/* ===================================
   Online Invoices Maker - Professional Invoice Generator
   Complete Stylesheet with 5 Templates
   =================================== */

/* ===================================
   CSS Variables & Theme
   =================================== */
:root {
  /* Primary Colors */
  --primary-color: #2563eb;
  --primary-dark: #1e40af;
  --primary-light: #3b82f6;
  
  /* Secondary Colors */
  --secondary-color: #10b981;
  --secondary-dark: #059669;
  --secondary-light: #34d399;
  
  /* Accent Colors */
  --accent-color: #f59e0b;
  --accent-dark: #d97706;
  --accent-light: #fbbf24;
  
  /* Neutral Colors */
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Status Colors */
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --info-color: #3b82f6;
  
  /* 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);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-secondary: 'Playfair Display', serif;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  
  /* Shorthand aliases for documentation pages */
  --primary: #2563eb;
  --secondary: #10b981;
  --card-bg: #ffffff;
  --border-color: #e5e7eb;
  --text-color: #111827;
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --white: #111827;
  --gray-50: #1f2937;
  --gray-100: #374151;
  --gray-200: #4b5563;
  --gray-300: #6b7280;
  --gray-400: #9ca3af;
  --gray-500: #d1d5db;
  --gray-600: #e5e7eb;
  --gray-700: #f3f4f6;
  --gray-800: #f9fafb;
  --gray-900: #ffffff;
  
  /* Dark mode aliases */
  --card-bg: #1f2937;
  --border-color: #374151;
  --text-color: #ffffff;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  color: var(--gray-900);
  background-color: var(--gray-50);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

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

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

/* ===================================
   Utility Classes
   =================================== */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.text-center {
  text-align: center;
}

.hidden {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* ===================================
   Header
   =================================== */
.header {
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) 0;
  gap: var(--spacing-lg);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

.logo-icon {
  font-size: 2rem;
}

.main-nav {
  display: flex;
  gap: var(--spacing-sm);
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--gray-700);
  font-weight: 500;
  transition: all var(--transition-fast);
}

.nav-btn:hover {
  background: var(--gray-100);
  color: var(--primary-color);
}

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

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

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--gray-700);
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background: var(--gray-100);
  color: var(--primary-color);
}

/* ===================================
   Ad Spaces
   =================================== */
.ad-container {
  padding: var(--spacing-lg) 0;
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
}

.ad-space {
  display: flex;
  justify-content: center;
  margin: var(--spacing-md) 0;
}

.ad-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--gray-100);
  border: 2px dashed var(--gray-300);
  border-radius: var(--radius-md);
  color: var(--gray-400);
  font-size: 0.875rem;
  font-weight: 500;
}

.desktop-ad .ad-placeholder {
  width: 728px;
  height: 90px;
}

.mobile-ad {
  display: none;
}

.mobile-ad .ad-placeholder {
  width: 320px;
  height: 50px;
}

.ad-vertical .ad-placeholder {
  width: 300px;
  height: 600px;
}

/* ===================================
   Main Content Grid
   =================================== */
.main-content {
  padding: var(--spacing-2xl) 0;
}

.content-grid {
  display: grid;
  grid-template-columns: 380px 1fr 320px;
  gap: var(--spacing-xl);
  align-items: start;
}

/* ===================================
   Sidebar (Form)
   =================================== */
.sidebar {
  position: sticky;
  top: calc(80px + var(--spacing-md));
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

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

.sidebar::-webkit-scrollbar {
  width: 6px;
}

.sidebar::-webkit-scrollbar-track {
  background: var(--gray-100);
  border-radius: var(--radius-sm);
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--gray-300);
  border-radius: var(--radius-sm);
}

.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--gray-400);
}

/* ===================================
   Form Styles
   =================================== */
.action-bar {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
}

.form-section {
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid var(--gray-200);
}

.form-section:last-child {
  border-bottom: none;
}

.section-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: var(--spacing-md);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

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

label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: var(--spacing-xs);
}

input[type="text"],
input[type="email"],
input[type="tel"],
input[type="url"],
input[type="date"],
input[type="number"],
select,
textarea {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-md);
  background: var(--white);
  color: var(--gray-900);
  font-size: 0.875rem;
  transition: all var(--transition-fast);
}

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

textarea {
  resize: vertical;
  min-height: 80px;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  opacity: 1;
}

/* ===================================
   Buttons
   =================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-weight: 500;
  font-size: 0.875rem;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--gray-100);
  color: var(--gray-700);
}

.btn-secondary:hover {
  background: var(--gray-200);
}

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

.btn-accent:hover {
  background: var(--accent-dark);
}

.btn-small {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.75rem;
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-lg);
  font-size: 1rem;
  font-weight: 600;
}

.btn-block {
  width: 100%;
}

/* ===================================
   Logo Upload
   =================================== */
.logo-upload {
  position: relative;
  border: 2px dashed var(--gray-300);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--gray-50);
}

.logo-upload:hover {
  border-color: var(--primary-color);
  background: var(--white);
}

.logo-preview {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--gray-500);
}

.logo-preview img {
  max-width: 150px;
  max-height: 80px;
  object-fit: contain;
}

.logo-hint {
  font-size: 0.75rem;
  color: var(--gray-400);
}

.remove-logo {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--error-color);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.remove-logo:hover {
  transform: scale(1.1);
}

