*{box-sizing:border-box;font-family:Arial,Helvetica,sans-serif}
body{
  background:#0b1220;
  min-height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  color:#fff;
}
.container{
  width:320px;
  background:#111a2e;
  padding:24px;
  border-radius:12px;
  box-shadow:0 10px 30px rgba(0,0,0,.4);
}
h1{margin-bottom:16px;text-align:center}
input{
  width:100%;
  padding:12px;
  margin:8px 0;
  border-radius:8px;
  border:none;
}
button{
  width:100%;
  padding:12px;
  margin-top:10px;
  border:none;
  border-radius:8px;
  background:#3b82f6;
  color:#fff;
  font-size:16px;
}
#msg{margin-top:10px;text-align:center}