diff --git a/app/(marketing)/documentatie/[category]/page.tsx b/app/(marketing)/documentatie/[category]/page.tsx
index ed0c422..6ea2813 100644
--- a/app/(marketing)/documentatie/[category]/page.tsx
+++ b/app/(marketing)/documentatie/[category]/page.tsx
@@ -52,8 +52,8 @@ export default async function ReleasePage({ params }: ReleasePageProps) {
   const { frontmatter, content } = release
 
   return (
-    <div className="min-h-screen bg-white pt-24 pb-16">
-      <article className="max-w-4xl mx-auto px-4 md:px-8">
+    <div className="min-h-screen bg-white pb-16">
+      <article className="max-w-4xl mx-auto px-4 md:px-8 pt-20 md:pt-8">
         {/* Header */}
         <header className="mb-8 pb-8 border-b border-slate-200">
           <div className="flex items-center gap-3 mb-4">
diff --git a/app/(marketing)/documentatie/components/release-sidebar.tsx b/app/(marketing)/documentatie/components/release-sidebar.tsx
index c15ccee..d1f1702 100644
--- a/app/(marketing)/documentatie/components/release-sidebar.tsx
+++ b/app/(marketing)/documentatie/components/release-sidebar.tsx
@@ -9,8 +9,8 @@
 
 import Link from 'next/link'
 import { usePathname } from 'next/navigation'
-import { ChevronRight, ChevronDown } from 'lucide-react'
-import { useState } from 'react'
+import { ChevronRight, ChevronDown, ChevronLeft, X } from 'lucide-react'
+import { useState, useEffect } from 'react'
 import type { ReleaseNote, GroupMetadata, CategoryMetadata } from '@/lib/mdx/documentatie'
 
 interface ReleaseSidebarProps {
@@ -23,6 +23,7 @@ interface ReleaseSidebarProps {
 
 export function ReleaseSidebar({ releases, metadata }: ReleaseSidebarProps) {
   const pathname = usePathname()
+  const [isExpanded, setIsExpanded] = useState(false)
   const [expandedGroups, setExpandedGroups] = useState<Record<string, boolean>>({
     foundation: true,
     features: true,
@@ -30,6 +31,11 @@ export function ReleaseSidebar({ releases, metadata }: ReleaseSidebarProps) {
     bugs: true,
   })
 
+  // Auto-close sidebar on navigation
+  useEffect(() => {
+    setIsExpanded(false)
+  }, [pathname])
+
   const toggleGroup = (groupId: string) => {
     setExpandedGroups(prev => ({
       ...prev,
@@ -50,34 +56,125 @@ export function ReleaseSidebar({ releases, metadata }: ReleaseSidebarProps) {
 
   return (
     <>
-      {/* Mobile: Horizontal scroll menu */}
-      <div className="lg:hidden bg-white border-b border-slate-200 sticky top-16 z-40">
-        <div className="flex gap-2 p-4 overflow-x-auto">
-          <Link
-            href="/documentatie"
-            className={`flex-shrink-0 px-4 py-2 rounded-lg text-sm font-medium transition-colors ${pathname === '/documentatie'
-                ? 'bg-teal-100 text-teal-700'
-                : 'bg-slate-100 text-slate-600 hover:bg-slate-200'
-              }`}
-          >
-            Overzicht
-          </Link>
-          {releases.map((release) => (
-            <Link
-              key={release.slug}
-              href={`/documentatie/${release.slug}`}
-              className={`flex-shrink-0 px-4 py-2 rounded-lg text-sm font-medium transition-colors ${pathname === `/documentatie/${release.slug}`
-                  ? 'bg-teal-100 text-teal-700'
-                  : 'bg-slate-100 text-slate-600 hover:bg-slate-200'
-                }`}
-            >
-              {release.frontmatter.title}
-            </Link>
-          ))}
-        </div>
-      </div>
+      {/* MOBILE: Overlay when expanded */}
+      {isExpanded && (
+        <div 
+          className="lg:hidden fixed inset-0 bg-black/40 backdrop-blur-sm z-30 top-16"
+          onClick={() => setIsExpanded(false)}
+          aria-hidden="true"
+        />
+      )}
 
