/* =========================================================
   DelimitIt — Stylesheet
   Light theme by default; dark theme via [data-theme="dark"]
   WCAG 2.2 AA compliant contrast ratios throughout
   ========================================================= */

/* ---------------------------------------------------------
   1. Custom Properties — Light Theme
   --------------------------------------------------------- */
:root {
  /* Surfaces */
  --color-bg:           #f4f6f9;
  --color-surface:      #ffffff;
  --color-surface-alt:  #eef1f6;
  --color-border:       #d0d7e3;

  /* Text */
  --color-text:         #1a2233;
  --color-text-muted:   #5a6478;
  --color-text-inverse: #ffffff;

  /* Accent — blue-teal */
  --color-accent:       #1a7fc1;
  --color-accent-hover: #155f91;
  --color-accent-light: #e3f0fb;

  /* Status / interactive */
  --color-success:      #1a7a4a;
  --color-focus-ring:   #1a7fc1;

  /* Header */
  --color-header-bg:    #1a2233;
  --color-header-text:  #ffffff;

  /* Footer */
  --color-footer-bg:    #e8ecf3;
  --color-footer-text:  #5a6478;

  /* Misc */
  --border-radius:      6px;
  --border-radius-lg:   10px;
  --shadow-sm:          0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md:          0 4px 12px rgba(0,0,0,.10), 0 2px 4px rgba(0,0,0,.06);
  --transition:         150ms ease;
  --font-mono:          'Cascadia Code', 'Consolas', 'Menlo', 'Monaco', monospace;
  --font-ui:            -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* ---------------------------------------------------------
   2. Custom Properties — Dark Theme
   --------------------------------------------------------- */
[data-theme="dark"] {
  --color-bg:           #111827;
  --color-surface:      #1e2736;
  --color-surface-alt:  #273042;
  --color-border:       #3a4559;

  --color-text:         #e4e9f2;
  --color-text-muted:   #8a97b0;
  --color-text-inverse: #111827;

  --color-accent:       #3ba8e8;
  --color-accent-hover: #6dc0f0;
  --color-accent-light: #1a2f45;

  --color-success:      #34c47a;
  --color-focus-ring:   #3ba8e8;

  --color-header-bg:    #0d1320;
  --color-header-text:  #e4e9f2;

  --color-footer-bg:    #0d1320;
  --color-footer-text:  #8a97b0;

  --shadow-sm:          0 1px 3px rgba(0,0,0,.30), 0 1px 2px rgba(0,0,0,.20);
  --shadow-md:          0 4px 12px rgba(0,0,0,.40), 0 2px 4px rgba(0,0,0,.20);
}

/* ---------------------------------------------------------
   3. OS-level dark mode default (before JS theme loads)
   --------------------------------------------------------- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg:           #111827;
    --color-surface:      #1e2736;
    --color-surface-alt:  #273042;
    --color-border:       #3a4559;
    --color-text:         #e4e9f2;
    --color-text-muted:   #8a97b0;
    --color-text-inverse: #111827;
    --color-accent:       #3ba8e8;
    --color-accent-hover: #6dc0f0;
    --color-accent-light: #1a2f45;
    --color-success:      #34c47a;
    --color-focus-ring:   #3ba8e8;
    --color-header-bg:    #0d1320;
    --color-header-text:  #e4e9f2;
    --color-footer-bg:    #0d1320;
    --color-footer-text:  #8a97b0;
    --shadow-sm:          0 1px 3px rgba(0,0,0,.30), 0 1px 2px rgba(0,0,0,.20);
    --shadow-md:          0 4px 12px rgba(0,0,0,.40), 0 2px 4px rgba(0,0,0,.20);
  }
}

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

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

body {
  font-family: var(--font-ui);
  background-color: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.5;
  transition: background-color var(--transition), color var(--transition);
}

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

/* ---------------------------------------------------------
   5. Focus Styles (visible, high-contrast)
   --------------------------------------------------------- */
:focus-visible {
  outline: 3px solid var(--color-focus-ring);
  outline-offset: 2px;
  border-radius: 3px;
}

/* ---------------------------------------------------------
   6. Header
   --------------------------------------------------------- */
.site-header {
  background-color: var(--color-header-bg);
  color: var(--color-header-text);
  padding: 0.5rem 1.5rem;
  min-height: 56px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  min-height: 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  min-width: 0;
}

.brand-mark {
  height: 2.5rem;
  width: auto;
  display: block;
  flex-shrink: 0;
}

.app-title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--color-header-text);
}

