diff --git a/Packages/AudioConductor/CHANGELOG.md b/Packages/AudioConductor/CHANGELOG.md
index 96a658a..d10fbeb 100644
--- a/Packages/AudioConductor/CHANGELOG.md
+++ b/Packages/AudioConductor/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## v2.4.0 - 2026/06/11
+
+- New Features
+  - Add `referenceSampleRate` to CueSheet: sample positions are automatically scaled at runtime when the clip's actual decoding frequency differs from the authored rate, preventing playback drift on platforms that resample audio (e.g. when Audio Import Settings do not use Preserve Sample Rate)
+- Fix Issues
+  - Auto-pause and resume audio when the WebGL app loses focus
+  - Fix pause/resume not working correctly when Pause is called immediately after Play
+
 ## v2.3.1 - 2026/06/11
 
 - Fix Issues
diff --git a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModel.cs b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModel.cs
index 7df6d83..cfbfa2f 100644
--- a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModel.cs
+++ b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModel.cs
@@ -4,6 +4,8 @@
 
 #nullable enable
 
+using System.Collections.Generic;
+using System.Linq;
 using AudioConductor.Core.Enums;
 using AudioConductor.Core.Models;
 using AudioConductor.Core.Shared;
@@ -19,17 +21,59 @@ internal sealed class CueSheetParameterPaneModel : ICueSheetParameterPaneModel
     {
         private readonly IAssetSaveService _assetSaveService;
         private readonly AutoIncrementHistory _history;
+        private readonly CueSheet _rawCueSheet;
         private readonly ObservableCueSheet _target;
 
         public CueSheetParameterPaneModel([NotNull] CueSheet cueSheet,
             [NotNull] AutoIncrementHistory history,
             [NotNull] IAssetSaveService assetSaveService)
         {
+            _rawCueSheet = cueSheet;
             _target = new ObservableCueSheet(cueSheet);
             _history = history;
             _assetSaveService = assetSaveService;
         }
 
+        public IReadOnlyObservableProperty<int> ReferenceSampleRateObservable => _target.ReferenceSampleRateObservable;
+
+        public bool CanApplyReferenceSampleRate => CollectClipFrequencies().Count == 1;
+
+        public void ApplyReferenceSampleRate()
+        {
+            var frequencies = CollectClipFrequencies();
+            if (frequencies.Count != 1)
+                return;
+            var frequency = frequencies.First();
+            var old = _target.ReferenceSampleRate;
+            _history.Register($"Set CueSheet {nameof(CueSheet.referenceSampleRate)} {frequency}", Redo, Undo);
+
+            #region LocalMethods
+
+            void Redo()
+            {
+                _target.ReferenceSampleRate = frequency;
+                _assetSaveService.Save();
+            }
+
+            void Undo()
+            {
+                _target.ReferenceSampleRate = old;
+                _assetSaveService.Save();
+            }
+
+            #endregion
+        }
+
+        private HashSet<int> CollectClipFrequencies()
+        {
+            var frequencies = new HashSet<int>();
+            foreach (var cue in _rawCueSheet.cueList)
+            foreach (var track in cue.trackList)
+                if (track.audioClip != null)
+                    frequencies.Add(track.audioClip.frequency);
+            return frequencies;
+        }
+
         #region Name
 
         public string Name
diff --git a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/Interfaces/ICueSheetParameterPaneModel.cs b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/Interfaces/ICueSheetParameterPaneModel.cs
index 3fb8dc0..af66cd1 100644
--- a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/Interfaces/ICueSheetParameterPaneModel.cs
+++ b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/Interfaces/ICueSheetParameterPaneModel.cs
@@ -34,5 +34,11 @@ internal interface ICueSheetParameterPaneModel
         bool PitchInvert { get; set; }
 
         IReadOnlyObservableProperty<bool> PitchInvertObservable { get; }
+
+        IReadOnlyObservableProperty<int> ReferenceSampleRateObservable { get; }
+
+        bool CanApplyReferenceSampleRate { get; }
+
+        void ApplyReferenceSampleRate();
     }
 }
diff --git a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/ObservableCueSheet.cs b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/ObservableCueSheet.cs
index e09f1d4..c84e501 100644
--- a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/ObservableCueSheet.cs
+++ b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Models/ObservableCueSheet.cs
@@ -18,6 +18,7 @@ internal sealed class ObservableCueSheet
         private readonly ObservableProperty<string> _name;
         private readonly ObservableProperty<float> _pitch;
         private readonly ObservableProperty<bool> _pitchInvert;
+        private readonly ObservableProperty<int> _referenceSampleRate;
         private readonly ObservableProperty<int> _throttleLimit;
         private readonly ObservableProperty<ThrottleType> _throttleType;
         private readonly ObservableProperty<float> _volume;
@@ -33,11 +34,20 @@ public ObservableCueSheet([NotNull] CueSheet cueSheet)
             _volume = new(_cueSheet.volume);
             _pitch = new(_cueSheet.pitch);
             _pitchInvert = new(_cueSheet.pitchInvert);
+            _referenceSampleRate = new(_cueSheet.referenceSampleRate);
             // ReSharper enable ArrangeObjectCreationWhenTypeNotEvident
         }
 
         public string Id => _cueSheet.Id;
 
+        public int ReferenceSampleRate
+        {
+            get => _referenceSampleRate.Value;
+            set => _referenceSampleRate.SetValueAndNotify(_cueSheet.referenceSampleRate = value);
+        }
+
+        public IReadOnlyObservableProperty<int> ReferenceSampleRateObservable => _referenceSampleRate;
+
         public string Name
         {
             get => _name.Value;
diff --git a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Presenters/CueSheetParameterPanePresenter.cs b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Presenters/CueSheetParameterPanePresenter.cs
index 6c8c643..d390386 100644
--- a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Presenters/CueSheetParameterPanePresenter.cs
+++ b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Presenters/CueSheetParameterPanePresenter.cs
@@ -68,6 +68,13 @@ private void Bind()
             _model.PitchInvertObservable
                 .Subscribe(_view.SetPitchInvert)
                 .DisposeWith(_bindDisposable);
+            _model.ReferenceSampleRateObservable
+                .Subscribe(value =>
+                {
+                    _view.SetReferenceSampleRate(value);
+                    _view.SetApplyButtonEnabled(_model.CanApplyReferenceSampleRate);
+                })
+                .DisposeWith(_bindDisposable);
         }
 
         private void Unbind()
@@ -95,6 +102,9 @@ private void SetupViewEventHandlers()
             _view.PitchInvertChangedAsObservable
                 .Subscribe(value => _model.PitchInvert = value)
                 .DisposeWith(_viewEventDisposable);
+            _view.ApplyReferenceSampleRateAsObservable
+                .Subscribe(_ => _model.ApplyReferenceSampleRate())
+                .DisposeWith(_viewEventDisposable);
         }
 
         private void CleanupViewEventHandlers()
diff --git a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Views/CueSheetParameterPaneView.cs b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Views/CueSheetParameterPaneView.cs
index f8207df..acc1feb 100644
--- a/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Views/CueSheetParameterPaneView.cs
+++ b/Packages/AudioConductor/Editor/Core/Tools/CueSheetEditor/Views/CueSheetParameterPaneView.cs
@@ -15,12 +15,16 @@ namespace AudioConductor.Editor.Core.Tools.CueSheetEditor.Views
 {
     internal sealed class CueSheetParameterPaneView : VisualElement, IDisposable
     {
+        private readonly Button _applyReferenceSampleRateButton;
+        private readonly Subject<Empty> _applyReferenceSampleRateSubject = new();
         private readonly Subject<string> _nameChangedSubject = new();
         private readonly TextField _nameField;
         private readonly Subject<float> _pitchChangedSubject = new();
         private readonly SliderAndFloatField _pitchField;
         private readonly Subject<bool> _pitchInvertChangedSubject = new();
         private readonly Toggle _pitchInvertField;
+        private readonly IntegerField _referenceSampleRateField;
+        private readonly HelpBox _referenceSampleRateWarning;
         private readonly Subject<int> _throttleLimitChangedSubject = new();
         private readonly IntegerField _throttleLimitField;
         private readonly Subject<ThrottleType> _throttleTypeChangedSubject = new();
@@ -45,6 +49,13 @@ public CueSheetParameterPaneView()
             _pitchField.lowValue = ValueRangeConst.Pitch.Min;
             _pitchField.highValue = ValueRangeConst.Pitch.Max;
 
+            _referenceSampleRateField = this.Q<IntegerField>("ReferenceSampleRate");
+            _referenceSampleRateField.SetEnabled(false);
+            _referenceSampleRateWarning = this.Q<HelpBox>("ReferenceSampleRateWarning");
+            _referenceSampleRateWarning.SetDisplay(false);
+            _applyReferenceSampleRateButton = this.Q<Button>("ApplyReferenceSampleRateButton");
+            _applyReferenceSampleRateButton.SetDisplay(false);
+
             ApplyTooltips();
         }
 
@@ -54,10 +65,12 @@ public CueSheetParameterPaneView()
         internal IObservable<float> VolumeChangedAsObservable => _volumeChangedSubject;
         internal IObservable<float> PitchChangedAsObservable => _pitchChangedSubject;
         internal IObservable<bool> PitchInvertChangedAsObservable => _pitchInvertChangedSubject;
+        internal IObservable<Empty> ApplyReferenceSampleRateAsObservable => _applyReferenceSampleRateSubject;
 
         public void Dispose()
         {
             CleanupEventHandlers();
+            _applyReferenceSampleRateSubject.Dispose();
             Localization.Localization.LanguageChanged -= OnLanguageChanged;
         }
 
