feat(portfolio): optimize navbar and experience section for mobile

Task: Seite für Besucher auf Mobilgeräten optimieren (#7)

## Desktop navbar
- Added "Mehr" dropdown grouping secondary links (Kompetenzen, Stärken,
  Skills) to keep the primary nav bar uncluttered (Projekte, Erfahrung,
  Über mich stay as primary links)
- Dropdown is click-activated with chevron indicator and closes on
  outside click; all links include data-testid attributes
- No link wrapping possible with this structure on any common desktop width

## Mobile menu
- Replaced flat link list with two logical section groups:
  - "Profil": Über mich, Kompetenzen, Stärken
  - "Erfahrung & Skills": Projekte, Erfahrung, Skills
- Each group has a small uppercase label as a visual divider
- Kontakt CTA remains at the bottom separated by a border
- All 6 page sections are now reachable from the mobile menu

## Timeline cards (experience.tsx)
- Shifted timeline spine from left-6 to left-5 freeing 4px of card width
- Reduced left padding from pl-14 to pl-11 on mobile, giving ~12px extra
  card width — critical at 320–375px viewports
- Added p-3.5 sm:p-5 so cards use tighter inner padding on very small
  screens (< 640px) and normal padding on larger ones
- Added break-words + min-w-0 to role, client, and task text to prevent
  horizontal overflow from long German compound words
- Wrapped task text in a <span> so flex layout doesn't clip overflow

Replit-Task-Id: 51a5a369-3f27-4245-903a-4dc59ee1a842

## No content changes — all section copy, order, and data is unchanged

artifacts/joachim-portfolio/src/components/experience.tsx

@@ -142,7 +142,7 @@ export function Experience() {
         </div>
 
         <div className="relative max-w-3xl mx-auto">
-          <div className="absolute left-6 top-0 bottom-0 w-px bg-border md:left-1/2" />
+          <div className="absolute left-5 top-0 bottom-0 w-px bg-border md:left-1/2" />
 
           {stations.map((station, index) => {
             const cfg = typeConfig[station.type];
@@ -156,36 +156,34 @@ export function Experience() {
                 whileInView={{ opacity: 1, y: 0 }}
                 viewport={{ once: true, margin: "-60px" }}
                 transition={{ duration: 0.5, delay: index * 0.08 }}
-                className={`relative flex gap-6 mb-10 md:mb-12 ${
+                className={`relative flex gap-6 mb-8 md:mb-12 ${
                   isLeft ? "md:flex-row" : "md:flex-row-reverse"
                 }`}
                 data-testid={`card-experience-${index}`}
               >
-                <div className="absolute left-6 -translate-x-1/2 md:left-1/2 z-10">
+                <div className="absolute left-5 -translate-x-1/2 md:left-1/2 z-10">
                   <div
                     className={`w-4 h-4 rounded-full border-2 border-white shadow-sm ${cfg.dot}`}
                   />
                 </div>
 
-                <div className={`pl-14 md:pl-0 w-full md:w-[calc(50%-2rem)] ${isLeft ? "md:pr-8 md:text-right" : "md:pl-8"}`}>
+                <div className={`pl-11 md:pl-0 w-full md:w-[calc(50%-2rem)] ${isLeft ? "md:pr-8 md:text-right" : "md:pl-8"}`}>
-                  <div
+                  <div className="p-3.5 sm:p-5 rounded-2xl bg-white border border-border card-hover">
-                    className={`p-5 rounded-2xl bg-white border border-border card-hover`}
+                    <div className={`flex items-start gap-2 mb-3 ${isLeft ? "md:flex-row-reverse" : ""}`}>
-                  >
+                      <div className={`w-7 h-7 rounded-lg border flex items-center justify-center shrink-0 ${cfg.badge}`}>
-                    <div className={`flex items-start gap-3 mb-3 ${isLeft ? "md:flex-row-reverse" : ""}`}>
+                        <Icon className="w-3.5 h-3.5" />
-                      <div className={`w-8 h-8 rounded-lg border flex items-center justify-center shrink-0 ${cfg.badge}`}>
-                        <Icon className="w-4 h-4" />
                       </div>
-                      <div className={isLeft ? "md:text-right" : ""}>
+                      <div className={`min-w-0 flex-1 ${isLeft ? "md:text-right" : ""}`}>
-                        <p className="text-xs font-semibold text-muted-foreground mb-0.5">
+                        <p className="text-xs font-semibold text-muted-foreground mb-0.5 tabular-nums">
                           {station.period}
                         </p>
-                        <p className="text-sm font-bold text-foreground leading-tight">
+                        <p className="text-sm font-bold text-foreground leading-tight break-words">
                           {station.role}
                         </p>
                       </div>
                     </div>
 
-                    <p className={`text-xs font-medium text-primary mb-3 ${isLeft ? "md:text-right" : ""}`}>
+                    <p className={`text-xs font-medium text-primary mb-3 break-words ${isLeft ? "md:text-right" : ""}`}>
                       {station.client}
                     </p>
 
