diff --git a/src/lib/components/Sidebar.svelte b/src/lib/components/Sidebar.svelte
new file mode 100644
index 0000000..fb1c74b
--- /dev/null
+++ b/src/lib/components/Sidebar.svelte
@@ -0,0 +1,428 @@
+<script>
+  import {
+    LayoutDashboard,
+    Database,
+    FileText,
+    Printer,
+    Users,
+    ClipboardList,
+    FlaskConical,
+    CheckCircle2,
+    Building2,
+    UserCircle,
+    LogOut,
+    List,
+    MapPin,
+    Stethoscope,
+    Briefcase,
+    Hash,
+    Globe,
+    ChevronDown
+  } from 'lucide-svelte';
+  import { auth } from '$lib/stores/auth.js';
+  import { goto } from '$app/navigation';
+  import { browser } from '$app/environment';
+
+  let { isOpen = $bindable(false) } = $props();
+
+  // Collapsible section states - default collapsed
+  let masterDataExpanded = $state(false);
+  let laboratoryExpanded = $state(false);
+  let administrationExpanded = $state(false);
+
+  // Load states from localStorage on mount
+  $effect(() => {
+    if (browser) {
+      const savedStates = localStorage.getItem('sidebar_section_states');
+      if (savedStates) {
+        try {
+          const parsed = JSON.parse(savedStates);
+          masterDataExpanded = parsed.masterData ?? false;
+          laboratoryExpanded = parsed.laboratory ?? false;
+          administrationExpanded = parsed.administration ?? false;
+        } catch (e) {
+          // Keep defaults if parsing fails
+        }
+      }
+    }
+  });
+
+  // Save states to localStorage when they change
+  $effect(() => {
+    if (browser) {
+      localStorage.setItem('sidebar_section_states', JSON.stringify({
+        masterData: masterDataExpanded,
+        laboratory: laboratoryExpanded,
+        administration: administrationExpanded
+      }));
+    }
+  });
+
+  // Close all sections when sidebar collapses
+  $effect(() => {
+    if (!isOpen) {
+      masterDataExpanded = false;
+      laboratoryExpanded = false;
+      administrationExpanded = false;
+    }
+  });
+
+  function handleLogout() {
+    auth.logout();
+    goto('/login');
+  }
+
+  function toggleMasterData() {
+    masterDataExpanded = !masterDataExpanded;
+  }
+
+  function toggleLaboratory() {
+    laboratoryExpanded = !laboratoryExpanded;
+  }
+
+  function toggleAdministration() {
+    administrationExpanded = !administrationExpanded;
+  }
+</script>
+
+<!-- Sidebar -->
+<div 
+  class="sidebar-container fixed lg:sticky left-0 top-0 h-screen max-h-screen z-40 bg-base-200 shadow-xl border-r border-base-300 transition-all duration-300 ease-out"
+  class:sidebar-expanded={isOpen}
+  class:sidebar-collapsed={!isOpen}
+>
+  <div class="h-screen overflow-y-auto flex flex-col sidebar-content" class:expanded={isOpen} class:collapsed={!isOpen}>
+    <div class="p-3">
+      <!-- Navigation Menu -->
+      <ul class="menu w-full gap-1" class:menu-collapsed={!isOpen}>
+        {#if isOpen}
+          <li class="menu-title uppercase font-bold text-xs text-emerald-600/70 mt-2">Main</li>
+        {/if}
+        <li>
+          <a 
+            href="/dashboard" 
+            class="menu-item text-gray-700 hover:bg-emerald-50 hover:text-emerald-700"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Dashboard' : ''}
+          >
+            <LayoutDashboard class="w-5 h-5 text-emerald-600 flex-shrink-0" />
+            {#if isOpen}
+              <span class="menu-text whitespace-nowrap overflow-hidden">Dashboard</span>
+            {/if}
+          </a>
+        </li>
+        <li class="collapsible-section">
+          <button 
+            onclick={toggleMasterData}
+            class="menu-item text-gray-700 hover:bg-emerald-50 hover:text-emerald-700 w-full text-left justify-between"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Master Data' : ''}
+          >
+            <div class="flex items-center gap-2">
+              <Database class="w-5 h-5 text-emerald-600 flex-shrink-0" />
+              {#if isOpen}
+                <span class="menu-text whitespace-nowrap overflow-hidden">Master Data</span>
+              {/if}
+            </div>
+            {#if isOpen}
+              <ChevronDown class="w-4 h-4 flex-shrink-0 transition-transform duration-200 {masterDataExpanded ? 'rotate-180' : ''}" />
+            {/if}
+          </button>
+          {#if isOpen && masterDataExpanded}
