountryQueryService {
 {
 r'$match': {
 r'$expr': {
- r'$eq': [r'$headquarters._id', r'$$countryId'],
+ r'$eq': [
+ r'$headquarters.id',
+ {r'$toString': r'$$countryId'},
+ ],
 },
 'status': ContentStatus.active.name,
 },
@@ -174,7 +180,7 @@ class CountryQueryService {
 });
 pipeline.add({
 r'$match': {
- 'matchingSources': {r'$ne': <dynamic>[]},
+ 'matchingSources': {r'$ne': []},
 },
 });
 }
@@ -191,7 +197,10 @@ class CountryQueryService {
 {
 r'$match': {
 r'$expr': {
- r'$eq': [r'$eventCountry._id', r'$$countryId'],
+ r'$eq': [
+ r'$eventCountry.id',
+ {r'$toString': r'$$countryId'},
+ ],
 },
 'status': ContentStatus.active.name,
 },
@@ -202,14 +211,14 @@ class CountryQueryService {
 });
 pipeline.add({
 r'$match': {
- 'matchingHeadlines': {r'$ne': <dynamic>[]},
+ 'matchingHeadlines': {r'$ne': []},
 },
 });
 }
 
 // --- Stage 4: Sorting ---
 if (sort != null && sort.isNotEmpty) {
- final sortStage = <string, dynamic>{};
+ final sortStage = <string, Object>{};
 for (final option in sort) {
 sortStage[option.field] = option.order == SortOrder.asc ? 1 : -1;
 }
</div><div class="naked_ctrl">
<form action="/index.cgi/larger-text" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://patch-diff.githubusercontent.com/raw/flutter-news-app-full-source-code/flutter-news-app-api-server-full-source-code/pull/54.diff">(-&gt;オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://patch-diff.githubusercontent.com/raw/flutter-news-app-full-source-code/flutter-news-app-api-server-full-source-code/pull/54.diff" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast">配色反転</option>
<option value="larger-text" selected="selected">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>