-      {/* Desktop: Fixed sidebar */}
+      {/* MOBILE: Collapsible sidebar from left */}
+      <aside 
+        className={`
+          lg:hidden
+          fixed top-16 bottom-0 left-0 z-40
+          bg-white border-r border-slate-200
+          transition-all duration-300 ease-in-out
+          ${isExpanded ? 'w-80 shadow-2xl' : 'w-12'}
+        `}
+      >
+        {/* Collapsed state: Icon bar */}
+        {!isExpanded && (
+          <div className="flex flex-col items-center pt-6">
+            <button
+              onClick={() => setIsExpanded(true)}
+              className="p-2 rounded-lg hover:bg-teal-50 transition-colors group"
+              aria-label="Open documentatie menu"
+            >
+              <ChevronRight className="w-6 h-6 text-slate-600 group-hover:text-teal-600 transition-colors" />
+            </button>
+          </div>
+        )}
+
+        {/* Expanded state: Full navigation */}
+        {isExpanded && (
+          <div className="p-6 overflow-y-auto h-full">
+            {/* Header met close button */}
+            <div className="flex items-center justify-between mb-6 pb-4 border-b border-slate-200">
+              <h2 className="text-lg font-bold text-slate-900">Documentatie</h2>
+              <button
+                onClick={() => setIsExpanded(false)}
+                className="p-1.5 rounded-lg hover:bg-slate-100 transition-colors group"
+                aria-label="Sluit menu"
+              >
+                <ChevronLeft className="w-5 h-5 text-slate-500 group-hover:text-slate-700 transition-colors" />
+              </button>
+            </div>
+
+            <nav className="space-y-1">
+              {/* Overzicht link */}
+              <Link
+                href="/documentatie"
+                className={`flex items-center justify-between px-3 py-2 rounded-lg text-sm font-medium transition-colors ${
+                  pathname === '/documentatie' && !isReleaseDetail
+                    ? 'bg-teal-50 text-teal-700'
+                    : 'text-slate-700 hover:bg-slate-50'
+                }`}
+              >
+                <span>Overzicht</span>
+              </Link>
+
+              {/* Grouped releases */}
+              {metadata?.groups && metadata.groups
+                .sort((a, b) => a.order - b.order)
+                .map((group) => {
+                  const groupReleases = releasesByGroup[group.id] || []
+                  const isGroupExpanded = expandedGroups[group.id]
+
+                  return (
+                    <div key={group.id} className="space-y-1">
+                      {/* Group header */}
+                      <button
+                        onClick={() => toggleGroup(group.id)}
+                        className="w-full flex items-center justify-between px-3 py-2 text-xs font-semibold text-slate-500 uppercase tracking-wide hover:text-slate-700 transition-colors"
+                      >
+                        <span>{group.title}</span>
+                        {isGroupExpanded ? (
+                          <ChevronDown className="w-4 h-4" />
+                        ) : (
+                          <ChevronRight className="w-4 h-4" />
+                        )}
+                      </button>
+
+                      {/* Group items */}
+                      {isGroupExpanded && (
+                        <div className="space-y-1 ml-2">
+                          {groupReleases.map((release) => {
+                            const isActive = pathname === `/documentatie/${release.slug}`
+
+                            return (
+                              <Link
+                                key={release.slug}
+                                href={`/documentatie/${release.slug}`}
+                                className={`flex items-center justify-between px-3 py-2 rounded-lg text-sm font-medium transition-colors group ${
+                                  isActive
+                                    ? 'bg-teal-50 text-teal-700'
+                                    : 'text-slate-700 hover:bg-slate-50'
+                                }`}
+                              >
+                                <div className="flex items-center gap-2 min-w-0">
+                                  <StatusDot status={release.frontmatter.status} />
+                                  <span className="whitespace-normal">{release.frontmatter.title}</span>
+                                </div>
+                                <ChevronRight className={`w-4 h-4 flex-shrink-0 transition-opacity ${
+                                  isActive ? 'opacity-100' : 'opacity-0 group-hover:opacity-50'
+                                }`} />
+                              </Link>
+                            )
+                          })}
+                        </div>
+                      )}
+                    </div>
+                  )
+                })}
+            </nav>
+          </div>
+        )}
+      </aside>
+
+      {/* DESKTOP: Fixed sidebar */}
       <aside className="hidden lg:block w-80 fixed top-16 bottom-0 bg-white border-r border-slate-200 overflow-y-auto">
         <div className="p-6">
           <h2 className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-4">
@@ -97,7 +194,7 @@ export function ReleaseSidebar({ releases, metadata }: ReleaseSidebarProps) {
             </Link>
 
