/*
 * HTML Formatter & Tidy — Styles
 * ================================
 * Reuses the exact design tokens from the OG Image Preview Tool.
 * Same dark-first theme, same spacing grid, same type scale.
 * Additional styles for the two-pane editor layout,
 * syntax highlighting overlay, and split button dropdown.
 */

/* ============================================================
   CUSTOM PROPERTIES (Design Tokens)
   Identical to the OG Image Preview Tool.
   ============================================================ */
:root {
  /* Colors — dark theme */
  --color-bg: #0f1117;
  --color-surface: #1a1d27;
  --color-surface-raised: #242734;
  --color-border: #2e3245;
  --color-border-hover: #454b66;
  --color-text: #e1e4ed;
  --color-text-muted: #8b90a5;
  --color-text-heading: #f0f2f8;
  --color-primary: #5b8af5;
  --color-primary-hover: #7aa2f7;
  --color-success: #4ade80;
  --color-warning: #facc15;
  --color-error: #f87171;
  --color-info: #60a5fa;

  /* Spacing — 4px base grid */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', 'Cascadia Code', 'Consolas', monospace;
  --text-sm: 0.8125rem;
  --text-base: 0.9375rem;
  --text-lg: 1.125rem;
  --text-xl: 1.5rem;
  --text-2xl: 1.875rem;
  --line-height: 1.6;

  /* Shared editor metrics — textarea and pre MUST match */
  --editor-font: var(--font-mono);
  --editor-size: var(--text-sm);
  --editor-line-height: 1.6;
  --editor-padding: var(--space-md);
  --editor-tab-size: 2;

  /* Layout */
  --max-width: 1400px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;

  /* Syntax highlighting — dark theme */
  --hl-tag: #f07178;
  --hl-attr: #c792ea;
  --hl-value: #c3e88d;
  --hl-comment: #546e7a;
  --hl-bracket: #89ddff;
}

/* Light theme override — respects OS preference */
@media (prefers-color-scheme: light) {
  :root {
    --color-bg: #f5f6fa;
    --color-surface: #ffffff;
    --color-surface-raised: #f0f1f5;
    --color-border: #d4d7e0;
    --color-border-hover: #b0b5c5;
    --color-text: #1a1d27;
    --color-text-muted: #5c6178;
    --color-text-heading: #0f1117;
    --color-primary: #3b6fd9;
    --color-primary-hover: #2d5bbf;
    --color-success: #16a34a;
    --color-warning: #ca8a04;
    --color-error: #dc2626;
    --color-info: #2563eb;

    /* Syntax highlighting — light theme */
    --hl-tag: #c41a16;
    --hl-attr: #7928a1;
    --hl-value: #3a7d0a;
    --hl-comment: #8e908c;
    --hl-bracket: #0550ae;
  }
}

/* ============================================================
   RESET & BASE
   ============================================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--line-height);
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  background-image: linear-gradient(
    180deg,
    var(--color-bg) 0%,
    color-mix(in srgb, var(--color-bg) 95%, var(--color-primary)) 100%
  );
  background-attachment: fixed;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-surface-raised);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

.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;
}

/* ============================================================
   LAYOUT
   ============================================================ */
.app-header,
main,
.app-footer {
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

/* ============================================================
   HEADER
   ============================================================ */
.app-header {
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-lg);
  text-align: center;
}

.app-header h1 {
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text-heading);
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--color-text-muted);
  margin-top: var(--space-sm);
  font-size: var(--text-base);
}

/* ============================================================
   FORMATTING BAR
   Compact single-row bar with indent-size + wrap-length.
   Replaces the old full options section.
   ============================================================ */
.formatting-bar {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-sm) var(--space-lg);
  margin-bottom: var(--space-md);
}

.option-group {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.option-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-weight: 600;
  white-space: nowrap;
}

.option-select {
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--text-sm);
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  outline: none;
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

.option-select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 25%, transparent);
}

/* Checkbox labels — used in tidy dropdown */
.option-checkbox {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--text-sm);
  cursor: pointer;
  white-space: nowrap;
  user-select: none;
}

.option-checkbox input[type="checkbox"] {
  accent-color: var(--color-primary);
  cursor: pointer;
}