@@ -85,6 +98,12 @@ private void ApplyTooltips()
             _volumeField.tooltip = Localization.Localization.Tr("cue_sheet_parameter.volume");
             _pitchField.tooltip = Localization.Localization.Tr("cue_sheet_parameter.pitch");
             _pitchInvertField.tooltip = Localization.Localization.Tr("cue_sheet_parameter.pitch_invert");
+            _referenceSampleRateField.tooltip =
+                Localization.Localization.Tr("cue_sheet_parameter.reference_sample_rate");
+            _referenceSampleRateWarning.text =
+                Localization.Localization.Tr("cue_sheet_parameter.reference_sample_rate_warning");
+            _applyReferenceSampleRateButton.text =
+                Localization.Localization.Tr("cue_sheet_parameter.apply_reference_sample_rate");
         }
 
         private void SetupEventHandlers()
@@ -95,10 +114,12 @@ private void SetupEventHandlers()
             _volumeField.RegisterValueChangedCallback(OnVolumeChanged);
             _pitchField.RegisterValueChangedCallback(OnPitchChanged);
             _pitchInvertField.RegisterValueChangedCallback(OnPitchInvertChanged);
+            _applyReferenceSampleRateButton.clicked += OnApplyReferenceSampleRateClicked;
         }
 
         private void CleanupEventHandlers()
         {
+            _applyReferenceSampleRateButton.clicked -= OnApplyReferenceSampleRateClicked;
             _pitchInvertField.UnregisterValueChangedCallback(OnPitchInvertChanged);
             _pitchField.UnregisterValueChangedCallback(OnPitchChanged);
             _volumeField.UnregisterValueChangedCallback(OnVolumeChanged);
@@ -139,6 +160,18 @@ internal void SetPitchInvert(bool value)
             _pitchInvertField.SetValueWithoutNotify(value);
         }
 
+        internal void SetReferenceSampleRate(int value)
+        {
+            _referenceSampleRateField.SetValueWithoutNotify(value);
+            _referenceSampleRateWarning.SetDisplay(value == 0);
+            _applyReferenceSampleRateButton.SetDisplay(value == 0);
+        }
+
+        internal void SetApplyButtonEnabled(bool enabled)
+        {
+            _applyReferenceSampleRateButton.SetEnabled(enabled);
+        }
+
         #endregion
 
         #region Methods - EventHandler
@@ -173,6 +206,11 @@ private void OnPitchInvertChanged(ChangeEvent<bool> evt)
             _pitchInvertChangedSubject.OnNext(evt.newValue);
         }
 
+        private void OnApplyReferenceSampleRateClicked()
+        {
+            _applyReferenceSampleRateSubject.OnNext(Empty.Default);
+        }
+
         private void OnLanguageChanged()
         {
             ApplyTooltips();
diff --git a/Packages/AudioConductor/Editor/Core/Tools/Shared/CueSheetAssetImportChecker.cs b/Packages/AudioConductor/Editor/Core/Tools/Shared/CueSheetAssetImportChecker.cs
index 16e3427..1948826 100644
--- a/Packages/AudioConductor/Editor/Core/Tools/Shared/CueSheetAssetImportChecker.cs
+++ b/Packages/AudioConductor/Editor/Core/Tools/Shared/CueSheetAssetImportChecker.cs
@@ -9,12 +9,16 @@
 using System.Linq;
 using AudioConductor.Core.Models;
 using UnityEditor;
+using UnityEngine;
 
 namespace AudioConductor.Editor.Core.Tools.Shared
 {
     [InitializeOnLoad]
     internal class CueSheetAssetImportChecker : AssetPostprocessor
     {
+        private const string ReferenceSampleRateMigrationSkipKey =
+            "AudioConductor.ReferenceSampleRateMigration.Skip";
+
         private static readonly Dictionary<string, CueSheetAsset> CueSheetAssets;
         private static readonly HashSet<string> CueSheetIds;
 
@@ -35,6 +39,8 @@ static CueSheetAssetImportChecker()
                 CueSheetIds.Add(asset.cueSheet.Id);
                 MigrateCueIds(asset);
             }
+
+            EditorApplication.delayCall += () => MigrateReferenceSampleRates(CueSheetAssets.Values);
         }
 
