/* CSS Variables for Design System */
:root {
  /* Colors - Light Theme */
  --primary-color: #1976d2;
  --primary-hover: #1565c0;
  --primary-light: #e8f5ff;
  --secondary-color: #388e3c;
  --background-color: #fafafa;
  --surface-color: #ffffff;
  --surface-hover: #f5f5f5;
  --text-primary: #212121;
  --text-secondary: #757575;
  --text-disabled: #bdbdbd;
  --border-color: #e0e0e0;
  --error-color: #d32f2f;
  --success-color: #388e3c;
  --warning-color: #f57c00;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-xxl: 3rem;
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  
  /* Z-index */
  --z-dropdown: 1000;
  --z-modal: 1050;
  --z-toast: 1100;
}

/* Dark Theme */
[data-theme="dark"] {
  --primary-color: #2196f3;
  --primary-hover: #1976d2;
  --primary-light: #1e3a8a;
  --background-color: #121212;
  --surface-color: #1e1e1e;
  --surface-hover: #2d2d2d;
  --text-primary: #ffffff;
  --text-secondary: #b3b3b3;
  --text-disabled: #666666;
  --border-color: #333333;
  --error-color: #f44336;
  --success-color: #4caf50;
  --warning-color: #ff9800;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  height: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-color);
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Loading Screen */
.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: var(--background-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity var(--transition-slow);
}

.loading-screen.hidden {
  opacity: 0;
  pointer-events: none;
}

.loading-spinner {
  width: 3rem;
  height: 3rem;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: var(--spacing-lg);
}

.loading-text {
  color: var(--text-secondary);
  font-weight: 500;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* App Container */
.app-container {
  display: flex;
  flex-direction: column;
  opacity: 0;
  animation: fadeIn 0.8s ease-out forwards;
  animation-delay: 0.3s;
  flex: 1; /* Take all available space, pushing footer down */
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Header */
.app-header {
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-md) var(--spacing-lg);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  transition: all var(--transition-normal);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1400px;
  margin: 0 auto;
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.home-button {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.home-button:hover {
  background-color: var(--surface-hover);
  transform: translateY(-1px);
}

.home-button:active {
  transform: translateY(0);
}

.header-icon {
  color: var(--primary-color);
  font-size: 2rem;
}

.header-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--text-primary);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

/* Mobile Menu */
.mobile-menu-btn {
  display: none;
  width: 2.5rem;
  height: 2.5rem;
  border: none;
  border-radius: 50%;
  background-color: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  position: relative;
}

.mobile-menu-btn:hover {
  background-color: var(--surface-hover);
  color: var(--primary-color);
  transform: scale(1.1);
}

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

.mobile-menu-btn.active {
  background-color: var(--primary-color);
  color: white;
}

.mobile-nav {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  transform: translateY(-100%);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  z-index: 99;
}

.mobile-nav.active {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.mobile-nav-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  width: 100%;
  padding: var(--spacing-lg);
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-size: var(--font-size-base);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  border-bottom: 1px solid var(--border-color);
}

.mobile-nav-item:hover {
  background-color: var(--surface-hover);
  color: var(--primary-color);
}

.mobile-nav-item:last-child {
  border-bottom: none;
}

.mobile-nav-item .material-icons {
  font-size: 1.5rem;
  color: var(--primary-color);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: 500;
  line-height: 1.5;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background-color: transparent;
  color: var(--primary-color);
  border: 1px solid var(--primary-color);
}

.btn-outline:hover:not(:disabled) {
  background-color: var(--primary-color);
  color: white;
}

.btn.full-width {
  width: 100%;
  justify-content: center;
}

.icon-button {
  width: 2.5rem;
  height: 2.5rem;
  border: none;
  border-radius: 50%;
  background-color: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  position: relative;
}

.icon-button:hover {
  background-color: var(--surface-hover);
  color: var(--primary-color);
  transform: scale(1.1);
}

.icon-button:active {
  transform: scale(0.95);
}

.icon-button.active {
  background-color: var(--primary-color);
  color: white;
}

/* Form Controls */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
}

label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
  color: var(--text-primary);
  font-size: var(--font-size-sm);
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
  margin-bottom: 0;
}

