body{font-family:sans-serif;display:flex;justify-content:center;align-items:center;height:100vh;background:#fafafa;}
.box{padding:24px;border:1px solid #ccc;border-radius:8px;background:#fff;min-width:260px;box-shadow:0 2px 8px #0001;}
.box input{display:block;width:100%;padding:8px;margin:6px 0;border:1px solid #ccc;border-radius:4px;}
.box button{width:100%;padding:8px;margin-top:8px;background:#1976d2;color:#fff;border:none;border-radius:4px;cursor:pointer;}
#msg{color:red;margin-top:6px;font-size:14px;text-align:center;}