/* ===================================
   Line Items
   =================================== */
.line-item {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr auto;
  gap: var(--spacing-sm);
  align-items: start;
  margin-bottom: var(--spacing-md);
  padding: var(--spacing-md);
  background: var(--gray-50);
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-200);
}

.line-item-field {
  display: flex;
  flex-direction: column;
}

.line-item-field label {
  font-size: 0.75rem;
  margin-bottom: 0.25rem;
}

.line-item-field input {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.875rem;
}

.remove-item-btn {
  display: flex;
  align-items: flex-end;
  padding-bottom: var(--spacing-xs);
}

.remove-item-btn button {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-md);
  background: var(--error-color);
  color: var(--white);
  transition: all var(--transition-fast);
}

.remove-item-btn button:hover {
  background: #dc2626;
  transform: scale(1.05);
}

/* ===================================
   Calculation Summary
   =================================== */
.calculation-summary {
  background: var(--gray-50);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.calc-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
  font-size: 0.875rem;
  color: var(--gray-700);
}

.calc-total {
  border-top: 2px solid var(--gray-300);
  margin-top: var(--spacing-sm);
  padding-top: var(--spacing-md);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--gray-900);
}

/* ===================================
   Form Actions
   =================================== */
.form-actions {
  margin-top: var(--spacing-xl);
}

.action-buttons-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-sm);
  margin-top: var(--spacing-sm);
}

/* ===================================
   Premium Teaser
   =================================== */
.premium-teaser {
  background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
  color: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  text-align: center;
  margin-top: var(--spacing-xl);
}

.premium-icon {
  font-size: 2rem;
  margin-bottom: var(--spacing-sm);
}

.premium-teaser h4 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-md);
}

.premium-features {
  list-style: none;
  text-align: left;
  margin: var(--spacing-md) 0;
}

.premium-features li {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  font-size: 0.875rem;
}

.premium-teaser .btn {
  margin-top: var(--spacing-md);
  background: var(--white);
  color: var(--accent-dark);
  font-weight: 600;
}

.premium-teaser .btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* ===================================
   Main Section (Preview)
   =================================== */
.main-section {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: var(--spacing-lg);
}

.preview-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--gray-200);
}

.preview-header h2 {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.25rem;
  color: var(--gray-900);
}

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

#zoomLevel {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-600);
  min-width: 3rem;
  text-align: center;
}

.preview-container {
  background: var(--gray-100);
  border-radius: var(--radius-md);
  padding: var(--spacing-xl);
  min-height: 600px;
  display: flex;
  justify-content: center;
  overflow: auto;
}

.invoice-preview {
  background: var(--white);
  width: 100%;
  max-width: 800px;
  min-height: 1000px;
  box-shadow: var(--shadow-xl);
  transition: transform var(--transition-normal);
  transform-origin: top center;
}

/* ===================================
   Right Sidebar
   =================================== */
.right-sidebar {
  position: sticky;
  top: calc(80px + var(--spacing-md));
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.newsletter-card,
.share-card,
.stats-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.newsletter-card h3,
.share-card h3,
.stats-card h3 {
  font-size: 1.125rem;
  margin-bottom: var(--spacing-md);
  color: var(--gray-900);
}

.newsletter-card p {
  font-size: 0.875rem;
  color: var(--gray-600);
  margin-bottom: var(--spacing-md);
}

.newsletter-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.privacy-note {
  font-size: 0.75rem;
  color: var(--gray-500);
  margin-top: var(--spacing-sm);
}

.share-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-sm);
}

.share-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--radius-md);
  color: var(--white);
  transition: all var(--transition-fast);
}

.share-twitter {
  background: #1DA1F2;
}

.share-facebook {
  background: #4267B2;
}

.share-linkedin {
  background: #0077B5;
}

.share-link {
  background: var(--gray-600);
}

.share-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.stat-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--gray-200);
}

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

.stat-label {
  font-size: 0.875rem;
  color: var(--gray-600);
}

.stat-value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--gray-900);
}

/* ===================================
   Invoice Templates - Base Styles
   =================================== */
.invoice-preview {
  padding: 2.5rem;
  font-size: 14px;
  line-height: 1.6;
}

.invoice-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 2px solid;
}

.invoice-logo {
  max-width: 200px;
  max-height: 80px;
  object-fit: contain;
}

.invoice-title {
  font-size: 2.5rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.invoice-details-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.detail-section h3 {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
}

.detail-section p {
  margin: 0.25rem 0;
  font-size: 0.875rem;
}

.invoice-meta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 2rem;
  padding: 1rem;
  border-radius: var(--radius-md);
}

.meta-item {
  display: flex;
  justify-content: space-between;
  font-size: 0.875rem;
}

.meta-label {
  font-weight: 600;
}

.status-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.status-paid {
  background: #d1fae5;
  color: #065f46;
}

.status-unpaid {
  background: #fef3c7;
  color: #92400e;
}

.status-overdue {
  background: #fee2e2;
  color: #991b1b;
}

.invoice-table {
  width: 100%;
  margin-bottom: 2rem;
  border-collapse: collapse;
}

.invoice-table th {
  text-align: left;
  font-weight: 600;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 1rem 0.5rem;
  border-bottom: 2px solid;
}

