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

:root {
  /* Light Theme Variables */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --accent-color: #4f46e5;
  --accent-hover: #4338ca;
  --accent-light: #e0e7ff;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --paper-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.08);
  --preview-bg: #f1f5f9;
  --input-bg: #ffffff;
  --input-border: #cbd5e1;
  --focus-ring: rgba(79, 70, 229, 0.2);
}

[data-theme="dark"] {
  /* Dark Theme Variables */
  --bg-primary: #0b0f19;
  --bg-secondary: #161e2e;
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --border-color: #243049;
  --accent-color: #6366f1;
  --accent-hover: #4f46e5;
  --accent-light: rgba(99, 102, 241, 0.15);
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
  --paper-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.4);
  --preview-bg: #0d131f;
  --input-bg: #1f2937;
  --input-border: #374151;
  --focus-ring: rgba(99, 102, 241, 0.3);
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Header */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

.logo-icon {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--accent-color), #818cf8);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
}

.theme-toggle-btn {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

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

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
}

.theme-toggle-btn .sun-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle-btn .moon-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle-btn .sun-icon {
  display: block;
}

/* Hero Section */
.hero {
  max-width: 1200px;
  margin: 2.5rem auto 1.5rem auto;
  padding: 0 1.5rem;
  text-align: center;
}

.hero h2 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.hero p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 1.5rem auto;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.btn-primary {
  background-color: var(--accent-color);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.2s ease, transform 0.1s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 10px rgba(79, 70, 229, 0.2);
}

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

.btn-primary:active {
  transform: translateY(1px);
}

.hero-subtitle-badge {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  background-color: var(--border-color);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  display: inline-block;
}

/* Main Layout */
.app-container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  gap: 2rem;
  align-items: flex-start;
}

/* Settings Panel */
.settings-panel {
  width: 420px;
  flex-shrink: 0;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.section-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
  margin-bottom: 0.75rem;
}

.presets-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
}

.preset-btn {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.5rem 0.25rem;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s ease;
}

.preset-btn:hover {
  background-color: var(--accent-light);
  border-color: var(--accent-color);
  color: var(--accent-color);
}

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

/* Form Groups */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
}

/* Segmented Control / Radio buttons */
.segmented-control {
  display: flex;
  background-color: var(--bg-primary);
  padding: 0.25rem;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.segmented-control label {
  flex: 1;
  text-align: center;
  padding: 0.5rem 0;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: 6px;
  transition: all 0.2s ease;
  user-select: none;
}

.segmented-control input[type="radio"] {
  display: none;
}

.segmented-control label:hover {
  color: var(--text-primary);
}

.segmented-control input[type="radio"]:checked + label {
  background-color: var(--bg-secondary);
  color: var(--accent-color);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  font-weight: 600;
}

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

.color-picker-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.color-preview-btn {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  cursor: pointer;
  padding: 0;
  overflow: hidden;
  position: relative;
}

.color-preview-btn input[type="color"] {
  position: absolute;
  top: -8px;
  left: -8px;
  width: 56px;
  height: 56px;
  cursor: pointer;
  border: none;
  background: none;
}

.color-value-text {
  font-size: 0.875rem;
  font-family: monospace;
  color: var(--text-secondary);
  text-transform: uppercase;
}

/* Margins Controls */
.margin-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

.margin-input-box {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  align-items: center;
}

.margin-input-box span {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

.margin-input-box input {
  width: 100%;
  padding: 0.35rem 0.5rem;
  border-radius: 6px;
  border: 1px solid var(--input-border);
  background-color: var(--input-bg);
  color: var(--text-primary);
  font-size: 0.85rem;
  text-align: center;
}

.margin-input-box input:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

/* Slider Controls */
.slider-group {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.slider-group input[type="range"] {
  flex: 1;
  accent-color: var(--accent-color);
  height: 5px;
  background-color: var(--border-color);
  border-radius: 5px;
  cursor: pointer;
}

.slider-val {
  width: 45px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 600;
  text-align: right;
}

