body{margin:0;background:#050505;color:white;font-family:Arial,sans-serif}
.container{max-width:520px;margin:auto;padding:16px}
.card{background:#121212;padding:16px;border-radius:18px;box-shadow:0 4px 18px rgba(0,255,120,.15);margin-bottom:14px}
button{width:100%;padding:15px;margin-top:10px;border:none;border-radius:14px;background:#00b85c;color:white;font-size:16px}
.page{display:none}.page.active{display:block}