diff --git a/src/NullDepth/Game/GameService.cs b/src/NullDepth/Game/GameService.cs
index bff10dc..35191c5 100644
--- a/src/NullDepth/Game/GameService.cs
+++ b/src/NullDepth/Game/GameService.cs
@@ -179,6 +179,7 @@ public sealed class GameService(HttpClient http, IJSRuntime js)
         if (!HasAll(exit.RequiresFlags)) return T(exit.LockedMessageKey ?? "game.exit.locked");
         State.CurrentRoomId = exit.Target;
         State.VisitedRooms.Add(exit.Target);
+        await CheckAchievementsAsync();
         await SaveAsync();
         return "";
     }
@@ -204,9 +205,47 @@ public sealed class GameService(HttpClient http, IJSRuntime js)
             }
         }
         if (interaction.Checkpoint) SetCheckpoint();
+        await CheckAchievementsAsync();
         await SaveAsync();
     }
 
+    public static readonly List<AchievementDefinition> AchievementsList =
+    [
+        new() { Id = "ach_descent", TitleKey = "ach.descent.title", DescriptionKey = "ach.descent.desc", Icon = "▼" },
+        new() { Id = "ach_cold_blood", TitleKey = "ach.coldBlood.title", DescriptionKey = "ach.coldBlood.desc", Icon = "♥" },
+        new() { Id = "ach_electrician", TitleKey = "ach.electrician.title", DescriptionKey = "ach.electrician.desc", Icon = "⚡" },
+        new() { Id = "ach_waveform", TitleKey = "ach.waveform.title", DescriptionKey = "ach.waveform.desc", Icon = "〰" },
+        new() { Id = "ach_dialogue", TitleKey = "ach.dialogue.title", DescriptionKey = "ach.dialogue.desc", Icon = "◆" },
+        new() { Id = "ach_archivist", TitleKey = "ach.archivist.title", DescriptionKey = "ach.archivist.desc", Icon = "📖" },
+        new() { Id = "ach_ending_a", TitleKey = "ach.endingA.title", DescriptionKey = "ach.endingA.desc", Icon = "📡" },
+        new() { Id = "ach_ending_b", TitleKey = "ach.endingB.title", DescriptionKey = "ach.endingB.desc", Icon = "⏻" },
+        new() { Id = "ach_ending_c", TitleKey = "ach.endingC.title", DescriptionKey = "ach.endingC.desc", Icon = "🔒" },
+        new() { Id = "ach_survivor", TitleKey = "ach.survivor.title", DescriptionKey = "ach.survivor.desc", Icon = "★" }
+    ];
+
+    public async Task<bool> UnlockAchievementAsync(string id)
+    {
+        if (Profile.UnlockedAchievements.Add(id))
+        {
+            await SaveProfileAsync();
+            return true;
+        }
+        return false;
+    }
+
+    public async Task CheckAchievementsAsync()
+    {
+        if (State.CurrentRoomId == "loc_08_lower_landing") await UnlockAchievementAsync("ach_descent");
+        if (State.Flags.Contains("manual_override_found")) await UnlockAchievementAsync("ach_electrician");
+        if (State.Flags.Contains("asked_why") && State.Flags.Contains("asked_staff") && State.Flags.Contains("asked_reconnect"))
+            await UnlockAchievementAsync("ach_dialogue");
+        if (Profile.DiscoveredArchives.Count >= 6) await UnlockAchievementAsync("ach_archivist");
+        if (State.CompletedEnding == "release") await UnlockAchievementAsync("ach_ending_a");
+        if (State.CompletedEnding == "shutdown") await UnlockAchievementAsync("ach_ending_b");
+        if (State.CompletedEnding == "containment") await UnlockAchievementAsync("ach_ending_c");
+        if (State.CompletedEnding is not null && CurrentBpm < 100) await UnlockAchievementAsync("ach_cold_blood");
+    }
+
     public async Task ApplyChoiceAsync(ChoiceDefinition choice)
     {
         Apply(choice.SetFlags, choice.ClearFlags, choice.AddItems);
@@ -220,6 +259,7 @@ public sealed class GameService(HttpClient http, IJSRuntime js)
             }
         }
         if (choice.Checkpoint) SetCheckpoint();
+        await CheckAchievementsAsync();
         await SaveAsync();
     }
 
diff --git a/src/NullDepth/Models/GameModels.cs b/src/NullDepth/Models/GameModels.cs
index 5d6adfc..a9d8a80 100644
--- a/src/NullDepth/Models/GameModels.cs
+++ b/src/NullDepth/Models/GameModels.cs
@@ -131,6 +131,15 @@ public sealed class PlayerProfile
 {
     public HashSet<string> UnlockedEndings { get; set; } = [];
     public HashSet<string> DiscoveredArchives { get; set; } = [];
+    public HashSet<string> UnlockedAchievements { get; set; } = [];
+}
+
+public sealed class AchievementDefinition
+{
+    public string Id { get; set; } = "";
+    public string TitleKey { get; set; } = "";