@@ -198,8 +196,8 @@ export function Experience() {
                           }`}
                           data-testid={`item-experience-${index}-${tIndex}`}
                         >
-                          <span className={`w-1 h-1 rounded-full bg-muted-foreground/40 mt-1.5 shrink-0`} />
+                          <span className="w-1 h-1 rounded-full bg-muted-foreground/40 mt-1.5 shrink-0" />
-                          {task}
+                          <span className="break-words min-w-0">{task}</span>
                         </li>
                       ))}
                     </ul>

artifacts/joachim-portfolio/src/components/navbar.tsx

@@ -1,21 +1,58 @@
-import { useState } from "react";
+import { useState, useRef, useEffect } from "react";
 import { motion, useScroll, useMotionValueEvent } from "framer-motion";
-import { Menu, X } from "lucide-react";
+import { Menu, X, ChevronDown } from "lucide-react";
+
+const primaryLinks = [
+  { name: "Projekte", href: "#projects" },
+  { name: "Erfahrung", href: "#experience" },
+  { name: "Über mich", href: "#bio" },
+];
+
+const secondaryLinks = [
+  { name: "Kompetenzen", href: "#competencies" },
+  { name: "Stärken", href: "#strengths" },
+  { name: "Skills", href: "#skills" },
+];
+
+const mobileGroups = [
+  {
+    label: "Profil",
+    links: [
+      { name: "Über mich", href: "#bio" },
+      { name: "Kompetenzen", href: "#competencies" },
+      { name: "Stärken", href: "#strengths" },
+    ],
+  },
+  {
+    label: "Erfahrung & Skills",
+    links: [
+      { name: "Projekte", href: "#projects" },
+      { name: "Erfahrung", href: "#experience" },
+      { name: "Skills", href: "#skills" },
+    ],
+  },
+];
 
 export function Navbar() {
   const [isScrolled, setIsScrolled] = useState(false);
   const [mobileOpen, setMobileOpen] = useState(false);
+  const [dropdownOpen, setDropdownOpen] = useState(false);
+  const dropdownRef = useRef<HTMLDivElement>(null);
   const { scrollY } = useScroll();
 
   useMotionValueEvent(scrollY, "change", (latest) => {
     setIsScrolled(latest > 20);
   });
 
-  const navLinks = [
+  useEffect(() => {
-    { name: "Projekte", href: "#projects" },
+    function handleClickOutside(e: MouseEvent) {
-    { name: "Erfahrung", href: "#experience" },
+      if (dropdownRef.current && !dropdownRef.current.contains(e.target as Node)) {
-    { name: "Über mich", href: "#bio" },
+        setDropdownOpen(false);
-  ];
+      }
+    }
+    document.addEventListener("mousedown", handleClickOutside);
+    return () => document.removeEventListener("mousedown", handleClickOutside);
+  }, []);
 
   return (
     <motion.header
@@ -41,7 +78,7 @@ export function Navbar() {
         </a>
 
         <nav className="hidden md:flex items-center gap-1">
-          {navLinks.map((link) => (
+          {primaryLinks.map((link) => (
             <a
               key={link.name}
               href={link.href}
@@ -51,6 +88,41 @@ export function Navbar() {
               {link.name}
             </a>
           ))}
+
+          <div className="relative" ref={dropdownRef}>
+            <button
+              onClick={() => setDropdownOpen(!dropdownOpen)}
+              className="flex items-center gap-1 px-4 py-2 text-sm font-medium text-muted-foreground hover:text-foreground hover:bg-secondary rounded-lg transition-all"
+              data-testid="button-nav-mehr"
+              aria-expanded={dropdownOpen}
+            >
+              Mehr
+              <ChevronDown
+                className={`w-3.5 h-3.5 transition-transform duration-200 ${dropdownOpen ? "rotate-180" : ""}`}
+              />
+            </button>
+
+            {dropdownOpen && (
+              <motion.div
+                initial={{ opacity: 0, y: -6 }}
+                animate={{ opacity: 1, y: 0 }}
+                transition={{ duration: 0.15 }}
+                className="absolute right-0 top-full mt-1.5 w-40 bg-white border border-border rounded-xl shadow-lg py-1.5"
+              >
+                {secondaryLinks.map((link) => (
+                  <a
+                    key={link.name}
+                    href={link.href}
+                    onClick={() => setDropdownOpen(false)}
+                    className="block px-4 py-2 text-sm font-medium text-muted-foreground hover:text-foreground hover:bg-secondary transition-all"
+                    data-testid={`link-nav-${link.name.toLowerCase()}`}
+                  >
+                    {link.name}
+                  </a>
+                ))}
+              </motion.div>
+            )}
+          </div>
         </nav>
 
         <div className="hidden md:block">
@@ -76,25 +148,37 @@ export function Navbar() {
         <motion.div
           initial={{ opacity: 0, y: -8 }}
           animate={{ opacity: 1, y: 0 }}
-          className="md:hidden bg-white border-t border-border px-4 py-4 flex flex-col gap-1"
+          className="md:hidden bg-white border-t border-border px-4 py-4 flex flex-col gap-4"
         >
-          {navLinks.map((link) => (
+          {mobileGroups.map((group) => (
+            <div key={group.label}>
+              <p className="px-4 mb-1 text-[10px] font-semibold uppercase tracking-widest text-muted-foreground/60">
+                {group.label}
+              </p>
+              <div className="flex flex-col gap-0.5">
+                {group.links.map((link) => (
                   <a
                     key={link.name}
                     href={link.href}
                     onClick={() => setMobileOpen(false)}
-              className="px-4 py-3 text-sm font-medium text-muted-foreground hover:text-foreground hover:bg-secondary rounded-lg transition-all"
+                    className="px-4 py-2.5 text-sm font-medium text-muted-foreground hover:text-foreground hover:bg-secondary rounded-lg transition-all"
                   >
                     {link.name}
                   </a>
                 ))}
+              </div>
+            </div>
+          ))}
+
+          <div className="pt-1 border-t border-border">
             <a
               href="#contact"
               onClick={() => setMobileOpen(false)}
-            className="mt-2 px-4 py-3 bg-primary text-white text-sm font-semibold rounded-lg text-center"
+              className="block px-4 py-3 bg-primary text-white text-sm font-semibold rounded-lg text-center"
             >
               Kontakt aufnehmen
             </a>
+          </div>
         </motion.div>
       )}
     </motion.header>