:root {
    --primary: #1e6f5c;
    --primary-dark: #16523f;
    --danger: #c0392b;
    --warning: #d9822b;
    --bg: #f4f6f5;
    --card-bg: #ffffff;
    --border: #e0e4e2;
    --text: #1f2a24;
    --text-muted: #6b7770;
    --radius: 10px;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

a { color: var(--primary); text-decoration: none; }

/* ---------- Login screen ---------- */
.login-body {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}
.login-card {
    background: var(--card-bg);
    padding: 40px 32px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 340px;
    text-align: center;
}
.login-card h1 { margin: 0 0 4px; }
.login-card input {
    width: 100%;
    padding: 12px 14px;
    font-size: 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin: 16px 0;
}

/* ---------- Nav ---------- */
.topnav {
    display: flex;
    align-items: center;
    gap: 24px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px;
    position: sticky;
    top: 0;
    z-index: 20;
}
.topnav-brand { font-weight: 700; font-size: 18px; margin-right: auto; }
.topnav-links { display: flex; gap: 18px; }
.topnav-links a { color: var(--text-muted); font-weight: 600; padding: 6px 4px; border-bottom: 2px solid transparent; }
.topnav-links a.active, .topnav-links a:hover { color: var(--primary); border-color: var(--primary); }
.topnav-logout { color: var(--danger); font-weight: 600; }

.page-wrap { max-width: 1200px; margin: 0 auto; padding: 20px; }

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 18px; border: none; border-radius: var(--radius);
    font-size: 15px; font-weight: 600; cursor: pointer; transition: opacity .15s;
}
.btn:hover { opacity: 0.9; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-secondary { background: #edf1ef; color: var(--text); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-sm { padding: 6px 10px; font-size: 13px; }
.btn-block { width: 100%; }

/* ---------- Cards / panels ---------- */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 18px;
}
h1.page-title { font-size: 22px; margin: 0 0 16px; }

.alert { padding: 10px 14px; border-radius: var(--radius); margin-bottom: 12px; font-size: 14px; }
.alert-error { background: #fdecea; color: var(--danger); }
.alert-success { background: #e8f6ee; color: var(--primary-dark); }
.muted { color: var(--text-muted); font-size: 14px; }

/* ---------- POS layout ---------- */
.pos-layout { display: grid; grid-template-columns: 1fr 360px; gap: 20px; align-items: start; }
@media (max-width: 900px) { .pos-layout { grid-template-columns: 1fr; } }

.pos-search { width: 100%; padding: 12px 14px; font-size: 16px; border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 14px; }

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 12px;
    max-height: 70vh;
    overflow-y: auto;
    padding-right: 4px;
}
.product-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 10px;
    text-align: center;
    cursor: pointer;
    user-select: none;
    transition: transform .1s, box-shadow .1s;
}
.product-card:hover { box-shadow: var(--shadow); transform: translateY(-1px); }
.product-card:active { transform: scale(0.97); }
.product-card.out-of-stock { opacity: 0.45; cursor: not-allowed; }
.product-card .p-name { font-weight: 600; font-size: 14px; margin-bottom: 6px; min-height: 34px; }
.product-card .p-price { color: var(--primary); font-weight: 700; }
.product-card .p-stock { font-size: 12px; color: var(--text-muted); margin-top: 4px; }

.cart-panel { position: sticky; top: 74px; }
.cart-items { max-height: 45vh; overflow-y: auto; margin-bottom: 12px; }
.cart-row { display: flex; align-items: center; gap: 8px; padding: 8px 0; border-bottom: 1px solid var(--border); }
.cart-row .ci-name { flex: 1; font-size: 14px; }
.cart-row .ci-qty-controls { display: flex; align-items: center; gap: 6px; }
.cart-row .ci-qty-controls button {
    width: 26px; height: 26px; border-radius: 6px; border: 1px solid var(--border);
    background: #fff; cursor: pointer; font-weight: 700;
}
.cart-row .ci-line-total { width: 70px; text-align: right; font-weight: 600; font-size: 14px; }
.cart-row .ci-remove { color: var(--danger); cursor: pointer; font-size: 13px; margin-left: 4px; }
.cart-empty { text-align: center; color: var(--text-muted); padding: 30px 0; }

.cart-total-row { display: flex; justify-content: space-between; font-size: 20px; font-weight: 700; padding: 12px 0; border-top: 2px solid var(--border); }

/* ---------- Tables ---------- */
table.data-table { width: 100%; border-collapse: collapse; font-size: 14px; }
table.data-table th, table.data-table td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); }
table.data-table th { color: var(--text-muted); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .04em; }
table.data-table tr:hover td { background: #fafcfb; }
table.data-table input { width: 90px; padding: 6px 8px; border: 1px solid var(--border); border-radius: 6px; }
tr.clickable-row { cursor: pointer; }

.toolbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-bottom: 16px; }
.toolbar input, .toolbar select { padding: 9px 12px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 14px; }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px; margin-bottom: 20px; }
.stat-card { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.stat-card .stat-label { font-size: 13px; color: var(--text-muted); margin-bottom: 6px; }
.stat-card .stat-value { font-size: 26px; font-weight: 700; color: var(--primary-dark); }

/* ---------- Modal ---------- */
.modal-backdrop {
    position: fixed; inset: 0; background: rgba(0,0,0,0.45);
    display: flex; align-items: center; justify-content: center; z-index: 100;
}
.modal { background: #fff; border-radius: var(--radius); padding: 24px; width: 100%; max-width: 420px; max-height: 85vh; overflow-y: auto; }
.modal h2 { margin-top: 0; }
.modal .form-row { margin-bottom: 14px; }
.modal label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; }
.modal input, .modal select { width: 100%; padding: 10px 12px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 15px; }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 18px; }
.hidden { display: none !important; }