/* ============================================================
   EDITOR SECTION
   Two-pane side-by-side editor with format controls in between.
   ============================================================ */
.editor-section {
  margin-bottom: var(--space-lg);
}

.editor-panes {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-md);
  align-items: stretch;
}

.editor-pane {
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  min-height: 500px;
}

.pane-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface-raised);
  flex-shrink: 0;
}

.pane-title {
  font-weight: 600;
  font-size: var(--text-sm);
  color: var(--color-text-heading);
}

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

.textarea-wrapper {
  flex: 1;
  display: flex;
  position: relative;
}

/* Rich text input (contenteditable) — Visual pane */
.editor-richtext {
  flex: 1;
  width: 100%;
  padding: var(--space-md);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  border: none;
  outline: none;
  overflow: auto;
  overflow-wrap: break-word;
  word-wrap: break-word;
  -webkit-user-modify: read-write;
}

.editor-richtext:empty::before {
  content: attr(data-placeholder);
  color: var(--color-text-muted);
  pointer-events: none;
  display: block;
}

.editor-richtext:focus {
  background: color-mix(in srgb, var(--color-bg) 95%, var(--color-primary));
}

/* Make pasted content look reasonable */
.editor-richtext img {
  max-width: 100%;
  height: auto;
}

.editor-richtext a {
  color: var(--color-primary);
}

/* ============================================================
   SOURCE EDITOR — Transparent textarea over highlighted <pre>
   Both elements share identical font metrics via CSS vars.
   ============================================================ */
.source-editor-wrapper {
  position: relative;
  flex: 1;
  display: flex;
  background: var(--color-bg);
}

.source-highlight {
  position: absolute;
  inset: 0;
  margin: 0;
  pointer-events: none;
  overflow: hidden;
  font-family: var(--editor-font);
  font-size: var(--editor-size);
  line-height: var(--editor-line-height);
  padding: var(--editor-padding);
  tab-size: var(--editor-tab-size);
  -moz-tab-size: var(--editor-tab-size);
  white-space: pre-wrap;
  overflow-wrap: break-word;
  word-wrap: break-word;
  color: var(--color-text);
  background: transparent;
  border: none;
  letter-spacing: normal;
}

.source-highlight code {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  background: none;
  padding: 0;
  border-radius: 0;
}

.source-textarea {
  position: relative;
  z-index: 1;
  flex: 1;
  width: 100%;
  margin: 0;
  font-family: var(--editor-font);
  font-size: var(--editor-size);
  line-height: var(--editor-line-height);
  padding: var(--editor-padding);
  tab-size: var(--editor-tab-size);
  -moz-tab-size: var(--editor-tab-size);
  white-space: pre-wrap;
  overflow-wrap: break-word;
  word-wrap: break-word;
  color: transparent;
  caret-color: var(--color-text);
  background: transparent;
  border: none;
  outline: none;
  resize: none;
  overflow: auto;
  letter-spacing: normal;
}

.source-textarea::placeholder {
  color: var(--color-text-muted);
}

.source-textarea:focus {
  background: transparent;
}

/* ============================================================
   SYNTAX HIGHLIGHTING TOKENS
   ============================================================ */
.hl-tag     { color: var(--hl-tag); }
.hl-attr    { color: var(--hl-attr); }
.hl-value   { color: var(--hl-value); }
.hl-comment { color: var(--hl-comment); font-style: italic; }
.hl-bracket { color: var(--hl-bracket); }

/* ============================================================
   CHARACTER COUNT
   ============================================================ */
.char-count {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* ============================================================
   FORMAT CONTROLS — Action buttons centered between panes
   ============================================================ */
.format-controls {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: stretch;
  gap: var(--space-sm);
  padding: var(--space-sm) 0;
  position: relative;
}

.btn-action {
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--text-sm);
  min-width: 100px;
}

/* ============================================================
   TIDY SPLIT BUTTON + DROPDOWN
   ============================================================ */
.tidy-button-group {
  display: flex;
}

.btn-tidy-main {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
  flex: 1;
}

.btn-dropdown-toggle {
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
  border-left: 1px solid color-mix(in srgb, #fff 20%, var(--color-primary));
  padding: var(--space-sm) var(--space-sm);
  min-width: auto;
  font-size: 0.625rem;
  line-height: 1;
}