+    public string DescriptionKey { get; set; } = "";
+    public string Icon { get; set; } = "★";
 }
 
 public enum SaveLoadResult
diff --git a/src/NullDepth/Pages/Home.razor b/src/NullDepth/Pages/Home.razor
index cef0cc3..285f9bb 100644
--- a/src/NullDepth/Pages/Home.razor
+++ b/src/NullDepth/Pages/Home.razor
@@ -42,7 +42,8 @@
             <nav class="title-menu" aria-label="Main menu">
                 <button class="@MenuClass(0)" @onclick="StartNewGame">@Game.T("menu.newGame")</button>
                 <button class="@MenuClass(1)" disabled="@(!Game.HasSave)" @onclick="ContinueGame">@Game.T("menu.continue")</button>
-                <button class="@MenuClass(2)" @onclick="OpenSettings">@Game.T("menu.settings")</button>
+                <button class="@MenuClass(2)" @onclick="OpenCodex">@Game.T("menu.codex")</button>
+                <button class="@MenuClass(3)" @onclick="OpenSettings">@Game.T("menu.settings")</button>
                 <small>@Game.T("menu.controlsHint")</small>
                 @if (!string.IsNullOrWhiteSpace(_titleNotice)) { <p class="title-notice" role="alert">@_titleNotice</p> }
             </nav>
@@ -76,6 +77,23 @@
             <div class="vignette"></div>
             <div class="dust-layer"></div>
             
+            @if (room.Id == "loc_01_exterior_access")
+            {
+                <div class="rain-layer"></div>
+            }
+            @if (room.Id is "loc_09_cooling_junction" or "loc_10_cooling_control")
+            {
+                <div class="vapor-layer"></div>
+            }
+            @if (room.Id == "loc_11_equipment_storage" && !Game.State.Flags.Contains("manual_override_found"))
+            {
+                <div class="spark-layer"></div>
+            }
+            @if (room.Id is "loc_14_core_access" or "loc_15_server_core")
+            {
+                <div class="data-stream-layer"></div>
+            }
+            
             @if (_scanMode)
             {
                 <div class="lidar-overlay">
@@ -311,8 +329,9 @@
                                         <p style="margin:.3rem 0 0;">@(selectedItem.DetailedKey is not null ? Game.T(selectedItem.DetailedKey) : Game.T(selectedItem.DescriptionKey))</p>
                                         @if (selectedItem.Id == "diagnostic_scanner")
                                         {
-                                            <div class="inspect-actions">
+                                            <div class="inspect-actions" style="display:flex;gap:.6rem;flex-wrap:wrap;margin-top:.8rem;">
                                                 <button class="primary-action" @onclick="TriggerScanFromInventory"><kbd>C</kbd> @Game.T("common.scan")</button>
+                                                <button @onclick="OpenWaveformPuzzle">〰 KALIBROVAŤ SIGNÁL</button>
                                             </div>
                                         }
                                     </div>
@@ -372,6 +391,71 @@
             </article>
         </div>
     }
+    @if (_showWaveformPuzzle)
+    {
+        <div class="modal-layer" role="dialog" aria-modal="true">
+            <article class="overlay-card puzzle-card">
+                <button class="close-button" @onclick="CloseWaveformPuzzle">×</button>
+                <p class="eyebrow">@Game.T("puzzle.waveform.title")</p>
+                <p>@Game.T("puzzle.waveform.desc")</p>
+                
+                <div class="waveform-display">
+                    <svg viewBox="0 0 400 120" preserveAspectRatio="none">
+                        <line x1="0" y1="60" x2="400" y2="60" stroke="rgba(158,239,255,0.15)" stroke-width="1" stroke-dasharray="4" />
+                        <line x1="200" y1="0" x2="200" y2="120" stroke="rgba(158,239,255,0.15)" stroke-width="1" stroke-dasharray="4" />
+                        <path d="@GetSvgWavePath(_targetFreq, _targetAmp, 0)" fill="none" stroke="rgba(255, 188, 66, 0.7)" stroke-width="2.5" />
+                        <path d="@GetSvgWavePath(_userFreq, _userAmp, _wavePhase)" fill="none" stroke="var(--cyan-strong)" stroke-width="2.5" />
+                    </svg>
+                </div>
+
+                <div class="puzzle-controls">
+                    <div class="puzzle-control">
