.quiz-option.selected{background:#667eea;color:#fff;border-color:#667eea}.quiz-result.show{display:block;animation:fadeIn .5s ease}.progress-item.completed{border-left-color:#28a745;background:#d4edda}.slider-result.show{display:block;animation:fadeIn .5s ease}.flip-card.flipped .flip-card-inner{transform:rotateY(180deg)}