.invoice-table td {
  padding: 1rem 0.5rem;
  border-bottom: 1px solid;
  font-size: 0.875rem;
}

.text-right {
  text-align: right;
}

.invoice-totals {
  margin-left: auto;
  width: 300px;
  margin-bottom: 2rem;
}

.total-row {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0;
  font-size: 0.875rem;
}

.total-row.final {
  border-top: 2px solid;
  margin-top: 0.5rem;
  padding-top: 1rem;
  font-size: 1.25rem;
  font-weight: 700;
}

.invoice-footer {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid;
}

.footer-section {
  margin-bottom: 1.5rem;
}

.footer-section h4 {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.5rem;
}

.footer-section p {
  font-size: 0.875rem;
  line-height: 1.6;
}

.watermark {
  text-align: center;
  font-size: 0.9rem; /* Larger size for excellent PDF visibility */
  color: #374151; /* Even darker gray - very clear in PDF */
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 2px solid #9ca3af; /* Darker, more visible border */
  opacity: 1; /* Fully visible */
  font-weight: 700; /* Bold for maximum PDF clarity */
  letter-spacing: 0.75px; /* Enhanced spacing for readability */
  text-transform: uppercase; /* Makes it stand out more */
  font-family: system-ui, -apple-system, sans-serif; /* Better font rendering in PDF */
}

/* ===================================
   Template 1: Modern Minimal
   =================================== */
.template-modern {
  font-family: var(--font-primary);
  color: #1f2937;
}

.template-modern .invoice-header {
  border-bottom-color: #2563eb;
}

.template-modern .invoice-title {
  color: #2563eb;
}

.template-modern .invoice-meta {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
}

.template-modern .invoice-table th {
  background: #f3f4f6;
  color: #1f2937;
  border-bottom-color: #2563eb;
}

.template-modern .invoice-table td {
  border-bottom-color: #e5e7eb;
}

.template-modern .total-row.final {
  background: #eff6ff;
  padding: 1rem;
  border-radius: var(--radius-md);
  border-top-color: #2563eb;
  color: #1e40af;
}

.template-modern .invoice-footer {
  border-top-color: #e5e7eb;
  color: #6b7280;
}

/* ===================================
   Template 2: Professional Corporate
   =================================== */
.template-corporate {
  font-family: var(--font-primary);
  color: #1f2937;
  background: #ffffff;
}

.template-corporate .invoice-header {
  border-bottom: 3px double #1f2937;
  background: #f9fafb;
  padding: 1.5rem;
  margin: -2.5rem -2.5rem 2rem -2.5rem;
}

.template-corporate .invoice-title {
  color: #1f2937;
  font-weight: 800;
}

.template-corporate .invoice-meta {
  background: #f9fafb;
  border: 2px solid #e5e7eb;
}

.template-corporate .invoice-table {
  border: 2px solid #1f2937;
}

.template-corporate .invoice-table th {
  background: #1f2937;
  color: #ffffff;
  border-bottom-color: #1f2937;
}

.template-corporate .invoice-table td {
  border-bottom-color: #d1d5db;
}

.template-corporate .invoice-table tr:last-child td {
  border-bottom: none;
}

.template-corporate .total-row.final {
  background: #1f2937;
  color: #ffffff;
  padding: 1rem;
  border-radius: 0;
  border-top: none;
}

.template-corporate .invoice-footer {
  border-top: 2px solid #1f2937;
  background: #f9fafb;
  padding: 1.5rem;
  margin: 2rem -2.5rem -2.5rem -2.5rem;
}

/* ===================================
   Template 3: Creative Colorful
   =================================== */
.template-creative {
  font-family: var(--font-primary);
  color: #1f2937;
  background: linear-gradient(135deg, #fef3c7 0%, #fce7f3 100%);
}

.template-creative .invoice-header {
  border-bottom: 4px solid;
  border-image: linear-gradient(90deg, #f59e0b, #ec4899, #8b5cf6) 1;
}

.template-creative .invoice-title {
  background: linear-gradient(90deg, #f59e0b, #ec4899, #8b5cf6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.template-creative .invoice-meta {
  background: #ffffff;
  border: 3px solid #f59e0b;
  box-shadow: 8px 8px 0 #fbbf24;
}

.template-creative .invoice-table th {
  background: linear-gradient(90deg, #f59e0b, #ec4899);
  color: #ffffff;
  border-bottom-color: #f59e0b;
}

.template-creative .invoice-table td {
  border-bottom-color: #fed7aa;
  background: #ffffff;
}

.template-creative .total-row.final {
  background: linear-gradient(90deg, #f59e0b, #ec4899);
  color: #ffffff;
  padding: 1rem;
  border-radius: var(--radius-lg);
  border-top: none;
  box-shadow: 4px 4px 0 #fbbf24;
}

.template-creative .invoice-footer {
  border-top: 3px solid #f59e0b;
  background: #ffffff;
  padding: 1.5rem;
  border-radius: var(--radius-md);
}

/* ===================================
   Template 4: Tech Startup
   =================================== */
.template-tech {
  font-family: var(--font-primary);
  color: #f9fafb;
  background: #0f172a;
}

.template-tech .invoice-header {
  border-bottom: 3px solid #3b82f6;
  background: linear-gradient(135deg, #1e293b, #0f172a);
}

