/* Modern UI Design for Invoice Generator */
:root {
  color-scheme: light dark;
  
  /* Light theme colors */
  --color-primary: #0ea5e9;
  --color-primary-hover: #0284c7;
  --color-primary-light: rgba(14, 165, 233, 0.16);
  --color-accent: #f97316;
  --color-secondary: #6b7280;
  --color-secondary-hover: #4b5563;
  --color-success: #10b981;
  --color-success-light: #d1fae5;
  --color-danger: #ef4444;
  --color-danger-light: #fee2e2;
  --color-warning: #f59e0b;
  
  --color-background: #ffffff;
  --color-surface: #f3f6fb;
  --color-surface-hover: #e9eef6;
  --color-border: #d5deeb;
  --color-border-light: #e6edf5;
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-ring: rgba(14, 165, 233, 0.3);
  --color-glow-1: rgba(14, 165, 233, 0.22);
  --color-glow-2: rgba(249, 115, 22, 0.16);
  
  /* Typography */
  --font-family: "Space Grotesk", "Manrope", "Noto Sans", system-ui, -apple-system, "Segoe UI", Arial, 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;
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-base: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Border radius */
  --radius-sm: 0.375rem;
  --radius-base: 0.5rem;
  --radius-md: 0.625rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #38bdf8;
    --color-primary-hover: #0ea5e9;
    --color-primary-light: rgba(14, 165, 233, 0.25);
    --color-accent: #fb923c;
    --color-secondary: #94a3b8;
    --color-secondary-hover: #e2e8f0;
    --color-success: #10b981;
    --color-success-light: #064e3b;
    --color-danger: #ef4444;
    --color-danger-light: #7f1d1d;
    
    --color-background: #0f172a;
    --color-surface: #111b2d;
    --color-surface-hover: #1f2a3e;
    --color-border: #24334b;
    --color-border-light: #2f3d55;
    --color-text: #f8fafc;
    --color-text-secondary: #cbd5f5;
    --color-text-muted: #94a3b8;
    --color-ring: rgba(56, 189, 248, 0.35);
    --color-glow-1: rgba(56, 189, 248, 0.25);
    --color-glow-2: rgba(251, 146, 60, 0.2);
  }
}

/* Base styles */
* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  margin: 0;
  padding: 0;
  background-color: var(--color-surface);
  background-image:
    radial-gradient(900px 500px at 10% -10%, var(--color-glow-1), transparent 70%),
    radial-gradient(900px 600px at 90% -20%, var(--color-glow-2), transparent 65%);
  color: var(--color-text);
  line-height: 1.5;
}

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

:focus-visible {
  outline: 3px solid var(--color-ring);
  outline-offset: 2px;
}

/* Container */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-6);
}

/* Header */
.header-section {
  margin-bottom: var(--space-8);
}

.header-content {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-6);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  color: white;
  position: relative;
  overflow: hidden;
}

.header-content::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(120px 120px at 12% 20%, rgba(255, 255, 255, 0.2), transparent 70%);
  pointer-events: none;
}

.header-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 4rem;
  height: 4rem;
  background: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(10px);
}

.header-content h1 {
  margin: 0;
  font-size: var(--font-size-3xl);
  font-weight: 700;
  letter-spacing: -0.025em;
}

.header-content .subtitle {
  margin: var(--space-2) 0 0 0;
  font-size: var(--font-size-lg);
  opacity: 0.9;
  font-weight: 400;
}

/* Main content layout */
.main-content {
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: var(--space-8);
  align-items: start;
}

@media (max-width: 1200px) {
  .main-content {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .preview-section {
    position: static;
  }
}

/* Form section */
.form-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.summary-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
}

.summary-card {
  padding: var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background:
    radial-gradient(180px 100px at top right, var(--color-primary-light), transparent 60%),
    var(--color-background);
  box-shadow: var(--shadow-base);
}

.summary-label {
  display: block;
  font-size: var(--font-size-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

.summary-value {
  display: block;
  font-size: var(--font-size-2xl);
  color: var(--color-text);
}

.summary-meta {
  display: block;
  margin-top: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* Cards */
.card {
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-base);
  overflow: hidden;
  transition: all 0.2s ease;
  backdrop-filter: blur(6px);
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-light);
}

.card-header {
  padding: var(--space-6);
  border-bottom: 1px solid var(--color-border-light);
  background: linear-gradient(180deg, var(--color-surface) 0%, transparent 100%);
}

