diff --git a/app/Actions/SearchPage/SearchAction.php b/app/Actions/SearchPage/SearchAction.php
index 4f6d43d..ffcac0c 100644
--- a/app/Actions/SearchPage/SearchAction.php
+++ b/app/Actions/SearchPage/SearchAction.php
@@ -36,15 +36,23 @@ private function addKeywordQuery(Builder $builder, string $keyword): void
         $builder->where(function (Builder $builder) use ($keyword): void {
             foreach (explode(' ', $keyword) as $word) {
                 $word = trim($word);
+                if ($word === '') {
+                    continue;
+                }
+
                 if (str_starts_with($word, '-')) {
                     $word = trim(substr($word, 1));
                     if ($word !== '' && $word !== '0') {
-                        $builder->where('title', 'not like', sprintf('%%%s%%', $word));
-                        $builder->orWhere('text', 'not like', sprintf('%%%s%%', $word));
+                        $builder->where(function (Builder $builder) use ($word): void {
+                            $builder->where('title', 'not like', sprintf('%%%s%%', $word));
+                            $builder->where('text', 'not like', sprintf('%%%s%%', $word));
+                        });
                     }
                 } else {
-                    $builder->where('title', 'like', sprintf('%%%s%%', $word));
-                    $builder->orWhere('text', 'like', sprintf('%%%s%%', $word));
+                    $builder->where(function (Builder $builder) use ($word): void {
+                        $builder->where('title', 'like', sprintf('%%%s%%', $word));
+                        $builder->orWhere('text', 'like', sprintf('%%%s%%', $word));
+                    });
                 }
             }
         });
diff --git a/tests/Feature/Actions/SearchPage/SearchActionTest.php b/tests/Feature/Actions/SearchPage/SearchActionTest.php
new file mode 100644
index 0000000..d61badf
--- /dev/null
+++ b/tests/Feature/Actions/SearchPage/SearchActionTest.php
@@ -0,0 +1,131 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\Actions\SearchPage;
+
+use App\Actions\SearchPage\SearchAction;
+use App\Enums\PakSlug;
+use App\Enums\SiteName;
+use App\Models\Page;
+use App\Models\Pak;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\Feature\TestCase;
+
+final class SearchActionTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private Pak $pak128;
+
+    private Pak $pak64;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->pak128 = Pak::factory()->create(['slug' => PakSlug::Pak128]);
+        $this->pak64 = Pak::factory()->create(['slug' => PakSlug::Pak64]);
+    }
+
+    public function test_filters_by_site_and_pak(): void
+    {
+        $page1 = Page::factory()->create(['site_name' => SiteName::Japan]);
+        $page1->paks()->attach($this->pak128);
+
+        $page2 = Page::factory()->create(['site_name' => SiteName::Portal]);
+        $page2->paks()->attach($this->pak128);
+
+        $page3 = Page::factory()->create(['site_name' => SiteName::Japan]);
+        $page3->paks()->attach($this->pak64);
+
+        $searchAction = new SearchAction;
+
+        $result = $searchAction([
+            'keyword' => '',
+            'sites' => [SiteName::Japan->value],
+            'paks' => [PakSlug::Pak128->value],
+        ]);
+
+        $this->assertCount(1, $result);
+        $this->assertSame($page1->id, $result->first()->id);
+    }
+
+    public function test_filters_by_keyword_including_exclude_logic(): void
+    {
+        $page1 = Page::factory()->create([
+            'site_name' => SiteName::Japan,
+            'title' => 'Train Addon',
+            'text' => 'This is a train',
+        ]);
+        $page1->paks()->attach($this->pak128);
+
+        $page2 = Page::factory()->create([
+            'site_name' => SiteName::Japan,
+            'title' => 'Bus Addon',
+            'text' => 'This is a bus',
+        ]);
+        $page2->paks()->attach($this->pak128);
+
+        $page3 = Page::factory()->create([
+            'site_name' => SiteName::Japan,
+            'title' => 'Electric Train Addon',
+            'text' => 'This is an electric train',
+        ]);
+        $page3->paks()->attach($this->pak128);
+
+        $searchAction = new SearchAction;
+
+        $baseQuery = [
+            'sites' => [SiteName::Japan->value],
+            'paks' => [PakSlug::Pak128->value],
+        ];
+
+        // Search for 'Train'
+        $result = $searchAction(array_merge($baseQuery, ['keyword' => 'Train']));
+        $this->assertCount(2, $result); // page1, page3
+
+        // Search for 'Train -Electric'
+        $result = $searchAction(array_merge($baseQuery, ['keyword' => 'Train -Electric']));
+        $this->assertCount(1, $result); // page1 only
+
+        // Search for 'Bus'
+        $result = $searchAction(array_merge($baseQuery, ['keyword' => 'Bus']));
+        $this->assertCount(1, $result); // page2
+        $this->assertSame($page2->id, $result->first()->id);
+    }
+
+    public function test_orders_by_last_modified_desc(): void