         private static void OnPostprocessAllAssets(string[] importedAssets,
@@ -165,5 +171,76 @@ private static void MigrateCueIds(CueSheetAsset asset)
             EditorUtility.SetDirty(asset);
             AssetDatabase.SaveAssets();
         }
+
+        internal static void MigrateReferenceSampleRates(IEnumerable<CueSheetAsset> assets)
+        {
+            if (EditorPrefs.GetBool(ReferenceSampleRateMigrationSkipKey, false))
+                return;
+
+            var toMigrate = new List<(CueSheetAsset asset, int frequency)>();
+            var inconsistentNames = new List<string>();
+
+            foreach (var asset in assets)
+            {
+                if (asset.cueSheet.referenceSampleRate != 0)
+                    continue;
+
+                var frequencies = CollectClipFrequencies(asset.cueSheet);
+                if (frequencies.Count == 0)
+                    continue;
+
+                if (frequencies.Count == 1)
+                    toMigrate.Add((asset, frequencies.First()));
+                else
+                    inconsistentNames.Add(asset.name);
+            }
+
+            foreach (var name in inconsistentNames)
+                Debug.LogWarning(string.Format(
+                    Localization.Localization.Tr("migration.reference_sample_rate.inconsistent_warning"),
+                    name));
+
+            if (toMigrate.Count == 0)
+                return;
+
+            var names = string.Join("\n", toMigrate.Select(x => $"  {x.asset.name} ({x.frequency} Hz)"));
+            var message =
+                $"{Localization.Localization.Tr("migration.reference_sample_rate.dialog_message")}\n\n{names}";
+
+            // 2: Don't show again
+            var result = EditorUtility.DisplayDialogComplex(
+                Localization.Localization.Tr("migration.reference_sample_rate.dialog_title"),
+                message,
+                Localization.Localization.Tr("migration.reference_sample_rate.apply"),
+                Localization.Localization.Tr("migration.reference_sample_rate.skip"),
+                Localization.Localization.Tr("migration.reference_sample_rate.dont_show_again"));
+
+            if (result == 2)
+            {
+                EditorPrefs.SetBool(ReferenceSampleRateMigrationSkipKey, true);
+                return;
+            }
+
+            if (result != 0)
+                return;
+
+            foreach (var (asset, frequency) in toMigrate)
+            {
+                asset.cueSheet.referenceSampleRate = frequency;
+                EditorUtility.SetDirty(asset);
+            }
+
+            AssetDatabase.SaveAssets();
+        }
+
+        internal static HashSet<int> CollectClipFrequencies(CueSheet cueSheet)
+        {
+            var frequencies = new HashSet<int>();
+            foreach (var cue in cueSheet.cueList)
+            foreach (var track in cue.trackList)
+                if (track.audioClip != null)
+                    frequencies.Add(track.audioClip.frequency);
+            return frequencies;
+        }
     }
 }
diff --git a/Packages/AudioConductor/Editor/Core/Tools/Shared/ReferenceSampleRateBuildPreprocessor.cs b/Packages/AudioConductor/Editor/Core/Tools/Shared/ReferenceSampleRateBuildPreprocessor.cs
new file mode 100644
index 0000000..83594b9
--- /dev/null
+++ b/Packages/AudioConductor/Editor/Core/Tools/Shared/ReferenceSampleRateBuildPreprocessor.cs
@@ -0,0 +1,47 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+using AudioConductor.Core.Models;
+using UnityEditor;
+using UnityEditor.Build;
+using UnityEditor.Build.Reporting;
+using UnityEngine;
+
+namespace AudioConductor.Editor.Core.Tools.Shared
+{
+    internal sealed class ReferenceSampleRateBuildPreprocessor : IPreprocessBuildWithReport
+    {
+        public int callbackOrder => 1;
+
+        public void OnPreprocessBuild(BuildReport report)
+        {
+            var guids = AssetDatabase.FindAssets("t:" + nameof(CueSheetAsset), new[] { "Assets" });
+            if (guids == null || guids.Length == 0)
+                return;
+
+            foreach (var guid in guids)
+            {
+                var path = AssetDatabase.GUIDToAssetPath(guid);
+                var asset = AssetDatabase.LoadAssetAtPath<CueSheetAsset>(path);
+                if (asset == null || asset.cueSheet.referenceSampleRate != 0)
+                    continue;
+
+                if (HasAnyClip(asset.cueSheet))
+                    Debug.LogWarning(
+                        $"[AudioConductor] CueSheet '{asset.name}' has no referenceSampleRate set. Sample positions may drift on platforms with different audio decoding frequencies (e.g. WebGL).");
+            }
+        }
+
+        private static bool HasAnyClip(CueSheet cueSheet)
+        {
+            foreach (var cue in cueSheet.cueList)
+            foreach (var track in cue.trackList)
+                if (track.audioClip != null)
+                    return true;
+            return false;
+        }
+    }
+}
diff --git a/Packages/AudioConductor/Editor/Core/Tools/Shared/ReferenceSampleRateBuildPreprocessor.cs.meta b/Packages/AudioConductor/Editor/Core/Tools/Shared/ReferenceSampleRateBuildPreprocessor.cs.meta
new file mode 100644
index 0000000..746ae69
--- /dev/null
+++ b/Packages/AudioConductor/Editor/Core/Tools/Shared/ReferenceSampleRateBuildPreprocessor.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 52f09777358374dec9dbf3aeed7e3a53
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Editor/Core/Tools/Validation/Rules/ReferenceSampleRateUnsetRule.cs b/Packages/AudioConductor/Editor/Core/Tools/Validation/Rules/ReferenceSampleRateUnsetRule.cs
new file mode 100644
index 0000000..4831cfd
--- /dev/null
+++ b/Packages/AudioConductor/Editor/Core/Tools/Validation/Rules/ReferenceSampleRateUnsetRule.cs
@@ -0,0 +1,28 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+using AudioConductor.Core.Models;
+
+namespace AudioConductor.Editor.Core.Tools.Validation.Rules
+{
+    internal sealed class ReferenceSampleRateUnsetRule : ICueSheetValidationRule
+    {
+        public void Validate(CueSheet cueSheet, ICueSheetValidationContext context)
+        {
+            if (cueSheet.referenceSampleRate != 0)
+                return;
+
+            foreach (var cue in cueSheet.cueList)
+            foreach (var track in cue.trackList)
+                if (track.audioClip != null)
+                {
+                    context.AddWarning("CueSheet.ReferenceSampleRateUnset",
+                        "referenceSampleRate is not set. Sample positions may drift on platforms with different audio decoding frequencies (e.g. WebGL).");
+                    return;
+                }
+        }
+    }
+}
diff --git a/Packages/AudioConductor/Editor/Core/Tools/Validation/Rules/ReferenceSampleRateUnsetRule.cs.meta b/Packages/AudioConductor/Editor/Core/Tools/Validation/Rules/ReferenceSampleRateUnsetRule.cs.meta
new file mode 100644
index 0000000..6e8dffe
--- /dev/null
+++ b/Packages/AudioConductor/Editor/Core/Tools/Validation/Rules/ReferenceSampleRateUnsetRule.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 6b29380a1704e4513bf39e8a391d77ed
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Editor/Localization/EnglishTranslations.cs b/Packages/AudioConductor/Editor/Localization/EnglishTranslations.cs
index cfbfb11..be54117 100644
--- a/Packages/AudioConductor/Editor/Localization/EnglishTranslations.cs
+++ b/Packages/AudioConductor/Editor/Localization/EnglishTranslations.cs
@@ -16,7 +16,10 @@ internal static class EnglishTranslations
             { "settings.throttle_limit", "Limit of concurrent play." },
             { "settings.managed_pool_size", "Number of managed AudioClipPlayers to pre-create on construction." },
             { "settings.oneshot_pool_size", "Number of one-shot AudioClipPlayers to pre-create on construction." },
-            { "settings.deactivate_pooled_objects", "When enabled, pooled AudioClipPlayer GameObjects are deactivated while idle. Reduces active GameObject overhead at the cost of SetActive calls on rent/return." },
+            {
+                "settings.deactivate_pooled_objects",
+                "When enabled, pooled AudioClipPlayer GameObjects are deactivated while idle. Reduces active GameObject overhead at the cost of SetActive calls on rent/return."
+            },
             { "category.name", "Category name." },
             { "category.throttle_type", "Concurrent play control type." },
             { "category.throttle_limit", "Limit of concurrent play." },
@@ -78,6 +81,15 @@ internal static class EnglishTranslations
             { "cue_sheet_parameter.volume", "Default CueSheet volume scale. (0.0 to 1.0)" },
             { "cue_sheet_parameter.pitch", "Default CueSheet pitch scale. (0.01 to 3.0)" },
             { "cue_sheet_parameter.pitch_invert", "Invert CueSheet pitch variation direction." },
+            {
+                "cue_sheet_parameter.reference_sample_rate",
+                "The sample rate at which sample positions in this CueSheet were authored. Read-only; set via migration dialog on startup."
+            },
+            {
+                "cue_sheet_parameter.reference_sample_rate_warning",
+                "referenceSampleRate is not set. Sample positions may drift on platforms with different audio decoding frequencies (e.g. WebGL). Re-open the project or run the migration via AudioConductor settings to apply."
+            },
+            { "cue_sheet_parameter.apply_reference_sample_rate", "Apply clip frequency as reference sample rate" },
             { "other_operation.export_csv", "Export CueSheet data to CSV." },
             { "other_operation.import_csv", "Import CueSheet data from CSV." },
             { "cue_enum_definition.default_output_path", "Default output directory for generated enum files." },
@@ -115,7 +127,22 @@ internal static class EnglishTranslations
             { "cue_enum_definition.asset.asset", "The CueSheetAsset reference." },
             { "cue_enum_definition.asset.cue_sheet_name", "Name of the CueSheet." },
             { "cue_enum_definition.asset.cue_count", "Number of cues in this CueSheet." },
-            { "cue_enum_definition.excluded.path_rule", "Glob pattern to auto-exclude CueSheetAssets." }
+            { "cue_enum_definition.excluded.path_rule", "Glob pattern to auto-exclude CueSheetAssets." },
+            {
+                "migration.reference_sample_rate.dialog_title",
+                "AudioConductor Migration"
+            },
+            {
+                "migration.reference_sample_rate.dialog_message",
+                "The following CueSheets have no referenceSampleRate set.\nApply the current clip frequencies?"
+            },
+            { "migration.reference_sample_rate.apply", "Apply" },
+            { "migration.reference_sample_rate.skip", "Skip" },
+            { "migration.reference_sample_rate.dont_show_again", "Don't show again" },
+            {
+                "migration.reference_sample_rate.inconsistent_warning",
+                "[AudioConductor] CueSheet '{0}' has mixed AudioClip sample rates. Set referenceSampleRate manually."
+            }
         };
     }
 }
diff --git a/Packages/AudioConductor/Editor/Localization/JapaneseTranslations.cs b/Packages/AudioConductor/Editor/Localization/JapaneseTranslations.cs
index c648213..e8665eb 100644
--- a/Packages/AudioConductor/Editor/Localization/JapaneseTranslations.cs
+++ b/Packages/AudioConductor/Editor/Localization/JapaneseTranslations.cs
@@ -16,7 +16,10 @@ internal static class JapaneseTranslations
             { "settings.throttle_limit", "同時発音数の上限" },
             { "settings.managed_pool_size", "構築時に事前生成するマネージド AudioClipPlayer の数" },
             { "settings.oneshot_pool_size", "構築時に事前生成するワンショット AudioClipPlayer の数" },
-            { "settings.deactivate_pooled_objects", "有効にすると、アイドル中のプール済み AudioClipPlayer の GameObject を非アクティブにします。アクティブな GameObject のオーバーヘッドを削減しますが、貸出/返却時に SetActive 呼び出しコストが発生します。" },
+            {
+                "settings.deactivate_pooled_objects",
+                "有効にすると、アイドル中のプール済み AudioClipPlayer の GameObject を非アクティブにします。アクティブな GameObject のオーバーヘッドを削減しますが、貸出/返却時に SetActive 呼び出しコストが発生します。"
+            },
             { "category.name", "カテゴリ名" },
             { "category.throttle_type", "同時発音の制御方式" },
             { "category.throttle_limit", "同時発音数の上限" },
@@ -78,6 +81,15 @@ internal static class JapaneseTranslations
             { "cue_sheet_parameter.volume", "CueSheet のデフォルト音量スケール (0.0 〜 1.0)" },
             { "cue_sheet_parameter.pitch", "CueSheet のデフォルトピッチスケール (0.01 〜 3.0)" },
             { "cue_sheet_parameter.pitch_invert", "CueSheet のピッチ変動方向を反転" },
+            {
+                "cue_sheet_parameter.reference_sample_rate",
+                "この CueSheet のサンプル位置が作成された基準サンプルレート。読み取り専用。起動時のマイグレーションダイアログで設定します。"
+            },
+            {
+                "cue_sheet_parameter.reference_sample_rate_warning",
+                "referenceSampleRate が未設定です。WebGL 等、オーディオデコード周波数が異なるプラットフォームでサンプル位置がずれる可能性があります。プロジェクトを再起動してマイグレーションを実行してください。"
+            },
+            { "cue_sheet_parameter.apply_reference_sample_rate", "クリップ周波数を基準サンプルレートとして適用" },
             { "other_operation.export_csv", "CueSheet データを CSV としてエクスポート" },
             { "other_operation.import_csv", "CSV から CueSheet データをインポート" },
             { "cue_enum_definition.default_output_path", "生成する enum ファイルのデフォルト出力先ディレクトリ" },
@@ -95,7 +107,22 @@ internal static class JapaneseTranslations
             { "cue_enum_definition.asset.asset", "CueSheetAsset の参照" },
             { "cue_enum_definition.asset.cue_sheet_name", "CueSheet の名前" },
             { "cue_enum_definition.asset.cue_count", "この CueSheet の Cue 数" },
-            { "cue_enum_definition.excluded.path_rule", "CueSheetAsset を自動除外する glob パターン" }
+            { "cue_enum_definition.excluded.path_rule", "CueSheetAsset を自動除外する glob パターン" },
+            {
+                "migration.reference_sample_rate.dialog_title",
+                "AudioConductor マイグレーション"
+            },
+            {
+                "migration.reference_sample_rate.dialog_message",
+                "以下の CueSheet は referenceSampleRate が未設定です。\n 現在のクリップ周波数を適用しますか？"
+            },
+            { "migration.reference_sample_rate.apply", "適用" },
+            { "migration.reference_sample_rate.skip", "スキップ" },
+            { "migration.reference_sample_rate.dont_show_again", "次回から表示しない" },
+            {
+                "migration.reference_sample_rate.inconsistent_warning",
+                "[AudioConductor] CueSheet '{0}' の AudioClip にサンプルレートの混在があります。referenceSampleRate を手動で設定してください。"
+            }
         };
     }
 }
diff --git a/Packages/AudioConductor/Editor/PackageResources/Uxml/CueSheetParameterPane.uxml b/Packages/AudioConductor/Editor/PackageResources/Uxml/CueSheetParameterPane.uxml
index 6dea7b7..5313b92 100644
--- a/Packages/AudioConductor/Editor/PackageResources/Uxml/CueSheetParameterPane.uxml
+++ b/Packages/AudioConductor/Editor/PackageResources/Uxml/CueSheetParameterPane.uxml
@@ -18,5 +18,10 @@
         <ui:VisualElement name="Row" style="flex-direction: row;">
             <ui:Toggle label="Pitch Invert" name="PitchInvert" style="flex-basis: 33.333%; padding-top: 2px;" />
         </ui:VisualElement>
+        <ui:VisualElement name="Row" style="flex-direction: row;">
+            <uie:IntegerField label="Reference Sample Rate" name="ReferenceSampleRate" style="flex-basis: 33.333%;" />
+        </ui:VisualElement>
+        <ui:HelpBox name="ReferenceSampleRateWarning" message-type="Warning" text="placeholder" />
+        <ui:Button name="ApplyReferenceSampleRateButton" text="placeholder" />
     </ui:VisualElement>
 </ui:UXML>
diff --git a/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.WebGL.cs b/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.WebGL.cs
new file mode 100644
index 0000000..6177da0
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.WebGL.cs
@@ -0,0 +1,100 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+#if UNITY_WEBGL
+namespace AudioConductor.Core
+{
+    internal sealed partial class AudioClipPlayer
+    {
+        private bool _isSystemPaused;
+
+        // The browser suspends rAF callbacks when the tab is hidden (MDN: Page Visibility API),
+        // and Unity's game loop runs on rAF by default (Unity Manual: WebGL performance).
+        // Therefore Stop()/Pause() cannot be called while system-paused.
+        internal void PauseBySystem()
+        {
+            if (_isSystemPaused || IsPaused || !_isPlaybackActive)
+                return;
+
+            _isSystemPaused = true;
+            _pauseStartTime = _dspClock.DspTime;
+
+            if (_isLoop)
+            {
+                if (_sources[0].IsPlaying)
+                {
+                    _sources[0].Pause();
+                    _pausedIndex = 0;
+                    _sources[1].Stop();
+                }
+                else if (_sources[1].IsPlaying)
+                {
+                    _sources[0].Stop();
+                    _sources[1].Pause();
+                    _pausedIndex = 1;
+                }
+                else
+                {
+                    // Neither source is playing yet (within PlayScheduleDelay window).
+                    // AudioSource.Pause() on a scheduled-but-not-yet-playing source has undefined
+                    // behavior per Unity docs, so stop both and reschedule fresh on ResumeBySystem.
+                    _sources[0].Stop();
+                    _sources[1].Stop();
+                    _wasStoppedBeforePlay = true;
+                }
+
+                return;
+            }
+
+            if (_sources[0].IsPlaying)
+            {
+                _sources[0].Pause();
+            }
+            else
+            {
+                _sources[0].Stop();
+                _wasStoppedBeforePlay = true;
+            }
+        }
+
+        internal void ResumeBySystem()
+        {
+            if (!_isSystemPaused)
+                return;
+
+            if (_wasStoppedBeforePlay)
+            {
+                _isSystemPaused = false;
+                if (_isPlaybackActive && !IsPaused)
+                {
+                    _wasStoppedBeforePlay = false;
+                    _nextPlayAudioSourceIndex = 0;
+                    SchedulePlayback(_dspClock.DspTime + PlayScheduleDelay, _startSample);
+                }
+                else if (!_isPlaybackActive)
+                {
+                    _wasStoppedBeforePlay = false;
+                }
+
+                return;
+            }
+
+            var pausedDuration = _dspClock.DspTime - _pauseStartTime;
+            ShiftScheduleByPauseDuration(pausedDuration);
+            _isSystemPaused = false;
+
+            if (_isLoop)
+            {
+                _sources[_pausedIndex].UnPause();
+                return;
+            }
+
+            _sources[0].UnPause();
+        }
+    }
+}
+
+#endif
diff --git a/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.WebGL.cs.meta b/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.WebGL.cs.meta
new file mode 100644
index 0000000..44d8f57
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.WebGL.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 7041e7cbe30694a4fa0fb40c8f76d9bb
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.cs b/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.cs
index 436f03a..5057213 100644
--- a/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.cs
+++ b/Packages/AudioConductor/Runtime/Core/AudioClipPlayer.cs
@@ -13,10 +13,15 @@
 
