:root{
  --bg:#f4f6f9; --surface:#ffffff; --surface-2:#eef1f5; --text:#1b2330; --muted:#667085;
  --border:#dde2ea; --primary:#2563eb; --primary-text:#ffffff; --danger:#dc2626; --ok:#16a34a; --warn:#d97706;
  --shadow:0 1px 2px rgba(16,24,40,.06),0 1px 3px rgba(16,24,40,.08); --radius:10px;
}
:root[data-theme="dark"]{
  --bg:#0f141b; --surface:#171e28; --surface-2:#1f2733; --text:#e6ebf2; --muted:#93a0b4;
  --border:#2a3445; --primary:#4f8bff; --primary-text:#0b1220; --danger:#f87171; --ok:#4ade80; --warn:#fbbf24;
  --shadow:none;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--text);font-size:15px;line-height:1.45}
a{color:var(--primary);text-decoration:none}
h1{font-size:1.35rem;margin:0 0 1rem}
h2{font-size:1.05rem;margin:0 0 .75rem}

/* Layout */
.app{display:flex;min-height:100vh}
.sidebar{width:230px;background:var(--surface);border-right:1px solid var(--border);padding:1rem .75rem;display:flex;flex-direction:column;gap:.25rem;position:sticky;top:0;height:100vh;overflow:auto}
.brand{font-weight:700;font-size:1.05rem;padding:.25rem .5rem 1rem}
.brand small{display:block;font-weight:400;color:var(--muted);font-size:.78rem}
.nav a{display:block;padding:.55rem .75rem;border-radius:8px;color:var(--text)}
.nav a:hover{background:var(--surface-2)}
.nav a.active{background:var(--primary);color:var(--primary-text)}
.sidebar .spacer{flex:1}
.main{flex:1;min-width:0;display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;gap:.75rem;padding:.65rem 1.25rem;border-bottom:1px solid var(--border);background:var(--surface)}
.topbar .grow{flex:1}
.menu-btn{display:none}
.content{padding:1.25rem;max-width:1200px;width:100%}

/* Components */
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:1rem;margin-bottom:1rem}
.grid{display:grid;gap:1rem}
.grid.cols-4{grid-template-columns:repeat(4,1fr)}
.grid.cols-2{grid-template-columns:repeat(2,1fr)}
.stat .label{color:var(--muted);font-size:.82rem}
.stat .value{font-size:1.45rem;font-weight:700;margin-top:.15rem}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.4rem;padding:.5rem .9rem;border-radius:8px;border:1px solid var(--border);background:var(--surface);color:var(--text);cursor:pointer;font:inherit}
.btn:hover{background:var(--surface-2)}
.btn.primary{background:var(--primary);color:var(--primary-text);border-color:var(--primary)}
.btn.danger{color:var(--danger);border-color:var(--danger)}
.btn.sm{padding:.3rem .6rem;font-size:.85rem}
.btn:disabled{opacity:.5;cursor:not-allowed}
input,select,textarea{width:100%;padding:.55rem .65rem;border:1px solid var(--border);border-radius:8px;background:var(--surface);color:var(--text);font:inherit}
input:focus,select:focus,textarea:focus{outline:2px solid var(--primary);outline-offset:-1px}
input[type=checkbox]{width:auto}
label{display:block;font-size:.85rem;color:var(--muted);margin-bottom:.2rem}
.field{margin-bottom:.8rem}
.row{display:flex;gap:.75rem;flex-wrap:wrap}
.row>*{flex:1;min-width:140px}
.actions{display:flex;gap:.5rem;align-items:center;flex-wrap:wrap}
.table-wrap{overflow-x:auto}
table{width:100%;border-collapse:collapse}
th,td{text-align:left;padding:.6rem .6rem;border-bottom:1px solid var(--border);vertical-align:middle}
th{font-size:.8rem;color:var(--muted);font-weight:600;white-space:nowrap}
td.num,th.num{text-align:right}
.badge{display:inline-block;padding:.1rem .5rem;border-radius:999px;font-size:.75rem;background:var(--surface-2);color:var(--muted)}
.badge.ok{background:rgba(22,163,74,.15);color:var(--ok)}
.badge.warn{background:rgba(217,119,6,.15);color:var(--warn)}
.badge.danger{background:rgba(220,38,38,.15);color:var(--danger)}
.alert{padding:.65rem .9rem;border-radius:8px;margin-bottom:1rem;border:1px solid var(--border)}
.alert.ok{background:rgba(22,163,74,.12);border-color:var(--ok)}
.alert.err{background:rgba(220,38,38,.12);border-color:var(--danger)}
.err-text{color:var(--danger);font-size:.82rem;margin-top:.2rem}
.muted{color:var(--muted)}
.pagination{display:flex;gap:.35rem;margin-top:1rem;flex-wrap:wrap}
.pagination a,.pagination span{padding:.3rem .6rem;border:1px solid var(--border);border-radius:6px;background:var(--surface);font-size:.85rem}
.pagination .active span{background:var(--primary);color:var(--primary-text)}

