body{background:#f5f8ff;margin:0;padding:20px;font-family:Arial}main{max-width:900px;margin:0 auto;padding:24px}.card{background:#fff;border-radius:16px;margin:16px 0;padding:18px;box-shadow:0 8px 25px #00000014}button{color:#fff;cursor:pointer;background:linear-gradient(135deg,#22c55e,#16a34a);border:none;border-radius:10px;padding:10px 14px}