/* ==========================================================================
   Battery Shop POS System - Main Application Stylesheet
   File: assets/css/app.css
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Google Fonts Import (Inter)
   -------------------------------------------------------------------------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

/* --------------------------------------------------------------------------
   2. Design Tokens (:root)
   -------------------------------------------------------------------------- */
:root {
  /* Color Palette */
  --sidebar-bg: #111827;
  --sidebar-header-bg: #0B0F19;
  --sidebar-hover: #1F2937;
  --sidebar-active-bg: rgba(22, 163, 74, 0.14);
  --sidebar-active-accent: #16A34A;
  --sidebar-text: #E2E8F0;
  --sidebar-text-muted: #94A3B8;
  --sidebar-border: #1F2937;

  --app-bg: #F8FAFC;
  --card-bg: #FFFFFF;

  --primary: #16A34A;
  --primary-hover: #15803D;
  --primary-focus: rgba(22, 163, 74, 0.25);
  --primary-tint: #DCFCE7;
  --primary-text: #14532D;

  --danger: #DC2626;
  --danger-hover: #B91C1C;
  --danger-focus: rgba(220, 38, 38, 0.25);
  --danger-tint: #FEE2E2;
  --danger-text: #7F1D1D;

  --warning: #F59E0B;
  --warning-hover: #D97706;
  --warning-focus: rgba(245, 158, 11, 0.25);
  --warning-tint: #FEF3C7;
  --warning-text: #78350F;

  --info: #0284C7;
  --info-tint: #E0F2FE;
  --info-text: #0369A1;

  --text-main: #0F172A;
  --text-muted: #64748B;
  --text-inverse: #FFFFFF;

  --border-color: #E2E8F0;
  --border-light: #F1F5F9;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 15px;
  --text-md: 16px;
  --text-lg: 18px;
  --text-xl: 20px;
  --text-2xl: 24px;
  --text-3xl: 28px;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-base: 1.55;
  --line-height-tight: 1.25;

  /* Spacing Scale (4, 8, 12, 16, 24, 32px) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;

  /* Radii */
  --radius-sm: 6px;
  --radius-btn: 8px;
  --radius-input: 8px;
  --radius-card: 10px;
  --radius-chip: 12px;
  --radius-badge: 12px;
  --radius-full: 9999px;

  /* Shadow - single soft elevation */
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-card: 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-drawer: 4px 0 24px rgba(15, 23, 42, 0.15);

  /* Layout dimensions */
  --sidebar-width: 260px;
  --topbar-height: 64px;
  --content-max-width: 1400px;
  --gutter-mobile: 16px;
  --gutter-desktop: 24px;

  /* Tap target & control heights */
  --control-height: 40px;
  --control-height-sm: 32px;
  --min-tap-target: 44px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

/* --------------------------------------------------------------------------
   3. Base Reset & Typography
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 15px;
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}

body {
  font-family: var(--font-family);
  font-size: var(--text-base);
  line-height: var(--line-height-base);
  color: var(--text-main);
  background-color: var(--app-bg);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body.sidebar-open {
  overflow: hidden;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
}

h1, .page-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.015em;
}

h2 {
  font-size: var(--text-xl);
  font-weight: var(--font-weight-semibold);
}

h3 {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-semibold);
}

p {
  margin-bottom: var(--space-2);
}

p:last-child {
  margin-bottom: 0;
}

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

a:hover {
  color: var(--primary-hover);
}

/* Tabular figures for all currency, numbers, stats, and tables */
table,
.stat-value,
.amount,
.tabular-nums,
.badge,
.price-tag,
[data-tabular="true"] {
  font-variant-numeric: tabular-nums;
}

/* --------------------------------------------------------------------------
   4. Accessibility & Focus States
   -------------------------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

button:focus:not(:focus-visible),
a:focus:not(:focus-visible),
input:focus:not(:focus-visible) {
  outline: none;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* --------------------------------------------------------------------------
   5. Layout Structure (Mobile-First)
   -------------------------------------------------------------------------- */
.app-layout {
  display: flex;
  min-height: 100vh;
  width: 100%;
}