.checkbox-input {
  width: auto;
  margin: 0;
  cursor: pointer;
}

.checkbox-text {
  font-weight: 500;
  color: var(--text-primary);
  font-size: var(--font-size-sm);
}

.form-control {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: var(--font-size-base);
  background-color: var(--surface-color);
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(25, 118, 210, 0.1);
}

.form-control.invalid {
  border-color: var(--error-color);
}

.form-control.invalid:focus {
  border-color: var(--error-color);
  box-shadow: 0 0 0 3px rgba(211, 47, 47, 0.1);
}

/* Main Content */
.main-content {
  flex: 1; /* Take remaining space to push footer down */
  padding: var(--spacing-lg);
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

/* Footer */
.app-footer {
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-sm) var(--spacing-lg);
  backdrop-filter: blur(10px);
  transition: all var(--transition-normal);
  flex-shrink: 0; /* Prevent footer from shrinking */
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: center;
  max-width: 1400px;
  margin: 0 auto;
}

.footer-link {
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--primary-color);
}

/* Content Sections */
.content-section {
  display: none;
  animation: slideIn var(--transition-slow) ease-out;
}

.content-section.active {
  display: block;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Section Headers */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-xl);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.section-header h2 {
  font-size: var(--font-size-2xl);
  font-weight: 600;
  color: var(--text-primary);
}

.section-description {
  margin-bottom: var(--spacing-xl);
  color: var(--text-secondary);
  font-style: italic;
  background-color: var(--surface-hover);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--primary-color);
}

/* Cards */
.card {
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--spacing-lg);
  transition: all var(--transition-normal);
  overflow: hidden;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.card-content {
  padding: var(--spacing-lg);
}

/* Invoice Grid */
.invoice-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xl);
}

.invoice-column {
  display: flex;
  flex-direction: column;
}

/* Animations */
.fade-in-up {
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.6s ease-out forwards;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Article Chips */
.article-chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.article-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background-color: var(--primary-light);
  color: var(--primary-color);
  border-radius: var(--radius-xl);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  border: 1px solid transparent;
}

.article-chip:hover {
  background-color: var(--primary-color);
  color: white;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.article-chip.default {
  background-color: var(--primary-color);
  color: white;
}

.article-chip .material-icons {
  font-size: 1rem;
}

/* No articles message */
.no-articles {
  color: var(--text-secondary);
  font-style: italic;
  text-align: center;
  padding: var(--spacing-lg);
  background-color: var(--surface-hover);
  border-radius: var(--radius-md);
  margin: 0;
}

/* Article list item styling for clickable cards */
.article-card {
  transition: all var(--transition-fast);
}

.article-card:hover {
  background-color: var(--surface-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.article-edit-form {
  padding: var(--spacing-md);
  background-color: var(--surface-hover);
  border-radius: var(--radius-md);
  margin-top: var(--spacing-sm);
  border: 1px solid var(--border-color);
}

/* Invoice Items */
.invoice-items {
  margin-bottom: var(--spacing-xl);
}

.invoice-item {
  background-color: var(--surface-hover);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  border: 1px solid var(--border-color);
  position: relative;
  transition: all var(--transition-normal);
  animation: slideInLeft 0.4s ease-out;
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.invoice-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-md);
}

.invoice-item-fields {
  display: grid;
  grid-template-columns: 1fr auto auto auto;
  gap: var(--spacing-md);
  align-items: end;
}

.invoice-item-total {
  text-align: right;
  margin-top: var(--spacing-sm);
}

.invoice-item-total .total-label {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.invoice-item-total .total-value {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--primary-color);
}

.remove-item-btn {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  width: 2rem;
  height: 2rem;
  border: none;
  border-radius: 50%;
  background-color: var(--error-color);
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  opacity: 0.7;
}

.remove-item-btn:hover {
  opacity: 1;
  transform: scale(1.1);
}

/* Totals Section */
.totals-section {
  border-top: 2px solid var(--border-color);
  padding-top: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.totals-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
  font-weight: 500;
}