             {/* Grouped releases */}
-            {metadata.groups
+            {metadata?.groups && metadata.groups
               .sort((a, b) => a.order - b.order)
               .map((group) => {
                 const groupReleases = releasesByGroup[group.id] || []
diff --git a/app/(marketing)/documentatie/layout.tsx b/app/(marketing)/documentatie/layout.tsx
index 5b3f748..287978f 100644
--- a/app/(marketing)/documentatie/layout.tsx
+++ b/app/(marketing)/documentatie/layout.tsx
@@ -5,27 +5,37 @@
  */
 
 import type { ReactNode } from 'react'
-import { getAllReleases, getCategoryMetadata } from '@/lib/mdx/documentatie'
-import { ReleaseSidebar } from './components/release-sidebar'
+import { getAllReleases, getCategoryMetadata, type ReleaseNote } from '@/lib/mdx/documentatie'
+import ReleaseSidebarWrapper from './components/release-sidebar-wrapper'
 
 interface ReleasesLayoutProps {
   children: ReactNode
 }
 
 export default async function ReleasesLayout({ children }: ReleasesLayoutProps) {
-  const releases = await getAllReleases()
-  const metadata = await getCategoryMetadata()
+  let releases: ReleaseNote[] = []
+  let metadata = { groups: [], categories: [] } as Awaited<ReturnType<typeof getCategoryMetadata>>
+
+  try {
+    releases = await getAllReleases()
+    metadata = await getCategoryMetadata()
+  } catch (error) {
+    console.error('Error loading releases or metadata:', error)
+  }
 
   return (
     <div className="min-h-screen bg-slate-50">
-      <div className="max-w-[1600px] mx-auto">
-        <div className="flex">
-          {/* Sidebar - hidden on mobile, fixed on desktop */}
-          <ReleaseSidebar releases={releases} metadata={metadata} />
+      {/* Mobile sidebar is sticky, so we need padding for header only */}
+      <div className="pt-16 lg:pt-0">
+        <div className="max-w-[1600px] mx-auto">
+          <div className="flex">
+            {/* Sidebar - collapsible on mobile (48px collapsed), fixed on desktop (320px) */}
+            <ReleaseSidebarWrapper releases={releases} metadata={metadata} />
 
-          {/* Main Content */}
-          <div className="flex-1 lg:ml-80">
-            {children}
+            {/* Main Content - margin for collapsed sidebar on mobile, fixed sidebar on desktop */}
+            <div className="flex-1 ml-12 lg:ml-80">
+              {children}
+            </div>
           </div>
         </div>
       </div>
diff --git a/app/(marketing)/documentatie/page.tsx b/app/(marketing)/documentatie/page.tsx
index 094f63f..accbe3e 100644
--- a/app/(marketing)/documentatie/page.tsx
+++ b/app/(marketing)/documentatie/page.tsx
@@ -21,38 +21,38 @@ export default async function ReleasesPage() {
   const planned = releases.filter(r => r.frontmatter.status === 'planned')
 
   return (
-    <div className="min-h-screen bg-slate-50 pt-24 pb-16">
-      <div className="max-w-4xl mx-auto px-4 md:px-8">
+    <div className="min-h-screen bg-slate-50 pb-16">
+      <div className="max-w-4xl mx-auto px-4 sm:px-6 md:px-8">
         {/* Header */}
-        <div className="mb-12">
-          <h1 className="text-4xl md:text-5xl font-bold text-slate-900 mb-4">
+        <div className="mb-8 md:mb-12 pt-20 md:pt-8">
+          <h1 className="text-3xl md:text-4xl lg:text-5xl font-bold text-slate-900 mb-3 md:mb-4">
             Feature Documentatie
           </h1>
-          <p className="text-xl text-slate-600 max-w-3xl">
+          <p className="text-lg md:text-xl text-slate-600 max-w-3xl leading-relaxed">
             Uitgebreide documentatie van alle gebouwde functionaliteit. Build in public met transparantie over features, implementatie en kosten.
           </p>
         </div>
 
