There is no white space between my items in my list. I tried adding margin on multiple places but nothing seems to work, and I don't know why.
I'm sorry if my XML pages are messy, but it's my first time making an app. My activity_main
<?xml version="1.0" encoding="utf-8"?>
<androidx.fragment.app.FragmentContainerView
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/overviewFragment"
    android:name="com.example.breweries.overview.OverviewFragment"
    android:layout_width="match_parent"
    android:layout_margin="20dp"
    android:layout_height="match_parent"
    tools:layout="@layout/fragment_overview" />
My fragment_overview
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">
    <data>
        <variable
            name="viewModel"
            type="com.example.breweries.overview.OverviewViewModel" />
    </data>
    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:context="com.example.breweries.overview.OverViewFragment">
        <androidx.recyclerview.widget.RecyclerView
            android:padding="6dp"
            android:clipToPadding="false"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:id="@+id/photos_grid"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
            app:spanCount="1"
            app:listData="@{viewModel.photos}"
            tools:itemCount="8"
            tools:listitem="@layout/grid_view_item"
            />
    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>
My grid_view_item
<?xml version="1.0" encoding="utf-8"?>
 <layout >
    <data>
        <variable
            name="photo"
            type="com.example.breweries.network.Brewery" />
    </data>
    <androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="120dp"
        android:layout_gravity="center"
        android:layout_marginBottom="30dp"
        android:layout_margin="5dp"
        app:cardCornerRadius="10dp"
        app:cardElevation="5dp">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
        </LinearLayout>
    </androidx.cardview.widget.CardView>
</layout>
Any other tips to make my XML pages better are highly appreciated!