fix: remove FRAGE/SATZ/ANTWORT/VOKABELN section labels from all cards

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/PairSentenceCard.jsx

@@ -175,7 +175,7 @@ export default function PairSentenceCard({ card, onComplete }) {
       <div className="pair-card-body" onClick={e => e.stopPropagation()} style={{ paddingTop: 18 }}>
 
         {/* Sentence + action buttons */}
-        <p className="pair-section-label">Satz</p>
+
         <div className="pair-sentence-row">
           <div className="pair-sentence-text">
             <p className="pair-sentence" style={{ opacity: showTranslation ? 0 : 1, transition: 'opacity 0.18s', margin: 0 }}>
@@ -249,7 +249,7 @@ export default function PairSentenceCard({ card, onComplete }) {
         {/* Vocabulary */}
         {vocab.length > 0 && (
           <div className="pair-vocab-section">
-            <p className="pair-section-label">Vokabeln</p>
+
             <div className="pair-vocab-chips">
               {vocab.map(v => (
                 <span key={v.id} className="pair-vocab-word">{v.label}</span>