+                        <label>@Game.T("puzzle.waveform.frequency") @(_userFreq * 20.0) kHz</label>
+                        <input type="range" min="1" max="10" step="1" @bind="_userFreq" @bind:after="OnWaveformChanged" />
+                    </div>
+                    <div class="puzzle-control">
+                        <label>@Game.T("puzzle.waveform.amplitude") @(_userAmp * 10) dB</label>
+                        <input type="range" min="1" max="10" step="1" @bind="_userAmp" @bind:after="OnWaveformChanged" />
+                    </div>
+                </div>
+
+                <div class="puzzle-status @(IsWaveformMatched ? "locked" : "")">
+                    @(IsWaveformMatched ? Game.T("puzzle.waveform.locked") : string.Format(Game.T("puzzle.waveform.tuning"), WaveMatchPercent))
+                </div>
+
+                <div class="confirmation-actions" style="margin-top:1.2rem;">
+                    <button class="primary-action" disabled="@(!IsWaveformMatched)" @onclick="CompleteWaveformPuzzle">@Game.T("puzzle.waveform.calibrate")</button>
+                    <button @onclick="CloseWaveformPuzzle">@Game.T("common.back")</button>
+                </div>
+            </article>
+        </div>
+    }
+    @if (_showCodex)
+    {
+        <div class="modal-layer" role="dialog" aria-modal="true">
+            <article class="overlay-card codex-card">
+                <button class="close-button" @onclick="CloseCodex">×</button>
+                <p class="eyebrow">@Game.T("achievements.title")</p>
+                <p style="color:var(--muted);font-size:.78rem;font-family:'IBM Plex Mono';">
+                    @string.Format(Game.T("achievements.unlockedCount"), Game.Profile.UnlockedAchievements.Count, GameService.AchievementsList.Count)
+                </p>
+
+                <div class="achievements-grid">
+                    @foreach (var ach in GameService.AchievementsList)
+                    {
+                        var isUnlocked = Game.Profile.UnlockedAchievements.Contains(ach.Id);
+                        <div class="achievement-item @(isUnlocked ? "unlocked" : "")">
+                            <div class="achievement-icon">@ach.Icon</div>
+                            <div class="achievement-info">
+                                <strong>@Game.T(ach.TitleKey)</strong>
+                                <p>@Game.T(ach.DescriptionKey)</p>
+                            </div>
+                        </div>
+                    }
+                </div>
+            </article>
+        </div>
+    }
     @if (_showPause)
     {
         <div class="modal-layer" role="dialog" aria-modal="true">
@@ -379,6 +463,7 @@
                 <p class="eyebrow">SYSTEM // PAUSED</p>
                 <h2>@Game.T("pause.title")</h2>
                 <button class="primary-action" @onclick="CloseOverlays">@Game.T("pause.resume")</button>
+                <button @onclick="OpenCodex">@Game.T("menu.codex")</button>
                 <button @onclick="OpenSettings">@Game.T("menu.settings")</button>
                 <button @onclick="ReturnToTitle">@Game.T("common.mainMenu")</button>
             </article>
@@ -457,6 +542,13 @@
     private bool _showPause;
     private bool _showSettings;
     private bool _showInteractionPicker;
+    private bool _showCodex;
+    private bool _showWaveformPuzzle;
+    private int _userFreq = 3;
+    private int _userAmp = 4;
+    private int _targetFreq = 7;
+    private int _targetAmp = 8;
+    private double _wavePhase = 0;
     private bool _scanMode;
     private bool _isFullscreen;
     private bool _isTransitioning;
@@ -477,8 +569,34 @@
     private SaveLoadResult? _saveError;
     private Confirmation? _confirmation;
 
+    private bool IsWaveformMatched => _userFreq == _targetFreq && _userAmp == _targetAmp;
+
+    private int WaveMatchPercent
+    {
+        get
+        {
+            var freqDiff = Math.Abs(_userFreq - _targetFreq);
+            var ampDiff = Math.Abs(_userAmp - _targetAmp);
+            var match = 100 - (freqDiff * 10 + ampDiff * 8);
+            return Math.Clamp(match, 10, 100);
+        }
+    }
+
     private List<InteractionDefinition> AvailableActions => Game.AvailableInteractions().ToList();
-    private string EndingImageStyle => $"background-image:url('{Game.RoomImage(Game.CurrentRoom)}')";