.template-tech .invoice-title {
  color: #60a5fa;
  text-shadow: 0 0 20px rgba(59, 130, 246, 0.5);
}

.template-tech .detail-section h3,
.template-tech .footer-section h4 {
  color: #60a5fa;
}

.template-tech .invoice-meta {
  background: #1e293b;
  border: 2px solid #3b82f6;
  box-shadow: 0 0 20px rgba(59, 130, 246, 0.3);
}

.template-tech .invoice-table th {
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  color: #ffffff;
  border-bottom-color: #3b82f6;
}

.template-tech .invoice-table td {
  border-bottom-color: #334155;
  color: #e2e8f0;
}

.template-tech .total-row {
  color: #e2e8f0;
}

.template-tech .total-row.final {
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  color: #ffffff;
  padding: 1rem;
  border-radius: var(--radius-md);
  border-top: none;
  box-shadow: 0 0 30px rgba(59, 130, 246, 0.5);
}

.template-tech .invoice-footer {
  border-top: 2px solid #3b82f6;
  background: #1e293b;
  color: #cbd5e1;
}

.template-tech .watermark {
  color: #e2e8f0; /* Lighter and very visible on dark theme */
  border-top-color: #64748b;
  opacity: 1; /* Fully visible */
  font-weight: 700; /* Bold for maximum clarity */
  border-top-width: 2px; /* Thicker border */
  font-size: 0.9rem; /* Consistent size */
  letter-spacing: 0.75px; /* Enhanced spacing */
  text-transform: uppercase; /* Stand out */
}

/* ===================================
   Template 5: Classic Elegant
   =================================== */
.template-classic {
  font-family: var(--font-secondary);
  color: #292524;
  background: #fefce8;
}

.template-classic .invoice-header {
  border-bottom: 3px double #78350f;
}

.template-classic .invoice-title {
  color: #78350f;
  font-family: var(--font-secondary);
  font-style: italic;
}

.template-classic .detail-section h3,
.template-classic .footer-section h4 {
  color: #78350f;
  font-family: var(--font-secondary);
}

.template-classic .invoice-meta {
  background: #fffbeb;
  border: 2px solid #d97706;
  border-radius: 0;
}

.template-classic .invoice-table th {
  background: #fef3c7;
  color: #78350f;
  border-bottom: 2px solid #78350f;
  font-family: var(--font-secondary);
}

.template-classic .invoice-table td {
  border-bottom: 1px solid #fde68a;
}

.template-classic .total-row.final {
  background: #fef3c7;
  color: #78350f;
  padding: 1rem;
  border-radius: 0;
  border-top: 3px double #78350f;
  font-family: var(--font-secondary);
}

.template-classic .invoice-footer {
  border-top: 2px solid #d97706;
  background: #fffbeb;
  padding: 1.5rem;
  border-radius: 0;
  color: #78350f;
}

.template-classic p,
.template-classic td,
.template-classic .meta-item {
  font-family: var(--font-primary);
}

/* ===================================
   Modals
   =================================== */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
  backdrop-filter: blur(4px);
}

.modal-content {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  max-width: 600px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  position: relative;
  animation: modalSlideIn 0.3s ease-out;
}

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

.close-modal {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--gray-200);
  color: var(--gray-700);
  font-size: 1.5rem;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  line-height: 1;
  padding: 0;
  z-index: 10;
}

.close-modal:hover {
  background: var(--gray-300);
  transform: rotate(90deg);
}

/* Welcome Modal */
.welcome-modal {
  max-width: 700px;
}

.welcome-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.welcome-icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
}

.welcome-header h2 {
  font-size: 2rem;
  color: var(--gray-900);
  margin-bottom: var(--spacing-sm);
}

.welcome-header p {
  font-size: 1.125rem;
  color: var(--gray-600);
}

.welcome-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.feature-item {
  text-align: center;
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  background: var(--gray-50);
}

.feature-item svg {
  width: 2.5rem;
  height: 2.5rem;
  color: var(--primary-color);
  margin-bottom: var(--spacing-sm);
}

.feature-item h3 {
  font-size: 1rem;
  margin-bottom: var(--spacing-xs);
  color: var(--gray-900);
}

.feature-item p {
  font-size: 0.875rem;
  color: var(--gray-600);
}

.welcome-footer {
  text-align: center;
  margin-top: var(--spacing-lg);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--gray-200);
}

.welcome-footer label {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--gray-600);
  cursor: pointer;
}

/* Shortcuts Modal */
.shortcuts-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.shortcut-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md);
  background: var(--gray-50);
  border-radius: var(--radius-md);
}

kbd {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: var(--gray-800);
  color: var(--white);
  border-radius: var(--radius-sm);
  font-family: monospace;
  font-size: 0.875rem;
  font-weight: 600;
  box-shadow: 0 2px 0 var(--gray-700);
}

/* ===================================
   Toast Notifications
   =================================== */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--gray-900);
  color: var(--white);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  z-index: 1001;
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
  max-width: 400px;
}

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

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

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

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

/* ===================================
   Footer
   =================================== */
.footer {
  background: var(--gray-900);
  color: var(--gray-300);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
  margin-top: var(--spacing-2xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
  color: var(--white);
  margin-bottom: var(--spacing-md);
  font-size: 1.125rem;
}

