:root {
    --primary: #2563eb;
    --success-bg: #dcfce7;
    --success-text: #166534;
    --error-bg: #fee2e2;
    --error-text: #991b1b;
}

body {
    background-color: #f1f5f9;
    font-family: 'Segoe UI', system-ui, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.payment-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
}

.order-summary {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.order-summary h3 { width: 100%; margin: 0 0 10px 0; font-size: 1rem; color: #64748b; text-transform: uppercase; }
.item-details { display: flex; flex-direction: column; }
.item-name { color: #1e293b; font-size: 1.1rem; }
.item-size { color: #64748b; font-size: 0.85rem; }
.item-price { font-size: 1.2rem; font-weight: bold; color: var(--primary); }

hr { border: 0; border-top: 1px solid #e2e8f0; margin: 1.5rem 0; }

.form-group { margin-bottom: 1rem; }
.form-row { display: flex; gap: 1rem; }
.flex-2 { flex: 2; }
.flex-1 { flex: 1; }

label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 0.4rem; color: #475569; }

input {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #cbd5e1;
    border-radius: 0.4rem;
    box-sizing: border-box;
}

.btn-pay {
    background-color: var(--primary);
    color: white;
    border: none;
    width: 100%;
    padding: 1rem;
    border-radius: 0.4rem;
    font-weight: bold;
    font-size: 1rem;
    cursor: pointer;
    margin-top: 1rem;
}

.alert {
    padding: 1rem;
    border-radius: 0.4rem;
    margin-bottom: 1rem;
    text-align: center;
    font-size: 0.9rem;
}

.success { background: var(--success-bg); color: var(--success-text); }
.error { background: var(--error-bg); color: var(--error-text); }
body.light {
        background: #ffffff;
        color: #000000;
    }

    body.dark {
        background: #121212;
        color: #eeeeee;
    }

    body.dark .top-bar,
    body.dark .profile-card,
    body.dark .product-card {
        background: #1e1e1e;
        color: #eeeeee;
    }

    body.dark a {
        color: #9ecfff;
    }