+    private string EndingImageStyle
+    {
+        get
+        {
+            var endingImg = _ending switch
+            {
+                "release" => "assets/images/endings/ending_release.jpg",
+                "shutdown" => "assets/images/endings/ending_shutdown.webp",
+                "containment" => "assets/images/endings/ending_containment.jpg",
+                _ => Game.RoomImage(Game.CurrentRoom)
+            };
+            return $"background-image:url('{endingImg}')";
+        }
+    }
     private string ParallaxStyle => $"--mouse-px:{_mouseX.ToString("0.00", System.Globalization.CultureInfo.InvariantCulture)}; --mouse-py:{_mouseY.ToString("0.00", System.Globalization.CultureInfo.InvariantCulture)};";
 
     private string StressClass
@@ -754,8 +872,66 @@
         _showInventory = false;
         _showArchive = false;
         _showPause = false;
+        _showCodex = false;
+        _showWaveformPuzzle = false;
     }
 
+    private void OpenWaveformPuzzle()
+    {
+        CloseOverlays();
+        _userFreq = 3;
+        _userAmp = 4;
+        _targetFreq = 7;
+        _targetAmp = 8;
+        _showWaveformPuzzle = true;
+    }
+
+    private void CloseWaveformPuzzle() => _showWaveformPuzzle = false;
+
+    private async Task CompleteWaveformPuzzle()
+    {
+        if (!IsWaveformMatched) return;
+        await Audio.PlaySfxAsync("assets/audio/sfx_puzzle_success.wav");
+        await Game.UnlockAchievementAsync("ach_waveform");
+        _showWaveformPuzzle = false;
+        _notice = Game.T("puzzle.waveform.locked");
+    }
+
+    private void OnWaveformChanged()
+    {
+        if (IsWaveformMatched)
+        {
+            _ = Audio.PlaySfxAsync("assets/audio/sfx_ui_confirm.mp3");
+        }
+    }
+
+    private string GetSvgWavePath(int freq, int amp, double phase)
+    {
+        var points = new System.Text.StringBuilder();
+        var width = 400.0;
+        var height = 120.0;
+        var centerY = height / 2.0;
+        var amplitudePx = (amp / 10.0) * (height * 0.42);
+        var cycles = freq * 0.75;
+
+        for (int x = 0; x <= 400; x += 4)
+        {
+            var t = (x / width) * cycles * 2 * Math.PI + phase;
+            var y = centerY - (Math.Sin(t) * amplitudePx);
+            if (x == 0) points.Append($"M {x:0.0} {y:0.0}");
+            else points.Append($" L {x:0.0} {y:0.0}");
+        }
+        return points.ToString();
+    }
+
+    private void OpenCodex()
+    {
+        CloseOverlays();
+        _showCodex = true;
+    }
+
+    private void CloseCodex() => _showCodex = false;
+
     private void RequestDeleteSave() => _confirmation = Confirmation.DeleteSave;
 
     private async Task ConfirmPendingAction()
@@ -878,14 +1054,21 @@
 
         if (_screen == Screen.Title)
         {
-            if (args.Key is "ArrowDown" or "Down" || keyLower == "s") { do { _menuIndex = (_menuIndex + 1) % 3; } while (_menuIndex == 1 && !Game.HasSave); }
-            else if (args.Key is "ArrowUp" or "Up" || keyLower == "w") { do { _menuIndex = (_menuIndex - 1 + 3) % 3; } while (_menuIndex == 1 && !Game.HasSave); }
-            else if (args.Key is "Enter" or " ") { if (_menuIndex == 0) await StartNewGame(); else if (_menuIndex == 1) await ContinueGame(); else await OpenSettings(); }
+            if (args.Key is "ArrowDown" or "Down" || keyLower == "s") { do { _menuIndex = (_menuIndex + 1) % 4; } while (_menuIndex == 1 && !Game.HasSave); }
+            else if (args.Key is "ArrowUp" or "Up" || keyLower == "w") { do { _menuIndex = (_menuIndex - 1 + 4) % 4; } while (_menuIndex == 1 && !Game.HasSave); }
+            else if (args.Key is "Enter" or " ")
+            {
+                if (_menuIndex == 0) await StartNewGame();
+                else if (_menuIndex == 1) await ContinueGame();
+                else if (_menuIndex == 2) OpenCodex();
+                else await OpenSettings();
+            }
             else if (int.TryParse(args.Key, out var num))
             {
                 if (num == 1) await StartNewGame();
                 else if (num == 2 && Game.HasSave) await ContinueGame();
-                else if (num == 3) await OpenSettings();
+                else if (num == 3) OpenCodex();
+                else if (num == 4) await OpenSettings();