/* Select Control */
.select-control {
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--input-border);
  background-color: var(--input-bg);
  color: var(--text-primary);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.select-control:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

/* Download Button styling */
.download-btn {
  background-color: #10b981;
  color: white;
  border: none;
  border-radius: 8px;
  padding: 0.85rem;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: background-color 0.2s ease, transform 0.1s ease;
  box-shadow: 0 4px 10px rgba(16, 185, 129, 0.2);
  margin-top: 0.5rem;
}

.download-btn:hover {
  background-color: #059669;
}

.download-btn:active {
  transform: translateY(1px);
}

/* Preview Workspace Panel */
.preview-container {
  flex: 1;
  background-color: var(--preview-bg);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 1.25rem;
  min-height: 600px;
  box-shadow: var(--card-shadow);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

/* Paper Info Display */
.paper-info-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  max-width: 680px;
  padding-bottom: 0.5rem;
  border-bottom: 1px dashed var(--border-color);
}

.paper-info-text {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.paper-scale-text {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  background-color: var(--bg-secondary);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
}

/* Paper Sheet Mockup */
.paper-sheet {
  background-color: #ffffff;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 2px;
  /* Deep shadows to create realistic paper depth and zoom feeling */
  box-shadow: 
    0 1px 3px rgba(0, 0, 0, 0.05),
    0 10px 30px rgba(0, 0, 0, 0.08),
    0 25px 60px rgba(0, 0, 0, 0.06);
  position: relative;
  width: 100%;
  max-width: 680px; /* Increased size to make paper the main focus */
  aspect-ratio: 0.707; /* A4 Ratio default */
  transition: aspect-ratio 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
  overflow: hidden;
}

/* Hover effect to enhance the zoom/interactive feeling */
.paper-sheet:hover {
  transform: translateY(-4px) scale(1.015);
  box-shadow: 
    0 2px 5px rgba(0, 0, 0, 0.03),
    0 15px 45px rgba(0, 0, 0, 0.12),
    0 35px 80px rgba(0, 0, 0, 0.08);
}

.paper-sheet svg {
  display: block;
  width: 100%;
  height: 100%;
}

/* Button States */
.download-btn:disabled {
  background-color: var(--text-muted) !important;
  cursor: not-allowed;
  opacity: 0.7;
}

.download-btn.complete {
  background-color: #10b981 !important; /* solid green success */
}

.preview-download-btn {
  width: 100%;
  max-width: 680px;
  margin-top: 0;
}

/* SEO & Content Section */
.seo-section {
  max-width: 1200px;
  margin: 4rem auto;
  padding: 0 1.5rem;
}

.seo-section h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 2rem;
  text-align: center;
  color: var(--text-primary);
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3.5rem;
}

.seo-card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.seo-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.seo-card p, .seo-card ol {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.seo-card ol {
  padding-left: 1.25rem;
}

.seo-card li {
  margin-bottom: 0.5rem;
}

/* FAQ Accordion */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-title {
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}

.faq-item {
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  padding: 0.5rem 0;
  gap: 1rem;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out, padding 0.3s ease-out;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
  padding: 0;
}

.faq-answer p {
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
}

.faq-icon {
  width: 18px;
  height: 18px;
  color: var(--text-secondary);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-item.active .faq-answer {
  max-height: 200px; /* arbitrary big height for transition */
}

/* Footer */
.site-footer {
  text-align: center;
  padding: 2.5rem 1rem;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

/* Responsive adjustments */
@media (max-width: 992px) {
  .app-container {
    flex-direction: column;
    align-items: stretch;
  }

  .settings-panel {
    width: 100%;
  }

  .content-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 600px) {
  .hero h2 {
    font-size: 1.8rem;
  }
  .hero p {
    font-size: 1rem;
  }
  .preview-container {
    padding: 1rem;
  }
  .margin-grid {
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
  }
}

/* Print Overrides */
@media print {
  body * {
    visibility: hidden;
  }
  #preview-svg, #preview-svg * {
    visibility: visible;
  }
  #preview-svg {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
  }
}