/* ===== CSS Variables & Reset ===== */
:root {
  --primary: #6C63FF;
  --primary-light: rgba(108, 99, 255, 0.1);
  --bg: #F5F7FA;
  --bg-card: #FFFFFF;
  --bg-input: #F0F2F5;
  --text: #1A1A2E;
  --text-secondary: #6B7280;
  --border: #E5E7EB;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.1);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 8px;
  --transition: 0.2s ease;
  --max-width: 900px;
}

[data-theme="dark"] {
  --bg: #0F0F1A;
  --bg-card: #1A1A2E;
  --bg-input: #252540;
  --text: #E8E8F0;
  --text-secondary: #9CA3AF;
  --border: #2D2D4A;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.4);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100dvh;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Layout ===== */
.app {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

/* ===== Header ===== */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  position: sticky;
  top: 0;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 10;
  transition: background var(--transition);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  color: var(--primary);
}

.header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), #FF6B8A);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: none;
  border-radius: var(--radius-xs);
  background: var(--bg-input);
  color: var(--text);
  cursor: pointer;
  transition: all var(--transition);
}

.icon-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
  transform: scale(1.05);
}

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

.icon {
  width: 20px;
  height: 20px;
}

/* Theme toggle icons */
[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
.sun-icon { display: none; }
.moon-icon { display: block; }

/* ===== Main ===== */
.main {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
  padding-bottom: 24px;
}

/* ===== Cards ===== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: all var(--transition);
}

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--text);
}

/* ===== Tabs ===== */
.tabs {
  display: flex;
  gap: 4px;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
  padding: 4px;
  margin-bottom: 20px;
}

.tab {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 12px;
  border: none;
  border-radius: var(--radius-xs);
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.tab:hover {
  color: var(--text);
}

.tab.active {
  background: var(--bg-card);
  color: var(--primary);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  font-weight: 600;
}

[data-theme="dark"] .tab.active {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.tab svg {
  flex-shrink: 0;
}

/* ===== Input Fields ===== */
.field-group {
  display: none;
  flex-direction: column;
  gap: 10px;
}

.field-group.active {
  display: flex;
}

.field-group label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}

input[type="text"],
input[type="url"],
input[type="email"],
input[type="tel"],
input[type="password"],
textarea,
select {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius-xs);
  background: var(--bg-input);
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: all var(--transition);
  outline: none;
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

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

select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236B7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
}

.field-row {
  display: flex;
  gap: 10px;
}

.field-col {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

/* ===== Options Panel ===== */
.options-panel {
  margin-top: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  overflow: hidden;
}

.options-panel summary {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
  transition: all var(--transition);
  list-style: none;
}

.options-panel summary::-webkit-details-marker {
  display: none;
}

.options-panel summary::after {
  content: '';
  margin-left: auto;
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 5px solid var(--text-secondary);
  transition: transform var(--transition);
}

.options-panel[open] summary::after {
  transform: rotate(180deg);
}

.options-panel summary:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  padding: 16px;
  border-top: 1px solid var(--border);
}

.option-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.option-group label {
  font-size: 0.825rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.color-input-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-input);
  border: 2px solid var(--border);
  border-radius: var(--radius-xs);
  padding: 6px 12px;
}

input[type="color"] {
  -webkit-appearance: none;
  appearance: none;
  width: 28px;
  height: 28px;
  border: 2px solid var(--border);
  border-radius: 6px;
  background: transparent;
  cursor: pointer;
  padding: 0;
}

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

input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: 4px;
}

.color-label {
  font-size: 0.825rem;
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  color: var(--text-secondary);
  text-transform: uppercase;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: 3px solid var(--bg-card);
  box-shadow: 0 2px 6px rgba(108, 99, 255, 0.3);
  transition: transform var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: 3px solid var(--bg-card);
  box-shadow: 0 2px 6px rgba(108, 99, 255, 0.3);
  transition: transform var(--transition);
}

input[type="range"]::-moz-range-thumb:hover {
  transform: scale(1.15);
}

input[type="range"]::-moz-range-track {
  height: 6px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 3px;
}

