/* FileChanger — "the conversion bench".
   The product turns one document into another, so the whole system is built
   around a single idea: source on one side, converted output on the other, a
   gold arrow doing the work between them. Petrol-teal is the instrument; gold is
   reserved for the moment of conversion and nothing else. */

:root {
  /* Light: ink on manuscript stock. */
  --bg: #ece7dc;
  --surface: #faf8f1;
  --surface-2: #f3efe5;
  --ink: #211e19;
  --muted: #6d665a;
  --border: #d8d1c1;
  --border-strong: #c4bba6;

  --primary: #145560;
  --primary-strong: #0e3f48;
  --on-primary: #f7f4ec;

  --accent: #bd8118;
  --accent-soft: rgba(189, 129, 24, 0.14);
  --source: #2c4a6e;

  --code-bg: #182629;
  --code-ink: #e7e2d6;

  --danger: #ab372c;
  --danger-soft: #f6e7e3;
  --success: #2f7d52;

  --radius: 6px;
  --radius-lg: 12px;
  --shadow: 0 1px 2px rgba(33, 30, 25, 0.05), 0 8px 24px -12px rgba(33, 30, 25, 0.18);
  --shadow-lift: 0 2px 4px rgba(33, 30, 25, 0.06), 0 18px 40px -20px rgba(33, 30, 25, 0.28);

  --font-mono: "Space Mono", ui-monospace, "SF Mono", "Menlo", "Consolas", monospace;
  --font-body: "Public Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

/* Dark: a real editor dark theme, deep ink-teal rather than pure black, the
   same petrol/gold duo brightened to hold up against it. Entry points mirror
   the original: explicit data-theme="dark" plus the OS-preference fallback. */
:root[data-theme="dark"] {
  --bg: #13181b;
  --surface: #1b2226;
  --surface-2: #222b2f;
  --ink: #e9e4d7;
  --muted: #8f9aa0;
  --border: #2b353a;
  --border-strong: #3a474d;

  --primary: #56b0bd;
  --primary-strong: #70c4cf;
  --on-primary: #0a2024;

  --accent: #e0a93e;
  --accent-soft: rgba(224, 169, 62, 0.16);
  --source: #6f98ca;

  --code-bg: #0d1518;
  --code-ink: #dde6e3;

  --danger: #e0695c;
  --danger-soft: #2c1f1d;
  --success: #5fb985;

  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 10px 30px -14px rgba(0, 0, 0, 0.6);
  --shadow-lift: 0 2px 6px rgba(0, 0, 0, 0.45), 0 22px 46px -22px rgba(0, 0, 0, 0.7);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg: #13181b;
    --surface: #1b2226;
    --surface-2: #222b2f;
    --ink: #e9e4d7;
    --muted: #8f9aa0;
    --border: #2b353a;
    --border-strong: #3a474d;
    --primary: #56b0bd;
    --primary-strong: #70c4cf;
    --on-primary: #0a2024;
    --accent: #e0a93e;
    --accent-soft: rgba(224, 169, 62, 0.16);
    --source: #6f98ca;
    --code-bg: #0d1518;
    --code-ink: #dde6e3;
    --danger: #e0695c;
    --danger-soft: #2c1f1d;
    --success: #5fb985;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 10px 30px -14px rgba(0, 0, 0, 0.6);
    --shadow-lift: 0 2px 6px rgba(0, 0, 0, 0.45), 0 22px 46px -22px rgba(0, 0, 0, 0.7);
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

a {
  color: var(--primary);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

/* Mono eyebrow used across sections: a real signal, not decoration. */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: lowercase;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 0.5ch;
}

.eyebrow .arrow {
  color: var(--accent);
}

/* ---- Header ---- */
.site-header {
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.1) blur(8px);
  border-bottom: 1px solid var(--border);
  padding: 0.85rem 0;
  position: sticky;
  top: 0;
  z-index: 50;
}

.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.logo {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
  display: inline-flex;
  align-items: baseline;
  gap: 0.1ch;
}

/* The logo carries the product idea: a gold conversion mark mid-wordmark. */
.logo::before {
  content: "›_";
  color: var(--accent);
  font-weight: 700;
  margin-right: 0.35ch;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.main-nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.92rem;
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius);
  transition: color 0.15s, background-color 0.15s;
}

.main-nav a:hover {
  color: var(--ink);
  background: var(--surface-2);
}

/* ---- Main ---- */
main {
  padding: 2rem 0 3rem;
  min-height: calc(100vh - 220px);
}

/* ---- Hero: the conversion bench ---- */
.hero {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 3rem;
  align-items: center;
  padding: 3.5rem 0 3rem;
}

.hero-copy h1 {
  font-family: var(--font-mono);
  font-size: clamp(2.4rem, 5vw, 3.4rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 1rem 0 1rem;
}

.hero-copy h1 .out {
  color: var(--accent);
}

.hero .tagline {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 34ch;
  margin-bottom: 1.75rem;
}

.cta-buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ---- Transmutation panel: the signature element ----
   Same content, two encodings. The source pane is fixed; the output pane cycles
   through formats to show the one thing FileChanger does. */
.transmute {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: stretch;
  gap: 0.75rem;
}

.doc-card {
  background: var(--code-bg);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lift);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.doc-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.85rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.03em;
  color: #aeb6b3;
}

.doc-dots {
  display: inline-flex;
  gap: 0.3rem;
}

.doc-dots span {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.16);
}

.format-chip {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.12rem 0.5rem;
  border-radius: 999px;
  border: 1px solid currentColor;
  letter-spacing: 0.02em;
}

