:root {
    --primary: #1e5f8a;
    --primary-dark: #164a6b;
    --accent: #f2994a;
    --bg: #f4f6f8;
    --card: #ffffff;
    --border: #dfe4ea;
    --text: #2b2f36;
    --muted: #6b7280;
    --danger: #c0392b;
    --success: #1e824c;
}
* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}
.container { max-width: 1200px; margin: 0 auto; padding: 20px; }

.topbar {
    display: flex; align-items: center; gap: 24px;
    background: var(--primary); color: #fff; padding: 12px 24px;
}
.topbar .brand { font-weight: 700; font-size: 1.1rem; }
.topbar nav { display: flex; gap: 16px; flex: 1; }
.topbar nav a { color: #eaf2f8; text-decoration: none; padding: 6px 10px; border-radius: 4px; }
.topbar nav a.active, .topbar nav a:hover { background: var(--primary-dark); }
.user-menu { display: flex; align-items: center; gap: 12px; font-size: 0.9rem; }
.btn-link { color: #fff; text-decoration: underline; }

.alert { padding: 10px 14px; border-radius: 6px; margin-bottom: 16px; }
.alert-success { background: #e3f6e9; color: var(--success); border: 1px solid #b7e4c7; }
.alert-error { background: #fdecea; color: var(--danger); border: 1px solid #f5c6cb; }

.login-wrap { display: flex; justify-content: center; align-items: center; min-height: 70vh; }
.login-card {
    background: var(--card); padding: 32px; border-radius: 10px; width: 320px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
}
.login-card h1 { text-align: center; font-size: 1.3rem; margin-bottom: 20px; color: var(--primary); }

input, select, textarea, button {
    font-family: inherit; font-size: 0.95rem;
}
label { display: block; margin: 10px 0 4px; font-weight: 600; font-size: 0.85rem; color: var(--muted); }
input[type=text], input[type=password], input[type=number], input[type=date], select, textarea {
    width: 100%; padding: 8px 10px; border: 1px solid var(--border); border-radius: 6px;
}
.btn {
    display: inline-block; padding: 8px 16px; border-radius: 6px; border: 1px solid var(--border);
    background: #fff; color: var(--text); text-decoration: none; cursor: pointer;
}
.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-dark); }
.btn-block { width: 100%; margin-top: 12px; }

.pos-layout { display: grid; grid-template-columns: 1.6fr 1fr; gap: 20px; }
.pos-catalog { background: var(--card); padding: 16px; border-radius: 10px; }
.pos-catalog input { margin-bottom: 12px; }
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; max-height: 65vh; overflow-y: auto; }
.product-card {
    border: 1px solid var(--border); border-radius: 8px; padding: 10px; cursor: pointer; background: #fafbfc;
}
.product-card:hover { border-color: var(--primary); background: #eef6fb; }
.product-card.out-of-stock { opacity: 0.5; cursor: not-allowed; }
.p-name { font-weight: 600; font-size: 0.9rem; }
.p-sku { font-size: 0.75rem; color: var(--muted); }
.p-price { color: var(--primary); font-weight: 700; margin-top: 4px; }
.p-stock { font-size: 0.75rem; color: var(--muted); }

.pos-cart { background: var(--card); padding: 16px; border-radius: 10px; }
.cart-table { width: 100%; border-collapse: collapse; margin-bottom: 12px; }
.cart-table th, .cart-table td { padding: 6px 4px; border-bottom: 1px solid var(--border); font-size: 0.85rem; }
.cart-table input.qty-input { width: 50px; padding: 4px; }
.btn-remove { background: none; border: none; color: var(--danger); font-size: 1.2rem; cursor: pointer; }
.cart-totals .row { display: flex; justify-content: space-between; padding: 4px 0; }
.cart-totals .total-row { font-weight: 700; font-size: 1.1rem; border-top: 1px solid var(--border); margin-top: 6px; padding-top: 8px; }
.cart-payment { margin-top: 10px; }

.data-table { width: 100%; border-collapse: collapse; background: var(--card); border-radius: 8px; overflow: hidden; }
.data-table th, .data-table td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); font-size: 0.9rem; }
.data-table thead { background: #eef1f4; }
.data-table tr.low-stock { background: #fff7e6; }

.filter-bar { display: flex; gap: 10px; align-items: flex-end; margin-bottom: 16px; }
.filter-bar input { width: auto; }
.page-actions { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }

.form-card { background: var(--card); padding: 20px; border-radius: 10px; max-width: 520px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.form-actions { margin-top: 16px; display: flex; gap: 10px; }

.stat-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin: 16px 0 24px; }
.stat-card { background: var(--card); border-radius: 10px; padding: 16px; text-align: center; }
.stat-card h3 { margin: 0; font-size: 1.6rem; color: var(--primary); }
.stat-card p { margin: 4px 0 0; color: var(--muted); }

.receipt-wrap { display: flex; flex-direction: column; align-items: center; gap: 16px; }
.receipt { background: #fff; width: 320px; padding: 20px; font-family: "Courier New", monospace; font-size: 0.85rem; border: 1px solid var(--border); }
.receipt h2 { text-align: center; margin: 0 0 6px; }
.receipt-table { width: 100%; border-collapse: collapse; }
.receipt-table th, .receipt-table td { padding: 3px 0; font-size: 0.8rem; text-align: left; }
.receipt-totals { line-height: 1.6; }
.receipt-footer { text-align: center; margin-top: 10px; }

@media print {
    .topbar, .no-print { display: none !important; }
    .container { padding: 0; }
    .receipt { border: none; width: 100%; }
}

@media (max-width: 900px) {
    .pos-layout { grid-template-columns: 1fr; }
    .topbar { flex-wrap: wrap; }
    .form-row, .stat-cards { grid-template-columns: 1fr; }
}