.app-title-delimit {
  color: #ffffff;
}

.app-title-it {
  color: var(--color-accent);
}

.header-actions {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.35rem;
  flex-shrink: 0;
}

/* ---------------------------------------------------------
   7. Buttons
   --------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  border: 1px solid transparent;
  border-radius: var(--border-radius);
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  line-height: 1;
  text-decoration: none;
  transition: background-color var(--transition), border-color var(--transition), color var(--transition), box-shadow var(--transition);
  white-space: nowrap;
  user-select: none;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

/* Primary button */
.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-text-inverse);
  border-color: var(--color-accent);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

/* Secondary button */
.btn-secondary {
  background-color: var(--color-surface-alt);
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-border);
}

/* Icon-only button (theme toggle) */
.btn-icon {
  background: transparent;
  border: none;
  color: var(--color-header-text);
  padding: 0.4rem 0.75rem;
  gap: 0.35rem;
  font-size: 0.8125rem;
  font-weight: 500;
}

.btn-icon:hover {
  background-color: rgba(255,255,255,0.10);
  border-radius: var(--border-radius);
}

.preferences-menu {
  position: relative;
}

.preferences-menu summary {
  list-style: none;
}

.preferences-menu summary::-webkit-details-marker {
  display: none;
}

.preferences-toggle {
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.preferences-toggle[aria-expanded="true"] {
  background-color: rgba(255,255,255,0.14);
  border-radius: var(--border-radius);
}

.preferences-label {
  font-size: 0.75rem;
  font-weight: 600;
}

.preferences-caret {
  transition: transform var(--transition);
}

.preferences-menu[open] .preferences-caret {
  transform: rotate(180deg);
}

.preferences-menu-panel {
  position: absolute;
  top: calc(100% + 0.45rem);
  right: 0;
  min-width: 14rem;
  display: flex;
  flex-direction: column;
  padding: 0.35rem;
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  background-color: var(--color-surface);
  box-shadow: var(--shadow-md);
}

.preferences-menu-item {
  width: 100%;
  border: none;
  border-radius: var(--border-radius);
  background-color: transparent;
  color: var(--color-text);
  cursor: pointer;
  font-family: var(--font-ui);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.7rem 0.8rem;
  text-align: left;
  text-transform: uppercase;
}

.preferences-menu-item:hover,
.preferences-menu-item:focus-visible {
  background-color: var(--color-surface-alt);
}

/* Small button variant */
.btn-sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.8125rem;
}

/* Icons inside buttons */
.icon {
  width: 1em;
  height: 1em;
  flex-shrink: 0;
  vertical-align: -0.1em;
}

/* ---------------------------------------------------------
   8. Theme Toggle
   --------------------------------------------------------- */

/* Show sun in dark mode (to switch back to light) */
[data-theme="dark"] .icon-sun  { display: none; }
[data-theme="dark"] .icon-moon { display: inline; }
[data-theme="dark"] .theme-label::before { content: 'Light'; }

/* Show moon in light mode (to switch to dark) */
:not([data-theme="dark"]) .icon-sun  { display: inline; }
:not([data-theme="dark"]) .icon-moon { display: none; }
:not([data-theme="dark"]) .theme-label { font-size: 0; } /* hide static "Dark" text */
:not([data-theme="dark"]) .theme-label::before { content: 'Dark'; font-size: 0.8125rem; }

/* ---------------------------------------------------------
   9. Main Layout
   --------------------------------------------------------- */
.main-layout {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 1.25rem 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ---------------------------------------------------------
   10. Options Bar
   --------------------------------------------------------- */
.options-bar {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 1rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 2rem;
  align-items: flex-start;
  transition: background-color var(--transition), border-color var(--transition);
}

.option-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  border: none;
  padding: 0;
  min-width: 0;
}

.option-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.option-input {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-text);
  background-color: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: 0.375rem 0.625rem;
  min-width: 0;
  transition: border-color var(--transition), background-color var(--transition);
}

.option-input:focus {
  border-color: var(--color-accent);
  background-color: var(--color-surface);
}

.delimiter-input {
  width: 3rem;
  text-align: center;
}

.hint-text {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  max-width: 22ch;
  line-height: 1.3;
}

/* Radio group */
.radio-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.875rem;
}

.radio-group-vertical {
  flex-direction: column;
  align-items: flex-start;
  gap: 0.45rem;
}

.radio-label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.875rem;
  color: var(--color-text);
  cursor: pointer;
  white-space: nowrap;
}

.radio-label input[type="radio"] {
  accent-color: var(--color-accent);
  width: 1rem;
  height: 1rem;
  cursor: pointer;
}

