:root {
    --bg-primary: #1a1d23;
    --bg-secondary: #22262e;
    --bg-card: #2a2f38;
    --text-primary: #e4e6eb;
    --text-secondary: #9ca3af;
    --accent-blue: #3b82f6;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    --accent-purple: #8b5cf6;
    --accent-orange: #f59e0b;
    --border-color: #374151;
    --sidebar-width: 250px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

/* Login */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a1d23 0%, #2d3748 100%);
}

.login-container { width: 100%; max-width: 400px; padding: 20px; }

.login-card {
    background: var(--bg-card);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.login-card h1 {
    text-align: center;
    font-size: 28px;
    margin-bottom: 5px;
    color: var(--accent-blue);
}

.subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.form-group { margin-bottom: 20px; }

.form-group label {
    display: block;
    margin-bottom: 6px;
    color: var(--text-secondary);
    font-size: 14px;
}

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 15px;
    transition: border-color 0.2s;
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--accent-blue);
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.2s;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary { background: var(--accent-blue); color: white; }
.btn-primary:hover { background: #2563eb; }
.btn-success { background: var(--accent-green); color: white; }
.btn-success:hover { background: #059669; }
.btn-danger { background: var(--accent-red); color: white; }
.btn-danger:hover { background: #dc2626; }
.btn-warning { background: var(--accent-orange); color: #1a1d23; }
.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn-block { width: 100%; }

.alert {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-error { background: rgba(239,68,68,0.15); color: var(--accent-red); border: 1px solid rgba(239,68,68,0.3); }
.alert-success { background: rgba(16,185,129,0.15); color: var(--accent-green); border: 1px solid rgba(16,185,129,0.3); }

/* Layout */
.sidebar {
    position: fixed;
    left: 0; top: 0; bottom: 0;
    width: var(--sidebar-width);
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    z-index: 100;
}

.sidebar-header {
    padding: 24px 20px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h2 {
    font-size: 20px;
    color: var(--accent-blue);
}

.nav-menu {
    list-style: none;
    padding: 12px 0;
    flex: 1;
}

.nav-menu li a {
    display: block;
    padding: 12px 20px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.2s;
    font-size: 15px;
}

.nav-menu li a:hover, .nav-menu li.active a {
    color: var(--text-primary);
    background: rgba(59,130,246,0.1);
    border-left: 3px solid var(--accent-blue);
}

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 14px;
    color: var(--text-secondary);
}

.content {
    margin-left: var(--sidebar-width);
    padding: 30px;
    min-height: 100vh;
}

.content h1 {
    font-size: 26px;
    margin-bottom: 24px;
}

/* Cards */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.card {
    background: var(--bg-card);
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.card h3 {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.card-value {
    font-size: 32px;
    font-weight: 700;
}

.card-sub {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 4px;
}

.card-blue .card-value { color: var(--accent-blue); }
.card-green .card-value { color: var(--accent-green); }
.card-red .card-value { color: var(--accent-red); }
.card-purple .card-value { color: var(--accent-purple); }

/* Tables */
.section { margin-bottom: 30px; }
.section h2 { font-size: 20px; margin-bottom: 16px; }

.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-card);
    border-radius: 12px;
    overflow: hidden;
}

.table th, .table td {
    padding: 14px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: var(--bg-secondary);
    font-size: 13px;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 0.5px;
}

.table td { font-size: 14px; }
.table tr:last-child td { border-bottom: none; }
.table tr:hover td { background: rgba(255,255,255,0.02); }
.text-center { text-align: center !important; }

/* POS Layout */
.pos-layout {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 20px;
    height: calc(100vh - 100px);
}

.pos-products {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pos-search {
    display: flex;
    gap: 10px;
    margin-bottom: 16px;
}

.pos-search input {
    flex: 1;
    padding: 12px 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 16px;
}

.pos-search input:focus { outline: none; border-color: var(--accent-blue); }

.products-list {
    flex: 1;
    overflow-y: auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 12px;
    align-content: start;
}

.product-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 16px;
    cursor: pointer;
    transition: all 0.2s;
}

.product-card:hover {
    border-color: var(--accent-blue);
    transform: translateY(-2px);
}

.product-card .p-name {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 6px;
    line-height: 1.3;
}

.product-card .p-price {
    font-size: 18px;
    font-weight: 700;
    color: var(--accent-green);
}

.product-card .p-stock {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 4px;
}

.product-card.out-of-stock {
    opacity: 0.5;
    pointer-events: none;
}

/* Cart */
.pos-cart {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

.cart-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.cart-items {
    flex: 1;
    overflow-y: auto;
    margin-bottom: 16px;
}

.cart-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 14px;
}

.cart-item-info { flex: 1; }
.cart-item-name { font-weight: 600; margin-bottom: 2px; }
.cart-item-price { color: var(--text-secondary); font-size: 13px; }

.cart-item-qty {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: 0 12px;
}

.cart-item-qty button {
    width: 28px; height: 28px;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.cart-item-qty span { min-width: 24px; text-align: center; font-weight: 600; }

.cart-item-total { font-weight: 700; min-width: 70px; text-align: right; }

.cart-item-remove {
    background: none; border: none;
    color: var(--accent-red);
    cursor: pointer;
    margin-left: 8px;
    font-size: 18px;
}

.cart-summary {
    border-top: 2px solid var(--border-color);
    padding-top: 16px;
}

.cart-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 14px;
}

.cart-row.total {
    font-size: 22px;
    font-weight: 700;
    color: var(--accent-green);
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px solid var(--border-color);
}

.cart-actions {
    margin-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.payment-select {
    width: 100%;
    padding: 10px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
}

.discount-input {
    width: 100%;
    padding: 10px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
}

/* Products CRUD */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.filters-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.filters-bar input, .filters-bar select {
    padding: 10px 14px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
}

.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.active { display: flex; }

.modal {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 30px;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal h2 { margin-bottom: 20px; font-size: 20px; }

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 20px;
}

.stock-low { color: var(--accent-red); font-weight: 600; }
.stock-ok { color: var(--accent-green); }

/* Responsive */
@media (max-width: 1024px) {
    .pos-layout { grid-template-columns: 1fr; height: auto; }
    .pos-cart { max-height: 500px; }
}

@media (max-width: 768px) {
    .sidebar { width: 60px; }
    .sidebar-header h2, .nav-menu li a span, .sidebar-footer span { display: none; }
    .nav-menu li a { padding: 14px; text-align: center; font-size: 18px; }
    .content { margin-left: 60px; padding: 16px; }
    .cards-grid { grid-template-columns: repeat(2, 1fr); }
    .page-header { flex-direction: column; gap: 10px; align-items: stretch; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #4b5563; }