.totals-row.total {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--primary-color);
  border-top: 1px solid var(--border-color);
  padding-top: var(--spacing-md);
  margin-top: var(--spacing-sm);
}

/* Processing Indicator */
.processing-indicator {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  color: var(--text-secondary);
  font-weight: 500;
}

.spinner {
  width: 1.5rem;
  height: 1.5rem;
  border: 2px solid var(--border-color);
  border-top: 2px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* Help Text */
.help-text {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin: 0;
  opacity: 0.8;
}

/* Article Categories */
.article-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.article-categories-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.category-section {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.category-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  background-color: var(--surface-hover);
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.category-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.category-title {
  margin: 0;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
}

.category-count {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  background-color: var(--primary-light);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-xl);
}

.category-actions {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

.add-article-to-category-btn {
  font-size: var(--font-size-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
}

.category-articles {
  padding: var(--spacing-lg);
}

.category-articles:empty::after {
  content: "Inga artiklar i denna kategori";
  color: var(--text-secondary);
  font-style: italic;
  display: block;
  text-align: center;
  padding: var(--spacing-lg);
}

.category-article-item {
  background-color: var(--background-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.category-article-item:hover {
  background-color: var(--surface-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.category-article-item:last-child {
  margin-bottom: 0;
}

.article-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-sm);
}

.article-item-title {
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.article-item-actions {
  display: flex;
  gap: var(--spacing-xs);
}

.article-item-details {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  line-height: 1.4;
}

[data-theme="dark"] .category-count {
  background-color: rgba(33, 150, 243, 0.1);
}

/* Lists */
.customer-list,
.article-list,
.category-list {
  display: grid;
  gap: var(--spacing-md);
}

.list-item {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.list-item:hover {
  box-shadow: var(--shadow-md);
}

.list-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-sm);
}

.list-item-title {
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.list-item-actions {
  display: flex;
  gap: var(--spacing-xs);
}

.list-item-details {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  line-height: 1.4;
}

/* Settings Grid */
.settings-grid {
  display: grid;
  gap: var(--spacing-xl);
}

/* Modals */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  backdrop-filter: blur(4px);
}

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

.modal {
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  width: 90%;
  max-width: 600px;
  max-height: 90vh;
  overflow-y: auto;
  transform: scale(0.9) translateY(20px);
  transition: all var(--transition-normal);
  display: none; /* Hidden by default */
}

.modal-overlay.active .modal {
  transform: scale(1) translateY(0);
}

/* Show modal when explicitly displayed */
.modal[style*="display: block"] {
  display: block !important;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
  margin: 0;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-content {
  padding: var(--spacing-lg);
}

.modal-footer {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  justify-content: flex-end;
}

/* Customer Articles Section */
.customer-articles-section {
  margin-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
  padding-top: var(--spacing-lg);
}

.section-divider h4 {
  margin: 0 0 var(--spacing-sm) 0;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
}

.customer-articles-list {
  margin: var(--spacing-lg) 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.customer-article-item {
  background-color: var(--surface-hover);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  position: relative;
  animation: slideInLeft 0.3s ease-out;
}

.customer-article-item .remove-article-btn {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  width: 1.5rem;
  height: 1.5rem;
  border: none;
  border-radius: 50%;
  background-color: var(--error-color);
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  opacity: 0.7;
  font-size: 0.875rem;
}

.customer-article-item .remove-article-btn:hover {
  opacity: 1;
  transform: scale(1.1);
}

.customer-article-fields {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-sm);
  align-items: end;
}

/* Customer Articles Summary */
.customer-articles-summary {
  margin-top: var(--spacing-sm);
  padding: var(--spacing-sm);
  background-color: var(--primary-light);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  border-left: 3px solid var(--primary-color);
}

[data-theme="dark"] .customer-articles-summary {
  background-color: rgba(33, 150, 243, 0.1);
  border-left: 3px solid var(--primary-color);
}

.customer-card {
  transition: all var(--transition-fast);
}

.customer-card:hover {
  background-color: var(--surface-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Article Form Styling */
.article-form {
  border: 2px solid var(--primary-color);
  background-color: var(--primary-light);
}