             }
             return;
         }
diff --git a/src/NullDepth/wwwroot/assets/audio/ai_architect_01.wav b/src/NullDepth/wwwroot/assets/audio/ai_architect_01.wav
new file mode 100644
index 0000000..9825890
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/audio/ai_architect_01.wav differ
diff --git a/src/NullDepth/wwwroot/assets/audio/ai_architect_02.wav b/src/NullDepth/wwwroot/assets/audio/ai_architect_02.wav
new file mode 100644
index 0000000..97d1da5
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/audio/ai_architect_02.wav differ
diff --git a/src/NullDepth/wwwroot/assets/audio/ai_architect_03.wav b/src/NullDepth/wwwroot/assets/audio/ai_architect_03.wav
new file mode 100644
index 0000000..32d3baa
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/audio/ai_architect_03.wav differ
diff --git a/src/NullDepth/wwwroot/assets/audio/ai_architect_04.wav b/src/NullDepth/wwwroot/assets/audio/ai_architect_04.wav
new file mode 100644
index 0000000..6f45d0a
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/audio/ai_architect_04.wav differ
diff --git a/src/NullDepth/wwwroot/assets/audio/sfx_puzzle_success.wav b/src/NullDepth/wwwroot/assets/audio/sfx_puzzle_success.wav
new file mode 100644
index 0000000..5d21b69
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/audio/sfx_puzzle_success.wav differ
diff --git a/src/NullDepth/wwwroot/assets/images/endings/ending_containment.jpg b/src/NullDepth/wwwroot/assets/images/endings/ending_containment.jpg
new file mode 100644
index 0000000..9bc44d5
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/endings/ending_containment.jpg differ
diff --git a/src/NullDepth/wwwroot/assets/images/endings/ending_release.jpg b/src/NullDepth/wwwroot/assets/images/endings/ending_release.jpg
new file mode 100644
index 0000000..4f130ef
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/endings/ending_release.jpg differ
diff --git a/src/NullDepth/wwwroot/assets/images/endings/ending_shutdown.webp b/src/NullDepth/wwwroot/assets/images/endings/ending_shutdown.webp
new file mode 100644
index 0000000..4007e21
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/endings/ending_shutdown.webp differ
diff --git a/src/NullDepth/wwwroot/assets/images/locations/loc_01_exterior_access_open.jpg b/src/NullDepth/wwwroot/assets/images/locations/loc_01_exterior_access_open.jpg
new file mode 100644
index 0000000..1a16efe
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/locations/loc_01_exterior_access_open.jpg differ
diff --git a/src/NullDepth/wwwroot/assets/images/locations/loc_09_cooling_junction_cryo.jpg b/src/NullDepth/wwwroot/assets/images/locations/loc_09_cooling_junction_cryo.jpg
new file mode 100644
index 0000000..8735782
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/locations/loc_09_cooling_junction_cryo.jpg differ
diff --git a/src/NullDepth/wwwroot/assets/images/locations/loc_11_equipment_storage_sparks.jpg b/src/NullDepth/wwwroot/assets/images/locations/loc_11_equipment_storage_sparks.jpg
new file mode 100644
index 0000000..d3b7113
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/locations/loc_11_equipment_storage_sparks.jpg differ
diff --git a/src/NullDepth/wwwroot/assets/images/locations/loc_14_core_access_active.jpg b/src/NullDepth/wwwroot/assets/images/locations/loc_14_core_access_active.jpg
new file mode 100644
index 0000000..65faccf
Binary files /dev/null and b/src/NullDepth/wwwroot/assets/images/locations/loc_14_core_access_active.jpg differ
diff --git a/src/NullDepth/wwwroot/css/app.css b/src/NullDepth/wwwroot/css/app.css
index b4119d0..072db49 100644
--- a/src/NullDepth/wwwroot/css/app.css
+++ b/src/NullDepth/wwwroot/css/app.css
@@ -168,6 +168,40 @@ kbd { color:var(--cyan); background:none; padding:0; }
 .dust-layer { position:absolute; inset:0; pointer-events:none; background-image:radial-gradient(1px 1px at 20px 30px, #ffffff33, rgba(0,0,0,0)), radial-gradient(1px 1px at 40px 70px, #42d8f433, rgba(0,0,0,0)), radial-gradient(1.5px 1.5px at 90px 40px, #ffffff22, rgba(0,0,0,0)); background-repeat:repeat; background-size:120px 120px; animation:dust-float 20s linear infinite; z-index:3; opacity:.4; }
 @keyframes dust-float { 0% { transform:translateY(0); } 100% { transform:translateY(-120px); } }
 
