diff --git a/htdocs/app/Http/Controllers/BiorepositoryController.php b/htdocs/app/Http/Controllers/BiorepositoryController.php
index 09b3e81c..da1fdde2 100644
--- a/htdocs/app/Http/Controllers/BiorepositoryController.php
+++ b/htdocs/app/Http/Controllers/BiorepositoryController.php
@@ -30,7 +30,7 @@ class BiorepositoryController extends Controller
 
         $data['cabinets'] = BioCabinet::with([
             'racks' => function ($query) {
-                $query->orderBy('level', 'ASC')->orderBy('rack_number', 'ASC');
+                $query->orderBy('rack_number', 'ASC')->orderBy('code', 'ASC');
             },
             'racks.specimens' => function ($query) {
                 $query->orderBy('stored_at', 'ASC');
@@ -79,10 +79,8 @@ class BiorepositoryController extends Controller
             'cabinet_id' => 'required|exists:bio_cabinets,id',
             'code' => 'required|max:50',
             'name' => 'required|max:150',
-            'level' => 'required|integer|min:1',
-            'rack_number' => 'required|integer|min:1',
-            'box_number' => 'required|integer|min:1',
-            'capacity' => 'required|integer|min:1',
+            'level' => 'required|integer|min:4|max:6',
+            'capacity' => 'required|integer|min:16|max:20',
             'notes' => 'nullable',
         ]);
 
@@ -98,13 +96,15 @@ class BiorepositoryController extends Controller
             return back()->withErrors(['code' => 'Kode rack sudah dipakai pada lemari ini.'])->withInput();
         }
 
+        $nextRackNumber = ((int) BioRack::where('cabinet_id', $request->input('cabinet_id'))->max('rack_number')) + 1;
+
         BioRack::create([
             'cabinet_id' => $request->input('cabinet_id'),
             'code' => $request->input('code'),
             'name' => $request->input('name'),
             'level' => $request->input('level'),
-            'rack_number' => $request->input('rack_number'),
-            'box_number' => $request->input('box_number'),
+            'rack_number' => $nextRackNumber,
+            'box_number' => 1,
             'capacity' => $request->input('capacity'),
             'notes' => $request->input('notes'),
         ]);
@@ -135,22 +135,26 @@ class BiorepositoryController extends Controller
         $expectedRackNo = $rack->rack_number ?: $rack->id;
         $expectedBoxNo = $rack->box_number ?: 1;
 
-        if ((int) $request->input('shelfnomor') !== (int) $rack->level ||
-            (int) $request->input('raknomor') !== (int) $expectedRackNo ||
+        if ((int) $request->input('raknomor') !== (int) $expectedRackNo ||
             (int) $request->input('boxnomor') !== (int) $expectedBoxNo) {
             return back()->withErrors(['slotnomor' => 'Posisi slot tidak sesuai dengan konfigurasi rack.'])->withInput();
         }
 
-        if ((int) $request->input('slotnomor') > (int) $rack->capacity) {
-            return back()->withErrors(['slotnomor' => 'Slot melebihi kapasitas rack.'])->withInput();
+        if ((int) $request->input('shelfnomor') < 1 || (int) $request->input('shelfnomor') > (int) $rack->level) {
+            return back()->withErrors(['shelfnomor' => 'Shelf melebihi konfigurasi rack.'])->withInput();
+        }
+
+        if ((int) $request->input('tubenomor') < 1 || (int) $request->input('tubenomor') > (int) $rack->capacity) {
+            return back()->withErrors(['tubenomor' => 'Nomor tube melebihi kapasitas box pada shelf ini.'])->withInput();
         }
 
         $slotTaken = BioSpecimen::where('rack_id', $rack->id)
-            ->where('slot_number', $request->input('slotnomor'))
+            ->where('shelf_number', $request->input('shelfnomor'))
+            ->where('tube_number', $request->input('tubenomor'))
             ->exists();
 
         if ($slotTaken) {
-            return back()->withErrors(['slotnomor' => 'Slot ini sudah terisi spesimen.'])->withInput();
+            return back()->withErrors(['tubenomor' => 'Posisi tube pada shelf ini sudah terisi spesimen.'])->withInput();
         }
 
