body{color:#333;background:#f0f4f8;margin:0;padding:0;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif}.app-container{background:#fff;border-radius:10px;max-width:600px;margin:50px auto;padding:30px;box-shadow:0 4px 12px #0000001a}h1,h2{text-align:center;margin-bottom:20px}.question{margin-bottom:20px;font-size:1.2em}.option{cursor:pointer;text-align:left;background:#e7ecf0;border:2px solid #0000;border-radius:6px;width:100%;margin:8px 0;padding:12px;transition:background .3s,border .3s;display:block}.option:hover{background:#d6dde5}.option.selected{background:#90caf9;border:2px solid #42a5f5}.nav-buttons{justify-content:space-between;margin-top:20px;display:flex}.nav-buttons button{color:#fff;cursor:pointer;background:#42a5f5;border:none;border-radius:6px;padding:10px 20px;font-size:1em;transition:background .3s}.nav-buttons button:hover{background:#1e88e5}.nav-buttons button:disabled{cursor:not-allowed;background:#a0c4e3}.restart-button{color:#fff;cursor:pointer;background:#42a5f5;border:none;border-radius:6px;margin:20px auto;padding:10px 20px;font-size:1em;transition:background .3s;display:block}.restart-button:hover{background:#1e88e5}.score{text-align:center;margin:20px 0;font-size:1.4em}