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

.tidy-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  min-width: 280px;
  max-height: 70vh;
  overflow-y: auto;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  padding: var(--space-md);
}

.tidy-dropdown-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.tidy-dropdown-divider {
  height: 1px;
  background: var(--color-border);
  margin: var(--space-sm) 0;
}

.tidy-dropdown-footer {
  margin-top: var(--space-sm);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-style: italic;
  text-align: center;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--text-base);
  font-family: var(--font-sans);
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  color: #fff;
  background: var(--color-primary);
  border-color: var(--color-primary);
}

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

.btn-secondary {
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}

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

.btn-small {
  padding: var(--space-xs) var(--space-md);
  font-size: var(--text-sm);
  color: var(--color-text);
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
}

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

/* Temporary flash for copy confirmation */
.btn-success-flash {
  background: color-mix(in srgb, var(--color-success) 15%, var(--color-surface-raised)) !important;
  border-color: var(--color-success) !important;
  color: var(--color-success) !important;
}

/* ============================================================
   STATS SECTION
   ============================================================ */
.stats-section {
  margin-bottom: var(--space-lg);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: var(--space-sm);
}

.stat-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.stat-value {
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-heading);
}

.stat-value.positive {
  color: var(--color-error);
}

.stat-value.negative {
  color: var(--color-success);
}

/* ============================================================
   PREVIEW SECTION
   ============================================================ */
.preview-section {
  margin-bottom: var(--space-2xl);
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.preview-header h2 {
  font-size: var(--text-lg);
  color: var(--color-text-heading);
}

.preview-frame-wrapper {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.preview-frame {
  width: 100%;
  height: 400px;
  border: none;
  display: block;
}

/* ============================================================
   ERROR DISPLAY
   ============================================================ */
.error-section {
  margin-bottom: var(--space-lg);
}

.error-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  background: color-mix(in srgb, var(--color-error) 10%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-error) 30%, var(--color-border));
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.error-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--color-error);
  color: #fff;
  border-radius: 50%;
  font-weight: 700;
  font-size: var(--text-sm);
  flex-shrink: 0;
}

.error-title {
  font-weight: 600;
  color: var(--color-error);
}

.error-detail {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-xs);
}

.error-dismiss {
  margin-left: auto;
  background: none;
  border: none;
  color: var(--color-text-muted);
  font-size: var(--text-xl);
  cursor: pointer;
  padding: 0 var(--space-xs);
  line-height: 1;
}

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

/* ============================================================
   FOOTER
   ============================================================ */
.app-footer {
  padding: var(--space-xl) var(--space-md);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-xl);
}

.footer-content {
  text-align: center;
}

.footer-content p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.footer-note {
  margin-top: var(--space-sm);
}

/* ============================================================
   RESPONSIVE DESIGN
   ============================================================ */

/* Stack panes vertically on narrow screens */
@media (max-width: 768px) {
  .editor-panes {
    grid-template-columns: 1fr;
  }

  .format-controls {
    flex-direction: row;
    justify-content: center;
    padding: var(--space-sm);
    flex-wrap: wrap;
  }

  .editor-pane {
    min-height: 300px;
  }

  .formatting-bar {
    flex-wrap: wrap;
  }

  .stats-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  /* Dropdown repositions on mobile */
  .tidy-dropdown {
    position: fixed;
    top: auto;
    bottom: var(--space-md);
    left: var(--space-md);
    right: var(--space-md);
    transform: none;
    max-height: 50vh;
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pane-actions {
    flex-wrap: wrap;
  }
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@media (prefers-reduced-motion: no-preference) {
  .stat-card {
    animation: fadeIn 0.3s ease both;
  }

  .stat-card {
    animation-delay: calc(var(--card-index, 0) * 50ms);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Focus-visible for keyboard users only */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* ============================================================
   PRINT STYLES
   ============================================================ */
@media print {
  .formatting-bar,
  .format-controls,
  .pane-actions,
  .stats-section,
  .preview-section,
  .app-footer {
    display: none;
  }

  body {
    background: white;
    color: black;
  }

  .editor-panes {
    grid-template-columns: 1fr;
  }
}