:root {
  --primary: #1a3a6b;
  --primary-dark: #0f2550;
  --primary-light: #2d5aa0;
  --accent: #2563eb;
  --bg: #f4f6fb;
  --surface: #ffffff;
  --surface-2: #f8f9fc;
  --border: #d1d9e8;
  --border-light: #e8edf5;
  --text: #1a2740;
  --text-secondary: #5a6a85;
  --text-muted: #8a98b0;
  --success: #16a34a;
  --success-bg: #f0fdf4;
  --success-border: #bbf7d0;
  --warning: #d97706;
  --warning-bg: #fffbeb;
  --warning-border: #fde68a;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --info: #0284c7;
  --info-bg: #f0f9ff;
  --info-border: #bae6fd;
  --nav-width: 220px;
  --header-h: 56px;
  --radius: 6px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.10);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 14px;
  color: var(--text);
  background: var(--bg);
  line-height: 1.5;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

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

.nav {
  width: var(--nav-width);
  background: var(--primary);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 100;
}

.nav-brand {
  padding: 0 20px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.02em;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.nav-menu { flex: 1; padding: 12px 0; overflow-y: auto; }

.nav-section {
  padding: 8px 16px 4px;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.35);
  font-weight: 600;
}

.nav-item {
  display: block;
  padding: 8px 20px;
  color: rgba(255,255,255,0.72);
  font-size: 13.5px;
  transition: background 0.15s, color 0.15s;
  border-left: 3px solid transparent;
}

.nav-item:hover {
  background: rgba(255,255,255,0.06);
  color: #fff;
  text-decoration: none;
}

.nav-item.active {
  background: rgba(255,255,255,0.10);
  color: #fff;
  border-left-color: #60a5fa;
}

.nav-footer {
  padding: 16px 20px;
  border-top: 1px solid rgba(255,255,255,0.08);
}

.nav-footer a {
  color: rgba(255,255,255,0.5);
  font-size: 12.5px;
}
.nav-footer a:hover { color: #fff; }

.main {
  margin-left: var(--nav-width);
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.topbar {
  height: var(--header-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  padding: 0 28px;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow);
}

.topbar-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.topbar-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

.content {
  flex: 1;
  padding: 24px 28px;
}

/* Cards */
.card {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.card-body { padding: 20px; }

/* Stats grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 16px 18px;
  box-shadow: var(--shadow);
}

.stat-label {
  font-size: 11.5px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  margin-bottom: 6px;
}

.stat-value {
  font-size: 26px;
  font-weight: 700;
  color: var(--text);
  line-height: 1;
}

.stat-value.danger { color: var(--danger); }
.stat-value.warning { color: var(--warning); }
.stat-value.success { color: var(--success); }

/* Tables */
.table-wrap { overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
}

thead th {
  background: var(--surface-2);
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

tbody tr { border-bottom: 1px solid var(--border-light); }
tbody tr:last-child { border-bottom: none; }
tbody tr:hover { background: var(--surface-2); }

tbody td {
  padding: 10px 14px;
  color: var(--text);
  vertical-align: middle;
}

/* Badges */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 20px;
  font-size: 11.5px;
  font-weight: 600;
  line-height: 1.6;
}

.badge-success { background: var(--success-bg); color: var(--success); border: 1px solid var(--success-border); }
.badge-danger { background: var(--danger-bg); color: var(--danger); border: 1px solid var(--danger-border); }
.badge-warning { background: var(--warning-bg); color: var(--warning); border: 1px solid var(--warning-border); }
.badge-info { background: var(--info-bg); color: var(--info); border: 1px solid var(--info-border); }
.badge-neutral { background: var(--surface-2); color: var(--text-secondary); border: 1px solid var(--border); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius);
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s;
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover { text-decoration: none; }

.btn-primary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); color: #fff; }

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border);
}
.btn-secondary:hover { background: var(--surface-2); color: var(--text); }

.btn-danger {
  background: var(--danger);
  color: #fff;
  border-color: var(--danger);
}
.btn-danger:hover { background: #b91c1c; color: #fff; }

.btn-sm { padding: 4px 10px; font-size: 12.5px; }
.btn-xs { padding: 2px 8px; font-size: 12px; }

/* Forms */
.form-group { margin-bottom: 16px; }

label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 5px;
}

input[type=text], input[type=password], input[type=number], input[type=email],
select, textarea {
  width: 100%;
  padding: 8px 11px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 13.5px;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.15s, box-shadow 0.15s;
  appearance: none;
  font-family: inherit;
}

input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

textarea { resize: vertical; min-height: 100px; }

.form-hint {
  font-size: 11.5px;
  color: var(--text-muted);
  margin-top: 4px;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

/* Alerts */
.alert {
  padding: 12px 16px;
  border-radius: var(--radius);
  margin-bottom: 20px;
  font-size: 13.5px;
  border: 1px solid;
}

.alert-success { background: var(--success-bg); color: var(--success); border-color: var(--success-border); }
.alert-error { background: var(--danger-bg); color: var(--danger); border-color: var(--danger-border); }
.alert-warning { background: var(--warning-bg); color: var(--warning); border-color: var(--warning-border); }
.alert-info { background: var(--info-bg); color: var(--info); border-color: var(--info-border); }

/* Warning table */
.warning-row { background: var(--warning-bg) !important; }
.critical-row { background: var(--danger-bg) !important; }

/* Page header */
.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.page-header h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

/* Chart container */
.chart-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 24px;
}

.chart-container {
  position: relative;
  height: 240px;
}

/* Login page */
.login-page {
  min-height: 100vh;
  background: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.login-box {
  background: var(--surface);
  border-radius: 8px;
  padding: 36px 40px;
  width: 360px;
  box-shadow: var(--shadow-md);
}

.login-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 24px;
  text-align: center;
}

/* Section spacing */
.section { margin-bottom: 24px; }

/* Filter bar */
.filter-bar {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.filter-bar select,
.filter-bar input {
  width: auto;
  min-width: 160px;
}

/* Truncate */
.truncate {
  max-width: 220px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  display: inline-block;
  vertical-align: bottom;
}

/* Danger text for low stock */
.text-danger { color: var(--danger); font-weight: 600; }
.text-warning { color: var(--warning); font-weight: 600; }
.text-success { color: var(--success); }
.text-muted { color: var(--text-muted); }

/* Checkbox group */
.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  max-height: 180px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px;
}

.checkbox-item {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
}

.checkbox-item input[type=checkbox] {
  width: auto;
}