 namespace AudioConductor.Core
 {
-    internal sealed class AudioClipPlayer : IFadeable
+    // ReSharper disable once PartialTypeWithSinglePart
+    internal sealed partial class AudioClipPlayer : IFadeable
     {
         private const int SourceNum = 2;
+
         private const float LoopLookaheadDuration = 1.0f;
+
+        // https://qiita.com/tatmos/items/4c78c127291a0c3b74ed
+        private const float PlayScheduleDelay = 0.1f;
         private const int VolumeScale = 10000;
         private readonly IDspClock _dspClock;
         private readonly IAudioPlayerLifecycle _lifecycle;
@@ -42,6 +47,7 @@ internal sealed class AudioClipPlayer : IFadeable
         private float _volumeCategory = 1f;
         private float _volumeMaster = 1f;
         private float _volumeRuntime;
+        private bool _wasStoppedBeforePlay;
 
         internal AudioClipPlayer(IAudioSourceWrapper[] sources, IDspClock dspClock,
             IAudioPlayerLifecycle lifecycle)
@@ -61,7 +67,12 @@ internal AudioClipPlayer(IAudioSourceWrapper[] sources, IDspClock dspClock,
         public PlayerState State
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get => IsPaused ? PlayerState.Paused
+            get =>
+#if UNITY_WEBGL
+                IsPaused || _isSystemPaused ? PlayerState.Paused
+#else
+                IsPaused ? PlayerState.Paused
+#endif
                 : _sources[0].IsPlaying || _sources[1].IsPlaying ? PlayerState.Playing
                 : PlayerState.Stopped;
         }
@@ -85,7 +96,8 @@ public void Setup(AudioMixerGroup? audioMixerGroup,
             bool isLoop,
             int startSample,
             int loopStartSample,
-            int endSample)
+            int endSample,
+            int referenceSampleRate = 0)
         {
             if (clip == null)
                 return;
@@ -98,7 +110,6 @@ public void Setup(AudioMixerGroup? audioMixerGroup,
             _sources[0].Clip = clip;
             _sources[0].PlayOnAwake = false;
             _sources[0].Loop = false;
-            _sources[0].TimeSamples = startSample;
             _sources[1].OutputAudioMixerGroup = audioMixerGroup;
             _sources[1].Clip = clip;
             _sources[1].PlayOnAwake = false;
@@ -108,14 +119,20 @@ public void Setup(AudioMixerGroup? audioMixerGroup,
             ClipSamples = clip.samples;
             CategoryId = categoryId;
 
+            var convertedStart = ConvertSample(startSample, referenceSampleRate, _frequency);
+            var convertedLoopStart = ConvertSample(loopStartSample, referenceSampleRate, _frequency);
+            var convertedEnd = ConvertSample(endSample, referenceSampleRate, _frequency);
+
+            _sources[0].TimeSamples = convertedStart;
+
             _volumeRuntime = 1f;
             SetPitchInternal(pitch);
             VolumeAsset = volume;
             UpdateVolume();
 
-            _startSample = ValueRangeConst.StartSample.Clamp(startSample, ClipSamples);
-            _loopStartSample = ValueRangeConst.LoopStartSample.Clamp(loopStartSample, ClipSamples);
-            _endSample = ValueRangeConst.EndSample.Clamp(endSample, ClipSamples);
+            _startSample = ValueRangeConst.StartSample.Clamp(convertedStart, ClipSamples);
+            _loopStartSample = ValueRangeConst.LoopStartSample.Clamp(convertedLoopStart, ClipSamples);
+            _endSample = ValueRangeConst.EndSample.Clamp(convertedEnd, ClipSamples);
         }
 
         public void Play()
@@ -123,13 +140,11 @@ public void Play()
             _sources[0].Stop();
             _sources[1].Stop();
 
+            _wasStoppedBeforePlay = false;
             _isPlaybackActive = true;
             _sources[1].Enabled = _isLoop;
 
-            // for smooth switching of AudioSource
-            // https://qiita.com/tatmos/items/4c78c127291a0c3b74ed
-            const float delay = 0.1f;
-            SchedulePlayback(_dspClock.DspTime + delay, _startSample);
+            SchedulePlayback(_dspClock.DspTime + PlayScheduleDelay, _startSample);
         }
 
         public void Restart()
@@ -158,12 +173,30 @@ public void Pause()
                     _sources[1].Pause();
                     _pausedIndex = 1;
                 }
+                else
+                {
+                    // Neither source is playing yet (within PlayScheduleDelay window).
+                    // AudioSource.Pause() on a scheduled-but-not-yet-playing source has undefined
+                    // behavior per Unity docs, so stop both and reschedule fresh on Resume.
+                    _sources[0].Stop();
+                    _sources[1].Stop();
+                    _wasStoppedBeforePlay = true;
+                }
 
                 IsPaused = true;
                 return;
             }
 
-            _sources[0].Pause();
+            if (_sources[0].IsPlaying)
+            {
+                _sources[0].Pause();
+            }
+            else
+            {
+                _sources[0].Stop();
+                _wasStoppedBeforePlay = true;
+            }
+
             IsPaused = true;
         }
 
@@ -172,6 +205,27 @@ public void Resume()
             if (!IsPaused)
                 return;
 
+            if (_wasStoppedBeforePlay)
+            {
+                IsPaused = false;
+                if (_isPlaybackActive
+#if UNITY_WEBGL
+                    && !_isSystemPaused
+#endif
+                   )
+                {
+                    _wasStoppedBeforePlay = false;
+                    _nextPlayAudioSourceIndex = 0;
+                    SchedulePlayback(_dspClock.DspTime + PlayScheduleDelay, _startSample);
+                }
+                else if (!_isPlaybackActive)
+                {
+                    _wasStoppedBeforePlay = false;
+                }
+
+                return;
+            }
+
             _pauseEndTime = _dspClock.DspTime;
             var pausedDuration = _pauseEndTime - _pauseStartTime;
             ShiftScheduleByPauseDuration(pausedDuration);
@@ -195,6 +249,7 @@ public void Stop()
                 _sources[1].Stop();
 
             _isPlaybackActive = false;
+            _wasStoppedBeforePlay = false;
             InvokeStopAction();
             IsPaused = false;
         }
@@ -294,7 +349,11 @@ public void ManualUpdate(float _)
 
             UpdateVolume();
 