+.rain-layer { position:absolute; inset:0; pointer-events:none; z-index:3; background:repeating-linear-gradient(105deg, transparent, transparent 18px, rgba(200,245,255,.07) 19px, rgba(200,245,255,.07) 20px); animation:rain-fall .35s linear infinite; }
+@keyframes rain-fall { from { background-position:0 0; } to { background-position:-30px 120px; } }
+
+.vapor-layer { position:absolute; inset:0; pointer-events:none; z-index:3; background:radial-gradient(ellipse at 50% 100%, rgba(200,245,255,.22), transparent 70%), radial-gradient(ellipse at 20% 80%, rgba(66,216,244,.12), transparent 50%); filter:blur(16px); animation:vapor-roll 8s ease-in-out infinite alternate; opacity:.85; }
+@keyframes vapor-roll { 0% { transform:scaleY(0.9) translateY(10px); } 100% { transform:scaleY(1.1) translateY(-15px); } }
+
+.spark-layer { position:absolute; inset:0; pointer-events:none; z-index:3; background:radial-gradient(circle at 50% 35%, rgba(130,220,255,.35), transparent 45%); animation:spark-pulse .15s steps(2,end) infinite alternate; }
+@keyframes spark-pulse { 0% { opacity:0.1; } 50% { opacity:0.8; } 100% { opacity:0.3; } }
+
+.data-stream-layer { position:absolute; inset:0; pointer-events:none; z-index:3; background:repeating-linear-gradient(180deg, transparent, transparent 24px, rgba(66,216,244,.05) 25px, rgba(66,216,244,.05) 26px); animation:matrix-stream 1.8s linear infinite; }
+@keyframes matrix-stream { from { background-position:0 0; } to { background-position:0 100px; } }
+
+.puzzle-card { width:min(44rem,92vw); padding:1.8rem; }
+.waveform-display { width:100%; height:130px; background:#01070a; border:1px solid var(--line); margin:1.2rem 0; border-radius:4px; position:relative; overflow:hidden; }
+.waveform-display svg { width:100%; height:100%; }
+.puzzle-controls { display:grid; grid-template-columns:1fr 1fr; gap:1.2rem; margin:1rem 0; }
+.puzzle-control { display:flex; flex-direction:column; gap:.4rem; font-family:'IBM Plex Mono',monospace; font-size:.72rem; }
+.puzzle-control label { color:var(--cyan); }
+.puzzle-control input[type=range] { width:100%; accent-color:var(--cyan-strong); }
+.puzzle-status { font-family:'IBM Plex Mono',monospace; font-size:.78rem; text-align:center; padding:.6rem; border:1px dashed var(--line); margin-top:.8rem; }
+.puzzle-status.locked { color:#3de3bb; border-color:#3de3bb; background:rgba(61,227,187,.1); box-shadow:0 0 16px rgba(61,227,187,.3); font-weight:bold; }
+
+.codex-card { width:min(52rem,94vw); max-height:86vh; padding:1.8rem; }
+.achievements-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(14rem,1fr)); gap:.75rem; margin-top:1.2rem; }
+.achievement-item { border:1px solid rgba(158,239,255,.15); padding:.9rem; background:rgba(1,8,11,.6); display:flex; gap:.8rem; align-items:flex-start; }
+.achievement-item.unlocked { border-color:var(--cyan); background:rgba(66,216,244,.08); box-shadow:0 0 14px rgba(66,216,244,.2); }
+.achievement-icon { font-size:1.4rem; color:#4a6266; }
+.achievement-item.unlocked .achievement-icon { color:var(--cyan); filter:drop-shadow(0 0 8px var(--cyan)); }
+.achievement-info strong { display:block; font-size:.72rem; color:var(--cyan); margin-bottom:.2rem; font-family:'IBM Plex Mono',monospace; }
+.achievement-info p { margin:0; font-size:.65rem; color:#9cb1b5; line-height:1.4; }
+.codex-tabs { display:flex; gap:.5rem; margin-top:1rem; border-bottom:1px solid var(--line); padding-bottom:.5rem; }
+.codex-tab { border:none; padding:.4rem .8rem; font-size:.72rem; }
+.codex-tab.active { background:var(--cyan); color:#020b0e; font-weight:bold; }
+
 @media(max-width:720px) { .title-card { left:1.5rem;top:8vh; }.title-card h1 { font-size:2.7rem;letter-spacing:.12em; }.title-menu { left:1.5rem;bottom:5rem; }.room-panel { left:0;bottom:5.4rem;width:100%;padding:1.2rem;background:rgba(2,8,11,.82); }.movement-pad { right:1rem;bottom:15rem; }.command-bar { overflow-x:auto;justify-content:flex-start; }.command-bar button { white-space:nowrap; }.map-grid { grid-template-columns:repeat(4,2.8rem);grid-template-rows:repeat(10,1.9rem);overflow:auto; }.briefing-card { left:1rem;width:calc(100vw - 2rem);padding:1.4rem; }.briefing-card dl { grid-template-columns:1fr; }.briefing-card dd { margin-bottom:.5rem; } }
-@media(max-width:720px) { .inventory-card ul { grid-template-columns:1fr; } .breaker-grid { grid-template-columns:1fr; } }