.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.875rem;
  color: var(--color-text);
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  accent-color: var(--color-accent);
  width: 1rem;
  height: 1rem;
  cursor: pointer;
}

.quote-preview {
  font-family: var(--font-mono);
  color: var(--color-accent);
}

/* Ignore characters group — hidden when in numeric mode */
.ignore-group {
  transition: opacity var(--transition);
}

.ignore-group.hidden {
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
}

/* ---------------------------------------------------------
   11. Panels Layout (3-column: input | convert | output)
   --------------------------------------------------------- */
.panels {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 0 1rem;
  align-items: stretch;
  min-height: 0;
}

/* Convert column — vertically centers the button */
.convert-column {
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 2.5rem; /* offset for panel-header height */
}

.btn-convert {
  flex-direction: column;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  font-weight: 600;
  gap: 0.5rem;
  box-shadow: var(--shadow-sm);
}

.btn-convert .icon-arrow {
  width: 1.1em;
  height: 1.1em;
}

/* On mobile, rotate convert arrow to point down */
@media (max-width: 767px) {
  .btn-convert .icon-arrow {
    transform: rotate(90deg);
  }
}

/* ---------------------------------------------------------
   12. Panel
   --------------------------------------------------------- */
.panel {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
  transition: background-color var(--transition), border-color var(--transition);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.625rem 0.875rem;
  border-bottom: 1px solid var(--color-border);
  background-color: var(--color-surface-alt);
  flex-wrap: wrap;
}

.panel-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  cursor: default;
}

.panel-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

/* Hide the native file input */
#fileInput {
  display: none;
}

/* ---------------------------------------------------------
   13. Textareas
   --------------------------------------------------------- */
.text-area {
  flex: none;
  display: block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-surface);
  border: none;
  resize: vertical;
  overflow: auto;
  padding: 0.875rem;
  min-height: 320px;
  width: 100%;
  outline: none;
  transition: background-color var(--transition), color var(--transition);
}

.text-area::placeholder {
  color: var(--color-text-muted);
  opacity: 0.7;
}

.text-area:focus {
  box-shadow: inset 0 0 0 2px var(--color-focus-ring);
}

/* Output textarea — distinct tint to signal it's read-only */
.panel-output .text-area {
  background-color: var(--color-surface-alt);
}

/* ---------------------------------------------------------
   14. Footer
   --------------------------------------------------------- */
.site-footer {
  background-color: var(--color-footer-bg);
  color: var(--color-footer-text);
  padding: 1rem;
  font-size: 0.8125rem;
  border-top: 1px solid var(--color-border);
  transition: background-color var(--transition);
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
}

.footer-tagline {
  max-width: 52rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  align-items: center;
}

.footer-links a {
  color: var(--color-accent);
  text-decoration: none;
}

.footer-links a:hover,
.footer-links a:focus-visible {
  text-decoration: underline;
}

/* ---------------------------------------------------------
   15. Responsive — Mobile (single column)
   --------------------------------------------------------- */
@media (max-width: 767px) {
  .site-header {
    padding: 0 1rem;
  }

  .header-inner {
    flex-wrap: wrap;
  }

  .header-actions {
    width: 100%;
    justify-content: flex-end;
  }

  .preferences-menu-panel {
    right: 0;
    min-width: min(14rem, calc(100vw - 2rem));
  }

  .main-layout {
    padding: 1rem 0.875rem 2rem;
    gap: 1rem;
  }

  .panels {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
    gap: 1rem 0;
  }

  /* Stack: input → convert button → output */
  .panel-input  { grid-row: 1; }
  .convert-column { grid-row: 2; padding-top: 0; }
  .panel-output { grid-row: 3; }

  .convert-column {
    padding: 0;
  }

  .btn-convert {
    flex-direction: row;
    width: 100%;
    justify-content: center;
  }

  .text-area {
    min-height: 220px;
  }

  .options-bar {
    gap: 1rem 1.5rem;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.4rem;
  }
}

/* ---------------------------------------------------------
   16. "Copied!" state for Copy button
   --------------------------------------------------------- */
.btn-copied {
  background-color: var(--color-success) !important;
  border-color: var(--color-success) !important;
  color: #ffffff !important;
}

/* ---------------------------------------------------------
   17. Print — basic clean output
   --------------------------------------------------------- */
@media print {
  .site-header, .options-bar, .panel-actions, .convert-column, .site-footer {
    display: none;
  }
  .panels {
    grid-template-columns: 1fr;
  }
  .text-area {
    border: 1px solid #ccc;
  }
}