-            if (IsPaused)
+            if (IsPaused
+#if UNITY_WEBGL
+                || _isSystemPaused
+#endif
+               )
                 return;
 
             if (_dspClock.DspTime < _nextEventTime)
@@ -360,6 +419,10 @@ public void ResetState()
             _pitchExternal = 1f;
             _nextPlayAudioSourceIndex = 0;
             IsPaused = false;
+            _wasStoppedBeforePlay = false;
+#if UNITY_WEBGL
+            _isSystemPaused = false;
+#endif
             _nextEventTime = 0;
             _pausedIndex = 0;
             _pauseStartTime = 0;
@@ -502,5 +565,14 @@ private void InvokeStopAction()
 
             return playing0 ? _sources[0] : playing1 ? _sources[1] : null;
         }
+
+        // Converts a sample position from referenceSampleRate to clipFrequency.
+        // When referenceFrequency is unset (0) or already matches clipFrequency, no conversion is applied.
+        private static int ConvertSample(int sample, int referenceFrequency, int clipFrequency)
+        {
+            if (referenceFrequency == 0 || referenceFrequency == clipFrequency)
+                return sample;
+            return Mathf.RoundToInt((float)sample * clipFrequency / referenceFrequency);
+        }
     }
 }
diff --git a/Packages/AudioConductor/Runtime/Core/AudioConductorWebGLBroadcaster.cs b/Packages/AudioConductor/Runtime/Core/AudioConductorWebGLBroadcaster.cs
new file mode 100644
index 0000000..5e787db
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/AudioConductorWebGLBroadcaster.cs
@@ -0,0 +1,53 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+#if UNITY_WEBGL && !UNITY_EDITOR
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using AOT;
+
+namespace AudioConductor.Core
+{
+    // Owns the single visibilitychange JS listener and forwards events to all active ConductorBehaviour instances.
+    // Registers the listener on first instance, unregisters when the last instance is removed.
+    internal static class AudioConductorWebGLBroadcaster
+    {
+        [DllImport("__Internal")]
+        private static extern void AudioConductor_RegisterVisibilityChange(VisibilityChangeCallback callback);
+
+        [DllImport("__Internal")]
+        private static extern void AudioConductor_UnregisterVisibilityChange();
+
+        private delegate void VisibilityChangeCallback(int isHidden);
+
+        // Keep a rooted reference to prevent GC collection of the delegate in IL2CPP/WebGL.
+        private static readonly VisibilityChangeCallback _visibilityChangeCallback = OnVisibilityChangedNative;
+        private static readonly List<ConductorBehaviour> _instances = new();
+
+        internal static void Register(ConductorBehaviour instance)
+        {
+            if (_instances.Count == 0)
+                AudioConductor_RegisterVisibilityChange(_visibilityChangeCallback);
+            _instances.Add(instance);
+        }
+
+        internal static void Unregister(ConductorBehaviour instance)
+        {
+            _instances.Remove(instance);
+            if (_instances.Count == 0)
+                AudioConductor_UnregisterVisibilityChange();
+        }
+
+        [MonoPInvokeCallback(typeof(VisibilityChangeCallback))]
+        private static void OnVisibilityChangedNative(int isHidden)
+        {
+            foreach (var instance in _instances)
+                instance.NotifySystemPause(isHidden == 1);
+        }
+    }
+}
+
+#endif
diff --git a/Packages/AudioConductor/Runtime/Core/AudioConductorWebGLBroadcaster.cs.meta b/Packages/AudioConductor/Runtime/Core/AudioConductorWebGLBroadcaster.cs.meta
new file mode 100644
index 0000000..698e44d
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/AudioConductorWebGLBroadcaster.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 743595fdc5b8549d9baf6c581259b6f2
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Runtime/Core/Conductor.Playback.cs b/Packages/AudioConductor/Runtime/Core/Conductor.Playback.cs
index aed4909..c2d2954 100644
--- a/Packages/AudioConductor/Runtime/Core/Conductor.Playback.cs
+++ b/Packages/AudioConductor/Runtime/Core/Conductor.Playback.cs
@@ -265,7 +265,7 @@ private PlaybackHandle PlayCue(uint cueSheetId, CueSheetRegistration registratio
             var pitch = Calculator.CalcPitch(cueSheet, cue, track);
             var isLoop = options?.IsLoop == true || track.isLoop;
             player.Setup(category?.audioMixerGroup, track.audioClip, cue.categoryId, volume, pitch, isLoop,
-                track.startSample, track.loopStartSample, track.endSample);
+                track.startSample, track.loopStartSample, track.endSample, cueSheet.referenceSampleRate);
             player.Play();
             if (options?.OnStop is { } onStop) player.SetStopAction(onStop);
             if (options?.OnEnd is { } onEnd) player.SetEndAction(onEnd);
@@ -304,7 +304,7 @@ private void PlayOneShotCue(uint cueSheetId, CueSheetRegistration registration,
             var volume = Calculator.CalcVolume(cueSheet, cue, track);
             var pitch = Calculator.CalcPitch(cueSheet, cue, track);
             player.Setup(category?.audioMixerGroup, track.audioClip, cue.categoryId, volume, pitch, false,
-                track.startSample, track.loopStartSample, track.endSample);
+                track.startSample, track.loopStartSample, track.endSample, cueSheet.referenceSampleRate);
             player.Play();
             if (options?.OnStop is { } onStop) player.SetStopAction(onStop);
             if (options?.OnEnd is { } onEnd) player.SetEndAction(onEnd);
diff --git a/Packages/AudioConductor/Runtime/Core/Conductor.WebGL.cs b/Packages/AudioConductor/Runtime/Core/Conductor.WebGL.cs
new file mode 100644
index 0000000..9d1b97e
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/Conductor.WebGL.cs
@@ -0,0 +1,33 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+#if UNITY_WEBGL
+namespace AudioConductor.Core
+{
+    public sealed partial class Conductor
+    {
+        internal void OnSystemPause(bool pause)
+        {
+            foreach (var playback in _managedPlaybacks.Values)
+            {
+                if (pause)
+                    playback.Player.PauseBySystem();
+                else
+                    playback.Player.ResumeBySystem();
+            }
+
+            foreach (var playback in _oneShotPlaybacks)
+            {
+                if (pause)
+                    playback.Player.PauseBySystem();
+                else
+                    playback.Player.ResumeBySystem();
+            }
+        }
+    }
+}
+
+#endif
diff --git a/Packages/AudioConductor/Runtime/Core/Conductor.WebGL.cs.meta b/Packages/AudioConductor/Runtime/Core/Conductor.WebGL.cs.meta
new file mode 100644
index 0000000..c5afaef
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/Conductor.WebGL.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 517528d39e7be4f72a00129444bba18d
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.WebGL.cs b/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.WebGL.cs
new file mode 100644
index 0000000..f5318f8
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.WebGL.cs
@@ -0,0 +1,50 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+#if UNITY_WEBGL && !UNITY_EDITOR
+using System.Runtime.InteropServices;
+
+namespace AudioConductor.Core
+{
+    internal sealed partial class ConductorBehaviour
+    {
+        [DllImport("__Internal")]
+        private static extern int AudioConductor_IsDocumentHidden();
+
+        private bool _isSystemPaused;
+
+        private void Awake()
+        {
+            AudioConductorWebGLBroadcaster.Register(this);
+        }
+
+        private void OnDestroy()
+        {
+            AudioConductorWebGLBroadcaster.Unregister(this);
+        }
+
+        // Fallback for iOS where visibilitychange can be unreliable.
+        // Filter canvas-blur false positives by checking document.hidden:
+        // canvas blur → hasFocus=false but document.hidden==false → skip.
+        // Screen lock / tab switch → hasFocus=false and document.hidden==true → allow.
+        private void OnApplicationFocus(bool hasFocus)
+        {
+            if (!hasFocus && AudioConductor_IsDocumentHidden() == 0)
+                return;
+            NotifySystemPause(!hasFocus);
+        }
+
+        internal void NotifySystemPause(bool pause)
+        {
+            if (_isSystemPaused == pause)
+                return;
+            _isSystemPaused = pause;
+            Conductor?.OnSystemPause(pause);
+        }
+    }
+}
+
+#endif
diff --git a/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.WebGL.cs.meta b/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.WebGL.cs.meta
new file mode 100644
index 0000000..97d644d
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.WebGL.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 137e0e650a3294575bc769714f061429
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.cs b/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.cs
index b61b45c..40288d7 100644
--- a/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.cs
+++ b/Packages/AudioConductor/Runtime/Core/ConductorBehaviour.cs
@@ -8,7 +8,7 @@
 
 namespace AudioConductor.Core
 {
-    internal sealed class ConductorBehaviour : MonoBehaviour
+    internal sealed partial class ConductorBehaviour : MonoBehaviour
     {
         internal Conductor? Conductor { get; set; }
 
diff --git a/Packages/AudioConductor/Runtime/Core/Models/CueSheet.cs b/Packages/AudioConductor/Runtime/Core/Models/CueSheet.cs
index 5bac5e4..4ce0285 100644
--- a/Packages/AudioConductor/Runtime/Core/Models/CueSheet.cs
+++ b/Packages/AudioConductor/Runtime/Core/Models/CueSheet.cs
@@ -48,6 +48,12 @@ public sealed class CueSheet
         /// </summary>
         public bool pitchInvert;
 