+            <ul class="ml-6 mt-1 space-y-1 collapsible-content">
+              <li>
+                <a 
+                  href="/master-data/valuesets" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <List class="w-4 h-4 flex-shrink-0" />
+                  <span>ValueSets</span>
+                </a>
+              </li>
+              <li>
+                <a 
+                  href="/master-data/locations" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <MapPin class="w-4 h-4 flex-shrink-0" />
+                  <span>Locations</span>
+                </a>
+              </li>
+              <li>
+                <a
+                  href="/master-data/contacts"
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Users class="w-4 h-4 flex-shrink-0" />
+                  <span>Contacts</span>
+                </a>
+              </li>
+              <li>
+                <a
+                  href="/master-data/specialties"
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Stethoscope class="w-4 h-4 flex-shrink-0" />
+                  <span>Specialties</span>
+                </a>
+              </li>
+              <li>
+                <a
+                  href="/master-data/occupations"
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Briefcase class="w-4 h-4 flex-shrink-0" />
+                  <span>Occupations</span>
+                </a>
+              </li>
+              <li>
+                <a
+                  href="/master-data/counters"
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Hash class="w-4 h-4 flex-shrink-0" />
+                  <span>Counters</span>
+                </a>
+              </li>
+              <li>
+                <a
+                  href="/master-data/geography"
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Globe class="w-4 h-4 flex-shrink-0" />
+                  <span>Geography</span>
+                </a>
+              </li>
+            </ul>
+          {/if}
+        </li>
+        <li>
+          <a 
+            href="/result-entry"
+            class="menu-item text-gray-700 hover:bg-emerald-50 hover:text-emerald-700"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Result Entry' : ''}
+          >
+            <FileText class="w-5 h-5 text-emerald-600 flex-shrink-0" />
+            {#if isOpen}
+              <span class="menu-text whitespace-nowrap overflow-hidden">Result Entry</span>
+            {/if}
+          </a>
+        </li>
+        <li>
+          <a 
+            href="/reports" 
+            class="menu-item text-gray-700 hover:bg-emerald-50 hover:text-emerald-700"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Reports' : ''}
+          >
+            <Printer class="w-5 h-5 text-emerald-600 flex-shrink-0" />
+            {#if isOpen}
+              <span class="menu-text whitespace-nowrap overflow-hidden">Reports</span>
+            {/if}
+          </a>
+        </li>
+
+        <li class="collapsible-section">
+          <button 
+            onclick={toggleLaboratory}
+            class="menu-item text-gray-700 hover:bg-emerald-50 hover:text-emerald-700 w-full text-left justify-between"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Laboratory' : ''}
+          >
+            <div class="flex items-center gap-2">
+              <FlaskConical class="w-5 h-5 text-emerald-600 flex-shrink-0" />
+              {#if isOpen}
+                <span class="menu-text whitespace-nowrap overflow-hidden">Laboratory</span>
+              {/if}
+            </div>
+            {#if isOpen}
+              <ChevronDown class="w-4 h-4 flex-shrink-0 transition-transform duration-200 {laboratoryExpanded ? 'rotate-180' : ''}" />
+            {/if}
+          </button>
+          {#if isOpen && laboratoryExpanded}
+            <ul class="ml-6 mt-1 space-y-1 collapsible-content">
+              <li>
+                <a 
+                  href="/patients" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Users class="w-4 h-4 flex-shrink-0" />
+                  <span>Patients</span>
+                </a>
+              </li>
+              <li>
+                <a 
+                  href="/orders" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <ClipboardList class="w-4 h-4 flex-shrink-0" />
+                  <span>Orders</span>
+                </a>
