@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  
  /* Monochromatic Dark Color Palette */
  --bg-primary: #121212;
  --bg-secondary: #0a0a0a;
  --bg-tertiary: #1e1e1e;
  --border-color: #262626;
  --border-hover: #404040;
  --text-primary: #f5f5f5;
  --text-secondary: #a3a3a3;
  --text-tertiary: #525252;
  --accent-color: #ffffff;
  --accent-text: #000000;
  --danger-color: #f43f5e;
  --success-bg: #1e1e1e;
  --success-text: #f5f5f5;
  --warning-bg: #18181b;
  --warning-text: #a3a3a3;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.6), 0 4px 6px -2px rgba(0, 0, 0, 0.4);
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

button, input {
  font-family: inherit;
}

/* Base Layout */
.app-container {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  background-color: var(--bg-primary);
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-lg);
  border-left: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
}

.header {
  padding: 24px 20px 16px 20px;
  border-bottom: 1px solid var(--border-color);
  background-color: rgba(18, 18, 18, 0.85);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header h1 {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.header-actions {
  display: flex;
  gap: 12px;
}

.main-content {
  flex: 1;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 24px;
  overflow-y: auto;
  padding-bottom: 80px; /* Space for bottom nav */
}

/* Typography Utilities */
.section-title {
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

/* Navigation Tabs */
.tab-container {
  display: flex;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 8px;
}

.tab-btn {
  flex: 1;
  background: none;
  border: none;
  padding: 12px 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  position: relative;
  transition: var(--transition-fast);
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  color: var(--text-primary);
  font-weight: 600;
}

.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--accent-color);
}

/* Card & Interactive Elements */
.card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: var(--transition-normal);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-sm);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.card-subtitle {
  font-size: 12px;
  color: var(--text-secondary);
  font-family: monospace;
  margin-top: 2px;
}

/* Form Controls */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  width: 100%;
}

.form-group label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
}

.input-field {
  padding: 10px 14px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: var(--transition-fast);
}

.input-field:focus {
  border-color: var(--accent-color);
}

.input-field::placeholder {
  color: var(--text-tertiary);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  border: 1px solid transparent;
  width: 100%;
}

.btn-primary {
  background-color: var(--accent-color);
  color: var(--accent-text);
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-0.5px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background-color: var(--bg-primary);
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background-color: var(--bg-secondary);
  border-color: var(--border-hover);
}

.btn-danger-link {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-fast);
  border-radius: var(--radius-sm);
}

.btn-danger-link:hover {
  color: var(--danger-color);
  background-color: var(--bg-tertiary);
}

/* Status Badge Styles */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 8px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
}

.badge-in-stock {
  background-color: var(--success-bg);
  color: var(--success-text);
  border: 1px solid var(--border-color);
}

.badge-low-stock {
  background-color: var(--success-bg);
  color: var(--success-text);
  border: 1px dashed var(--border-hover);
}

.badge-out-of-stock {
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.badge-unknown {
  background-color: var(--bg-secondary);
  color: var(--text-tertiary);
  border: 1px solid var(--border-color);
}

/* PIN Verification Page */
.pin-container {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 40px 20px;
  background-color: var(--bg-primary);
  gap: 32px;
}

.pin-header {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.pin-header h2 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.pin-header p {
  font-size: 14px;
  color: var(--text-secondary);
}

.pin-input-group {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
  max-width: 280px;
}

.pin-dots {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 24px;
}

.pin-dot {
  width: 12px;
  height: 12px;
  border-radius: var(--radius-full);
  border: 1px solid var(--text-tertiary);
  transition: var(--transition-fast);
}

.pin-dot.filled {
  background-color: var(--accent-color);
  border-color: var(--accent-color);
  transform: scale(1.1);
}

.pin-keypad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  width: 100%;
}

.keypad-btn {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  aspect-ratio: 1;
  font-size: 20px;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-fast);
}

.keypad-btn:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--border-hover);
}

.keypad-btn:active {
  transform: scale(0.95);
}

.keypad-btn.empty {
  background: none;
  border: none;
  cursor: default;
}

.keypad-btn.empty:active {
  transform: none;
}

/* Bottom Navigation (Mobile Feel) */
.bottom-nav {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 64px;
  border-top: 1px solid var(--border-color);
  background-color: rgba(18, 18, 18, 0.9);
  backdrop-filter: blur(10px);
  display: flex;
  justify-content: space-around;
  align-items: center;
  z-index: 10;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 10px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
}

.nav-item:hover {
  color: var(--text-primary);
}

.nav-item.active {
  color: var(--text-primary);
  font-weight: 600;
}

/* Empty State */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary);
  gap: 12px;
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-md);
}

.empty-state p {
  font-size: 14px;
}

/* Toggle Switch (Minimalist) */
.switch-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 0;
}

.switch {
  position: relative;
  display: inline-block;
  width: 44px;
  height: 24px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-tertiary);
  transition: var(--transition-fast);
  border-radius: 24px;
  border: 1px solid var(--border-color);
}

.slider:before {
  position: absolute;
  content: "";
  height: 16px;
  width: 16px;
  left: 3px;
  bottom: 3px;
  background-color: var(--text-secondary);
  transition: var(--transition-fast);
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--accent-color);
  border-color: var(--accent-color);
}

input:checked + .slider:before {
  transform: translateX(20px);
  background-color: var(--accent-text);
}

/* Toast Message */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background-color: var(--text-primary);
  color: var(--bg-primary);
  padding: 10px 18px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  z-index: 100;
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
  box-shadow: var(--shadow-lg);
  pointer-events: none;
  white-space: nowrap;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* Dialog/Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  display: flex;
  justify-content: center;
  align-items: flex-end;
  z-index: 50;
  animation: fadeIn 0.2s ease-out;
}

.modal-content {
  background-color: var(--bg-primary);
  width: 100%;
  max-width: 480px;
  border-top-left-radius: var(--radius-lg);
  border-top-right-radius: var(--radius-lg);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  animation: slideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 -10px 25px -5px rgba(0, 0, 0, 0.1);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { transform: translateY(100%); }
  to { transform: translateY(0); }
}

/* Utilities */
.text-danger {
  color: var(--danger-color) !important;
}

.list-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
}