/* ============================================================
   QR Studio — style.css
   Mightora Design Language
   ============================================================ */

/* --- Variables --- */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #7c3aed;
  --success: #16a34a;
  --warning: #d97706;
  --danger: #dc2626;
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f3f4f6;
  --border: #e5e7eb;
  --border-focus: #2563eb;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 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);
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --transition: 0.2s ease;
}

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text-primary);
  background: var(--bg-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }
ul, ol { list-style: none; }
button { cursor: pointer; font-family: inherit; }
input, select, textarea { font-family: inherit; }

/* --- Container --- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.25; color: var(--text-primary); }
h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.25rem; }
p { color: var(--text-secondary); line-height: 1.7; }
code {
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.85em;
  background: var(--bg-tertiary);
  padding: 0.1em 0.4em;
  border-radius: 0.25rem;
  color: var(--accent);
}

/* --- App-specific overrides for Mightora shared header --- */
/* The site-logo-text span uses shared-ui --accent colour for the "Studio" span */
.site-logo-text span { color: var(--accent); }

/* --- Hero --- */
.hero {
  background: linear-gradient(135deg, #1e40af 0%, #2563eb 40%, #7c3aed 100%);
  padding: 5rem 0 4rem;
  overflow: hidden;
  position: relative;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-content {
  position: relative;
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(255,255,255,0.15);
  color: rgba(255,255,255,0.9);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.35rem 1rem;
  border-radius: 2rem;
  border: 1px solid rgba(255,255,255,0.25);
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.hero-title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  color: white;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  text-shadow: 0 2px 20px rgba(0,0,0,0.2);
}
.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: rgba(255,255,255,0.85);
  margin-bottom: 2rem;
  line-height: 1.6;
  font-weight: 400;
}
.hero-features {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  justify-content: center;
}
.feature-badge {
  background: rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.95);
  border: 1px solid rgba(255,255,255,0.2);
  padding: 0.4rem 1rem;
  border-radius: 2rem;
  font-size: 0.85rem;
  font-weight: 500;
  transition: background var(--transition);
}
.feature-badge:hover { background: rgba(255,255,255,0.2); }

/* --- Section Base --- */
.section { padding: 4rem 0; }
.bg-secondary { background: var(--bg-secondary); }
.section-header { text-align: center; margin-bottom: 2.5rem; }
.section-title { font-size: 1.875rem; font-weight: 700; color: var(--text-primary); margin-bottom: 0.5rem; }
.section-desc { color: var(--text-secondary); font-size: 1rem; max-width: 600px; margin: 0 auto; }
.section-text { color: var(--text-secondary); margin-bottom: 1rem; font-size: 0.9rem; line-height: 1.7; }

/* --- Cards --- */
.card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow var(--transition);
  margin-bottom: 1.25rem;
}
#file-encoder-card { display: none; }
.card:hover { box-shadow: var(--shadow); }
.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.card-header.collapsible { cursor: pointer; user-select: none; }
.card-header.collapsible:hover { background: var(--bg-tertiary); }
.card-title { font-size: 1rem; font-weight: 600; color: var(--text-primary); flex: 1; }
.card-desc { font-size: 0.85rem; color: var(--text-secondary); margin-top: 0.15rem; }
.card-body { padding: 1.5rem; }
.collapse-icon { font-size: 0.75rem; color: var(--text-muted); transition: transform var(--transition); }
.card-header.collapsed .collapse-icon { transform: rotate(-90deg); }

/* --- QR Type Grid --- */
.qr-type-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.75rem;
}
.qr-type-card {
  background: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 0.75rem;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  box-shadow: var(--shadow-sm);
}
.qr-type-card:hover {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1), var(--shadow);
  transform: translateY(-2px);
}
.qr-type-card.active {
  border-color: var(--primary);
  background: linear-gradient(135deg, rgba(37,99,235,0.06) 0%, rgba(124,58,237,0.04) 100%);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.15), var(--shadow);
}
.qr-type-icon { font-size: 1.75rem; line-height: 1; }
.qr-type-name { font-size: 0.8rem; font-weight: 600; color: var(--text-primary); }
.qr-type-desc { font-size: 0.7rem; color: var(--text-muted); line-height: 1.3; }

/* --- Workspace Layout --- */
.workspace-grid {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 1.5rem;
  align-items: start;
}
.builder-panel { min-width: 0; }
.preview-panel { position: sticky; top: 80px; display: flex; flex-direction: column; gap: 0; }

/* --- Form Elements --- */
.form-group { margin-bottom: 1.25rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}
.form-label--inline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}
.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.9rem;
  color: var(--text-primary);
  background: var(--bg-primary);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
.form-input::placeholder, .form-textarea::placeholder { color: var(--text-muted); }
.form-textarea { resize: vertical; min-height: 80px; }
.form-select { appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.75rem center; padding-right: 2.5rem; }
.form-range {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg-tertiary);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}
.form-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  box-shadow: 0 0 0 3px rgba(37,99,235,0.2);
  transition: box-shadow var(--transition);
}
.form-range::-webkit-slider-thumb:hover { box-shadow: 0 0 0 5px rgba(37,99,235,0.25); }
.field-hint { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.35rem; line-height: 1.4; }
.form-checkbox-row { display: flex; align-items: center; gap: 0.5rem; }
.form-checkbox { width: 16px; height: 16px; cursor: pointer; accent-color: var(--primary); }