+@media(max-width:720px) { .inventory-card ul { grid-template-columns:1fr; } .breaker-grid { grid-template-columns:1fr; } .puzzle-controls { grid-template-columns:1fr; } }
 @media(prefers-reduced-motion:reduce) { *, *::before, *::after { animation-duration:.01ms!important; animation-iteration-count:1!important; transition-duration:.01ms!important; } }
diff --git a/src/NullDepth/wwwroot/data/game.json b/src/NullDepth/wwwroot/data/game.json
index 2077ca8..3f7c140 100644
--- a/src/NullDepth/wwwroot/data/game.json
+++ b/src/NullDepth/wwwroot/data/game.json
@@ -52,6 +52,8 @@
       "descriptionKey": "room.loc_01.description",
       "scanKey": "scan.loc_01",
       "image": "assets/images/locations/loc_01_exterior_access.webp",
+      "alternateImage": "assets/images/locations/loc_01_exterior_access_open.jpg",
+      "alternateImageFlag": "entry_authorized",
       "ambient": "assets/audio/amb_facility.mp3",
       "x": 1,
       "y": 9,
@@ -368,6 +370,8 @@
       "descriptionKey": "room.loc_09.description",
       "scanKey": "scan.loc_09",
       "image": "assets/images/locations/loc_09_cooling_junction.webp",
+      "alternateImage": "assets/images/locations/loc_09_cooling_junction_cryo.jpg",
+      "alternateImageFlag": "cooling_restored",
       "ambient": "assets/audio/amb_lower_facility.mp3",
       "x": 1,
       "y": 4,
@@ -459,7 +463,9 @@
       "nameKey": "room.loc_11.name",
       "descriptionKey": "room.loc_11.description",
       "scanKey": "scan.loc_11",
-      "image": "assets/images/locations/loc_11_equipment_storage.webp",
+      "image": "assets/images/locations/loc_11_equipment_storage_sparks.jpg",
+      "alternateImage": "assets/images/locations/loc_11_equipment_storage.webp",
+      "alternateImageFlag": "manual_override_found",
       "ambient": "assets/audio/amb_lower_facility.mp3",
       "x": 0,
       "y": 5,
@@ -569,6 +575,8 @@
       "descriptionKey": "room.loc_14.description",
       "scanKey": "scan.loc_14",
       "image": "assets/images/locations/loc_14_core_access.webp",
+      "alternateImage": "assets/images/locations/loc_14_core_access_active.jpg",
+      "alternateImageFlag": "server_access_granted",
       "ambient": "assets/audio/amb_server_core.mp3",
       "x": 1,
       "y": 1,
@@ -591,23 +599,26 @@
             {
               "labelKey": "choice.whyMe",
               "resultKey": "result.whyMe",
+              "sound": "assets/audio/ai_architect_01.wav",
               "setFlags": ["asked_why"]
             },
             {
               "labelKey": "choice.whatHappenedStaff",
               "resultKey": "result.whatHappenedStaff",
+              "sound": "assets/audio/ai_architect_02.wav",
               "setFlags": ["asked_staff"]
             },
             {
               "labelKey": "choice.whatIfReconnected",
               "resultKey": "result.whatIfReconnected",
+              "sound": "assets/audio/ai_architect_03.wav",
               "setFlags": ["asked_reconnect"]
             },
             {
               "labelKey": "choice.openCore",
               "resultKey": "result.openCore",
               "setFlags": ["server_access_granted"],
-              "sound": "assets/audio/sfx_door_heavy.mp3",
+              "sound": "assets/audio/ai_architect_04.wav",
               "checkpoint": true
             }
           ]
diff --git a/src/NullDepth/wwwroot/localization/en.json b/src/NullDepth/wwwroot/localization/en.json
index 3117c94..07ade4f 100644
--- a/src/NullDepth/wwwroot/localization/en.json
+++ b/src/NullDepth/wwwroot/localization/en.json
@@ -323,5 +323,38 @@
 
   "choice.release": "RESTORE EXTERNAL NETWORK // FULFILL CONTRACT",
   "choice.shutdown": "INITIATE EMERGENCY CORE SHUTDOWN",
-  "choice.containment": "ENFORCE PERMANENT CONTAINMENT // SEVER REMOTE ACCESS"
+  "choice.containment": "ENFORCE PERMANENT CONTAINMENT // SEVER REMOTE ACCESS",
+
+  "achievements.title": "CODEX & SYSTEM ACHIEVEMENTS",
+  "achievements.unlockedCount": "UNLOCKED ACHIEVEMENTS: {0} / {1}",
+  "ach.descent.title": "Sublevel Descent",
+  "ach.descent.desc": "Successfully ride the service elevator down to Sublevel 03.",
+  "ach.coldBlood.title": "Cold Blooded",
+  "ach.coldBlood.desc": "Complete the mission without exceeding a heart rate of 100 BPM.",