+              </li>
+              <li>
+                <a 
+                  href="/specimens" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <FlaskConical class="w-4 h-4 flex-shrink-0" />
+                  <span>Specimens</span>
+                </a>
+              </li>
+              <li>
+                <a 
+                  href="/results" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <CheckCircle2 class="w-4 h-4 flex-shrink-0" />
+                  <span>Results</span>
+                </a>
+              </li>
+            </ul>
+          {/if}
+        </li>
+
+        <li class="collapsible-section">
+          <button 
+            onclick={toggleAdministration}
+            class="menu-item text-gray-700 hover:bg-emerald-50 hover:text-emerald-700 w-full text-left justify-between"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Administration' : ''}
+          >
+            <div class="flex items-center gap-2">
+              <Building2 class="w-5 h-5 text-emerald-600 flex-shrink-0" />
+              {#if isOpen}
+                <span class="menu-text whitespace-nowrap overflow-hidden">Administration</span>
+              {/if}
+            </div>
+            {#if isOpen}
+              <ChevronDown class="w-4 h-4 flex-shrink-0 transition-transform duration-200 {administrationExpanded ? 'rotate-180' : ''}" />
+            {/if}
+          </button>
+          {#if isOpen && administrationExpanded}
+            <ul class="ml-6 mt-1 space-y-1 collapsible-content">
+              <li>
+                <a 
+                  href="/organization" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <Building2 class="w-4 h-4 flex-shrink-0" />
+                  <span>Organization</span>
+                </a>
+              </li>
+              <li>
+                <a 
+                  href="/users" 
+                  class="menu-item py-1 px-2 text-sm text-gray-600 hover:bg-emerald-50 hover:text-emerald-700"
+                >
+                  <UserCircle class="w-4 h-4 flex-shrink-0" />
+                  <span>Users</span>
+                </a>
+              </li>
+            </ul>
+          {/if}
+        </li>
+        
+        <!-- Logout -->
+        {#if isOpen}
+          <li class="mt-2 pt-2 border-t border-gray-200"></li>
+        {/if}
+        <li>
+          <button 
+            onclick={handleLogout} 
+            class="menu-item text-red-500 hover:bg-red-50 w-full text-left"
+            class:centered={!isOpen}
+            title={!isOpen ? 'Logout' : ''}
+          >
+            <LogOut class="w-5 h-5 flex-shrink-0" />
+            {#if isOpen}
+              <span class="menu-text whitespace-nowrap overflow-hidden">Logout</span>
+            {/if}
+          </button>
+        </li>
+      </ul>
+    </div>
+  </div>
+</div>
+
+<style>
+  .sidebar-container {
+    overflow: visible;
+    transition: width 300ms ease-out;
+  }
+
+  .sidebar-expanded {
+    width: 14rem;
+  }
+
+  .sidebar-collapsed {
+    width: 4rem;
+  }
+
+  .sidebar-content {
+    transition: width 300ms ease-out;
+  }
+
+  .sidebar-content.expanded {
+    width: 14rem;
+  }
+
+  .sidebar-content.collapsed {
+    width: 4rem;
+  }
+
+  .menu-item {
+    display: flex;
+    align-items: center;
+    padding: 0.5rem 0.75rem;
+    border-radius: 0.375rem;
+    transition: all 0.2s;
+    gap: 0.5rem;
+  }
+
+  .menu-item.centered {
+    justify-content: center;
+    padding: 0.5rem 0;
+    width: 2.5rem;
+    margin-left: auto;
+    margin-right: auto;
+  }
+
+  .menu-text {
+    flex: 1;
+    transition: opacity 300ms ease-out;
+  }
+
+  /* Collapsed menu styling */
+  .menu-collapsed :global(li > a),
+  .menu-collapsed :global(li > button) {
+    justify-content: center !important;
+    padding-left: 0 !important;
+    padding-right: 0 !important;
+  }
+
+  /* Collapsible section styles */
+  .collapsible-section button {
+    display: flex;
+    align-items: center;
+  }
+
+  .collapsible-section button.centered {
+    justify-content: center;
+  }
+
+  .collapsible-content {
+    animation: slideDown 0.2s ease-out;
+  }
+
+  @keyframes slideDown {
+    from {
+      opacity: 0;
+      transform: translateY(-4px);
+    }
+    to {
+      opacity: 1;
+      transform: translateY(0);
+    }
+  }
+</style>