+        /// <summary>
+        ///     The sample rate at which sample positions in this CueSheet's tracks were authored.
+        ///     Zero means unset; no frequency conversion is applied at runtime.
+        /// </summary>
+        public int referenceSampleRate;
+
         /// <summary>
         ///     List of <see cref="Cue" />.
         /// </summary>
diff --git a/Packages/AudioConductor/Runtime/Plugins.meta b/Packages/AudioConductor/Runtime/Plugins.meta
new file mode 100644
index 0000000..67e1a5b
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Plugins.meta
@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: c88ef6e73aa2149d09387ac84978a99c
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Runtime/Plugins/WebGL.meta b/Packages/AudioConductor/Runtime/Plugins/WebGL.meta
new file mode 100644
index 0000000..f0a56f3
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Plugins/WebGL.meta
@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 5cb0c64a209234e21825f157d8b2cf9e
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Runtime/Plugins/WebGL/AudioConductorWebGL.jslib b/Packages/AudioConductor/Runtime/Plugins/WebGL/AudioConductorWebGL.jslib
new file mode 100644
index 0000000..5b4d2ee
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Plugins/WebGL/AudioConductorWebGL.jslib
@@ -0,0 +1,21 @@
+var _audioConductorListener = null;
+
+mergeInto(LibraryManager.library, {
+    AudioConductor_RegisterVisibilityChange: function (callbackPtr) {
+        _audioConductorListener = function () {
+            {{{ makeDynCall('vi', 'callbackPtr') }}}(document.hidden ? 1 : 0);
+        };
+        document.addEventListener("visibilitychange", _audioConductorListener);
+    },
+
+    AudioConductor_UnregisterVisibilityChange: function () {
+        if (_audioConductorListener) {
+            document.removeEventListener("visibilitychange", _audioConductorListener);
+            _audioConductorListener = null;
+        }
+    },
+
+    AudioConductor_IsDocumentHidden: function () {
+        return document.hidden ? 1 : 0;
+    }
+});
diff --git a/Packages/AudioConductor/Runtime/Plugins/WebGL/AudioConductorWebGL.jslib.meta b/Packages/AudioConductor/Runtime/Plugins/WebGL/AudioConductorWebGL.jslib.meta
new file mode 100644
index 0000000..a007b64
--- /dev/null
+++ b/Packages/AudioConductor/Runtime/Plugins/WebGL/AudioConductorWebGL.jslib.meta
@@ -0,0 +1,32 @@
+fileFormatVersion: 2
+guid: 72bd0fcb6035f4833b6c050d635b3f93
+PluginImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  iconMap: {}
+  executionOrder: {}
+  defineConstraints: []
+  isPreloaded: 0
+  isOverridable: 1
+  isExplicitlyReferenced: 0
+  validateReferences: 1
+  platformData:
+  - first:
+      Any: 
+    second:
+      enabled: 0
+      settings: {}
+  - first:
+      Editor: Editor
+    second:
+      enabled: 0
+      settings:
+        DefaultValueInitialized: true
+  - first:
+      WebGL: WebGL
+    second:
+      enabled: 1
+      settings: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerTests.cs b/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerTests.cs
index 507d2c2..bbc5446 100644
--- a/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerTests.cs
+++ b/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerTests.cs
@@ -444,6 +444,22 @@ public void Pause_Loop_Source1Playing_StopsSource0PausesSource1()
             Assert.That(_source0.StopCount, Is.GreaterThanOrEqualTo(1));
         }
 
+        [Test]
+        public void Pause_Loop_NeitherSourcePlaying_SetsStatePausedWithoutPausingAnySources()
+        {
+            _clock.DspTime = 0.0;
+            SetupPlayer(isLoop: true, endSample: _clip.samples);
+            _player.Play();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _source1.IsPlaying = false;
+
+            _player.Pause();
+
+            Assert.That(_source0.PauseCount, Is.EqualTo(0));
+            Assert.That(_source1.PauseCount, Is.EqualTo(0));
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
         [Test]
         public void Pause_NonLoop_PausesSource0()
         {
@@ -456,6 +472,20 @@ public void Pause_NonLoop_PausesSource0()
             Assert.That(_source0.PauseCount, Is.EqualTo(1));
         }
 
+        [Test]
+        public void Pause_NonLoop_NeitherSourcePlaying_SetsStatePausedWithoutPausingAnySources()
+        {
+            _clock.DspTime = 0.0;
+            SetupPlayer(isLoop: false, endSample: _clip.samples);
+            _player.Play();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+
+            _player.Pause();
+
+            Assert.That(_source0.PauseCount, Is.EqualTo(0));
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
         // --- Resume (loop branch) ---
 
         [Test]
@@ -490,6 +520,23 @@ public void Resume_Loop_PausedSource1_UnPausesSource1()
             Assert.That(_source0.UnPauseCount, Is.EqualTo(0));
         }
 
+        [Test]
+        public void Resume_Loop_WasStoppedBeforePlay_Reschedules()
+        {
+            _clock.DspTime = 0.0;
+            SetupPlayer(isLoop: true, endSample: _clip.samples);
+            _player.Play();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _source1.IsPlaying = false;
+            _player.Pause();
+
+            _player.Resume();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Playing));
+            Assert.That(_source0.IsPlaying, Is.True);
+            Assert.That(_source1.IsPlaying, Is.False);
+        }
+
         [Test]
         public void Resume_NonLoop_UnPausesSource0()
         {
@@ -503,6 +550,21 @@ public void Resume_NonLoop_UnPausesSource0()
             Assert.That(_source0.UnPauseCount, Is.EqualTo(1));
         }
 
+        [Test]
+        public void Resume_NonLoop_WasStoppedBeforePlay_Reschedules()
+        {
+            _clock.DspTime = 0.0;
+            SetupPlayer(isLoop: false, endSample: _clip.samples);
+            _player.Play();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _player.Pause();
+
+            _player.Resume();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Playing));
+            Assert.That(_source0.IsPlaying, Is.True);
+        }
+
         // --- SetEndAction / _onEnd fire ---
 
         [Test]
@@ -522,6 +584,48 @@ public void SetEndAction_OnPlaybackEnd_InvokesCallback()
             Assert.That(called, Is.True);
         }
 
+        // --- Setup with referenceSampleRate ---
+
+        [Test]
+        public void Setup_ReferenceSampleRateZero_EndSampleNotScaled()
+        {
+            // referenceSampleRate=0 means unset; no conversion applied
+            _clock.DspTime = 0.0;
+            _player.Setup(null, _clip, 0, 1f, 1f, false, 0, 0, 22050, 0);
+
+            _player.Play();
+
+            // scheduledEndTime = PlayScheduleDelay(0.1) + 22050/44100 = 0.6
+            Assert.That(_source0.LastScheduledEndTime, Is.EqualTo(0.6).Within(0.001));
+        }
+
+        [Test]
+        public void Setup_ReferenceSampleRateMatchesClipFrequency_EndSampleNotScaled()
+        {
+            // referenceSampleRate == clipFrequency → no conversion
+            _clock.DspTime = 0.0;
+            _player.Setup(null, _clip, 0, 1f, 1f, false, 0, 0, 22050, 44100);
+
+            _player.Play();
+
+            // same as referenceSampleRate=0 case: 0.1 + 22050/44100 = 0.6
+            Assert.That(_source0.LastScheduledEndTime, Is.EqualTo(0.6).Within(0.001));
+        }
+
+        [Test]
+        public void Setup_ReferenceSampleRateDiffersFromClipFrequency_EndSampleScaled()
+        {
+            // referenceSampleRate=22050, clipFrequency=44100 → endSample scaled by 44100/22050 = 2
+            _clock.DspTime = 0.0;
+            _player.Setup(null, _clip, 0, 1f, 1f, false, 0, 0, 22050, 22050);
+
+            _player.Play();
+
+            // convertedEnd = RoundToInt(22050 * 44100 / 22050) = 44100
+            // scheduledEndTime = 0.1 + 44100/44100 = 1.1
+            Assert.That(_source0.LastScheduledEndTime, Is.EqualTo(1.1).Within(0.001));
+        }
+
         // --- GetCurrentSample / SetCurrentSample ---
 
