feat: pure black theme

Closes #254

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/pages/search/widgets/hot_keyword.dart

@@ -23,6 +23,7 @@ class HotKeyword extends StatelessWidget {
           SizedBox(
             width: width! / 2 - 4,
             child: Material(
+              color: Colors.transparent,
               borderRadius: BorderRadius.circular(3),
               clipBehavior: Clip.hardEdge,
               child: InkWell(

lib/pages/search/widgets/search_text.dart

@@ -31,9 +31,11 @@ class SearchText extends StatelessWidget {
         onTap: () {
           onTap?.call(text);
         },
-        onLongPress: () {
-          onLongPress?.call(text);
-        },
+        onLongPress: onLongPress != null
+            ? () {
+                onLongPress!(text);
+              }
+            : null,
         borderRadius: BorderRadius.circular(6),
         child: Padding(
           padding: padding ??