replace multieffect shadows with rectangularshadow ones

.config/quickshell/modules/common/Appearance.qml

@@ -128,7 +128,7 @@ Singleton {
         property color colTooltip: "#3C4043" // m3colors.m3inverseSurface in the specs, but the m3 website actually uses this color
         property color colOnTooltip: "#F8F9FA" // m3colors.m3inverseOnSurface in the specs, but the m3 website actually uses this color
         property color colScrim: ColorUtils.transparentize(m3colors.m3scrim, 0.5)
-        property color colShadow: ColorUtils.transparentize(m3colors.m3shadow, 0.75)
+        property color colShadow: ColorUtils.transparentize(m3colors.m3shadow, 0.85)
     }
 
     rounding: QtObject {

.config/quickshell/modules/common/widgets/NotificationGroup.qml

@@ -106,7 +106,14 @@ Item { // Notification group area
     }
 
     
-
+    RectangularShadow {
+        visible: popup
+        anchors.fill: background
+        radius: background.radius
+        blur: 1.2 * Appearance.sizes.elevationMargin
+        spread: 1
+        color: Appearance.colors.colShadow
+    }
     Rectangle { // Background of the notification
         id: background
         anchors.left: parent.left
@@ -134,16 +141,6 @@ Item { // Notification group area
             animation: Appearance.animation.elementMoveFast.numberAnimation.createObject(this)
         }
 
-        layer.enabled: true
-        layer.effect: MultiEffect {
-            source: background
-            anchors.fill: background
-            shadowEnabled: popup
-            shadowColor: Appearance.colors.colShadow
-            shadowVerticalOffset: 1
-            shadowBlur: 0.5
-        }
-
         RowLayout { // Left column for icon, right column for content
             id: row
             anchors.top: parent.top