html,body{color:#f0f0f0;background-color:#1e1e1e;height:100%;margin:0;font-family:sans-serif}.App{justify-content:center;align-items:center;min-height:100%;display:flex}.container{text-align:center;background-color:#2b2b2b;border-radius:12px;padding:2rem;box-shadow:0 0 20px #00000080}.start-btn{color:#fff;cursor:pointer;background-color:#4caf50;border:none;border-radius:8px;margin-top:1rem;padding:1rem 2rem;font-size:1.2rem}.start-btn:hover{background-color:#45a049}