/* Off-canvas Overlay */
.sidebar-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(2px);
  z-index: 1040;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.sidebar-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* Sidebar (Drawer on mobile < 1024px) */
.app-sidebar,
.sidebar {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  width: var(--sidebar-width);
  background-color: var(--sidebar-bg);
  color: var(--sidebar-text);
  z-index: 1050;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-drawer);
  transform: translateX(-100%);
  transition: transform var(--transition-normal) cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

.app-sidebar.open,
.sidebar.active {
  transform: translateX(0);
}

/* Sidebar Header */
.sidebar-header {
  padding: var(--space-5) var(--space-4);
  background-color: var(--sidebar-header-bg);
  border-bottom: 1px solid var(--sidebar-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--sidebar-text);
}

.sidebar-brand-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-btn);
  background-color: var(--primary);
  color: var(--text-inverse);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: var(--font-weight-bold);
  flex-shrink: 0;
}

.sidebar-brand-text h2 {
  font-size: var(--text-md);
  font-weight: var(--font-weight-bold);
  color: var(--text-inverse);
  line-height: 1.2;
}

.sidebar-brand-text span {
  font-size: var(--text-xs);
  color: var(--sidebar-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: var(--font-weight-medium);
}

.sidebar-close-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--min-tap-target);
  height: var(--min-tap-target);
  background: transparent;
  border: none;
  color: var(--sidebar-text-muted);
  font-size: 20px;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.sidebar-close-btn:hover {
  color: var(--text-inverse);
  background-color: var(--sidebar-hover);
}

/* Sidebar Nav */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-3) 0;
}

.sidebar-menu {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar-menu li {
  margin-bottom: 2px;
}

.sidebar-menu a,
.sidebar-nav-link {
  display: flex;
  align-items: center;
  padding: var(--space-3) var(--space-4);
  color: var(--sidebar-text);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  min-height: var(--min-tap-target);
  position: relative;
  transition: background-color var(--transition-fast), color var(--transition-fast), padding-left var(--transition-fast);
}

.sidebar-menu a .nav-icon,
.sidebar-nav-link .nav-icon {
  width: 20px;
  height: 20px;
  margin-right: var(--space-3);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--sidebar-text-muted);
  transition: color var(--transition-fast);
}

.sidebar-menu a:hover,
.sidebar-nav-link:hover {
  background-color: var(--sidebar-hover);
  color: var(--text-inverse);
}

.sidebar-menu a:hover .nav-icon,
.sidebar-nav-link:hover .nav-icon {
  color: var(--text-inverse);
}

/* Active Link State */
.sidebar-menu a.active,
.sidebar-menu a[aria-current="page"],
.sidebar-nav-link.active {
  background-color: var(--sidebar-active-bg);
  color: var(--text-inverse);
  font-weight: var(--font-weight-semibold);
}

.sidebar-menu a.active::before,
.sidebar-menu a[aria-current="page"]::before,
.sidebar-nav-link.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background-color: var(--sidebar-active-accent);
  border-top-right-radius: 2px;
  border-bottom-right-radius: 2px;
}

.sidebar-menu a.active .nav-icon,
.sidebar-menu a[aria-current="page"] .nav-icon,
.sidebar-nav-link.active .nav-icon {
  color: var(--sidebar-active-accent);
}

/* Dropdown Menu in Sidebar */
.sidebar-menu .dropdown > a,
.sidebar-dropdown-toggle {
  cursor: pointer;
  user-select: none;
}

.sidebar-menu .dropdown > a .dropdown-chevron,
.sidebar-dropdown-toggle .dropdown-chevron {
  margin-left: auto;
  width: 16px;
  height: 16px;
  transition: transform var(--transition-normal);
}

.sidebar-menu .dropdown.open > a .dropdown-chevron,
.sidebar-dropdown.open > .sidebar-dropdown-toggle .dropdown-chevron {
  transform: rotate(180deg);
}

