.quiz-option.selected{background:#74b9ff;color:white;border-color:#0984e3}.btn{background:linear-gradient(135deg,#667eea,#764ba2);color:white;border:none;border-radius:25px;padding:15px 30px;font-size:16px;font-weight:600;cursor:pointer;transition:all .3s ease;box-shadow:0 5px 15px rgba(0,0,0,.2)}.btn:hover{transform:translateY(-3px);box-shadow:0 10px 25px rgba(0,0,0,.3)}.hidden{display:none}.fade-in{animation:fadeIn .6s ease-in}