.footer-section p {
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: var(--spacing-md);
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-section ul li a {
  color: var(--gray-300);
  font-size: 0.875rem;
  transition: color var(--transition-fast);
}

.footer-section ul li a:hover {
  color: var(--white);
}

.footer-social {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: var(--gray-800);
  color: var(--gray-300);
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background: var(--primary-color);
  color: var(--white);
  transform: translateY(-2px);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--gray-800);
  font-size: 0.875rem;
}

.footer-bottom p {
  margin: var(--spacing-sm) 0;
}

.watermark-note {
  color: var(--gray-500);
}

.watermark-note a {
  color: var(--primary-light);
}

/* ===================================
   Tooltip
   =================================== */
.tooltip-trigger {
  position: relative;
  display: inline-flex;
  cursor: help;
}

.tooltip-trigger svg {
  width: 1rem;
  height: 1rem;
  color: var(--gray-400);
}

.tooltip-trigger:hover svg {
  color: var(--primary-color);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1200px) {
  .content-grid {
    grid-template-columns: 350px 1fr 280px;
    gap: var(--spacing-md);
  }
  
  .right-sidebar .ad-space {
    display: none;
  }
}

@media (max-width: 1024px) {
  .content-grid {
    grid-template-columns: 1fr;
  }
  
  .sidebar {
    position: static;
    max-height: none;
    order: 2;
  }
  
  .main-section {
    order: 1;
  }
  
  .right-sidebar {
    position: static;
    order: 3;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: auto;
    display: grid;
  }
  
  .desktop-ad {
    display: none !important;
  }
  
  .mobile-ad {
    display: flex;
  }
}

@media (max-width: 768px) {
  /* Enhanced Mobile Layout */
  body {
    font-size: 14px;
  }
  
  .header-content {
    flex-wrap: wrap;
    padding: var(--spacing-sm) 0;
  }
  
  .logo {
    font-size: 1.25rem;
  }
  
  .logo-icon {
    font-size: 1.5rem;
  }
  
  .main-nav {
    order: 3;
    width: 100%;
    justify-content: space-between;
    margin-top: var(--spacing-sm);
  }
  
  .nav-btn {
    padding: var(--spacing-sm);
    font-size: 0.75rem;
    flex: 1;
    justify-content: center;
  }
  
  .nav-btn span {
    display: none;
  }
  
  .nav-btn svg {
    width: 20px;
    height: 20px;
  }
  
  /* Mobile Form Improvements */
  .sidebar-content {
    padding: var(--spacing-md);
  }
  
  .form-section {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
  }
  
  .section-title {
    font-size: 1rem;
  }
  
  .form-row {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .form-group label {
    font-size: 0.8125rem;
  }
  
  input, select, textarea {
    font-size: 16px; /* Prevents iOS zoom */
    padding: var(--spacing-sm);
  }
  
  /* Mobile Line Items */
  .line-item {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
  }
  
  .line-item-field label {
    font-size: 0.75rem;
  }
  
  .remove-item-btn {
    align-items: flex-start;
    padding-bottom: 0;
    margin-top: var(--spacing-sm);
  }
  
  /* Mobile Buttons */
  .action-bar {
    gap: var(--spacing-xs);
  }
  
  .action-bar .btn {
    flex: 1;
    font-size: 0.75rem;
    padding: var(--spacing-xs) var(--spacing-sm);
  }
  
  .action-buttons-row {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
  
  .btn {
    padding: var(--spacing-sm);
    font-size: 0.875rem;
  }
  
  .btn-large {
    padding: var(--spacing-md);
    font-size: 1rem;
  }
  
  /* Mobile Preview */
  .preview-container {
    padding: var(--spacing-sm);
    background: var(--gray-50);
  }
  
  .invoice-preview {
    padding: 1rem;
    font-size: 11px;
    line-height: 1.5;
    box-shadow: var(--shadow-md);
  }
  
  .invoice-header {
    margin-bottom: 1rem;
    padding-bottom: 1rem;
  }
  
  .invoice-title {
    font-size: 1.5rem;
    letter-spacing: 1px;
  }
  
  .invoice-logo {
    max-width: 120px;
    max-height: 60px;
  }
  
  .invoice-details-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
  }
  
  .detail-section {
    text-align: left !important;
  }
  
  .invoice-meta {
    grid-template-columns: 1fr;
    gap: 0.5rem;
    padding: 0.75rem;
    margin-bottom: 1rem;
  }
  
  .invoice-table {
    font-size: 0.75rem;
  }
  
  .invoice-table th,
  .invoice-table td {
    padding: 0.5rem 0.25rem;
  }
  
  .invoice-totals {
    width: 100%;
    margin-bottom: 1rem;
  }
  
  .total-row {
    font-size: 0.8125rem;
  }
  
  .total-row.final {
    font-size: 1rem;
    padding: 0.75rem;
  }
  
  /* Mobile Footer */
  .footer-content {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
  }
  
  .footer-section h4 {
    font-size: 1rem;
  }
  
  /* Mobile Modals */
  .modal {
    padding: var(--spacing-md);
  }
  
  .modal-content {
    padding: var(--spacing-lg);
    max-height: 85vh;
  }
  
  .welcome-features {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .feature-item {
    padding: var(--spacing-sm);
  }
  
