优化

app/src/main/res/layout/dialog_read_aloud.xml

@@ -144,6 +144,7 @@
             android:id="@+id/tv_timer"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:background="?android:attr/selectableItemBackgroundBorderless"
             android:textColor="@color/primaryText"
             android:text="@string/timer_m" />