body {
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    margin: 0;
    padding: 20px;
}
.container {
    max-width: 800px;
    margin: auto;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
h1, h2, h3 {
    color: #333;
}
.balance-box {
    background: #e9ecef;
    padding: 10px;
    border-radius: 5px;
    margin-bottom: 20px;
}
input, button {
    padding: 8px;
    margin: 5px 0;
    border-radius: 4px;
    border: 1px solid #ccc;
}
button {
    background: #28a745;
    color: white;
    border: none;
    cursor: pointer;
}
button:hover {
    background: #218838;
}
.error {
    color: red;
}
.logout {
    display: inline-block;
    margin-top: 20px;
    color: #dc3545;
    text-decoration: none;
}
.referral-box input {
    width: 80%;
}