  /* Mobile Sidebar */
  .right-sidebar {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .share-buttons {
    grid-template-columns: repeat(4, 1fr);
  }
  
  /* Mobile Toast */
  .toast {
    bottom: 1rem;
    right: 1rem;
    left: 1rem;
    max-width: none;
    font-size: 0.875rem;
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  /* Premium Teaser Mobile */
  .premium-teaser {
    padding: var(--spacing-md);
  }
  
  .premium-icon {
    font-size: 1.5rem;
  }
  
  .premium-teaser h4 {
    font-size: 1.125rem;
  }
  
  /* Calculation Summary Mobile */
  .calculation-summary {
    padding: var(--spacing-sm);
  }
  
  .calc-row {
    font-size: 0.8125rem;
  }
  
  /* Newsletter Card Mobile */
  .newsletter-card input {
    font-size: 16px; /* Prevents iOS zoom */
  }
  
  /* Zoom Controls Mobile */
  .preview-header {
    flex-direction: column;
    gap: var(--spacing-sm);
    align-items: flex-start;
  }
  
  .preview-actions {
    width: 100%;
    justify-content: space-between;
  }
  
  /* Logo Upload Mobile */
  .logo-upload {
    padding: var(--spacing-md);
  }
  
  .logo-preview {
    font-size: 0.875rem;
  }
  
  /* Better touch targets */
  button, 
  a,
  input[type="checkbox"],
  input[type="radio"] {
    min-height: 44px;
    min-width: 44px;
  }
  
  .icon-btn {
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 480px) {
  /* Extra Small Mobile (iPhone SE, etc.) */
  body {
    font-size: 13px;
  }
  
  .header-content {
    padding: var(--spacing-xs) 0;
  }
  
  .logo-text {
    font-size: 1rem;
  }
  
  .nav-btn {
    font-size: 0.7rem;
    padding: var(--spacing-xs);
  }
  
  .sidebar-content {
    padding: var(--spacing-sm);
  }
  
  .section-title {
    font-size: 0.9375rem;
  }
  
  input, select, textarea {
    font-size: 16px; /* Prevents iOS zoom */
    padding: 0.625rem;
  }
  
  .invoice-preview {
    padding: 0.75rem;
    font-size: 10px;
  }
  
  .invoice-title {
    font-size: 1.25rem;
  }
  
  .invoice-table {
    font-size: 9px;
    overflow-x: auto;
    display: block;
  }
  
  .invoice-table thead,
  .invoice-table tbody,
  .invoice-table tr {
    display: table;
    width: 100%;
    table-layout: fixed;
  }
  
  .invoice-table th,
  .invoice-table td {
    padding: 0.375rem 0.125rem;
  }
  
  .total-row.final {
    font-size: 0.9375rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .footer-section {
    text-align: center;
  }
  
  .welcome-icon {
    font-size: 3rem;
  }
  
  .modal-content {
    padding: var(--spacing-md);
  }
  
  .btn-small {
    padding: 0.375rem 0.5rem;
    font-size: 0.6875rem;
  }
  
  /* Stack action buttons vertically on very small screens */
  .action-bar {
    flex-direction: column;
    gap: var(--spacing-xs);
  }
  
  .action-bar .btn {
    width: 100%;
  }
  
  /* Simplify line items for tiny screens */
  .line-item {
    border-left: 3px solid var(--primary-color);
  }
  
  .line-item-field input {
    font-size: 14px;
  }
}

/* ===================================
   ENHANCED MOBILE OPTIMIZATIONS
   Modern Device Support (2024)
   =================================== */

/* iPhone 12/13/14 (390px) and Similar Devices */
@media (max-width: 414px) {
  /* Optimize container padding for narrow screens */
  .container {
    padding: 0 0.75rem;
  }
  
  /* Better modal sizing */
  .modal-content {
    width: 95%;
    max-width: 95%;
    padding: 1rem;
    margin: 1rem auto;
  }
  
  .modal-header {
    padding-bottom: 0.75rem;
  }
  
  .modal-close {
    top: 0.5rem;
    right: 0.5rem;
    width: 36px;
    height: 36px;
    font-size: 1.75rem;
  }
  
  /* Welcome modal optimization */
  .welcome-features {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  
  .feature-item {
    padding: 0.75rem;
  }
  
  .welcome-icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
  }
  
  /* Enhanced header for small screens */
  .header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--white);
    box-shadow: var(--shadow-sm);
  }
  
  .logo-text {
    font-size: 1.1rem;
  }
  
  .logo-icon {
    font-size: 1.25rem;
  }
  
  /* Navigation improvements */
  .main-nav {
    gap: 0.25rem;
    padding-top: 0.5rem;
  }
  
  .nav-btn {
    padding: 0.5rem 0.375rem;
    font-size: 0.65rem;
    border-radius: 6px;
  }
  
  .nav-btn svg {
    width: 18px;
    height: 18px;
    margin: 0 auto;
  }
  
  /* Form optimizations */
  .form-section {
    margin-bottom: 1rem;
    padding-bottom: 1rem;
  }
  
