frontend: Fix settings scrollbar size

frontend/data/themes/Yami.obt

@@ -139,6 +139,7 @@
     --volume_slider_label: calc(var(--volume_slider_box) * 2);
 
     --scrollbar_size: 12px;
+    --settings_scrollbar_size: calc(var(--scrollbar_size) + 9px);
     --scrollbar_handle: var(--grey4);
     
     --scrollbar_bg: var(--grey6);
@@ -634,10 +635,12 @@ QListWidget QLineEdit:focus {
 
 OBSBasicSettings QScrollBar:vertical {
     width: var(--scrollbar_size);
+    width: var(--settings_scrollbar_size);
+    margin-left: 9px;
 }
 
 OBSBasicSettings QScrollBar:horizontal {
-    height: var(--scrollbar_size);
+    height: var(--settings_scrollbar_size);
 }
 
 /* Settings properties view */
@@ -736,6 +739,11 @@ QAbstractScrollArea {
     border-radius: var(--border_radius);
 }
 
+/* ScrollAreaContents */
+QScrollArea > QWidget > QWidget {
+    background: transparent;
+}
+
 /* Qt enforces a padding inside its status bar, so we
  * oversize it and use margin to crunch it back down
  */