*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:Arial, sans-serif;
}

body{
    background:#f2f2f2;
    display:flex;
    justify-content:center;
    align-items:center;
    min-height:100vh;
    padding:20px;
}

.login-box{
    background:white;
    width:100%;
    max-width:350px;
    padding:25px;
    border-radius:12px;
    box-shadow:0 0 15px rgba(0,0,0,0.1);
}

h2{
    text-align:center;
    margin-bottom:20px;
}

input{
    width:100%;
    padding:12px;
    margin-bottom:15px;
    border:1px solid #ccc;
    border-radius:8px;
    font-size:16px;
}

button{
    width:100%;
    padding:12px;
    border:none;
    background:#0066ff;
    color:white;
    font-size:16px;
    border-radius:8px;
    cursor:pointer;
}

button:hover{
    opacity:0.9;
}

.error{
    background:#ffdddd;
    color:#c00;
    padding:10px;
    margin-bottom:15px;
    border-radius:8px;
    text-align:center;
}

.demo{
    margin-top:20px;
    text-align:center;
    color:#555;
    font-size:14px;
}