Aligning Horizontal Custom Inspector Elements

 Hello, I've written a custom inspector for a pickup script but fields in horizontal group seem to be out of alignment. They don't look like the fields of default MonoBehaviour objects. What am I doing wrong here? :)

 using UnityEditor;
 using UnityEditor.SceneManagement;
 using UnityEngine;
 
 [CustomEditor(typeof(Pickup))]
 public class PickupInspector : Editor
 {
     private Pickup inspectedObject;
 
     public override void OnInspectorGUI()
     {
         inspectedObject = (Pickup)target;
 
         GUI.enabled = false;
         EditorGUILayout.ObjectField("Script ", MonoScript.FromMonoBehaviour(inspectedObject), typeof(Pickup), true);
         EditorGUILayout.Space();
         GUI.enabled = true;
 
         EditorGUILayout.BeginHorizontal();
         EditorGUILayout.LabelField("Ability Name");
         inspectedObject.AbilityName = EditorGUILayout.TextField(inspectedObject.AbilityName);
         EditorGUILayout.EndHorizontal();
 
         EditorGUILayout.BeginHorizontal();
         EditorGUILayout.LabelField("Is Instant?");
         inspectedObject.IsInstant = EditorGUILayout.Toggle(inspectedObject.IsInstant);
         EditorGUILayout.EndHorizontal();
 
         if (!inspectedObject.IsInstant)
         {
             EditorGUILayout.BeginHorizontal();
             EditorGUILayout.LabelField("Is Duration Based?");
             inspectedObject.IsDurationBased = EditorGUILayout.Toggle(inspectedObject.IsDurationBased);
             EditorGUILayout.EndHorizontal();
 
             EditorGUILayout.BeginHorizontal();
             EditorGUILayout.LabelField("Ability Duration");
             inspectedObject.AbilityDuration = EditorGUILayout.FloatField(inspectedObject.AbilityDuration);
             EditorGUILayout.EndHorizontal();
         }
 
         if (GUI.changed)
             EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
     }
 }