[data-theme="dark"] .article-form {
  background-color: rgba(33, 150, 243, 0.1);
}

.article-edit-form {
  padding: var(--spacing-md);
  background-color: var(--surface-hover);
  border-radius: var(--radius-md);
  margin-top: var(--spacing-sm);
}

.form-actions {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
  flex-wrap: wrap;
}

.form-actions .btn {
  flex: 1;
  min-width: 120px;
}

/* VAT Number Group */
.vat-number-group {
  display: flex;
  gap: 2px;
}

.vat-prefix {
  width: 55px;
  background-color: var(--border-color);
  color: var(--text-secondary);
  text-align: center;
  cursor: not-allowed;
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}

.vat-number {
  flex: 1;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
  border-left: none;
}

/* Add Item Controls */
.add-item-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.add-item-controls select {
  min-width: 200px;
  flex: 1;
}

.add-item-controls .btn {
  white-space: nowrap;
}

/* Toast Notifications */
.toast {
  position: fixed;
  top: var(--spacing-lg);
  right: var(--spacing-lg);
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-toast);
  transform: translateX(100%);
  transition: transform var(--transition-normal), opacity var(--transition-normal);
  max-width: 400px;
  min-width: 280px;
  cursor: pointer;
  user-select: none;
  touch-action: pan-x; /* Allow horizontal panning for swipe */
}

.toast.show {
  transform: translateX(0);
  opacity: 1;
}

.toast.success {
  border-left: 4px solid var(--success-color);
}

.toast.error {
  border-left: 4px solid var(--error-color);
}

.toast.warning {
  border-left: 4px solid var(--warning-color);
}

.toast-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.toast-content .material-icons {
  font-size: 1.2rem;
  flex-shrink: 0;
}

.toast.success .material-icons {
  color: var(--success-color);
}

.toast.error .material-icons {
  color: var(--error-color);
}

.toast.warning .material-icons {
  color: var(--warning-color);
}

.toast-content span:last-child {
  font-weight: 500;
  line-height: 1.4;
  color: var(--text-primary);
}

/* Responsive Design */
@media (max-width: 1024px) {
  .invoice-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .main-content {
    padding: var(--spacing-md);
  }
}

@media (max-width: 768px) {
  .header-content {
    padding: 0 var(--spacing-md);
  }
  
  .header-title {
    font-size: var(--font-size-xl);
  }
  
  /* Show mobile menu button and hide regular nav buttons */
  .mobile-menu-btn {
    display: flex;
  }
  
  .header-right .icon-button:not(.mobile-menu-btn) {
    display: none;
  }
  
  .section-header {
    flex-direction: column;
    align-items: stretch;
  }
  
  .form-row {
    grid-template-columns: 1fr;
  }
  
  .invoice-item-fields {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
  
  .card-header {
    flex-direction: column;
    align-items: stretch;
  }
  
  .modal {
    width: 95%;
    margin: var(--spacing-md);
  }
  
  .modal-footer {
    flex-direction: column;
  }
  
  .btn.full-width-mobile {
    width: 100%;
    justify-content: center;
  }
  
  /* Customer articles responsive */
  .customer-article-fields {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
  
  /* Add item controls responsive */
  .add-item-controls {
    flex-direction: column;
    align-items: stretch;
  }
  
  .add-item-controls select {
    min-width: auto;
    margin-bottom: var(--spacing-sm);
  }
  
  /* Footer responsive */
  .app-footer {
    padding: var(--spacing-xs) var(--spacing-md);
  }
  
  .main-content {
    padding: var(--spacing-md);
  }
  
  /* Mobile toast notifications */
  .toast {
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    left: var(--spacing-sm);
    width: auto;
    max-width: none;
    min-width: auto;
  }
}

@media (max-width: 480px) {
  .main-content {
    padding: var(--spacing-sm);
  }
  
  .card-content,
  .card-header {
    padding: var(--spacing-md);
  }
  
  .header-right {
    gap: var(--spacing-xs);
  }
  
  .article-chips {
    gap: var(--spacing-xs);
  }
  
  .article-chip {
    font-size: var(--font-size-xs);
    padding: 0.25rem var(--spacing-sm);
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --border-color: #000000;
    --text-secondary: #000000;
  }
  
