:root {
    --bg: #0f172a;
    --card-bg: #1e293b;
    --text: #f8fafc;
    --primary: #3b82f6;
    --success: #10b981;
}
body {
    font-family: system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    margin: 0;
    padding: 2rem;
}
.physical-card {
    background: linear-gradient(135deg, #2563eb, #1e40af);
    border-radius: 1rem;
    padding: 1.5rem;
    width: 350px;
    height: 200px;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
    overflow: hidden;
}
.card-chip {
    width: 40px; height: 30px; background: gold; border-radius: 4px;
}
.balance { font-size: 2rem; font-weight: bold; margin: 0; }
.card-number { letter-spacing: 2px; font-family: monospace; }
/* Form styling for JS-free approach */
form { background: var(--card-bg); padding: 1.5rem; border-radius: 0.5rem; margin-top: 1rem; }
input { display: block; width: 100%; padding: 0.5rem; margin-bottom: 1rem; border-radius: 0.25rem; border: none; }
button { background: var(--primary); color: white; padding: 0.5rem 1rem; border: none; border-radius: 0.25rem; cursor: pointer; }
.disclaimer { font-size: 0.75rem; color: #94a3b8; margin-top: 1rem; text-align: center; }