ui: avoid explicitly setting stylesheets

src/config.h

@@ -1,7 +1,7 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 01:34:52
- * @LastEditTime: 2025-08-07 22:28:11
+ * @LastEditTime: 2025-08-07 23:24:02
  * @Description: Configuration manager.
  */
 #ifndef CONFIG_H
@@ -16,10 +16,10 @@ class Config : public QObject {
 
   public:
     enum class SortType : int {
-        None = 0,
-        Name,
-        Date,
-        Size,
+        None = 0,  // "none"
+        Name,      // "name"
+        Date,      // "date"
+        Size,      // "size"
     };
 
     struct WallpaperConfigItems {

src/designer/images_carousel.ui

@@ -22,9 +22,6 @@
   <layout class="QHBoxLayout" name="horizontalLayout">
    <item>
     <widget class="ImagesCarouselScrollArea" name="scrollArea">
-     <property name="styleSheet">
-      <string notr="true">border: none</string>
-     </property>
      <property name="verticalScrollBarPolicy">
       <enum>Qt::ScrollBarPolicy::ScrollBarAlwaysOff</enum>
      </property>
@@ -36,8 +33,8 @@
        <rect>
         <x>0</x>
         <y>0</y>
-        <width>382</width>
-        <height>282</height>
+        <width>380</width>
+        <height>280</height>
        </rect>
       </property>
       <layout class="QHBoxLayout" name="horizontalLayout_2"/>

src/images_carousel.cpp

@@ -1,7 +1,7 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 01:22:53
- * @LastEditTime: 2025-08-07 22:17:41
+ * @LastEditTime: 2025-08-08 00:43:47
  * @Description: Animated carousel widget for displaying and selecting images.
  */
 #include "images_carousel.h"
@@ -37,10 +37,12 @@ ImagesCarousel::ImagesCarousel(const Config::StyleConfigItems& styleConfig,
       m_sortType(sortConfig.type),
       m_sortReverse(sortConfig.reverse) {
     ui->setupUi(this);
-    m_scrollArea = dynamic_cast<ImagesCarouselScrollArea*>(ui->scrollArea);
-
+    m_scrollArea   = dynamic_cast<ImagesCarouselScrollArea*>(ui->scrollArea);
     m_imagesLayout = dynamic_cast<QHBoxLayout*>(ui->scrollAreaWidgetContents->layout());
 
+    // Remove border
+    ui->scrollArea->setFrameShape(QFrame::NoFrame);
+
     // Load initial images
     connect(this,
             &ImagesCarousel::loadingCompleted,