body{margin:0;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;background-color:#121212;color:#fff}.app{text-align:center;padding:20px}.start-screen{margin-top:60px}h1{font-size:2.5rem;margin-bottom:20px;color:#0ff}p{font-size:1.2rem;margin:10px 0 20px}.dropdown{padding:10px;font-size:1rem;border-radius:6px;border:none;margin-bottom:20px}.btn{padding:10px 25px;font-size:1rem;border:none;border-radius:8px;background-color:#00bfff;color:#fff;cursor:pointer;transition:background-color .3s ease;margin-top:10px}.btn:hover{background-color:#009acd}.loading{font-size:1.5rem;color:#fc0;margin-top:50px}.question-card{margin-top:50px;background-color:#1e1e1e;padding:30px;border-radius:12px;max-width:800px;margin-left:auto;margin-right:auto;box-shadow:0 0 15px #00bfff33}.question-text{font-size:1.25rem;margin-bottom:30px}.options{display:flex;flex-direction:column;gap:15px}.option-btn{padding:12px 20px;border:none;border-radius:8px;background-color:#2e2e2e;color:#fff;font-size:1rem;text-align:left;transition:background-color .3s ease,transform .2s;cursor:pointer}.option-btn:hover{background-color:#00bfff;transform:translateY(-2px)}.option-btn.correct{background-color:#28a745!important;color:#fff}.option-btn.incorrect{background-color:#dc3545!important;color:#fff}.score-card{margin-top:40px;padding:20px;max-width:800px;margin-left:auto;margin-right:auto;background-color:#1e1e1e;border-radius:12px;box-shadow:0 0 15px #ffffff0d}.score-card h2{color:#0ff;margin-bottom:20px}.answer-list{margin-top:20px}.answer-block{margin-bottom:20px;background-color:#2c2c2c;padding:15px;border-radius:8px;text-align:left}.answer-block.correct{border-left:6px solid #28a745}.answer-block.wrong{border-left:6px solid #dc3545}.answer-block h4{margin:0 0 10px;color:#fff}.answer-block p{margin:4px 0;color:#ccc}.footer{margin-top:40px;text-align:center;color:#ccc;font-size:.9rem;padding-bottom:20px}.footer a{color:#00bfff;text-decoration:none}.footer a:hover{text-decoration:underline}