/* ===== Focus Visible ===== */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

input[type="range"]:focus-visible {
  outline-offset: 4px;
}

input[type="color"]:focus-visible {
  outline-offset: 2px;
  border-radius: 6px;
}

/* ===== Buttons ===== */
.btn-primary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 14px 24px;
  margin-top: 20px;
  border: none;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--primary), #8B83FF);
  color: #FFFFFF;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 4px 16px rgba(108, 99, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 24px rgba(108, 99, 255, 0.4);
}

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

.btn-secondary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 2px solid var(--border);
  border-radius: var(--radius-xs);
  background: var(--bg-card);
  color: var(--text);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

.btn-secondary:active {
  transform: scale(0.97);
}

/* ===== QR Preview ===== */
.preview-section {
  position: sticky;
  top: 80px;
}

.qr-preview {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
  padding: 32px;
  border: 2px dashed var(--border);
  transition: all var(--transition);
}

.qr-preview.has-qr {
  border-style: solid;
  background: var(--bg-card);
}

.qr-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
}

.qr-placeholder p {
  font-size: 0.9rem;
}

#qrCanvas {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
}

/* ===== Actions ===== */
.actions {
  display: flex;
  gap: 10px;
  margin-top: 16px;
  flex-wrap: wrap;
}

.actions .btn-secondary {
  flex: 1;
  min-width: 0;
}

/* ===== History ===== */
.history-section {
  grid-column: 1 / -1;
}

.history-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.history-header .card-title {
  margin-bottom: 0;
}

.btn-text {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.825rem;
  font-weight: 500;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-xs);
  transition: all var(--transition);
}

.btn-text:hover {
  color: #EF4444;
  background: rgba(239, 68, 68, 0.1);
}

.history-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.history-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 0.85rem;
  color: var(--text);
  font-family: inherit;
  text-align: left;
}

.history-item:hover {
  border-color: var(--primary);
  background: var(--primary-light);
  color: var(--primary);
}

.history-icon {
  font-size: 0.9rem;
  opacity: 0.7;
  flex-shrink: 0;
}

.history-label {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 500;
}

.history-time {
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0.7;
  flex-shrink: 0;
  white-space: nowrap;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: var(--bg);
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 100;
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 24px 0;
  color: var(--text-secondary);
  font-size: 0.825rem;
}

/* ===== Noscript ===== */
.noscript-message {
  text-align: center;
  padding: 3rem 1rem;
  font-family: system-ui, sans-serif;
}

/* ===== Utility ===== */
.hidden {
  display: none !important;
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.qr-preview.has-qr #qrCanvas {
  animation: fadeIn 0.3s ease;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .app {
    padding: 0 16px;
  }

  .main {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .header h1 {
    font-size: 1.25rem;
  }

  .card {
    padding: 20px;
  }

  .preview-section {
    position: static;
    order: -1;
  }

  .tabs {
    gap: 2px;
  }

  .tab {
    padding: 8px 6px;
    font-size: 0.8rem;
    gap: 4px;
  }

  .tab svg {
    width: 16px;
    height: 16px;
  }

  .options-grid {
    grid-template-columns: 1fr;
  }

  .qr-preview {
    min-height: 220px;
    padding: 24px;
  }

  .actions {
    gap: 8px;
  }

  .actions .btn-secondary {
    padding: 10px 12px;
    font-size: 0.8rem;
  }
}

@media (max-width: 400px) {
  .tab {
    font-size: 0.75rem;
    padding: 8px 4px;
  }

  .tab svg {
    display: none;
  }
}

/* ===== Print ===== */
@media print {
  .header, .input-section, .actions, .footer, .toast, .history-section {
    display: none !important;
  }

  .main {
    grid-template-columns: 1fr;
  }

  .preview-section {
    box-shadow: none;
    border: none;
  }
}