         [Test]
diff --git a/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerWebGLTests.cs b/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerWebGLTests.cs
new file mode 100644
index 0000000..6e5d29f
--- /dev/null
+++ b/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerWebGLTests.cs
@@ -0,0 +1,320 @@
+// --------------------------------------------------------------
+// Copyright 2026 CyberAgent, Inc.
+// --------------------------------------------------------------
+
+#nullable enable
+
+#if UNITY_WEBGL
+using AudioConductor.Core;
+using AudioConductor.Core.Enums;
+using AudioConductor.Editor.Core.Tests.Fakes;
+using NUnit.Framework;
+using UnityEngine;
+using Object = UnityEngine.Object;
+
+namespace AudioConductor.Editor.Core.Tests
+{
+    [TestFixture]
+    internal sealed class AudioClipPlayerWebGLTests
+    {
+        [SetUp]
+        public void SetUp()
+        {
+            _source0 = new SpyAudioSourceWrapper();
+            _source1 = new SpyAudioSourceWrapper();
+            _clock = new StubDspClock();
+            _player = new AudioClipPlayer(new IAudioSourceWrapper[] { _source0, _source1 }, _clock,
+                NullLifecycle.Instance);
+            _clip = AudioClip.Create("test", 44100, 1, 44100, false);
+        }
+
+        [TearDown]
+        public void TearDown()
+        {
+            Object.DestroyImmediate(_clip);
+        }
+
+        private SpyAudioSourceWrapper _source0 = null!;
+        private SpyAudioSourceWrapper _source1 = null!;
+        private StubDspClock _clock = null!;
+        private AudioClipPlayer _player = null!;
+        private AudioClip _clip = null!;
+
+        private void SetupAndPlay(bool isLoop = false)
+        {
+            _player.Setup(null, _clip, 0, 1f, 1f, isLoop, 0, 0, _clip.samples);
+            _player.Play();
+        }
+
+        // --- PauseBySystem ---
+
+        [Test]
+        public void PauseBySystem_WhenPlaying_SetsStatePaused()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+
+            _player.PauseBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        [Test]
+        public void PauseBySystem_WhenAlreadySystemPaused_NoOp()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _player.PauseBySystem();
+
+            _player.PauseBySystem();
+
+            Assert.That(_source0.PauseCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void PauseBySystem_WhenUserPaused_DoesNotSystemPause()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _player.Pause();
+
+            _player.PauseBySystem();
+
+            // Only the user Pause() call should have called Pause on the source
+            Assert.That(_source0.PauseCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void PauseBySystem_WhenNotPlaying_NoOp()
+        {
+            _player.Setup(null, _clip, 0, 1f, 1f, false, 0, 0, _clip.samples);
+
+            _player.PauseBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Stopped));
+        }
+
+        [Test]
+        public void PauseBySystem_Loop_Source0Playing_PausesSource0StopsSource1()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _source0.IsPlaying = true;
+            _source1.IsPlaying = false;
+
+            _player.PauseBySystem();
+
+            Assert.That(_source0.PauseCount, Is.EqualTo(1));
+            Assert.That(_source1.StopCount, Is.GreaterThanOrEqualTo(1));
+        }
+
+        [Test]
+        public void PauseBySystem_Loop_NeitherSourcePlaying_SetsStatePausedWithoutPausingAnySources()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _source1.IsPlaying = false;
+
+            _player.PauseBySystem();
+
+            Assert.That(_source0.PauseCount, Is.EqualTo(0));
+            Assert.That(_source1.PauseCount, Is.EqualTo(0));
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        // --- ResumeBySystem ---
+
+        [Test]
+        public void ResumeBySystem_WhenNotSystemPaused_DoesNotThrow()
+        {
+            _player.Setup(null, _clip, 0, 1f, 1f, false, 0, 0, _clip.samples);
+
+            Assert.DoesNotThrow(() => _player.ResumeBySystem());
+        }
+
+        [Test]
+        public void ResumeBySystem_WhenUserPaused_DoesNotUnpauseUser()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _player.Pause();
+            _player.PauseBySystem();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        [Test]
+        public void ResumeBySystem_ShiftsScheduledEndTime()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _source0.IsPlaying = true;
+            var endTimeBefore = _source0.LastScheduledEndTime;
+
+            _clock.DspTime = 1.0;
+            _player.PauseBySystem();
+            _clock.DspTime = 3.0;
+            _player.ResumeBySystem();
+
+            Assert.That(_source0.LastScheduledEndTime, Is.EqualTo(endTimeBefore + 2.0).Within(0.0001));
+        }
+
+        [Test]
+        public void ResumeBySystem_Loop_Source0Paused_UnpausesSource0()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _source0.IsPlaying = true;
+            _source1.IsPlaying = false;
+            _player.PauseBySystem();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_source0.UnPauseCount, Is.EqualTo(1));
+            Assert.That(_source1.UnPauseCount, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void ResumeBySystem_Loop_Source1Paused_UnpausesSource1()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _source0.IsPlaying = false;
+            _source1.IsPlaying = true;
+            _player.PauseBySystem();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_source1.UnPauseCount, Is.EqualTo(1));
+            Assert.That(_source0.UnPauseCount, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void ResumeBySystem_Loop_Source1Paused_ShiftsScheduledEndTimeOnSource1()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _clock.DspTime = 0.5;
+            _player.ManualUpdate(0f);
+            _source0.IsPlaying = false;
+            _source1.IsPlaying = true;
+            var scheduledEndTime = _source1.LastScheduledEndTime;
+
+            _clock.DspTime = 1.0;
+            _player.PauseBySystem();
+            _clock.DspTime = 3.0;
+            _player.ResumeBySystem();
+
+            Assert.That(_source1.LastScheduledEndTime, Is.EqualTo(scheduledEndTime + 2.0).Within(0.0001));
+        }
+
+        [Test]
+        public void ResumeBySystem_Loop_WasStoppedBeforePlay_Reschedules()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _source1.IsPlaying = false;
+            _player.PauseBySystem();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Playing));
+            Assert.That(_source0.IsPlaying, Is.True);
+            Assert.That(_source1.IsPlaying, Is.False);
+        }
+
+        [Test]
+        public void ResumeBySystem_Loop_WasStoppedBeforePlay_WhenUserAlsoPaused_DoesNotReschedule()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay(true);
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _source1.IsPlaying = false;
+            _player.PauseBySystem();
+            _player.Pause();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        [Test]
+        public void PauseBySystem_NonLoop_NeitherSourcePlaying_SetsStatePausedWithoutPausingAnySources()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+
+            _player.PauseBySystem();
+
+            Assert.That(_source0.PauseCount, Is.EqualTo(0));
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        [Test]
+        public void ResumeBySystem_NonLoop_WasStoppedBeforePlay_Reschedules()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _player.PauseBySystem();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Playing));
+            Assert.That(_source0.IsPlaying, Is.True);
+        }
+
+        [Test]
+        public void ResumeBySystem_NonLoop_WasStoppedBeforePlay_WhenUserAlsoPaused_DoesNotReschedule()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _source0.IsPlaying = false; // simulate PlayScheduleDelay window
+            _player.PauseBySystem();
+            _player.Pause();
+
+            _player.ResumeBySystem();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        // --- ManualUpdate interaction ---
+
+        [Test]
+        public void ManualUpdate_WhenSystemPaused_DoesNotTriggerStop()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            var stopped = false;
+            _player.SetStopAction(() => stopped = true);
+
+            _player.PauseBySystem();
+            _clock.DspTime = 100.0;
+            _player.ManualUpdate(0f);
+
+            Assert.That(stopped, Is.False);
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Paused));
+        }
+
+        // --- ResetState ---
+
+        [Test]
+        public void ResetState_ClearsSystemPaused()
+        {
+            _clock.DspTime = 0.0;
+            SetupAndPlay();
+            _player.PauseBySystem();
+
+            _player.ResetState();
+
+            Assert.That(_player.State, Is.EqualTo(PlayerState.Stopped));
+        }
+    }
+}
+
+#endif
diff --git a/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerWebGLTests.cs.meta b/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerWebGLTests.cs.meta
new file mode 100644
index 0000000..61a077c
--- /dev/null
+++ b/Packages/AudioConductor/Tests/Editor/Core/AudioClipPlayerWebGLTests.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: bd6be98fd4f994e91b8768c8893efe46
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Packages/AudioConductor/Tests/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModelTests.cs b/Packages/AudioConductor/Tests/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModelTests.cs
index d65ede4..c0c552f 100644
--- a/Packages/AudioConductor/Tests/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModelTests.cs
+++ b/Packages/AudioConductor/Tests/Editor/Core/Tools/CueSheetEditor/Models/CueSheetParameterPaneModelTests.cs
@@ -4,6 +4,7 @@
 
 #nullable enable
 
+using System.Collections.Generic;
 using AudioConductor.Core.Enums;
 using AudioConductor.Core.Models;
 using AudioConductor.Core.Shared;
@@ -13,11 +14,132 @@
 using AudioConductor.Editor.Foundation.TinyRx;
 using NUnit.Framework;
 using UnityEngine;
+using Object = UnityEngine.Object;
 
 namespace AudioConductor.Editor.Core.Tools.CueSheetEditor.Models.Tests
 {
     internal sealed class CueSheetParameterPaneModelTests
     {
+        private readonly List<AudioClip> _clips = new();
+
+        [TearDown]
+        public void TearDown()
+        {
+            foreach (var clip in _clips)
+                Object.DestroyImmediate(clip);
+            _clips.Clear();
+        }
+
+        private AudioClip CreateClip(int frequency)
+        {
+            var clip = AudioClip.Create("test", frequency, 1, frequency, false);
+            _clips.Add(clip);
+            return clip;
+        }
+
+        private static CueSheet BuildCueSheet(params AudioClip?[] clipsPerTrack)
+        {
+            var cue = new Cue { name = "cue" };
+            foreach (var clip in clipsPerTrack)
+                cue.trackList.Add(new Track { name = "track", audioClip = clip });
+            return new CueSheet { name = "sheet", cueList = { cue } };
+        }
+
+        // --- CanApplyReferenceSampleRate ---
+
+        [Test]
+        public void CanApplyReferenceSampleRate_NoCues_ReturnsFalse()
+        {
+            var cueSheet = new CueSheet { name = "sheet" };
+            var model = new CueSheetParameterPaneModel(cueSheet, new AutoIncrementHistory(), new AssetSaveService());
+
+            Assert.That(model.CanApplyReferenceSampleRate, Is.False);
+        }
+
+        [Test]
+        public void CanApplyReferenceSampleRate_TracksWithNoClips_ReturnsFalse()
+        {
+            var cueSheet = BuildCueSheet(null, null);
+            var model = new CueSheetParameterPaneModel(cueSheet, new AutoIncrementHistory(), new AssetSaveService());
+
+            Assert.That(model.CanApplyReferenceSampleRate, Is.False);
+        }
+
+        [Test]
+        public void CanApplyReferenceSampleRate_AllTracksHaveSameFrequency_ReturnsTrue()
+        {
+            var clip1 = CreateClip(44100);
+            var clip2 = CreateClip(44100);
+            var cueSheet = BuildCueSheet(clip1, clip2);
+            var model = new CueSheetParameterPaneModel(cueSheet, new AutoIncrementHistory(), new AssetSaveService());
+
+            Assert.That(model.CanApplyReferenceSampleRate, Is.True);
+        }
+
+        [Test]
+        public void CanApplyReferenceSampleRate_TracksHaveDifferentFrequencies_ReturnsFalse()
+        {
+            var clip1 = CreateClip(44100);
+            var clip2 = CreateClip(48000);
+            var cueSheet = BuildCueSheet(clip1, clip2);
+            var model = new CueSheetParameterPaneModel(cueSheet, new AutoIncrementHistory(), new AssetSaveService());
+
+            Assert.That(model.CanApplyReferenceSampleRate, Is.False);
+        }
+
+        // --- ApplyReferenceSampleRate ---
+
+        [Test]
+        public void ApplyReferenceSampleRate_SetsClipFrequency()
+        {
+            var clip = CreateClip(44100);
+            var cueSheet = BuildCueSheet(clip);
+            var model = new CueSheetParameterPaneModel(cueSheet, new AutoIncrementHistory(), new AssetSaveService());
+
+            model.ApplyReferenceSampleRate();
+
+            Assert.That(model.ReferenceSampleRateObservable.Value, Is.EqualTo(44100));
+            Assert.That(cueSheet.referenceSampleRate, Is.EqualTo(44100));
+        }
+
+        [Test]
+        public void ApplyReferenceSampleRate_InconsistentFrequencies_DoesNothing()
+        {
+            var clip1 = CreateClip(44100);
+            var clip2 = CreateClip(48000);
+            var cueSheet = BuildCueSheet(clip1, clip2);
+            var model = new CueSheetParameterPaneModel(cueSheet, new AutoIncrementHistory(), new AssetSaveService());
+
+            model.ApplyReferenceSampleRate();
+
+            Assert.That(model.ReferenceSampleRateObservable.Value, Is.EqualTo(0));
+            Assert.That(cueSheet.referenceSampleRate, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void ApplyReferenceSampleRate_History()
+        {
+            var clip = CreateClip(44100);
+            var cueSheet = BuildCueSheet(clip);
+            var history = new AutoIncrementHistory();
+            var model = new CueSheetParameterPaneModel(cueSheet, history, new AssetSaveService());
+
+            model.ApplyReferenceSampleRate();
+
+            Assert.That(model.ReferenceSampleRateObservable.Value, Is.EqualTo(44100));
+            Assert.That(cueSheet.referenceSampleRate, Is.EqualTo(44100));
+
+            history.Undo();
+
+            Assert.That(model.ReferenceSampleRateObservable.Value, Is.EqualTo(0));
+            Assert.That(cueSheet.referenceSampleRate, Is.EqualTo(0));
+
+            history.Redo();
+
+            Assert.That(model.ReferenceSampleRateObservable.Value, Is.EqualTo(44100));
+            Assert.That(cueSheet.referenceSampleRate, Is.EqualTo(44100));
+        }
+
         [Test]
         public void NameHistory()
         {
diff --git a/Packages/AudioConductor/package.json b/Packages/AudioConductor/package.json
index eeb77b3..ad7a667 100644
--- a/Packages/AudioConductor/package.json
+++ b/Packages/AudioConductor/package.json
@@ -1,6 +1,6 @@
 {
   "name": "jp.co.cyberagent.audioconductor",
-  "version": "2.3.1",
+  "version": "2.4.0",
   "displayName": "Audio Conductor",
   "unity": "2022.3",
   "license": "MIT",
diff --git a/docs/Images/edit_cuesheet_02.png b/docs/Images/edit_cuesheet_02.png
index 2687724..0c6cf65 100644
Binary files a/docs/Images/edit_cuesheet_02.png and b/docs/Images/edit_cuesheet_02.png differ
diff --git a/docs/Images/migration_dialog_01.png b/docs/Images/migration_dialog_01.png
new file mode 100644
index 0000000..73f9784
Binary files /dev/null and b/docs/Images/migration_dialog_01.png differ
diff --git a/docs/README.md b/docs/README.md
index c17a135..da36b90 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -133,6 +133,7 @@ It has the following parameters:
 - Volume
 - Pitch
 - Pitch invert
+- Reference sample rate
 - Cue list
 