         {/* Stats */}
-        <div className="grid grid-cols-3 gap-4 mb-12">
-          <div className="bg-white rounded-lg border border-slate-200 p-4 text-center">
-            <div className="text-3xl font-bold text-teal-600">{completed.length}</div>
-            <div className="text-sm text-slate-500 mt-1">Voltooid</div>
+        <div className="grid grid-cols-1 sm:grid-cols-3 gap-4 mb-12">
+          <div className="bg-white rounded-lg border border-slate-200 p-6 text-center shadow-sm">
+            <div className="text-4xl md:text-5xl font-bold text-teal-600 mb-2">{completed.length}</div>
+            <div className="text-sm font-medium text-slate-600">Voltooid</div>
           </div>
-          <div className="bg-white rounded-lg border border-slate-200 p-4 text-center">
-            <div className="text-3xl font-bold text-amber-600">{inProgress.length}</div>
-            <div className="text-sm text-slate-500 mt-1">In Progress</div>
+          <div className="bg-white rounded-lg border border-slate-200 p-6 text-center shadow-sm">
+            <div className="text-4xl md:text-5xl font-bold text-amber-600 mb-2">{inProgress.length}</div>
+            <div className="text-sm font-medium text-slate-600">In Progress</div>
           </div>
-          <div className="bg-white rounded-lg border border-slate-200 p-4 text-center">
-            <div className="text-3xl font-bold text-slate-400">{planned.length}</div>
-            <div className="text-sm text-slate-500 mt-1">Gepland</div>
+          <div className="bg-white rounded-lg border border-slate-200 p-6 text-center shadow-sm">
+            <div className="text-4xl md:text-5xl font-bold text-slate-400 mb-2">{planned.length}</div>
+            <div className="text-sm font-medium text-slate-600">Gepland</div>
           </div>
         </div>
 
         {/* Completed Releases */}
         {completed.length > 0 && (
-          <section className="mb-12">
-            <h2 className="text-2xl font-bold text-slate-900 mb-4">
+          <section className="mb-10 md:mb-12">
+            <h2 className="text-xl md:text-2xl font-bold text-slate-900 mb-4 md:mb-6">
               ✅ Voltooid
             </h2>
             <div className="space-y-4">
@@ -65,8 +65,8 @@ export default async function ReleasesPage() {
 
         {/* In Progress Releases */}
         {inProgress.length > 0 && (
-          <section className="mb-12">
-            <h2 className="text-2xl font-bold text-slate-900 mb-4">
+          <section className="mb-10 md:mb-12">
+            <h2 className="text-xl md:text-2xl font-bold text-slate-900 mb-4 md:mb-6">
               🔄 In Progress
             </h2>
             <div className="space-y-4">
@@ -79,8 +79,8 @@ export default async function ReleasesPage() {
 
         {/* Planned Releases */}
         {planned.length > 0 && (
-          <section className="mb-12">
-            <h2 className="text-2xl font-bold text-slate-900 mb-4">
+          <section className="mb-10 md:mb-12">
+            <h2 className="text-xl md:text-2xl font-bold text-slate-900 mb-4 md:mb-6">
               ⏳ Gepland
             </h2>
             <div className="space-y-4">
@@ -99,33 +99,33 @@ function ReleaseCard({ release }: { release: any }) {
   return (
     <Link
       href={`/documentatie/${release.slug}`}
-      className="block bg-white rounded-lg border border-slate-200 p-6 hover:border-teal-300 hover:shadow-md transition-all"
+      className="block bg-white rounded-lg border border-slate-200 p-5 md:p-6 hover:border-teal-300 hover:shadow-md transition-all active:scale-[0.98]"
     >
-      <div className="flex items-start justify-between gap-4">
-        <div className="flex-1">
-          <div className="flex items-center gap-3 mb-2">
-            <h3 className="text-xl font-bold text-slate-900">
+      <div className="flex flex-col sm:flex-row sm:items-start sm:justify-between gap-3 sm:gap-4">
+        <div className="flex-1 min-w-0">
+          <div className="flex flex-col sm:flex-row sm:items-center gap-2 sm:gap-3 mb-2">
+            <h3 className="text-lg md:text-xl font-bold text-slate-900 leading-tight">
               {release.frontmatter.title}
             </h3>
             <StatusBadge status={release.frontmatter.status} />
           </div>
-          <p className="text-slate-600 mb-3">
+          <p className="text-slate-600 mb-3 text-sm md:text-base leading-relaxed">
             {release.frontmatter.description}
           </p>
-          <div className="flex items-center gap-4 text-sm text-slate-500">
+          <div className="flex flex-wrap items-center gap-2 md:gap-4 text-xs md:text-sm text-slate-500">
             <span className="capitalize">{release.frontmatter.group.replace('-', ' ')}</span>
-            <span>•</span>
+            <span className="hidden sm:inline">•</span>
             <span>v{release.frontmatter.version}</span>
-            <span>•</span>
-            <span>{new Date(release.frontmatter.releaseDate).toLocaleDateString('nl-NL', {
+            <span className="hidden sm:inline">•</span>
+            <span className="whitespace-nowrap">{new Date(release.frontmatter.releaseDate).toLocaleDateString('nl-NL', {
               year: 'numeric',
               month: 'long',
               day: 'numeric'
             })}</span>
           </div>
         </div>
-        <div className="text-slate-400">
-          <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <div className="text-slate-400 flex-shrink-0 self-start sm:self-center">
+          <svg className="w-5 h-5 md:w-6 md:h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
             <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" />
           </svg>
         </div>
diff --git a/app/epd/clients/actions.ts b/app/epd/clients/actions.ts
index ba7458d..1a22630 100644
--- a/app/epd/clients/actions.ts
+++ b/app/epd/clients/actions.ts
@@ -22,8 +22,11 @@ export async function getClients(filters?: ClientFilters) {
 
