body {
    background: #0d0d0f;
    color: white;
    font-family: -apple-system, BlinkMacSystemFont, sans-serif;
    margin: 0;
    padding: 15px;
}

.logo {
    width: 80px;
    display: block;
    margin: 0 auto 20px;
    opacity: 0.9;
}

.card {
    background: #151518;
    padding: 20px;
    border-radius: 18px;
    margin-bottom: 15px;
    box-shadow: 0 0 25px rgba(0,0,0,0.4);
}

.balance {
    font-size: 42px;
    font-weight: 700;
    text-align: center;
}

.btn {
    width: 100%;
    margin-top: 10px;
    padding: 15px;
    font-size: 18px;
    background: #26262b;
    border: none;
    color: white;
    border-radius: 14px;
}