  [data-theme="dark"] {
    --border-color: #ffffff;
    --text-secondary: #ffffff;
  }
}

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

/* Print styles */
@media print {
  .app-header,
  .app-footer,
  .modal-overlay {
    display: none !important;
  }
  
  .main-content {
    padding: 0;
    max-width: none;
    padding-bottom: 0;
  }
  
  .card {
    box-shadow: none;
    border: 1px solid #ccc;
    break-inside: avoid;
  }
}

/* Focus styles for accessibility */
*:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

.btn:focus,
.form-control:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(25, 118, 210, 0.2);
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background-color: var(--background-color);
}

::-webkit-scrollbar-thumb {
  background-color: var(--border-color);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background-color: var(--text-disabled);
}

/* ================================
   PWA SPECIFIC STYLES
   ================================ */

/* PWA Variables */
:root {
  --pwa-safe-area-top: 0px;
  --pwa-safe-area-bottom: 0px;
  --pwa-safe-area-left: 0px;
  --pwa-safe-area-right: 0px;
}

/* PWA Standalone Mode */
.pwa-standalone {
  padding-top: var(--pwa-safe-area-top);
  padding-bottom: var(--pwa-safe-area-bottom);
}

.pwa-standalone .app-header {
  padding-top: calc(var(--spacing-md) + var(--pwa-safe-area-top));
}

.pwa-standalone .app-footer {
  padding-bottom: calc(var(--spacing-sm) + var(--pwa-safe-area-bottom));
}

.pwa-standalone .main-content {
  padding-bottom: calc(var(--spacing-lg) + var(--pwa-safe-area-bottom));
}

/* PWA Install Button */
.pwa-install-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.pwa-install-btn:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.pwa-install-btn .material-icons {
  font-size: 1rem;
}

/* Desktop install button styling */
.desktop-install-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  gap: var(--spacing-sm);
}

.desktop-install-btn .material-icons {
  font-size: 1.2rem;
}

/* Mobile install button - completely reset to match other nav items */
.mobile-nav-item.pwa-install-btn {
  /* Use exact same styling as regular mobile-nav-item */
  display: flex !important;
  align-items: center !important;
  gap: var(--spacing-md) !important;
  width: 100% !important;
  padding: var(--spacing-lg) !important;
  border: none !important;
  background: transparent !important;
  color: var(--text-primary) !important;
  font-size: var(--font-size-base) !important;
  font-weight: 500 !important;
  cursor: pointer !important;
  transition: all var(--transition-fast) !important;
  border-bottom: 1px solid var(--border-color) !important;
  border-radius: 0 !important;
  margin: 0 !important;
  transform: none !important;
  box-shadow: none !important;
}

.mobile-nav-item.pwa-install-btn:hover {
  background-color: var(--surface-hover) !important;
  color: var(--primary-color) !important;
  transform: none !important;
  box-shadow: none !important;
}

.mobile-nav-item.pwa-install-btn .material-icons {
  font-size: 1.5rem !important;
  color: var(--primary-color) !important;
}

/* Make sure it's the last item with no border */
.mobile-nav-item.pwa-install-btn:last-child {
  border-bottom: none !important;
}

/* PWA Update Dialog */
.pwa-update-dialog {
  position: fixed;
  top: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 350px;
  max-width: calc(100vw - 2 * var(--spacing-lg));
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  z-index: var(--z-toast);
  animation: pwaSlideInRight 0.4s ease-out;
}

.pwa-update-content {
  padding: var(--spacing-lg);
}

.pwa-update-icon {
  text-align: center;
  margin-bottom: var(--spacing-md);
}

.pwa-update-icon .material-icons {
  font-size: 2.5rem;
  color: var(--primary-color);
}

.pwa-update-dialog h3 {
  margin: 0 0 var(--spacing-sm) 0;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  text-align: center;
}

.pwa-update-dialog p {
  margin: 0 0 var(--spacing-lg) 0;
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  line-height: 1.5;
  text-align: center;
}

.pwa-update-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.pwa-update-actions .btn {
  flex: 1;
  font-size: var(--font-size-sm);
  padding: var(--spacing-sm) var(--spacing-md);
}