+    {
+        $page1 = Page::factory()->create([
+            'site_name' => SiteName::Japan,
+            'last_modified' => now()->subDays(2),
+        ]);
+        $page1->paks()->attach($this->pak128);
+
+        $page2 = Page::factory()->create([
+            'site_name' => SiteName::Japan,
+            'last_modified' => now(),
+        ]);
+        $page2->paks()->attach($this->pak128);
+
+        $page3 = Page::factory()->create([
+            'site_name' => SiteName::Japan,
+            'last_modified' => now()->subDays(1),
+        ]);
+        $page3->paks()->attach($this->pak128);
+
+        $searchAction = new SearchAction;
+
+        $result = $searchAction([
+            'keyword' => '',
+            'sites' => [SiteName::Japan->value],
+            'paks' => [PakSlug::Pak128->value],
+        ]);
+
+        $this->assertCount(3, $result);
+        $this->assertSame($page2->id, $result->items()[0]->id);
+        $this->assertSame($page3->id, $result->items()[1]->id);
+        $this->assertSame($page1->id, $result->items()[2]->id);
+    }
+}
diff --git a/tests/Feature/Actions/SyncNotion/SyncActionTest.php b/tests/Feature/Actions/SyncNotion/SyncActionTest.php
new file mode 100644
index 0000000..1604f57
--- /dev/null
+++ b/tests/Feature/Actions/SyncNotion/SyncActionTest.php
@@ -0,0 +1,96 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\Actions\SyncNotion;
+
+use App\Actions\SyncNotion\SyncAction;
+use App\Enums\PakSlug;
+use App\Enums\SiteName;
+use App\Models\Page;
+use App\Models\Pak;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Mockery;
+use Notion\Databases\Database;
+use Notion\Notion;
+use Notion\Pages\Page as NotionPage;
+use Notion\Pages\PageParent;
+use Notion\Pages\Properties\Url;
+use Tests\Feature\TestCase;
+
+final class SyncActionTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_sync_action_creates_updates_and_deletes_pages(): void
+    {
+        $pak = Pak::factory()->create(['slug' => PakSlug::Pak128]);
+
+        // This page should be created in Notion
+        $pageToCreate = Page::factory()->create([
+            'title' => 'New Addon',
+            'site_name' => SiteName::Japan,
+            'url' => 'https://example.com/new',
+            'last_modified' => now(),
+        ]);
+        $pageToCreate->paks()->attach($pak);
+
+        // This page exists in both DB and Notion, should be updated
+        Page::factory()->create([
+            'title' => 'Updated Addon',
+            'site_name' => SiteName::Japan,
+            'url' => 'https://example.com/update',
+            'last_modified' => now(),
+        ]);
+
+        $database = Database::fromArray([
+            'id' => 'test_database_id',
+            'created_time' => '2023-01-01T00:00:00.000Z',
+            'last_edited_time' => '2023-01-01T00:00:00.000Z',
+            'title' => [],
+            'description' => [],
+            'icon' => null,
+            'cover' => null,
+            'properties' => [
+                'Title' => [
+                    'id' => 'title',
+                    'type' => 'title',
+                    'name' => 'Title',
+                    'title' => [],
+                ],
+                'パックセット' => [
+                    'id' => 'prop_id',
+                    'type' => 'multi_select',
+                    'name' => 'パックセット',
+                    'multi_select' => [
+                        'options' => [
+                            ['name' => '128', 'id' => 'opt_128', 'color' => 'default'],
+                        ],
+                    ],
+                ],
+            ],
+            'parent' => ['type' => 'workspace', 'workspace' => true],
+            'url' => 'https://notion.so',
+            'is_inline' => false,
+        ]);
+
+        $notionPageToUpdate = NotionPage::create(PageParent::database('test_database_id'));
+        $notionPageToUpdate = $notionPageToUpdate->addProperty('URL', Url::create('https://example.com/update'));
+
+        $notionPageToDelete = NotionPage::create(PageParent::database('test_database_id'));
+        $notionPageToDelete = $notionPageToDelete->addProperty('URL', Url::create('https://example.com/delete'));
+
+        $mock = Mockery::mock(Notion::class);
+        $mock->shouldReceive('databases->find')->with('test_database_id')->andReturn($database);
+        $mock->shouldReceive('databases->queryAllPages')->with($database)->andReturn([$notionPageToUpdate, $notionPageToDelete]);
+
+        $mock->shouldReceive('pages->delete')->once()->with($notionPageToDelete);
+
+        $mock->shouldReceive('pages->update')->once()->with(Mockery::on(fn (NotionPage $notionPage): bool => $notionPage->getProperty('URL')->url === 'https://example.com/update'));
+
+        $mock->shouldReceive('pages->create')->once()->with(Mockery::on(fn (NotionPage $notionPage): bool => $notionPage->getProperty('URL')->url === 'https://example.com/new'));
+
+        $syncAction = new SyncAction($mock);
+        $syncAction('test_database_id', 10);
+    }
+}