/* Auth */
.auth{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:1rem}
.auth .box{width:100%;max-width:420px}

/* POS */
.pos{display:grid;grid-template-columns:1fr 380px;gap:1rem;height:calc(100vh - 110px)}
.pos-left,.pos-right{display:flex;flex-direction:column;min-height:0}
.pos-tools{display:flex;gap:.5rem;margin-bottom:.6rem}
.chips{display:flex;gap:.4rem;overflow-x:auto;padding-bottom:.5rem}
.chip{white-space:nowrap;padding:.3rem .75rem;border-radius:999px;border:1px solid var(--border);background:var(--surface);cursor:pointer;font-size:.85rem}
.chip.active{background:var(--primary);color:var(--primary-text);border-color:var(--primary)}
.products{flex:1;overflow:auto;display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:.6rem;align-content:start}
.pcard{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:.7rem;cursor:pointer;text-align:left;display:flex;flex-direction:column;gap:.2rem;font:inherit;color:inherit}
.pcard:hover{border-color:var(--primary)}
.pcard .n{font-weight:600}
.pcard .p{color:var(--primary);font-weight:700}
.pcard .s{font-size:.78rem;color:var(--muted)}
.pcard.out{opacity:.45}
.cart{flex:1;overflow:auto}
.cart-item{display:grid;grid-template-columns:1fr auto;gap:.25rem;padding:.5rem 0;border-bottom:1px solid var(--border)}
.qty{display:flex;align-items:center;gap:.35rem}
.qty button{width:28px;height:28px;border-radius:6px;border:1px solid var(--border);background:var(--surface-2);color:var(--text);cursor:pointer}
.totals{border-top:2px solid var(--border);padding-top:.6rem;margin-top:.4rem}
.totals .line{display:flex;justify-content:space-between;padding:.15rem 0}
.totals .grand{font-size:1.3rem;font-weight:700}
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,.5);display:none;align-items:center;justify-content:center;z-index:50;padding:1rem}
.modal-bg.open{display:flex}
.modal{background:var(--surface);border-radius:var(--radius);padding:1.1rem;width:100%;max-width:420px;max-height:90vh;overflow:auto}
.net{font-size:.78rem;padding:.15rem .5rem;border-radius:999px}
.net.on{background:rgba(22,163,74,.15);color:var(--ok)}
.net.off{background:rgba(220,38,38,.15);color:var(--danger)}

/* Receipt */
.receipt{max-width:340px;margin:0 auto;font-family:ui-monospace,Menlo,monospace;font-size:.85rem}
.receipt hr{border:0;border-top:1px dashed var(--border)}
.receipt .r{display:flex;justify-content:space-between}

@media (max-width:900px){
  .grid.cols-4{grid-template-columns:repeat(2,1fr)}
  .grid.cols-2{grid-template-columns:1fr}
  .sidebar{position:fixed;left:-250px;z-index:40;transition:left .2s;height:100%}
  .sidebar.open{left:0}
  .menu-btn{display:inline-flex}
  .pos{grid-template-columns:1fr;height:auto}
  .products{max-height:50vh}
}
@media print{
  .sidebar,.topbar,.no-print{display:none!important}
  body{background:#fff;color:#000}
  .card{border:0;box-shadow:none}
}