  .section-title {
    font-size: 0.95rem;
    padding: 0.5rem 0;
  }
  
  .form-group {
    margin-bottom: 0.75rem;
  }
  
  .form-group label {
    font-size: 0.8rem;
    margin-bottom: 0.375rem;
  }
  
  input, select, textarea {
    font-size: 16px !important;
    padding: 0.65rem 0.75rem;
    border-radius: 8px;
  }
  
  textarea {
    min-height: 100px;
  }
  
  /* Line items mobile-first */
  .line-items-container {
    max-height: none;
  }
  
  .line-item {
    padding: 0.75rem;
    margin-bottom: 0.75rem;
    border-radius: 8px;
  }
  
  .line-item-field {
    margin-bottom: 0.5rem;
  }
  
  .line-item-field label {
    font-size: 0.75rem;
    margin-bottom: 0.25rem;
  }
  
  .line-item-field input {
    font-size: 15px;
  }
  
  .remove-item-btn {
    margin-top: 0.5rem;
    padding: 0.5rem;
    font-size: 0.75rem;
  }
  
  .add-item-btn {
    padding: 0.75rem;
    font-size: 0.875rem;
  }
  
  /* Action buttons stack beautifully */
  .action-buttons-row {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  
  .btn {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    min-height: 44px;
    border-radius: 8px;
  }
  
  .btn svg {
    width: 18px;
    height: 18px;
  }
  
  /* Invoice preview mobile-optimized */
  .preview-container {
    padding: 0.5rem;
  }
  
  .preview-header {
    padding: 0.75rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
  }
  
  .preview-title {
    font-size: 1rem;
    text-align: center;
  }
  
  .preview-actions {
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem;
  }
  
  .zoom-controls {
    width: 100%;
    justify-content: center;
  }
  
  .zoom-controls button {
    flex: 1;
    max-width: 80px;
  }
  
  .invoice-preview {
    padding: 0.875rem;
    font-size: 10.5px;
    border-radius: 8px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .invoice-header {
    flex-direction: column;
    gap: 1rem;
  }
  
  .invoice-logo {
    max-width: 100px;
    max-height: 50px;
    margin: 0 auto;
  }
  
  .invoice-title {
    font-size: 1.35rem;
    text-align: center;
  }
  
  .invoice-details-grid {
    grid-template-columns: 1fr;
    gap: 0.875rem;
  }
  
  .invoice-table {
    font-size: 9.5px;
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .invoice-table thead,
  .invoice-table tbody,
  .invoice-table tr {
    display: table;
    width: 100%;
    table-layout: fixed;
  }
  
  .invoice-table th,
  .invoice-table td {
    padding: 0.4rem 0.2rem;
    word-break: break-word;
  }
  
  /* Better totals display */
  .invoice-totals {
    width: 100%;
    margin: 1rem 0;
  }
  
  .total-row {
    padding: 0.5rem 0.75rem;
    font-size: 0.8rem;
  }
  
  .total-row.final {
    font-size: 0.95rem;
    padding: 0.75rem;
  }
  
  /* Footer mobile-friendly */
  .footer-content {
    grid-template-columns: 1fr;
    gap: 1.5rem;
    text-align: center;
  }
  
  .footer-section {
    padding: 0;
  }
  
  .footer-section h4 {
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
  }
  
  .footer-links {
    gap: 0.5rem;
  }
  
  .footer-social {
    justify-content: center;
    gap: 1rem;
  }
  
  /* Newsletter card mobile */
  .newsletter-card {
    padding: 1rem;
  }
  
  .newsletter-card h4 {
    font-size: 1rem;
  }
  
  .newsletter-card input {
    font-size: 16px;
    padding: 0.65rem 0.75rem;
  }
  
  .newsletter-card button {
    padding: 0.65rem 1rem;
    font-size: 0.875rem;
  }
  
  /* Toast notifications */
  .toast {
    bottom: 1rem;
    left: 1rem;
    right: 1rem;
    max-width: none;
    font-size: 0.875rem;
    padding: 0.75rem 1rem;
    border-radius: 8px;
  }
  
  /* Calculation summary */
  .calculation-summary {
    padding: 0.75rem;
    font-size: 0.8125rem;
  }
  
  .calc-row {
    padding: 0.375rem 0;
  }
  
  /* Share buttons */
  .share-buttons {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
  }
  
  .share-btn {
    padding: 0.65rem;
    font-size: 0.75rem;
  }
  
  /* Logo upload area */
  .logo-upload {
    padding: 1rem;
    min-height: 120px;
  }
  
  .logo-preview {
    padding: 1rem;
  }
  
  .logo-preview img {
    max-width: 100px;
    max-height: 50px;
  }
}

/* iPhone SE and Small Android (360px-375px) */
@media (max-width: 375px) {
  /* Further optimize for very small screens */
  body {
    font-size: 13px;
  }
  
  .container {
    padding: 0 0.5rem;
  }
  
  .modal-content {
    width: 96%;
    padding: 0.875rem;
  }
  
  .logo-text {
    font-size: 1rem;
  }
  
  .nav-btn {
    padding: 0.4rem 0.25rem;
    font-size: 0.6rem;
  }
  
  .nav-btn svg {
    width: 16px;
    height: 16px;
  }
  
  .section-title {
    font-size: 0.9rem;
  }
  
  input, select, textarea {
    font-size: 16px !important;
    padding: 0.6rem 0.65rem;
  }
  