.sidebar-menu .dropdown-menu,
.sidebar-submenu {
  list-style: none;
  padding: 0;
  margin: 0;
  max-height: 0;
  overflow: hidden;
  background-color: rgba(0, 0, 0, 0.2);
  transition: max-height var(--transition-normal) ease, opacity var(--transition-normal) ease;
  opacity: 0;
}

.sidebar-menu .dropdown.open .dropdown-menu,
.sidebar-dropdown.open .sidebar-submenu {
  max-height: 400px;
  opacity: 1;
}

.sidebar-menu .dropdown-menu a,
.sidebar-submenu a {
  padding: var(--space-2) var(--space-4) var(--space-2) calc(var(--space-4) + 28px);
  font-size: var(--text-sm);
  color: var(--sidebar-text-muted);
  min-height: 38px;
}

.sidebar-menu .dropdown-menu a:hover,
.sidebar-submenu a:hover {
  color: var(--text-inverse);
  background-color: var(--sidebar-hover);
}

.sidebar-menu .dropdown-menu a.active,
.sidebar-submenu a.active {
  color: var(--text-inverse);
  background-color: var(--sidebar-active-bg);
  font-weight: var(--font-weight-medium);
}

/* Sidebar User Info & Footer */
.sidebar-user-info,
.sidebar .user-info {
  padding: var(--space-4);
  border-top: 1px solid var(--sidebar-border);
  background-color: var(--sidebar-header-bg);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.sidebar-user-info .user-name,
.sidebar .user-info p {
  font-size: var(--text-sm);
  color: var(--sidebar-text-muted);
  margin-bottom: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-user-info .user-name strong,
.sidebar .user-info strong {
  color: var(--text-inverse);
  font-weight: var(--font-weight-semibold);
}

.sidebar-user-info .user-role {
  display: inline-flex;
  align-items: center;
  font-size: var(--text-xs);
  color: var(--primary);
  font-weight: var(--font-weight-medium);
}

/* Logout link special style */
.sidebar-menu .logout-btn,
.sidebar-logout-link {
  color: #F87171 !important;
  border-top: 1px solid var(--sidebar-border);
  margin-top: var(--space-2);
}

.sidebar-menu .logout-btn:hover,
.sidebar-logout-link:hover {
  background-color: rgba(220, 38, 38, 0.15) !important;
  color: #FCA5A5 !important;
}

/* --------------------------------------------------------------------------
   6. Topbar & App Shell Main
   -------------------------------------------------------------------------- */
.app-wrapper {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  width: 100%;
}

.app-topbar,
.top-bar {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--topbar-height);
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 0 var(--gutter-mobile);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  box-shadow: var(--shadow-sm);
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-width: 0;
}

.hamburger-btn,
.toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--min-tap-target);
  height: var(--min-tap-target);
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-btn);
  color: var(--text-main);
  font-size: 20px;
  cursor: pointer;
  flex-shrink: 0;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.hamburger-btn:hover,
.toggle-btn:hover {
  background-color: var(--border-light);
}

/* Breadcrumbs */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--primary);
}

.breadcrumb-separator {
  color: var(--text-muted);
  opacity: 0.6;
}

.breadcrumb-current {
  color: var(--text-main);
  font-weight: var(--font-weight-semibold);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.user-badge {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background-color: var(--app-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
}

.user-badge .user-name {
  font-weight: var(--font-weight-medium);
  color: var(--text-main);
  display: none;
}

@media (min-width: 480px) {
  .user-badge .user-name {
    display: inline;
  }
}

.role-chip {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: capitalize;
  background-color: var(--primary-tint);
  color: var(--primary-text);
}

.role-chip.admin {
  background-color: #EDE9FE;
  color: #5B21B6;
}

.role-chip.staff {
  background-color: var(--primary-tint);
  color: var(--primary-text);
}

