body{margin:0;font-family:Inter,Arial,sans-serif;background:#f9fafb;color:#333;display:flex;justify-content:center;align-items:flex-start;min-height:100vh;padding:2rem}.flashcards-container{text-align:center;max-width:500px;width:100%;margin:auto}.flashcards-container h1{font-size:1.8rem;margin-bottom:.2rem}.flashcards-container h2{font-size:1.2rem;margin-bottom:1rem;color:#555}.flashcards-container h3{font-size:1rem;color:#666;margin-bottom:2rem}.flashcard-container{display:flex;justify-content:center;margin:1rem 0}.flashcard{background:#fff;border-radius:16px;box-shadow:0 6px 15px #0000001a;padding:2rem;font-size:1.5rem;font-weight:500;min-width:280px;max-width:90%;word-wrap:break-word;text-align:center}.input-answer{width:80%;max-width:350px;padding:.7rem;border:2px solid #ddd;border-radius:12px;font-size:1rem;margin:1rem 0;outline:none;text-align:center;transition:border .2s}.input-answer:focus{border-color:#2563eb}.button-group{display:flex;justify-content:center;gap:.6rem;flex-wrap:wrap;margin-top:1rem}button{padding:.6rem 1.2rem;border:none;border-radius:12px;font-size:1rem;cursor:pointer;transition:transform .15s ease,background .2s ease}.btn-primary{background:#2563eb;color:#fff}.btn-primary:hover{background:#1d4ed8;transform:scale(1.05)}.btn-submit{background:#10b981;color:#fff}.btn-submit:hover{background:#059669;transform:scale(1.05)}.answer-key-screen{text-align:left;background:#fff;padding:2rem;border-radius:16px;box-shadow:0 6px 15px #0000001a}.answer-key-screen h2{margin-bottom:1rem;text-align:center}.answer-key-screen .score{font-weight:700;text-align:center;font-size:1.2rem;margin-bottom:1rem}.answer-key p{background:#f3f4f6;padding:.6rem;border-radius:10px;margin-bottom:.6rem;font-size:.95rem;line-height:1.4}.answer-key strong{color:#111827}.score{font-size:2.5rem;font-weight:700;color:#1a73e8;margin-bottom:1.5rem;text-align:center}.correct{color:green;font-weight:700;margin-left:.25rem}.incorrect{color:red;font-weight:700;margin-left:.25rem}