.card-title {
  margin: 0;
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.card-title svg {
  color: var(--color-primary);
  flex-shrink: 0;
}

.card-content {
  padding: var(--space-6);
}

/* Grid layout */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-8);
}

@media (max-width: 768px) {
  .summary-strip {
    grid-template-columns: 1fr;
  }

  .grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
}

@media (max-width: 600px) {
  .form-row { grid-template-columns: 1fr; }
}

/* Input groups */
.input-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.group-title {
  margin: 0 0 var(--space-2) 0;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text);
  padding-bottom: var(--space-2);
  border-bottom: 2px solid var(--color-primary-light);
}

/* Form row grid */
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Form fields */
.form-field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-field label {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-1);
}

.form-field input,
.form-field textarea,
.form-field select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-base);
  background: var(--color-background);
  color: var(--color-text);
  font-size: var(--font-size-base);
  transition: all 0.2s ease;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.2);
}

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

.form-field input:hover,
.form-field textarea:hover,
.form-field select:hover {
  border-color: var(--color-primary);
}

.form-field input[type="color"] {
  padding: var(--space-1);
  height: 44px;
  cursor: pointer;
}

.form-field input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

.form-field input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: var(--radius-sm);
}

/* Item field wrapper - transparent on desktop */
.item-field {
  display: contents;
}

/* Items table */
.items-container {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

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

.items-actions .btn-add {
  margin-right: auto;
}

.items-table {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-base);
  overflow: hidden;
  background: var(--color-background);
  box-shadow: var(--shadow-sm);
}

.items-head {
  display: grid;
  grid-template-columns: 2fr 0.7fr 1fr 1fr 40px;
  gap: var(--space-2);
  align-items: center;
  padding: var(--space-4);
  background: linear-gradient(135deg, var(--color-surface), transparent);
  border-bottom: 1px solid var(--color-border);
  font-weight: 600;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.item-row {
  display: grid;
  grid-template-columns: 2fr 0.7fr 1fr 1fr 40px;
  gap: var(--space-2);
  align-items: center;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border-light);
  transition: background-color 0.2s ease;
}

.item-row:hover {
  background: var(--color-surface);
}

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

.item-row input {
  width: 100%;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-background);
  color: var(--color-text);
  font-size: var(--font-size-sm);
  transition: all 0.2s ease;
  font-variant-numeric: tabular-nums;
}

.item-row input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-ring);
}

.item-row input.line {
  background: var(--color-surface);
  border-style: dashed;
  color: var(--color-text-secondary);
}

.item-row .remove {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: none;
  background: var(--color-danger-light);
  color: var(--color-danger);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
}

.item-row .remove:hover {
  background: var(--color-danger);
  color: white;
  transform: scale(1.05);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-base);
  background: var(--color-background);
  color: var(--color-text);
  font-size: var(--font-size-base);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

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

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

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-hover) 100%);
  border-color: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  box-shadow: var(--shadow-lg);
}

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

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

.btn-add {
  background: linear-gradient(135deg, var(--color-success) 0%, #059669 100%);
  border-color: var(--color-success);
  color: white;
  align-self: flex-start;
}

.btn-add:hover {
  box-shadow: var(--shadow-lg);
}

.btn-small {
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
}

.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text-secondary);
}

.btn-ghost:hover {
  background: var(--color-surface-hover);
  color: var(--color-text);
}

.btn-danger {
  background: var(--color-danger-light);
  border-color: var(--color-danger-light);
  color: var(--color-danger);
}

.btn-danger:hover {
  background: var(--color-danger);
  border-color: var(--color-danger);
  color: white;
}

.btn:focus-visible {
  outline: 3px solid var(--color-ring);
  outline-offset: 2px;
}

.status-message {
  margin: var(--space-3) 0 0;
  font-size: var(--font-size-sm);
  color: var(--color-success);
  min-height: 1.25rem;
}

.status-message.is-error {
  color: var(--color-danger);
}

.form-field.is-disabled {
  opacity: 0.6;
}

.form-field.is-disabled input {
  cursor: not-allowed;
  background: var(--color-surface);
}

.logo-upload {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.logo-controls {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.logo-preview {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-base);
  background: var(--color-surface);
}

.logo-preview.dragover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.logo-preview img {
  max-width: 140px;
  max-height: 48px;
  object-fit: contain;
  display: none;
}

.logo-preview.has-logo img {
  display: inline-block;
}

.logo-preview.has-logo .logo-placeholder {
  display: none;
}

.logo-placeholder {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* Totals section */
.totals-section {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: var(--space-6);
  flex-wrap: wrap;
}