/* Content Container */
.content,
.app-main {
  flex: 1;
  padding: var(--space-4) var(--gutter-mobile);
  width: 100%;
  margin-left: 0 !important;
  transition: margin-left var(--transition-normal);
}

.app-container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  width: 100%;
}

/* Page Header */
.page-header {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

@media (min-width: 768px) {
  .page-header {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.page-header h1 {
  margin: 0;
}

.page-header p {
  color: var(--text-muted);
  font-size: var(--text-sm);
  margin-top: var(--space-1);
}

.page-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

/* Footer */
.app-footer,
.footer {
  padding: var(--space-4) var(--gutter-mobile);
  text-align: center;
  font-size: var(--text-xs);
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  background-color: var(--card-bg);
  margin-top: auto;
}

/* --------------------------------------------------------------------------
   7. Desktop Layout (min-width: 1024px)
   -------------------------------------------------------------------------- */
@media (min-width: 1024px) {
  .sidebar-overlay {
    display: none !important;
  }

  .app-sidebar,
  .sidebar {
    transform: translateX(0) !important;
    box-shadow: none;
    border-right: 1px solid var(--sidebar-border);
  }

  .sidebar-close-btn {
    display: none;
  }

  .hamburger-btn,
  .toggle-btn {
    display: none !important;
  }

  .app-wrapper {
    margin-left: var(--sidebar-width);
    width: calc(100% - var(--sidebar-width));
  }

  .app-topbar,
  .top-bar {
    padding: 0 var(--gutter-desktop);
  }

  .content,
  .app-main {
    padding: var(--space-5) var(--gutter-desktop);
  }

  .app-footer,
  .footer {
    padding: var(--space-4) var(--gutter-desktop);
  }
}

/* --------------------------------------------------------------------------
   8. Buttons (.btn)
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: var(--control-height);
  padding: 0 var(--space-4);
  font-family: var(--font-family);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  text-decoration: none;
  border-radius: var(--radius-btn);
  border: 1px solid transparent;
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.btn:disabled,
.btn[disabled] {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

/* Primary Button */
.btn-primary,
.btn-success {
  background-color: var(--primary);
  color: var(--text-inverse) !important;
  border-color: var(--primary);
}

.btn-primary:hover,
.btn-success:hover {
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
  color: var(--text-inverse) !important;
}

.btn-primary:focus-visible,
.btn-success:focus-visible {
  box-shadow: 0 0 0 3px var(--primary-focus);
}

/* Secondary Button */
.btn-secondary,
.btn-outline {
  background-color: var(--card-bg);
  color: var(--text-main) !important;
  border-color: var(--border-color);
}

.btn-secondary:hover,
.btn-outline:hover {
  background-color: var(--border-light);
  border-color: #CBD5E1;
  color: var(--text-main) !important;
}

/* Danger Button */
.btn-danger {
  background-color: var(--danger);
  color: var(--text-inverse) !important;
  border-color: var(--danger);
}

.btn-danger:hover {
  background-color: var(--danger-hover);
  border-color: var(--danger-hover);
  color: var(--text-inverse) !important;
}

.btn-danger:focus-visible {
  box-shadow: 0 0 0 3px var(--danger-focus);
}

/* Small Button */
.btn-sm {
  height: var(--control-height-sm);
  padding: 0 var(--space-3);
  font-size: var(--text-xs);
  border-radius: var(--radius-sm);
}

/* Icon-only button */
.btn-icon {
  width: var(--control-height);
  padding: 0;
  flex-shrink: 0;
}

.btn-icon.btn-sm {
  width: var(--control-height-sm);
}

/* Sticky Bottom-Right FAB for Mobile (< 768px) */
@media (max-width: 767px) {
  .page-header .btn-primary,
  .fab-new-sale {
    position: fixed;
    bottom: 20px;
    right: 20px;
    height: 52px;
    padding: 0 20px;
    border-radius: var(--radius-full);
    box-shadow: 0 4px 12px rgba(22, 163, 74, 0.4);
    z-index: 990;
    font-size: var(--text-base);
    font-weight: var(--font-weight-semibold);
  }
}