   // Apply search filter
   if (filters?.search) {
-    const search = `%${filters.search}%`;
-    query = query.or(`first_name.ilike.${search},last_name.ilike.${search}`);
+    const searchTerm = filters.search.trim();
+    // Use PostgREST or() syntax: column.operator.value,column.operator.value
+    // Format: column.operator.value,column.operator.value (no quotes needed for ilike)
+    const searchPattern = `%${searchTerm}%`;
+    query = query.or(`first_name.ilike.${searchPattern},last_name.ilike.${searchPattern}`);
   }
 
   // Apply sorting
diff --git a/app/globals.css b/app/globals.css
index 6814778..71847f2 100644
--- a/app/globals.css
+++ b/app/globals.css
@@ -247,6 +247,16 @@ body {
   }
 }
 
+/* Scrollbar hide utility for horizontal scroll menus */
+.scrollbar-hide {
+  -ms-overflow-style: none;  /* IE and Edge */
+  scrollbar-width: none;  /* Firefox */
+}
+
+.scrollbar-hide::-webkit-scrollbar {
+  display: none;  /* Chrome, Safari and Opera */
+}
+
 /* AI source highlighting (gebruikt in Intake editor) */
 .ai-source-highlight {
   background-color: #fef08a; /* lichtgeel */
diff --git a/components/ui/bento-grid.tsx b/components/ui/bento-grid.tsx
index a04fa8d..256749b 100644
--- a/components/ui/bento-grid.tsx
+++ b/components/ui/bento-grid.tsx
@@ -1,7 +1,7 @@
 'use client'
 
 import { ReactNode } from "react";
-import { ArrowRightIcon } from "@radix-ui/react-icons";
+import { ArrowRight } from "lucide-react";
 
 import { cn } from "@/lib/utils";
 
@@ -71,7 +71,7 @@ const BentoCard = ({
         className="pointer-events-auto inline-flex items-center justify-center rounded-md text-sm font-medium hover:bg-accent hover:text-accent-foreground h-9 px-3"
       >
         {cta}
-        <ArrowRightIcon className="ml-2 h-4 w-4" />
+        <ArrowRight className="ml-2 h-4 w-4" />
       </a>
     </div>
     <div className="pointer-events-none absolute inset-0 transform-gpu transition-all duration-300 group-hover:bg-black/[.03] group-hover:dark:bg-neutral-800/10" />
diff --git a/lib/mdx/documentatie.ts b/lib/mdx/documentatie.ts
index badc6fa..9010241 100644
--- a/lib/mdx/documentatie.ts
+++ b/lib/mdx/documentatie.ts
@@ -116,7 +116,24 @@ interface IndexData {
 }
 
 export async function getCategoryMetadata(): Promise<IndexData> {
-  const indexPath = path.join(RELEASES_DIR, '_index.json')
-  const indexContent = fs.readFileSync(indexPath, 'utf-8')
-  return JSON.parse(indexContent)
+  try {
+    const indexPath = path.join(RELEASES_DIR, '_index.json')
+
+    if (!fs.existsSync(indexPath)) {
+      console.warn('_index.json not found, returning empty metadata')
+      return {
+        groups: [],
+        categories: []
+      }
+    }
+
+    const indexContent = fs.readFileSync(indexPath, 'utf-8')
+    return JSON.parse(indexContent)
+  } catch (error) {
+    console.error('Error loading category metadata:', error)
+    return {
+      groups: [],
+      categories: []
+    }
+  }
 }