@media (max-width: 768px) {
  .totals-section {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-4);
  }
}

.totals-summary {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  min-width: min(250px, 100%);
}

.total-line {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-3) 0;
  font-size: var(--font-size-base);
}

.balance-due {
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: var(--space-3);
}

.balance-due.is-negative {
  color: var(--color-danger);
  background: var(--color-danger-light);
}

.balance-due.is-negative strong {
  color: var(--color-danger);
}

.total-line:not(:last-child) {
  border-bottom: 1px solid var(--color-border-light);
}

.grand-total {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  border-bottom: 2px solid var(--color-primary) !important;
  background: linear-gradient(135deg, var(--color-primary-light), rgba(255, 255, 255, 0));
  border-radius: var(--radius-base);
  padding: var(--space-4);
  margin-top: var(--space-2);
}

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

@media (max-width: 768px) {
  .actions {
    justify-content: stretch;
  }
  
  .actions .btn {
    flex: 1;
  }
}

/* Preview section */
.preview-section {
  position: sticky;
  top: var(--space-6);
  height: fit-content;
}

.preview-card {
  height: 100%;
}

.preview-container {
  height: 600px;
  border-radius: var(--radius-base);
  overflow: hidden;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
}

.preview-container iframe {
  width: 100%;
  height: 100%;
  border: none;
  border-radius: var(--radius-base);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .container {
    padding: var(--space-4);
  }
  
  .header-content {
    flex-direction: column;
    text-align: center;
    padding: var(--space-4);
  }
  
  .header-content h1 {
    font-size: var(--font-size-2xl);
  }
  
  .card-content,
  .card-header {
    padding: var(--space-4);
  }
  
  .items-head,
  .item-row {
    grid-template-columns: 1.5fr 0.5fr 0.8fr 0.8fr 32px;
    gap: var(--space-1);
    font-size: var(--font-size-xs);
  }
  
  .preview-container {
    height: 400px;
  }

  .items-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .items-actions .btn-add {
    margin-right: 0;
  }
}

@media (max-width: 480px) {
  .items-head,
  .item-row {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }
  
  .items-head {
    display: none;
  }
  
  .item-row {
    display: flex;
    flex-direction: column;
    padding: var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    margin-bottom: var(--space-2);
  }
  
  .item-row .remove {
    align-self: flex-end;
  }

  .item-field {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
  }

  .item-field::before {
    content: attr(data-label);
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  .btn {
    min-height: 44px;
  }

  .preview-container {
    height: 300px;
  }
}

/* Print styles */
@media print {
  body {
    background: white !important;
    background-image: none !important;
  }

  .container {
    max-width: 100% !important;
    padding: 0 !important;
  }

  .form-section,
  .header-section,
  .totals-card,
  .notes-terms-card {
    display: none !important;
  }
  
  .main-content {
    grid-template-columns: 1fr !important;
    gap: 0 !important;
  }
  
  .preview-section {
    position: static !important;
    width: 100% !important;
  }

  .preview-card {
    border: none !important;
    box-shadow: none !important;
    background: transparent !important;
  }

  .preview-card .card-header {
    display: none !important;
  }

  .preview-container {
    height: auto !important;
    min-height: 100vh !important;
    border: none !important;
    box-shadow: none !important;
    background: white !important;
  }

  .preview-container iframe {
    height: 100vh !important;
  }
}

/* Loading states and animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.card {
  animation: fadeIn 0.3s ease-out;
}

/* Focus styles for accessibility */
.btn:focus-visible,
.form-field input:focus-visible,
.form-field textarea:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-border: #000000;
    --color-text: #000000;
    --color-background: #ffffff;
  }
  
  .card {
    border: 2px solid var(--color-border);
  }
}

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

/* Notes & Terms grid */
.notes-terms-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
}

@media (max-width: 768px) {
  .notes-terms-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
}

/* Preview paper shadow */
.preview-container {
  position: relative;
  box-shadow: 0 4px 24px -4px rgba(0, 0, 0, 0.12), 0 8px 16px -8px rgba(0, 0, 0, 0.08);
}

/* Loading spinner overlay */
.preview-container.is-loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 24px;
  height: 24px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  z-index: 10;
  pointer-events: none;
}

@keyframes spin {
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

/* Smooth section transitions */
.card-content {
  transition: max-height 0.3s ease, opacity 0.3s ease;
}