/* --------------------------------------------------------------------------
   9. Cards & Stat Widgets
   -------------------------------------------------------------------------- */
.card,
.summary-card,
.stat-card,
.login-box {
  background-color: var(--card-bg);
  border-radius: var(--radius-card);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-card);
  padding: var(--space-5);
  margin-bottom: var(--space-5);
}

/* Stat Cards Grid */
.dashboard-stats,
.sales-summary {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
}

@media (min-width: 640px) {
  .sales-summary {
    grid-template-columns: repeat(2, 1fr);
  }
  .dashboard-stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .dashboard-stats {
    grid-template-columns: repeat(3, 1fr);
  }
}

.summary-card,
.stat-card {
  margin-bottom: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
}

.summary-card h3,
.stat-card h3,
.stat-label {
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-2);
}

.summary-card .amount,
.stat-card .stat-info h3,
.stat-value {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-main);
  margin: 0;
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
}

.stat-alert {
  display: inline-flex;
  align-items: center;
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  color: var(--danger);
  font-weight: var(--font-weight-medium);
}

/* --------------------------------------------------------------------------
   10. Forms, Inputs & Filters
   -------------------------------------------------------------------------- */
.form-group {
  margin-bottom: var(--space-4);
}

.form-group label,
label {
  display: block;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-main);
  margin-bottom: var(--space-2);
}

input[type="text"],
input[type="number"],
input[type="password"],
input[type="email"],
input[type="date"],
input[type="search"],
select,
textarea {
  width: 100%;
  height: var(--control-height);
  padding: 0 var(--space-3);
  font-family: var(--font-family);
  font-size: 16px; /* Prevents iOS zoom */
  color: var(--text-main);
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-input);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
}

textarea {
  height: auto;
  min-height: 90px;
  padding: var(--space-3);
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2364748B'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 36px;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-focus);
  outline: none;
}

.form-error,
.field-error {
  display: block;
  font-size: var(--text-xs);
  color: var(--danger);
  margin-top: var(--space-1);
  font-weight: var(--font-weight-medium);
}

/* Filters Bar */
.filters,
.filter-bar {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.filters select,
.filter-bar select {
  max-width: 240px;
  height: var(--control-height);
}

/* POS Layout & POS Components */
.pos-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  align-items: start;
}

@media (min-width: 1024px) {
  .pos-container {
    grid-template-columns: minmax(0, 1fr) 430px;
  }

  .pos-cart {
    position: sticky;
    top: calc(var(--topbar-height) + 16px);
  }
}

.pos-search-bar {
  margin-bottom: var(--space-4);
  position: relative;
}

.pos-search-bar input {
  padding-left: 38px;
}

.pos-search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: var(--space-3);
}

.product-card {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card);
  padding: var(--space-3);
  cursor: pointer;
  background-color: var(--card-bg);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 120px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
  user-select: none;
}

.product-card:hover {
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(22, 163, 74, 0.12);
  transform: translateY(-2px);
}

.product-card:active {
  transform: scale(0.98);
}

.product-card .product-name {
  font-weight: var(--font-weight-semibold);
  font-size: var(--text-sm);
  color: var(--text-main);
  line-height: 1.35;
  margin-bottom: var(--space-1);
}

.product-card .product-stock {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.product-card .product-price {
  font-weight: var(--font-weight-bold);
  font-size: var(--text-base);
  color: var(--primary);
  margin-top: var(--space-2);
  font-variant-numeric: tabular-nums;
}

/* Cart Quantity Stepper */
.cart-qty-stepper {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--card-bg);
  overflow: hidden;
}

.qty-step-btn {
  width: 26px;
  height: 28px;
  padding: 0;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--app-bg);
  border: none;
  color: var(--text-main);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: background-color var(--transition-fast);
  user-select: none;
}