         $atccByUser = strtoupper(preg_replace('/[^A-Za-z0-9]/', '', Session::get('nama', 'UNKNOWN')));
@@ -182,7 +186,7 @@ class BiorepositoryController extends Controller
             'category_storage' => $request->input('kategorisimpan'),
             'shelf_number' => $request->input('shelfnomor'),
             'rack_number' => $request->input('raknomor'),
-            'slot_number' => $request->input('slotnomor'),
+            'slot_number' => $request->input('shelfnomor'),
             'box_number' => $request->input('boxnomor'),
             'tube_number' => $request->input('tubenomor'),
             'bacteria_name' => $request->input('nmbakteri'),
diff --git a/htdocs/resources/views/admin/biorepository.blade.php b/htdocs/resources/views/admin/biorepository.blade.php
index 8d7bbcd1..c720787c 100644
--- a/htdocs/resources/views/admin/biorepository.blade.php
+++ b/htdocs/resources/views/admin/biorepository.blade.php
@@ -34,6 +34,19 @@
         gap: 6px;
         margin-top: 10px;
     }
+    .shelf-section {
+        border: 1px dashed #bfd3e8;
+        border-radius: 8px;
+        padding: 8px;
+        margin-top: 8px;
+        background: #fbfdff;
+    }
+    .tube-grid {
+        display: grid;
+        grid-template-columns: repeat(10, minmax(24px, 1fr));
+        gap: 5px;
+        margin-top: 8px;
+    }
     .slot-btn {
         border: 1px solid #bfd3e8;
         background: #f4f9ff;
@@ -150,8 +163,8 @@
                         <div class="alert alert-warning m-b-20">Belum ada data spesimen.</div>
                     @endif
 
-                    <h4 class="m-b-20">Visualisasi Lemari, Rack, dan Slot</h4>
-                    <p class="text-muted">Klik slot berwarna biru untuk mengisi spesimen. Slot merah artinya sudah terisi.</p>
+                    <h4 class="m-b-20">Visualisasi Lemari, Rack, Shelf, Box, dan Tube</h4>
+                    <p class="text-muted">Klik nomor tube berwarna biru untuk mengisi spesimen. Tube merah artinya sudah terisi.</p>
 
                     @forelse($cabinets as $cabinet)
                         <div class="cabinet-visual">
@@ -159,39 +172,47 @@
                             <div class="rack-grid">
                                 @forelse($cabinet->racks as $rack)
                                     @php
-                                        $slotMap = [];
+                                        $tubeMap = [];
                                         foreach ($rack->specimens as $item) {
-                                            if ($item->slot_number) {
-                                                $slotMap[$item->slot_number] = $item;
+                                            if ($item->shelf_number && $item->tube_number) {
+                                                $tubeMap[$item->shelf_number.'-'.$item->tube_number] = $item;
                                             }
                                         }
-                                        $capacity = (int) $rack->capacity;
+                                        $shelfCount = (int) $rack->level;
+                                        $tubeCapacity = (int) $rack->capacity;
                                     @endphp
                                     <div class="rack-box">
                                         <div class="rack-header">{{ $rack->code }} - {{ $rack->name }}</div>
-                                        <div style="font-size:12px;">Shelf {{ $rack->level }} | Rack {{ $rack->rack_number ?? $rack->id }} | Box {{ $rack->box_number ?? 1 }}</div>
-                                        <div style="font-size:12px;">Slot: {{ $capacity }} | Terisi: {{ $rack->specimens->count() }}</div>
+                                        <div style="font-size:12px;">Rack No {{ $rack->rack_number ?? $rack->id }} | Total Shelf {{ $shelfCount }} | 1 Box per Shelf | Tube per Box {{ $tubeCapacity }}</div>
+                                        <div style="font-size:12px;">Terisi: {{ $rack->specimens->count() }}</div>
 
