*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;line-height:1.6;color:#333;background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh;display:flex;align-items:center;justify-content:center}#app{background:#fff;padding:2rem;border-radius:12px;box-shadow:0 10px 40px #0000001a;text-align:center;max-width:600px;width:90%}h1{color:#667eea;margin-bottom:1rem;font-size:2.5rem}#message{font-size:1.2rem;margin:1.5rem 0;color:#555;min-height:1.5rem}#clickButton{background:#667eea;color:#fff;border:none;padding:.75rem 2rem;font-size:1rem;border-radius:6px;cursor:pointer;transition:background .3s ease,transform .1s ease;font-weight:500}#clickButton:hover{background:#5568d3;transform:translateY(-2px)}#clickButton:active{transform:translateY(0)}