.qty-step-btn:hover {
  background-color: var(--border-color);
}

.qty-step-btn:active {
  background-color: #CBD5E1;
}

.pos-qty-input {
  width: 36px !important;
  height: 28px !important;
  padding: 0 2px !important;
  margin: 0 !important;
  border: none !important;
  border-left: 1px solid var(--border-color) !important;
  border-right: 1px solid var(--border-color) !important;
  border-radius: 0 !important;
  text-align: center !important;
  font-size: 13px !important;
  font-weight: 600 !important;
  color: var(--text-main) !important;
  background: var(--card-bg) !important;
  font-variant-numeric: tabular-nums !important;
  -moz-appearance: textfield;
}

.pos-qty-input::-webkit-outer-spin-button,
.pos-qty-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* --------------------------------------------------------------------------
   11. Data Tables & Responsive Stacked Cards Pattern
   -------------------------------------------------------------------------- */
.table-card,
.table-responsive {
  background-color: var(--card-bg);
  border-radius: var(--radius-card);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  margin-bottom: var(--space-5);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: var(--text-sm);
  background-color: var(--card-bg);
}

.data-table thead {
  background-color: var(--app-bg);
  border-bottom: 1px solid var(--border-color);
}

.data-table th {
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  white-space: nowrap;
}

.data-table td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-light);
  color: var(--text-main);
  vertical-align: middle;
}

.data-table tbody tr {
  transition: background-color var(--transition-fast);
}

.data-table tbody tr:hover {
  background-color: #F8FAFC;
}

.data-table tbody tr:last-child td {
  border-bottom: none;
}

/* Mobile Stacked Card Pattern (< 768px) */
@media (max-width: 767px) {
  .table-responsive,
  .table-card {
    background: transparent;
    border: none;
    box-shadow: none;
    overflow: visible;
  }

  .data-table {
    display: block;
    background: transparent;
  }

  .data-table thead {
    display: none; /* Hide column headers on mobile */
  }

  .data-table tbody {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
  }

  .data-table tbody tr {
    display: block;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-card);
    padding: var(--space-4);
  }

  .data-table td {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-2) 0;
    border-bottom: 1px solid var(--border-light);
    font-size: var(--text-sm);
  }

  .data-table td:last-child {
    border-bottom: none;
    padding-top: var(--space-3);
  }

  /* Key data-label generator */
  .data-table td::before {
    content: attr(data-label);
    font-weight: var(--font-weight-medium);
    font-size: var(--text-xs);
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    flex-shrink: 0;
    margin-right: var(--space-3);
  }

  /* Specific styling for action buttons in mobile cards */
  .data-table td[data-label="Actions"],
  .data-table td.actions-cell {
    display: flex;
    justify-content: stretch;
  }

  .data-table td[data-label="Actions"]::before,
  .data-table td.actions-cell::before {
    display: none;
  }

  .data-table td[data-label="Actions"] .btn,
  .data-table td.actions-cell .btn {
    width: 100%;
  }

  /* Primary emphasised row for amount */
  .data-table td.amount-cell,
  .data-table td[data-label="Final Amount"],
  .data-table td[data-label="Total Amount"] {
    font-size: var(--text-md);
    font-weight: var(--font-weight-bold);
    color: var(--text-main);
  }

  .data-table td.muted-cell,
  .data-table td[data-label="Staff"],
  .data-table td[data-label="Payment Method"] {
    font-size: var(--text-xs);
    color: var(--text-muted);
  }
}

/* --------------------------------------------------------------------------
   12. Badges & Status Chips
   -------------------------------------------------------------------------- */
.badge,
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 3px 10px;
  border-radius: var(--radius-chip);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  line-height: 1.3;
  text-transform: capitalize;
  white-space: nowrap;
}

/* Status variants */
.badge-success,
.status-badge.completed,
.status-badge.in-stock,
.status-badge.paid {
  background-color: var(--primary-tint);
  color: var(--primary-text);
}