 ### Runtime settings
@@ -254,7 +255,15 @@ If you don't want to specify a version, you can also update the version by editi
 
 ### Sample-based parameters and AudioClip import settings
 
-Start sample, End sample, and Loop start sample are interpreted based on `AudioClip.frequency`. If Audio Import Settings convert the sample rate, the configured sample values will no longer match the intended playback positions. Ensure that the sample rate is consistent across all AudioClips and all build targets.
+Start sample, End sample, and Loop start sample are stored as integer sample indices relative to `AudioClip.frequency`. If the audio is decoded at a different frequency — because Audio Import Settings do not use **Preserve Sample Rate**, or because a platform resamples audio at runtime — the same sample index corresponds to a different point in time, shifting the playback position away from what was intended.
+
+`referenceSampleRate` records the sample rate at which the CueSheet's sample positions were authored. At runtime, AudioConductor scales each sample index to match the clip's actual decoding frequency. The value is stored per CueSheet rather than per track to keep asset data compact. All AudioClips in a project must share a single sample rate — if clip frequencies are inconsistent within a CueSheet, no single reference value can be recorded for it.
+
+When you open a project with CueSheets that have `referenceSampleRate` unset, a migration dialog appears and offers to apply the current clip frequencies automatically. You can also apply the value at any time using the **Apply** button in the **Reference Sample Rate** section of the CueSheet parameter pane.
+
+<p align="center">
+  <img width="30%" src="./Images/migration_dialog_01.png" alt="Migration Dialog">
+</p>
 
 ## Create setting assets
 
@@ -310,7 +319,9 @@ At the top of the window, there is a **Settings** dropdown where you select the
 
 ### Edit cue-sheet parameters
 
-In this pane, you edit the cue-sheet name, concurrent play control, volume, pitch, etc.  
+In this pane, you edit the cue-sheet name, concurrent play control, volume, pitch, etc.
+
+The **Reference Sample Rate** field is shown as read-only. When it is unset (0), a warning is displayed. If all AudioClips in the CueSheet share the same sample rate, the **Apply** button becomes enabled and sets the value from the clip frequency.  
 
 <p align="center">
   <img width="70%" src="./Images/edit_cuesheet_02.png" alt="Edit CueSheet Parameters">
@@ -708,6 +719,7 @@ Clicking a result row opens the CueSheet Editor window and focuses the relevant
 
 **Warnings**:
 - CueSheet: Cue list is empty.
+- CueSheet: `referenceSampleRate` is not set and the CueSheet has AudioClips assigned. Sample positions may drift if Audio Import Settings resample the audio or if a platform decodes at a different rate.
 - Cue: `Throttle limit` exceeds the parent CueSheet's throttle limit (when both are non-zero).
 - Cue: `Category ID` is not found in the selected AudioConductorSettings.
 - Track: Play type is Random but some tracks have `Random weight` = 0 (those tracks will never be selected).
diff --git a/docs/README_JA.md b/docs/README_JA.md
index c6ea674..ef5d168 100644
--- a/docs/README_JA.md
+++ b/docs/README_JA.md
@@ -134,6 +134,7 @@ Unity のオーディオ機能 (AudioClip/AudioSource) をより便利に扱う
 - ボリューム
 - ピッチ
 - ピッチ反転 (Pitch invert)
+- 基準サンプルレート (Reference sample rate)
 - キューリスト
 
 ### ランタイム設定
@@ -258,7 +259,15 @@ AudioSource に設定されるピッチはキューシート/キュー/トラッ
 
 ### サンプル値パラメータと AudioClip のインポート設定
 
-開始サンプル値・終了サンプル値・ループ時開始サンプル値は `AudioClip.frequency` を基準に解釈されます。Audio Import Settings によってサンプリングレートが変換される場合、設定したサンプル値と意図した再生位置がずれます。すべての AudioClip ・すべてのビルドターゲットでサンプリングレートが一致していることを確認してください。
+開始サンプル値・終了サンプル値・ループ時開始サンプル値は、`AudioClip.frequency` を基準とするサンプルインデックスとして保存されています。Audio Import Settings で **Preserve Sample Rate** を使用しない場合や、プラットフォームがランタイムにオーディオをリサンプリングする場合は、オーディオが異なる周波数でデコードされるため、同じサンプルインデックスでも再生される時間位置が変わり、意図したタイミングからずれます。
+
+`referenceSampleRate` はキューシートのサンプル値を記述した際の基準サンプルレートを記録します。AudioConductor はランタイムでクリップの実際のデコード周波数に合わせて各サンプルインデックスをスケーリングします。データ量を抑えるためトラック単位ではなくキューシート単位で管理しています。キューシート内のクリップ間で周波数がばらつくと 1 つの値で基準サンプルレートを記録できないため、プロジェクト内のすべてのサウンドファイルのサンプルレートを統一してください。
+
+`referenceSampleRate` が未設定のキューシートが存在する状態でプロジェクトを開くと、マイグレーションダイアログが表示され、現在のクリップ周波数を自動適用できます。また、キューシートのパラメータペインの **Reference Sample Rate** セクションの **Apply** ボタンからいつでも適用することもできます。
+
+<p align="center">
+  <img width="30%" src="./Images/migration_dialog_01.png" alt="Migration Dialog">
+</p>
 
 ## アセットを作成する
 
@@ -314,7 +323,9 @@ AudioSource に設定されるピッチはキューシート/キュー/トラッ
 
 ### キューシートのパラメータを編集する
 
-このペインではキューシートの名前、同時再生制御、ボリューム、ピッチなどを編集します。  
+このペインではキューシートの名前、同時再生制御、ボリューム、ピッチなどを編集します。
+
+**Reference Sample Rate** フィールドは読み取り専用で表示されます。未設定（0）の場合は警告が表示されます。キューシート内のすべての AudioClip が同じサンプルレートを持つ場合、**Apply** ボタンが有効になり、クリップの周波数を値として設定できます。  
 
 <p align="center">
   <img width="70%" src="./Images/edit_cuesheet_02.png" alt="Edit CueSheet Parameters">
@@ -714,6 +725,7 @@ CueSheet Editor でキューシートを編集中にその場でチェックす
 
 **警告**:
 - キューシート: キューリストが空。
+- キューシート: `referenceSampleRate` が未設定で、かつ AudioClip が割り当てられているトラックが存在する。Audio Import Settings でリサンプリングが行われる場合や、プラットフォームのデコード周波数がクリップのネイティブレートと異なる場合にサンプル位置がずれる可能性があります。
 - キュー: `Throttle limit` が親キューシートの `Throttle limit` を超えている（両方が非 0 のとき）。
 - キュー: `Category ID` が選択した AudioConductorSettings に存在しない。
 - トラック: 再生タイプが Random の中に `Random weight` が 0 のトラックが存在する（そのトラックは選ばれない）。