-                                        @if($capacity > 0)
-                                            <div class="slot-grid">
-                                                @for($i = 1; $i <= $capacity; $i++)
-                                                    @if(isset($slotMap[$i]))
-                                                        <div class="slot-btn slot-filled" title="{{ $slotMap[$i]->specimen_code }} - {{ $slotMap[$i]->bacteria_name ?? $slotMap[$i]->specimen_name }}">{{ $i }}</div>
-                                                    @else
-                                                        <button type="button"
-                                                            class="slot-btn js-slot"
-                                                            data-rack-id="{{ $rack->id }}"
-                                                            data-shelf="{{ $rack->level }}"
-                                                            data-rackno="{{ $rack->rack_number ?? $rack->id }}"
-                                                            data-slot="{{ $i }}"
-                                                            data-box="{{ $rack->box_number ?? 1 }}">
-                                                            {{ $i }}
-                                                        </button>
-                                                    @endif
-                                                @endfor
-                                            </div>
+                                        @if($shelfCount > 0 && $tubeCapacity > 0)
+                                            @for($shelf = 1; $shelf <= $shelfCount; $shelf++)
+                                                <div class="shelf-section">
+                                                    <div style="font-size:12px;"><b>Shelf {{ $shelf }}</b> - Box 1 (Tube 1-{{ $tubeCapacity }})</div>
+                                                    <div class="tube-grid">
+                                                        @for($tube = 1; $tube <= $tubeCapacity; $tube++)
+                                                            @php $tubeKey = $shelf.'-'.$tube; @endphp
+                                                            @if(isset($tubeMap[$tubeKey]))
+                                                                <div class="slot-btn slot-filled" title="{{ $tubeMap[$tubeKey]->specimen_code }} - {{ $tubeMap[$tubeKey]->bacteria_name ?? $tubeMap[$tubeKey]->specimen_name }}">{{ $tube }}</div>
+                                                            @else
+                                                                <button type="button"
+                                                                    class="slot-btn js-slot"
+                                                                    data-rack-id="{{ $rack->id }}"
+                                                                    data-shelf="{{ $shelf }}"
+                                                                    data-rackno="{{ $rack->rack_number ?? $rack->id }}"
+                                                                    data-slot="{{ $shelf }}"
+                                                                    data-box="1"
+                                                                    data-tube="{{ $tube }}">
+                                                                    {{ $tube }}
+                                                                </button>
+                                                            @endif
+                                                        @endfor
+                                                    </div>
+                                                </div>
+                                            @endfor
                                         @else
-                                            <div class="alert alert-light m-b-0 m-t-10">Kapasitas slot belum diatur.</div>
+                                            <div class="alert alert-light m-b-0 m-t-10">Konfigurasi rack belum lengkap.</div>
                                         @endif
                                     </div>
                                 @empty
@@ -343,23 +364,16 @@
                         </div>
                     </div>
                     <div class="form-row">
-                        <div class="form-group col-md-3">
-                            <label>Shelf</label>
-                            <input type="number" name="level" class="form-control" min="1" value="1" required>
+                        <div class="form-group col-md-6">
+                            <label>Jumlah Shelf per Rack (4-6)</label>
+                            <input type="number" name="level" class="form-control" min="4" max="6" value="4" required>
                         </div>
-                        <div class="form-group col-md-3">
-                            <label>Rack No</label>
-                            <input type="number" name="rack_number" class="form-control" min="1" value="1" required>
-                        </div>
-                        <div class="form-group col-md-3">
-                            <label>Box No</label>
-                            <input type="number" name="box_number" class="form-control" min="1" value="1" required>
-                        </div>
-                        <div class="form-group col-md-3">
-                            <label>Jumlah Slot</label>
-                            <input type="number" name="capacity" class="form-control" min="1" value="24" required>
+                        <div class="form-group col-md-6">
+                            <label>Tube per Box (16-20)</label>
+                            <input type="number" name="capacity" class="form-control" min="16" max="20" value="16" required>
                         </div>
                     </div>
+                    <small class="text-muted">Rack number dibuat otomatis oleh sistem. Struktur: 1 rack memiliki 4-6 shelf, setiap shelf memiliki 1 box, setiap box 16-20 tube.</small>
                 </div>
                 <div class="modal-footer">
                     <button type="button" class="btn btn-secondary" data-dismiss="modal">Batal</button>
@@ -404,16 +418,16 @@
                             <input type="number" class="form-control" id="raknomor" name="raknomor" readonly>
                         </div>
                         <div class="col-lg-4">
-                            <label>Slot Number</label>
+                            <label>Slot Number (Sama dengan Shelf)</label>
                             <input type="number" class="form-control" id="slotnomor" name="slotnomor" readonly>
                         </div>
                         <div class="col-lg-4">
-                            <label>Box Number</label>
+                            <label>Box Number (1 per Shelf)</label>
                             <input type="number" class="form-control" id="boxnomor" name="boxnomor" readonly>
                         </div>
                         <div class="col-lg-4">
                             <label>Tube Number</label>
-                            <input type="number" class="form-control" id="tubenomor" name="tubenomor" required>
+                            <input type="number" class="form-control" id="tubenomor" name="tubenomor" readonly required>
                         </div>
                         <div class="col-lg-4">
                             <label>Tanggal Simpan</label>
@@ -474,7 +488,7 @@
         $('#raknomor').val($(this).data('rackno'));
         $('#slotnomor').val($(this).data('slot'));
         $('#boxnomor').val($(this).data('box'));
-        $('#tubenomor').val('');
+        $('#tubenomor').val($(this).data('tube'));
         buildSampleCodePreview();
         $('#modalIsiSlot').modal('show');
     });