@keyframes pwaSlideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* PWA Dialog Overlay */
.pwa-dialog-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  animation: pwaFadeIn 0.3s ease-out;
  backdrop-filter: blur(2px);
}

@keyframes pwaFadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pwaSlideInUp {
  from {
    transform: translateY(30px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.pwa-dialog {
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  max-width: 500px;
  width: 90%;
  box-shadow: var(--shadow-xl);
  animation: pwaSlideInUp 0.4s ease-out;
}

.pwa-dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

.pwa-dialog-header h3 {
  margin: 0;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
}

.pwa-dialog-close {
  width: 2rem;
  height: 2rem;
  border: none;
  background: transparent;
  font-size: 1.5rem;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.pwa-dialog-close:hover {
  background-color: var(--surface-hover);
  color: var(--text-primary);
}

.pwa-dialog-content {
  padding: var(--spacing-lg);
  color: var(--text-secondary);
  line-height: 1.6;
}

.pwa-dialog-content ol {
  margin: var(--spacing-md) 0;
  padding-left: var(--spacing-lg);
}

.pwa-dialog-content li {
  margin-bottom: var(--spacing-sm);
}

.pwa-dialog-actions {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
}

/* PWA Install Instructions Dialog */
.install-instruction-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  animation: pwaFadeIn 0.3s ease-out;
  backdrop-filter: blur(4px);
}

.install-instruction-content {
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  max-width: 500px;
  width: 90%;
  box-shadow: var(--shadow-xl);
  animation: pwaSlideInUp 0.4s ease-out;
}

.install-instruction-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

.install-instruction-header h3 {
  margin: 0;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
}

.install-instruction-close {
  width: 2rem;
  height: 2rem;
  border: none;
  background: transparent;
  font-size: 1.5rem;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.install-instruction-close:hover {
  background-color: var(--surface-hover);
  color: var(--text-primary);
}

.install-instruction-body {
  padding: var(--spacing-lg);
}

.install-instructions p {
  margin: 0 0 var(--spacing-md) 0;
  color: var(--text-secondary);
  line-height: 1.6;
}

.install-steps {
  margin: var(--spacing-md) 0;
}

.install-step {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  padding: var(--spacing-sm);
  background-color: var(--surface-hover);
  border-radius: var(--radius-md);
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  background-color: var(--primary-color);
  color: white;
  border-radius: 50%;
  font-weight: 600;
  font-size: var(--font-size-sm);
  flex-shrink: 0;
}

.step-text {
  color: var(--text-primary);
  font-weight: 500;
  line-height: 1.5;
}

.step-text .material-icons {
  font-size: 1.2em;
  vertical-align: middle;
  color: var(--primary-color);
}

.install-benefit {
  margin: var(--spacing-lg) 0 0 0 !important;
  padding: var(--spacing-sm);
  background-color: var(--primary-light);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary-color);
  font-weight: 500;
  color: var(--primary-color);
}

[data-theme="dark"] .install-benefit {
  background-color: rgba(33, 150, 243, 0.1);
}

/* iOS Version Note */
.ios-version-note {
  margin: var(--spacing-md) 0 !important;
  padding: var(--spacing-sm);
  background-color: var(--success-color);
  color: white;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: 500;
  text-align: center;
}

[data-theme="dark"] .ios-version-note {
  background-color: rgba(76, 175, 80, 0.2);
  color: var(--success-color);
  border: 1px solid var(--success-color);
}

.install-instruction-footer {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
}

/* PWA Install Instructions Dialog - Mobile */
@media (max-width: 768px) {
  .install-instruction-content {
    width: 95%;
    margin: var(--spacing-md);
  }
  
  .install-instruction-header,
  .install-instruction-body,
  .install-instruction-footer {
    padding: var(--spacing-md);
  }
  
  .install-step {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-sm);
  }
  
  .step-number {
    align-self: center;
  }
}
.pwa-offline .app-header::after {
  content: "Offline";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--warning-color);
  color: white;
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-xs);
  font-weight: 500;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  animation: pwaPulse 2s infinite;
}