/* --- Color Picker --- */
.color-picker {
  width: 100%;
  height: 42px;
  padding: 3px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  background: var(--bg-primary);
  transition: border-color var(--transition);
}
.color-picker:hover { border-color: var(--border-focus); }

.style-preset-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(92px, 1fr));
  gap: 0.55rem;
}
.style-preset-card {
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-primary);
  padding: 0.45rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  transition: all var(--transition);
}
.style-preset-card:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}
.style-preset-card.active {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.14);
}
.style-preset-preview {
  width: 70px;
  height: 70px;
  border-radius: 8px;
  background: #f8fafc;
}
.style-preset-name {
  font-size: 0.72rem;
  color: var(--text-secondary);
  font-weight: 600;
  line-height: 1.2;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  transition: all var(--transition);
  cursor: pointer;
  text-decoration: none;
}
.btn--primary {
  background: var(--primary);
  color: white;
}
.btn--primary:hover { background: var(--primary-dark); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37,99,235,0.3); }
.btn--secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border);
}
.btn--secondary:hover { background: var(--border); }
.btn--danger { background: var(--danger); color: white; }
.btn--danger:hover { background: #b91c1c; }
.btn + .btn { margin-left: 0.5rem; }

.icon-btn {
  width: 32px;
  height: 32px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-primary);
  color: var(--text-secondary);
  font-size: 1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}
.icon-btn:hover { background: var(--bg-tertiary); border-color: var(--primary); color: var(--primary); }
.icon-btn.active { background: var(--primary); color: white; border-color: var(--primary); }

/* --- Preview Panel --- */
.preview-card { }
.preview-controls { display: flex; gap: 0.35rem; }
.preview-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  overflow: hidden;
}
.preview-container.grid-overlay::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(37,99,235,0.1) 1px, transparent 1px), linear-gradient(90deg, rgba(37,99,235,0.1) 1px, transparent 1px);
  background-size: 20px 20px;
  pointer-events: none;
}
.qr-display {
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition);
}
.qr-display img, .qr-display canvas, .qr-display table { border-radius: 4px; }
.qr-empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem;
}
.qr-empty-state .empty-icon { font-size: 3rem; margin-bottom: 0.75rem; opacity: 0.5; }
.qr-empty-state p { font-size: 0.9rem; color: var(--text-muted); }

/* --- Stats / Analysis --- */
.stats-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-bottom: 1rem; }
.stat-card {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 1rem;
  border: 1px solid var(--border);
}
.stat-label { font-size: 0.75rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.35rem; }
.stat-value { font-size: 1.1rem; font-weight: 700; color: var(--text-primary); margin-bottom: 0.5rem; }
.stat-bar-wrap { height: 6px; background: var(--bg-tertiary); border-radius: 3px; overflow: hidden; }
.stat-bar {
  height: 100%;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--success), var(--warning));
  transition: width 0.4s ease;
  width: 0%;
}
.scan-score-wrap { display: flex; justify-content: center; margin-top: 0.5rem; }
.scan-score {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: conic-gradient(var(--success) 0%, var(--bg-tertiary) 0%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-primary);
  border: 2px solid var(--border);
  transition: all 0.4s ease;
}
.scan-score.score-easy { border-color: var(--success); color: var(--success); }
.scan-score.score-medium { border-color: var(--warning); color: var(--warning); }
.scan-score.score-hard { border-color: var(--danger); color: var(--danger); }
.warnings-list { display: flex; flex-direction: column; gap: 0.4rem; }
.warning-item {
  font-size: 0.8rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius);
  border-left: 3px solid var(--warning);
  background: rgba(217,119,6,0.08);
  color: #92400e;
}
.warning-item.danger { border-left-color: var(--danger); background: rgba(220,38,38,0.08); color: #991b1b; }

/* --- Export Panel --- */
.export-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.6rem; }
.export-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  padding: 1rem 0.75rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-primary);
  cursor: pointer;
  transition: all var(--transition);
}
.export-btn:hover {
  border-color: var(--primary);
  background: rgba(37,99,235,0.04);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.export-icon { font-size: 1.5rem; line-height: 1; }
.export-label { font-size: 0.8rem; font-weight: 700; color: var(--text-primary); }
.export-desc { font-size: 0.7rem; color: var(--text-muted); }
.export-actions { display: flex; gap: 0.5rem; margin-top: 1rem; flex-wrap: wrap; }

