:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --success: #16a34a;
  --danger: #dc2626;
  --warning: #d97706;
  --bg: #f1f5f9;
  --card: #ffffff;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
  --radius: 10px;
}

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

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

/* ---- Layout shell ---- */
.app-shell { display: flex; min-height: 100vh; }

.sidebar {
  width: 230px;
  background: #0f172a;
  color: #cbd5e1;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}
.sidebar .brand {
  padding: 18px 16px;
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  border-bottom: 1px solid #1e293b;
}
.sidebar nav { flex: 1; padding: 10px 0; }
.sidebar nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  color: #94a3b8;
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: 0.15s;
}
.sidebar nav a:hover { background: #1e293b; color: #fff; }
.sidebar nav a.active {
  background: #1e293b; color: #fff; border-left-color: var(--primary);
}
.sidebar .logout {
  padding: 14px 16px;
  border-top: 1px solid #1e293b;
  color: #94a3b8;
  text-decoration: none;
}
.sidebar .logout:hover { color: var(--danger); }

.main {
  flex: 1;
  padding: 20px;
  overflow-x: hidden;
}

/* ---- Top header ---- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
  flex-wrap: wrap;
  gap: 10px;
}
.topbar h1 { font-size: 22px; }
.topbar .user { font-size: 14px; color: var(--muted); }

/* ---- Cards / grid ---- */
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: 1fr 1fr; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 16px;
  border: 1px solid var(--border);
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.card h2 { font-size: 16px; margin-bottom: 12px; }

/* ---- Forms ---- */
label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 4px; }
input, select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  background: #fff;
  color: var(--text);
}
input:focus, select:focus, textarea:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
}
.form-group { margin-bottom: 14px; }

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 16px;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: 0.15s;
  text-decoration: none;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { filter: brightness(1.08); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { filter: brightness(1.08); }
.btn-warning { background: var(--warning); color: #fff; }
.btn-ghost { background: transparent; color: var(--muted); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--bg); }
.btn-block { width: 100%; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-sm { padding: 6px 10px; font-size: 13px; }

/* ---- Tables ---- */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 500px; }
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); }
th { background: #f8fafc; color: var(--muted); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: 0.03em; }
tr:hover td { background: #f8fafc; }
td.num, th.num { text-align: right; }
.text-right { text-align: right; }

/* ---- Alerts ---- */
.alert {
  padding: 12px 14px;
  border-radius: 8px;
  margin-bottom: 14px;
  font-size: 14px;
}
.alert-success { background: #dcfce7; color: #166534; }
.alert-error { background: #fee2e2; color: #991b1b; }
.alert-info { background: #dbeafe; color: #1e40af; }

/* ---- POS specific ---- */
.pos-layout { display: grid; grid-template-columns: 1fr 380px; gap: 16px; align-items: start; }
.pos-items {
  max-height: 55vh;
  overflow-y: auto;
}
.pos-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 8px;
  background: #fff;
}
.pos-item .info { flex: 1; }
.pos-item .pname { font-weight: 600; font-size: 14px; }
.pos-item .psub { color: var(--muted); font-size: 12px; }
.pos-item .qty-ctrl { display: flex; align-items: center; gap: 6px; }
.pos-item .qty-ctrl button {
  width: 30px; height: 30px;
  border: 1px solid var(--border); border-radius: 6px;
  background: #fff; cursor: pointer; font-size: 16px;
}
.pos-item .qty-ctrl input {
  width: 48px; text-align: center; padding: 6px; font-size: 14px;
}
.pos-totals { margin: 12px 0; }
.pos-totals .row { display: flex; justify-content: space-between; padding: 8px 0; font-size: 15px; }
.pos-totals .grand { font-size: 22px; font-weight: 700; border-top: 2px solid var(--border); padding-top: 10px; }
.payment-methods { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; margin-bottom: 12px; }
.payment-methods button {
  padding: 12px 8px;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: #fff;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
}
.payment-methods button.active { border-color: var(--primary); background: #eff6ff; color: var(--primary); }
.scan-bar { display: flex; gap: 8px; margin-bottom: 14px; }
.scan-bar input { flex: 1; font-size: 17px; }

/* ---- Login ---- */
.login-wrap {
  display: flex; align-items: center; justify-content: center;
  min-height: 100vh; background: linear-gradient(135deg, #1e3a8a, #2563eb);
}
.login-card {
  background: #fff; border-radius: 14px; padding: 36px;
  width: 100%; max-width: 380px; box-shadow: 0 20px 50px rgba(0,0,0,0.25);
}
.login-card h1 { font-size: 22px; margin-bottom: 6px; text-align: center; }
.login-card p { text-align: center; color: var(--muted); margin-bottom: 22px; font-size: 14px; }

/* ---- Badges ---- */
.badge {
  display: inline-block; padding: 3px 8px; border-radius: 20px;
  font-size: 12px; font-weight: 600;
}
.badge-green { background: #dcfce7; color: #166534; }
.badge-red { background: #fee2e2; color: #991b1b; }
.badge-gray { background: #e2e8f0; color: #475569; }
.badge-yellow { background: #fef3c7; color: #92400e; }

/* ---- Modal ---- */
.modal-overlay {
  display: none;
  position: fixed; inset: 0;
  background: rgba(15,23,42,0.5);
  z-index: 100;
  align-items: center; justify-content: center;
  padding: 20px;
}
.modal-overlay.show { display: flex; }
.modal {
  background: #fff; border-radius: 12px;
  padding: 22px; width: 100%; max-width: 440px; max-height: 90vh; overflow-y: auto;
}
.modal h3 { margin-bottom: 16px; }

/* ---- Helpers ---- */
.flex { display: flex; gap: 8px; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }
.mt-1 { margin-top: 6px; } .mt-2 { margin-top: 12px; } .mt-3 { margin-top: 18px; }
.mb-2 { margin-bottom: 12px; }
.text-muted { color: var(--muted); }
.small { font-size: 12px; }

/* ---- Mobile responsive ---- */
.hamburger { display: none; }

@media (max-width: 900px) {
  .pos-layout, .grid-2, .grid-3 { grid-template-columns: 1fr; }
}

.product-thumb {
  width: 40px;
  height: 40px;
  object-fit: cover;
  border-radius: 4px;
  border: 1px solid var(--border);
}
.product-thumb-empty {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--muted);
  font-size: 10px;
  text-align: center;
}
.cart-item-img {
  width: 50px;
  height: 50px;
  object-fit: cover;
  border-radius: 6px;
  border: 1px solid var(--border);
  margin-right: 8px;
}

@media (max-width: 768px) {
  .sidebar {
    position: fixed; left: 0; top: 0; bottom: 0; z-index: 200;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    width: 250px;
  }
  .sidebar.open { transform: translateX(0); }
  .main { padding: 14px; }
  .overlay {
    display: none;
    position: fixed; inset: 0; background: rgba(0,0,0,0.4); z-index: 150;
  }
  .overlay.show { display: block; }
  .hamburger {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px; background: var(--card); border: 1px solid var(--border);
    border-radius: 8px; cursor: pointer; font-size: 20px;
  }
  .topbar { flex-direction: row; }
}