@keyframes pwaPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

/* PWA Status Bar */
.pwa-status-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: var(--primary-color);
  color: white;
  padding: var(--spacing-sm);
  text-align: center;
  font-size: var(--font-size-xs);
  font-weight: 500;
  transform: translateY(100%);
  transition: transform var(--transition-normal);
  z-index: var(--z-toast);
}

.pwa-status-bar.show {
  transform: translateY(0);
}

.pwa-status-bar.success {
  background-color: var(--success-color);
}

.pwa-status-bar.error {
  background-color: var(--error-color);
}

.pwa-status-bar.warning {
  background-color: var(--warning-color);
}

/* PWA Splash Screen Support */
.pwa-splash {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  color: white;
}

.pwa-splash-icon {
  width: 120px;
  height: 120px;
  background-color: white;
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-xl);
  box-shadow: var(--shadow-xl);
  animation: pwaSplashPulse 2s infinite;
}

.pwa-splash-icon .material-icons {
  font-size: 3rem;
  color: var(--primary-color);
}

.pwa-splash-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.pwa-splash-subtitle {
  font-size: var(--font-size-base);
  opacity: 0.9;
  margin-bottom: var(--spacing-xl);
}

.pwa-splash-loading {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-top: 3px solid white;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes pwaSplashPulse {
  0%, 100% { 
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.7);
  }
  50% { 
    transform: scale(1.05);
    box-shadow: 0 0 0 20px rgba(255, 255, 255, 0);
  }
}

/* PWA Navigation Enhancements */
.pwa-standalone .app-header {
  -webkit-app-region: drag;
}

.pwa-standalone .app-header .header-content {
  -webkit-app-region: no-drag;
}

/* PWA Theme Adaptations */
@media (prefers-color-scheme: dark) {
  .pwa-install-btn {
    background-color: var(--primary-color);
  }
}

/* PWA iOS specific adjustments */
@supports (-webkit-touch-callout: none) {
  .pwa-standalone {
    padding-top: constant(safe-area-inset-top);
    padding-top: env(safe-area-inset-top);
    padding-bottom: constant(safe-area-inset-bottom);
    padding-bottom: env(safe-area-inset-bottom);
  }
  
  .pwa-standalone .app-header {
    padding-top: calc(var(--spacing-md) + constant(safe-area-inset-top));
    padding-top: calc(var(--spacing-md) + env(safe-area-inset-top));
  }
}

/* PWA Android specific adjustments */
@media (display-mode: standalone) {
  .app-header {
    padding-top: max(var(--spacing-md), env(safe-area-inset-top));
  }
}

/* PWA Responsive adjustments */
@media (max-width: 768px) {
  .pwa-update-dialog {
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    left: var(--spacing-sm);
    width: auto;
    max-width: none;
  }
  
  .pwa-dialog {
    width: 95%;
  }
  
  .pwa-install-btn {
    padding: var(--spacing-sm);
    font-size: var(--font-size-xs);
  }
  
  .pwa-install-btn span {
    display: none;
  }
}

@media (max-width: 480px) {
  .pwa-splash-icon {
    width: 80px;
    height: 80px;
  }
  
  .pwa-splash-icon .material-icons {
    font-size: 2rem;
  }
  
  .pwa-splash-title {
    font-size: var(--font-size-2xl);
  }
  
  .pwa-offline .app-header::after {
    font-size: 0.625rem;
    padding: 2px var(--spacing-xs);
  }
}

/* PWA Accessibility enhancements */
@media (prefers-reduced-motion: reduce) {
  .pwa-install-btn,
  .pwa-update-dialog,
  .pwa-splash-icon {
    animation: none;
  }
}

/* PWA High contrast mode */
@media (prefers-contrast: high) {
  .pwa-install-btn {
    border: 2px solid white;
  }
  
  .pwa-update-dialog,
  .pwa-dialog {
    border: 2px solid var(--text-primary);
  }
}

/* PWA Print styles */
@media print {
  .pwa-install-btn,
  .pwa-update-dialog,
  .pwa-dialog-overlay,
  .pwa-status-bar {
    display: none !important;
  }
}