fix(andreknie.de): keep testimonial carousel centered

privat/CV/andreknie.de/src/components/TestimonialSlider.css

@@ -35,7 +35,8 @@
   scroll-snap-type: x mandatory;
   scroll-behavior: smooth;
   gap: 24px;
-  padding-bottom: 32px; /* Space for scrollbar and shadow */
+  padding: 0 calc((100% - min(100%, var(--container-max))) / 2) 32px;
+  scroll-padding-inline: calc((100% - 88%) / 2);
   cursor: grab;
   user-select: none;
   
@@ -57,7 +58,7 @@
 .testimonial-card {
   /* On mobile, show ~85% width so the next card peeks in */
   flex: 0 0 calc(88% - 24px);
-  scroll-snap-align: start;
+  scroll-snap-align: center;
   
   /* Equal heights trick: cards stretch to the tallest sibling */
   display: flex;
@@ -70,6 +71,10 @@
 }
 
 @media (min-width: 768px) {
+  .testimonial-scroll-container {
+    scroll-padding-inline: calc((100% - 60%) / 2);
+  }
+
   .testimonial-card {
     /* On tablet, show ~60% width */
     flex: 0 0 calc(60% - 24px);
@@ -77,6 +82,10 @@
 }
 
 @media (min-width: 1024px) {
+  .testimonial-scroll-container {
+    scroll-padding-inline: calc((100% - 45%) / 2);
+  }
+
   .testimonial-card {
     /* On desktop, show ~45% width */
     flex: 0 0 calc(45% - 24px);

privat/CV/andreknie.de/src/components/TestimonialSlider.jsx

@@ -1,7 +1,10 @@
-import React, { useEffect, useRef, useState } from 'react'
+import React, { useLayoutEffect, useRef, useState } from 'react'
 import { ChevronLeft, ChevronRight } from 'lucide-react'
 import './TestimonialSlider.css'
 
+const LOOP_SETS = 9
+const MIDDLE_SET = Math.floor(LOOP_SETS / 2)
+
 /**
  * Manual testimonial slider (carousel).
  * Equal heights, horizontal scroll, no autoplay.
@@ -11,49 +14,80 @@ export default function TestimonialSlider({ testimonials = [] }) {
   const dragStateRef = useRef({ isDragging: false, startX: 0, scrollLeft: 0 })
   const [isDragging, setIsDragging] = useState(false)
   const canLoop = testimonials.length > 1
-  const visibleTestimonials = canLoop ? [...testimonials, ...testimonials, ...testimonials] : testimonials
+  const visibleTestimonials = canLoop
+    ? Array.from({ length: LOOP_SETS }, () => testimonials).flat()
+    : testimonials
 
-  const getCardStep = () => {
+  const getCenteredScrollLeft = (cardIndex) => {
     const scroller = scrollerRef.current
-    const firstCard = scroller?.querySelector('.testimonial-card')
-    if (!scroller || !firstCard) return 0
+    const card = scroller?.querySelectorAll('.testimonial-card')[cardIndex]
+    if (!scroller || !card) return 0
 
-    const gap = parseFloat(window.getComputedStyle(scroller).columnGap || '0')
-    return firstCard.offsetWidth + gap
+    return card.offsetLeft - (scroller.clientWidth - card.offsetWidth) / 2
   }
 
-  useEffect(() => {
+  const getClosestCardIndex = () => {
     const scroller = scrollerRef.current
-    if (!canLoop || !scroller) return
+    const cards = Array.from(scroller?.querySelectorAll('.testimonial-card') || [])
+    if (!scroller || cards.length === 0) return 0
 
-    const cardStep = getCardStep()
-    if (!cardStep) return
+    const scrollerCenter = scroller.scrollLeft + scroller.clientWidth / 2
+    return cards.reduce((closestIndex, card, index) => {
+      const cardCenter = card.offsetLeft + card.offsetWidth / 2
+      const closestCard = cards[closestIndex]
+      const closestCenter = closestCard.offsetLeft + closestCard.offsetWidth / 2
 
-    scroller.scrollLeft = cardStep * testimonials.length
+      return Math.abs(cardCenter - scrollerCenter) < Math.abs(closestCenter - scrollerCenter)
+        ? index
+        : closestIndex
+    }, 0)
+  }
+
+  const centerCard = (cardIndex, behavior = 'auto') => {
+    const scroller = scrollerRef.current
+    if (!scroller) return
+
+    scroller.scrollTo({
+      left: getCenteredScrollLeft(cardIndex),
+      behavior,
+    })
+  }
+
+  useLayoutEffect(() => {
+    if (!canLoop) return undefined
+
+    const frameId = window.requestAnimationFrame(() => {
+      const scroller = scrollerRef.current
+      const card = scroller?.querySelectorAll('.testimonial-card')[testimonials.length * MIDDLE_SET]
+      if (!scroller || !card) return
+
+      scroller.scrollLeft = card.offsetLeft - (scroller.clientWidth - card.offsetWidth) / 2
+    })
+
+    return () => window.cancelAnimationFrame(frameId)
   }, [canLoop, testimonials.length])
 
   const scrollByCard = (direction) => {
     const scroller = scrollerRef.current
-    const cardStep = getCardStep()
-    if (!scroller || !cardStep) return
+    if (!scroller) return
 
-    scroller.scrollBy({
-      left: direction * cardStep,
-      behavior: 'smooth',
-    })
+    const targetIndex = getClosestCardIndex() + direction
+    centerCard(targetIndex, 'smooth')
+
+    window.setTimeout(recenterIfNeeded, 450)
   }
 
-  const keepLoopCentered = () => {
+  const recenterIfNeeded = () => {
     const scroller = scrollerRef.current
-    const cardStep = getCardStep()
-    if (!canLoop || !scroller || !cardStep) return
+    if (!canLoop || !scroller) return
 
-    const segmentWidth = cardStep * testimonials.length
-    if (scroller.scrollLeft < segmentWidth * 0.5) {
-      scroller.scrollLeft += segmentWidth
-    } else if (scroller.scrollLeft > segmentWidth * 1.5) {
-      scroller.scrollLeft -= segmentWidth
-    }
+    const currentIndex = getClosestCardIndex()
+    const lowBoundary = testimonials.length
+    const highBoundary = testimonials.length * (LOOP_SETS - 1)
+    if (currentIndex >= lowBoundary && currentIndex < highBoundary) return
+
+    const normalizedIndex = ((currentIndex % testimonials.length) + testimonials.length) % testimonials.length
+    centerCard(testimonials.length * MIDDLE_SET + normalizedIndex)
   }
 
   const handlePointerDown = (event) => {
@@ -82,7 +116,7 @@ export default function TestimonialSlider({ testimonials = [] }) {
     const scroller = scrollerRef.current
     dragStateRef.current.isDragging = false
     setIsDragging(false)
-    keepLoopCentered()
+    recenterIfNeeded()
 
     if (scroller?.hasPointerCapture?.(event.pointerId)) {
       scroller.releasePointerCapture(event.pointerId)
@@ -108,7 +142,6 @@ export default function TestimonialSlider({ testimonials = [] }) {
         onPointerMove={handlePointerMove}
         onPointerUp={stopDragging}
         onPointerCancel={stopDragging}
-        onScroll={keepLoopCentered}
         onPointerLeave={(event) => {
           if (dragStateRef.current.isDragging) stopDragging(event)
         }}