.badge-warning,
.status-badge.pending,
.status-badge.low-stock {
  background-color: var(--warning-tint);
  color: var(--warning-text);
}

.badge-danger,
.status-badge.cancelled,
.status-badge.out-of-stock {
  background-color: var(--danger-tint);
  color: var(--danger-text);
}

.badge-info,
.status-badge.in_progress {
  background-color: var(--info-tint);
  color: var(--info-text);
}

.badge-neutral {
  background-color: var(--border-light);
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   13. Alerts & Notifications
   -------------------------------------------------------------------------- */
.alert {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-btn);
  font-size: var(--text-sm);
  margin-bottom: var(--space-4);
  border: 1px solid transparent;
  animation: slideDownFade 300ms ease forwards;
}

.alert-success {
  background-color: var(--primary-tint);
  color: var(--primary-text);
  border-color: #86EFAC;
}

.alert-error,
.alert-danger {
  background-color: var(--danger-tint);
  color: var(--danger-text);
  border-color: #FCA5A5;
}

.alert-warning {
  background-color: var(--warning-tint);
  color: var(--warning-text);
  border-color: #FDE68A;
}

@keyframes slideDownFade {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* --------------------------------------------------------------------------
   14. Empty States
   -------------------------------------------------------------------------- */
.empty-state {
  padding: var(--space-6) var(--space-4);
  text-align: center;
  background-color: var(--card-bg);
  border-radius: var(--radius-card);
  border: 1px solid var(--border-color);
  margin-bottom: var(--space-5);
}

.empty-state-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto var(--space-3);
  color: var(--text-muted);
  opacity: 0.6;
}

.empty-state-title {
  font-size: var(--text-md);
  font-weight: var(--font-weight-semibold);
  color: var(--text-main);
  margin-bottom: var(--space-1);
}

.empty-state-text {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

/* --------------------------------------------------------------------------
   15. Login Page Styles
   -------------------------------------------------------------------------- */
.login-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background-color: var(--sidebar-bg);
  padding: var(--space-4);
}

.login-container {
  width: 100%;
  max-width: 420px;
}

.login-box {
  background: var(--card-bg);
  border-radius: var(--radius-card);
  padding: var(--space-6);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2);
}

.login-header {
  text-align: center;
  margin-bottom: var(--space-5);
}

.login-header h1 {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-main);
  margin-bottom: var(--space-1);
}

.login-header p {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.login-box .btn-primary {
  width: 100%;
  height: 44px;
  font-size: var(--text-base);
  margin-top: var(--space-2);
}

.demo-accounts {
  margin-top: var(--space-5);
  padding: var(--space-3) var(--space-4);
  background-color: var(--app-bg);
  border-radius: var(--radius-btn);
  border: 1px solid var(--border-color);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.demo-accounts p {
  margin-bottom: var(--space-1);
}

/* --------------------------------------------------------------------------
   16. Print Stylesheet (80mm Thermal Receipt)
   -------------------------------------------------------------------------- */
@media print {
  body {
    background: #FFFFFF !important;
    color: #000000 !important;
    font-family: var(--font-mono) !important;
    font-size: 12px !important;
    width: 80mm !important;
    margin: 0 !important;
    padding: 4mm !important;
  }

  .app-sidebar,
  .sidebar,
  .sidebar-overlay,
  .app-topbar,
  .top-bar,
  .app-footer,
  .footer,
  .no-print,
  button,
  .btn {
    display: none !important;
  }

  .app-wrapper,
  .content,
  .app-main,
  .app-container {
    margin: 0 !important;
    padding: 0 !important;
    width: 100% !important;
    max-width: 80mm !important;
  }

  .receipt-container {
    width: 80mm !important;
    margin: 0 auto !important;
    box-shadow: none !important;
    border: none !important;
    padding: 0 !important;
  }

  table {
    width: 100% !important;
    border-collapse: collapse !important;
  }

  th, td {
    font-variant-numeric: tabular-nums !important;
    padding: 2px 0 !important;
  }
}