  .btn {
    padding: 0.65rem 0.875rem;
    font-size: 0.8125rem;
  }
  
  .invoice-preview {
    padding: 0.75rem;
    font-size: 10px;
  }
  
  .invoice-title {
    font-size: 1.25rem;
  }
  
  .invoice-table {
    font-size: 9px;
  }
  
  .total-row.final {
    font-size: 0.875rem;
  }
}

/* Landscape Mode Optimization for Mobile Devices */
@media (max-height: 500px) and (orientation: landscape) {
  /* Optimize for landscape mobile viewing */
  .header {
    position: sticky;
    top: 0;
  }
  
  .modal-content {
    max-height: 85vh;
    overflow-y: auto;
  }
  
  .content-grid {
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
  }
  
  .sidebar,
  .main-section {
    order: initial;
  }
  
  .invoice-preview {
    max-height: 70vh;
    overflow-y: auto;
  }
  
  .footer {
    margin-top: 1rem;
  }
}

/* Touch-Specific Improvements for All Mobile Devices */
@media (hover: none) and (pointer: coarse) {
  /* Enhance touch targets */
  button,
  a,
  .btn,
  .nav-btn,
  input[type="checkbox"],
  input[type="radio"],
  select {
    min-height: 44px;
    min-width: 44px;
  }
  
  /* Better tap feedback */
  button:active,
  .btn:active,
  .nav-btn:active {
    transform: scale(0.97);
    transition: transform 100ms ease;
  }
  
  /* Improve scrolling */
  .sidebar-content,
  .preview-container,
  .modal-content,
  .invoice-preview,
  .line-items-container {
    -webkit-overflow-scrolling: touch;
    scroll-behavior: smooth;
  }
  
  /* Better input focus for touch */
  input:focus,
  textarea:focus,
  select:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    transform: none;
  }
  
  /* Optimize tables for touch scrolling */
  .invoice-table {
    -webkit-overflow-scrolling: touch;
  }
  
  /* Better modal touch handling */
  .modal {
    -webkit-overflow-scrolling: touch;
  }
  
  /* Prevent zoom on input focus (iOS Safari) */
  input[type="text"],
  input[type="email"],
  input[type="number"],
  input[type="tel"],
  input[type="date"],
  textarea,
  select {
    font-size: 16px !important;
  }
}

/* High DPI / Retina Display Optimization */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  /* Crisp borders and shadows for retina displays */
  .invoice-preview,
  .modal-content,
  .card,
  .form-section {
    border-width: 0.5px;
  }
  
  .invoice-table th,
  .invoice-table td {
    border-width: 0.5px;
  }
}

/* iOS Safari Specific Fixes */
@supports (-webkit-touch-callout: none) {
  /* Fix iOS Safari 100vh issue */
  .modal {
    height: -webkit-fill-available;
  }
  
  /* Better input styling for iOS */
  input,
  textarea,
  select {
    -webkit-appearance: none;
    border-radius: 8px;
  }
  
  /* Fix iOS bounce scrolling */
  body {
    overscroll-behavior-y: contain;
  }
  
  /* Better modal scrolling on iOS */
  .modal-content {
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
  }
}

/* Android Chrome Specific Optimizations */
@supports (display: -webkit-box) {
  /* Optimize for Android Chrome */
  .invoice-preview {
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
  }
}

/* ===================================
   Documentation Page Text Fix
   =================================== */
.doc-section,
.doc-section h2,
.doc-section h3,
.doc-section h4,
.doc-section p,
.doc-section li,
.doc-section strong,
.stat-card p,
.stat-card strong,
.value-card h3,
.value-card p {
  color: var(--gray-900) !important;
}

[data-theme="dark"] .doc-section,
[data-theme="dark"] .doc-section h2,
[data-theme="dark"] .doc-section h3,
[data-theme="dark"] .doc-section h4,
[data-theme="dark"] .doc-section p,
[data-theme="dark"] .doc-section li,
[data-theme="dark"] .doc-section strong,
[data-theme="dark"] .stat-card p,
[data-theme="dark"] .stat-card strong,
[data-theme="dark"] .value-card h3,
[data-theme="dark"] .value-card p {
  color: var(--gray-100) !important;
}

/* ===================================
   Print Styles
   =================================== */
@media print {
  body {
    background: white;
  }
  
  .header,
  .ad-container,
  .sidebar,
  .right-sidebar,
  .footer,
  .preview-header,
  .action-bar,
  .form-actions,
  .premium-teaser,
  .modal,
  .toast {
    display: none !important;
  }
  
  .main-content {
    padding: 0;
  }
  
  .content-grid {
    display: block;
  }
  
  .main-section {
    box-shadow: none;
    padding: 0;
  }
  
  .preview-container {
    padding: 0;
    background: white;
  }
  
  .invoice-preview {
    box-shadow: none;
    max-width: none;
    width: 100%;
  }
}

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

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

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

/* ===================================
   Accessibility
   =================================== */
.skip-to-content {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary-color);
  color: white;
  padding: 8px;
  text-decoration: none;
  z-index: 100;
}

.skip-to-content:focus {
  top: 0;
}

*:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  :root {
    --gray-100: #000000;
    --gray-800: #ffffff;
  }
}

/* Reduced Motion */
@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;
  }
}