/* --- Info Boxes --- */
.info-box {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-lg);
  margin-bottom: 1rem;
}
.info-box--blue { background: rgba(37,99,235,0.07); border: 1px solid rgba(37,99,235,0.2); }
.info-box--purple { background: rgba(124,58,237,0.07); border: 1px solid rgba(124,58,237,0.2); }
.info-box--green { background: rgba(22,163,74,0.07); border: 1px solid rgba(22,163,74,0.2); }
.info-box-title { font-weight: 600; font-size: 0.85rem; color: var(--text-primary); margin-bottom: 0.4rem; }
.info-box p { font-size: 0.85rem; color: var(--text-secondary); margin: 0; }

.warning-box {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  background: rgba(217,119,6,0.1);
  border: 1px solid rgba(217,119,6,0.3);
  color: #92400e;
  font-size: 0.85rem;
  font-weight: 500;
  margin-top: 0.75rem;
}

/* --- Stats Box --- */
.stats-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
}
.stat-item { display: flex; justify-content: space-between; align-items: center; padding: 0.25rem 0; font-size: 0.85rem; }
.stat-item + .stat-item { border-top: 1px solid var(--border); margin-top: 0.25rem; padding-top: 0.5rem; }

/* --- Multi-Part Grid --- */
.multipart-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}
.multipart-qr-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1rem;
  text-align: center;
}
.multipart-qr-item .part-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.multipart-qr-item .part-number {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
}

/* --- Password Toggle --- */
.password-field { position: relative; }
.password-toggle {
  position: absolute;
  right: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  font-size: 0.8rem;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.2rem 0.4rem;
}
.password-toggle:hover { color: var(--primary); }

/* --- Copy Payload Button --- */
.copy-payload-row {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}
.payload-preview {
  flex: 1;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: monospace;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 200px;
}

/* --- Accordion --- */
.accordion { display: flex; flex-direction: column; gap: 0.5rem; }
.accordion-item {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition);
}
.accordion-item:hover { box-shadow: var(--shadow-sm); }
.accordion-trigger {
  width: 100%;
  text-align: left;
  padding: 1.1rem 1.5rem;
  background: none;
  border: none;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background var(--transition);
}
.accordion-trigger::after { content: '＋'; font-size: 1rem; color: var(--text-muted); transition: transform var(--transition); font-weight: 300; }
.accordion-trigger.open::after { transform: rotate(45deg); }
.accordion-trigger:hover { background: var(--bg-secondary); }
.accordion-content {
  display: none;
  padding: 0 1.5rem 1.25rem;
  border-top: 1px solid var(--border);
}
.accordion-content.open { display: block; }
.accordion-content p, .accordion-content ul, .accordion-content li { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.7; }
.accordion-content p + p { margin-top: 0.75rem; }
.accordion-content ul { padding-left: 1.25rem; list-style: disc; margin-top: 0.5rem; }
.accordion-content li { margin-bottom: 0.35rem; }

/* --- Privacy Grid --- */
.privacy-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
}
.privacy-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 1.75rem 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  text-align: center;
}
.privacy-card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.privacy-icon { font-size: 2.5rem; margin-bottom: 1rem; }
.privacy-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 0.5rem; }
.privacy-card p { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.6; margin: 0; }

/* --- Toast Notifications --- */
.toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 360px;
}
.toast {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.875rem 1.25rem;
  border-radius: var(--radius-lg);
  background: #1f2937;
  color: white;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  animation: toast-in 0.3s ease;
  position: relative;
  overflow: hidden;
}
.toast::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
}
.toast--success::before { background: var(--success); }
.toast--error::before { background: var(--danger); }
.toast--warning::before { background: var(--warning); }
.toast-icon { font-size: 1rem; flex-shrink: 0; }
.toast-msg { flex: 1; line-height: 1.4; }
.toast-close { background: none; border: none; color: rgba(255,255,255,0.5); cursor: pointer; font-size: 1rem; padding: 0; line-height: 1; }
.toast-close:hover { color: white; }
@keyframes toast-in { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
@keyframes toast-out { to { transform: translateX(100%); opacity: 0; } }
.toast.removing { animation: toast-out 0.3s ease forwards; }

/* --- Loading State --- */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(255,255,255,0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9998;
}
.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* --- Responsive --- */
@media (max-width: 1024px) {
  .workspace-grid { grid-template-columns: 1fr; }
  .preview-panel { position: static; }
}
@media (max-width: 768px) {
  .container { padding: 0 1rem; }
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  .hero { padding: 3rem 0 2.5rem; }
  .section { padding: 2.5rem 0; }
  .qr-type-grid { grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); gap: 0.5rem; }
  .stats-grid { grid-template-columns: 1fr; }
  .export-grid { grid-template-columns: 1fr 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .privacy-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .privacy-grid { grid-template-columns: 1fr; }
  .qr-type-grid { grid-template-columns: repeat(3, 1fr); }
}

/* --- Density Meter --- */
.density-meter { height: 8px; background: var(--bg-tertiary); border-radius: 4px; overflow: hidden; margin: 0.5rem 0; }
.density-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.4s ease, background 0.4s ease;
}

/* --- Misc --- */
.main-content { padding: 2rem 0; }
.hidden { display: none !important; }
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.divider { border: none; border-top: 1px solid var(--border); margin: 1.5rem 0; }