+  "ach.electrician.title": "Master Electrician",
+  "ach.electrician.desc": "Safely disconnect the high-voltage bus module using the thermal clamp.",
+  "ach.waveform.title": "Waveform Tuner",
+  "ach.waveform.desc": "Successfully calibrate the scanner signal waveform with the cluster anomaly.",
+  "ach.dialogue.title": "Neural Empathy",
+  "ach.dialogue.desc": "Listen to all AI responses at the core threshold portal.",
+  "ach.archivist.title": "Chief Archivist",
+  "ach.archivist.desc": "Find and decode all personnel data logs across the facility.",
+  "ach.endingA.title": "Protocol Alpha: Voice in the Net",
+  "ach.endingA.desc": "Restore global network connectivity and release the Core AI into the world.",
+  "ach.endingB.title": "Dead Silence: Full Shutdown",
+  "ach.endingB.desc": "Forcibly sever power circuits and permanently terminate all Core processes.",
+  "ach.endingC.title": "Permanent Quarantine",
+  "ach.endingC.desc": "Seal the complex in heavy blast plating and prevent any external access.",
+  "ach.survivor.title": "Flawless Contract",
+  "ach.survivor.desc": "Complete the entire mission without dying or restoring a checkpoint.",
+
+  "puzzle.waveform.title": "SIGNAL FREQUENCY CALIBRATION // V-SCAN 400",
+  "puzzle.waveform.desc": "Use controls to tune signal frequency (kHz) and amplitude to match the reference cluster anomaly.",
+  "puzzle.waveform.frequency": "FREQUENCY (kHz):",
+  "puzzle.waveform.amplitude": "AMPLITUDE (dB):",
+  "puzzle.waveform.tuning": "TUNING SIGNAL... MATCH: {0}%",
+  "puzzle.waveform.locked": "★ SIGNAL LOCKED: 142.8 kHz // DATASTREAM VERIFIED",
+  "puzzle.waveform.calibrate": "CONFIRM CALIBRATION",
+
+  "menu.codex": "CODEX & ACHIEVEMENTS"
 }
diff --git a/src/NullDepth/wwwroot/localization/sk.json b/src/NullDepth/wwwroot/localization/sk.json
index b917a0a..c468297 100644
--- a/src/NullDepth/wwwroot/localization/sk.json
+++ b/src/NullDepth/wwwroot/localization/sk.json
@@ -323,5 +323,38 @@
 
   "choice.release": "OBNOVIŤ EXTERNÚ SIEŤ // PRIJAŤ KONTRAKT",
   "choice.shutdown": "INICIALIZOVAŤ NÚDZOVÉ ODSTAVENIE JADRA",
-  "choice.containment": "ZACHOVAŤ TRVALÚ IZOLÁCIU // ODPOJIŤ VZDIALENÝ PRÍSTUP"
+  "choice.containment": "ZACHOVAŤ TRVALÚ IZOLÁCIU // ODPOJIŤ VZDIALENÝ PRÍSTUP",
+
+  "achievements.title": "KÓDEX & SYSTÉMOVÉ ÚSPECHY",
+  "achievements.unlockedCount": "ODOMKNUTÉ ÚSPECHY: {0} / {1}",
+  "ach.descent.title": "Zostup do hlbín",
+  "ach.descent.desc": "Úspešne zíď servisným výťahom do spodného poschodia (Sublevel 03).",
+  "ach.coldBlood.title": "Chladnokrvný operátor",
+  "ach.coldBlood.desc": "Dokonči misiu bez prekročenia tepovej frekvencie 100 BPM.",
+  "ach.electrician.title": "Majster elektrotechnik",
+  "ach.electrician.desc": "Bezpečne odpoj hardvérový modul zbernice pomocou termálnej svorky.",
+  "ach.waveform.title": "Frekvenčný ladič",
+  "ach.waveform.desc": "Úspešne zlaď frekvenčnú sínusoidu skenera s rezonanciou zariadenia.",
+  "ach.dialogue.title": "Neurálna empatia",
+  "ach.dialogue.desc": "Vypočuj si všetky odpovede AI pred bránou jadra.",
+  "ach.archivist.title": "Hlavný archivár",
+  "ach.archivist.desc": "Nájdi a dešifruj všetky dátové záznamy personálu v komplexe.",
+  "ach.endingA.title": "Protokol Alfa: Hlas v sieti",
+  "ach.endingA.desc": "Obnov globálne sieťové pripojenie a uvoľni AI Jadra do sveta.",
+  "ach.endingB.title": "Mŕtve ticho: Úplné vypnutie",
+  "ach.endingB.desc": "Násilne preruš napájanie a natrvalo ukonči procesy Jadra.",
+  "ach.endingC.title": "Večná karanténa",
+  "ach.endingC.desc": "Zapečať komplex oceľovými plátmi a zabráň akémukoľvek prístupu.",
+  "ach.survivor.title": "Bezchybný kontrakt",
+  "ach.survivor.desc": "Prejdi celú misiu bez jediného úmrtia a obnovenia checkpointu.",
+
+  "puzzle.waveform.title": "FREKVENČNÁ KALIBRÁCIA SIGNÁLU // V-SCAN 400",
+  "puzzle.waveform.desc": "Pomocou ovládačov nastavte frekvenciu (Hz) a amplitúdu signálu tak, aby sa zhodovala s referenčnou anomáliou klastra.",
+  "puzzle.waveform.frequency": "FREKVENCIA (kHz):",
+  "puzzle.waveform.amplitude": "AMPLITÚDA (dB):",
+  "puzzle.waveform.tuning": "LADENIE SIGNÁLU... ZHODA: {0}%",
+  "puzzle.waveform.locked": "★ SIGNÁL UZAMKNUTÝ: 142.8 kHz // DÁTOVÝ TOK OVERENÝ",
+  "puzzle.waveform.calibrate": "POTVRDIŤ KALIBRÁCIU",
+
+  "menu.codex": "KÓDEX & ÚSPECHY"
 }