.doc-card.source .format-chip {
  color: var(--source);
}

.doc-card.output .format-chip {
  color: var(--accent);
}

.doc-body {
  padding: 1rem 1.05rem 1.2rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--code-ink);
  white-space: pre;
  overflow: hidden;
  min-height: 9.5rem;
}

.doc-body .tok-h {
  color: var(--accent);
}

.doc-body .tok-em {
  color: #e98f7a;
}

.doc-body .tok-mut {
  color: #7f8a87;
}

/* The output pane stacks three encodings and cross-fades between them. Three
   panes on a 15s loop, each shown for a third with a short overlap so one
   format is always on screen, no blank gap. */
.output-stack {
  display: grid;
  min-height: 9.5rem;
}

.output-stack .doc-body {
  grid-area: 1 / 1;
  animation: cycle 15s infinite;
  opacity: 0;
}

.output-stack .doc-body:nth-child(1) { animation-delay: 0s; }
.output-stack .doc-body:nth-child(2) { animation-delay: 5s; }
.output-stack .doc-body:nth-child(3) { animation-delay: 10s; }

@keyframes cycle {
  0% { opacity: 0; transform: translateY(5px); }
  3% { opacity: 1; transform: translateY(0); }
  30% { opacity: 1; transform: translateY(0); }
  35% { opacity: 0; transform: translateY(-5px); }
  100% { opacity: 0; transform: translateY(-5px); }
}

/* The conversion arrow: the only place gold gets to move. */
.transmute-arrow {
  align-self: center;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  text-align: center;
  animation: nudge 2.6s ease-in-out infinite;
}

@keyframes nudge {
  0%, 100% { transform: translateX(0); opacity: 0.75; }
  50% { transform: translateX(3px); opacity: 1; }
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5ch;
  padding: 0.7rem 1.25rem;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color 0.15s, border-color 0.15s, transform 0.05s, box-shadow 0.15s;
}

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

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

.btn-primary:hover {
  background-color: var(--primary-strong);
  box-shadow: var(--shadow);
}

.btn-secondary {
  background-color: transparent;
  color: var(--ink);
  border-color: var(--border-strong);
}

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

.btn-danger {
  background-color: transparent;
  color: var(--danger);
  border-color: color-mix(in srgb, var(--danger) 45%, var(--border));
  padding: 0.45rem 0.9rem;
  font-size: 0.85rem;
}

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

.btn-google, .btn-github {
  background-color: var(--surface);
  color: var(--ink);
  border: 1px solid var(--border-strong);
  justify-content: center;
}

.btn-google:hover, .btn-github:hover {
  border-color: var(--primary);
}

/* ---- Section scaffolding ---- */
.section {
  padding: 3rem 0;
  border-top: 1px solid var(--border);
}

.section-head {
  margin-bottom: 2rem;
}

.section-head h2 {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  letter-spacing: -0.01em;
  margin-top: 0.4rem;
}

/* keep legacy hooks the markup/tests still reference */
.features { padding: 3rem 0; border-top: 1px solid var(--border); }
.features h2, .formats-section h2 {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  letter-spacing: -0.01em;
  margin-bottom: 0.4rem;
}
.formats-section { padding: 3rem 0; border-top: 1px solid var(--border); }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1rem;
  margin-top: 1.75rem;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--primary);
  border-radius: var(--radius);
  padding: 1.4rem 1.4rem 1.5rem;
  transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s;
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-left-color: var(--accent);
}

.feature-card h3 {
  font-family: var(--font-mono);
  font-size: 1.02rem;
  color: var(--ink);
  margin-bottom: 0.5rem;
}

.feature-card p {
  color: var(--muted);
  font-size: 0.94rem;
}

/* ---- Formats: genuinely a list of mono tokens ---- */
.format-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  max-width: 620px;
  margin-top: 1.75rem;
}

.format-column h3 {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-bottom: 0.9rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.format-column ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.format-column li {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--ink);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.2rem 0.6rem;
}

/* ---- Dashboard ---- */
.dashboard {
  max-width: 820px;
  margin: 0 auto;
}

.dashboard h1, .api-key-page h1, .convert-page h1, .key-created h1 {
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
  margin-bottom: 1.5rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 2.1rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-top: 0.6rem;
}

.dashboard-actions {
  margin-top: 1.5rem;
}

/* ---- API key pages ---- */
.api-key-page {
  max-width: 640px;
  margin: 0 auto;
}

.api-key-page h2 {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  margin: 2rem 0 0.75rem;
}

.key-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.key-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
}

.key-item .key-info {
  border: none;
  background: none;
  padding: 0;
  margin: 0;
}

.key-info {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.key-info p {
  margin-bottom: 0.4rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.key-info strong {
  color: var(--ink);
}

.key-info code {
  font-family: var(--font-mono);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05rem 0.35rem;
  font-size: 0.85rem;
}

.status-active { color: var(--success); font-weight: 600; }
.status-disabled { color: var(--danger); font-weight: 600; }

.key-created {
  max-width: 640px;
  margin: 0 auto;
}

.key-created p {
  margin-bottom: 1rem;
  color: var(--muted);
}

.api-key {
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  word-break: break-all;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border-strong);
}

/* ---- Forms ---- */
.form-group {
  margin-bottom: 1.25rem;
}

.form-group label,
.form-row-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  margin-bottom: 0.45rem;
}

/* In the convert row, the label/select grid gap handles the spacing. */
.form-row-label {
  margin-bottom: 0;
}

.form-group input[type="text"],
.form-group input[type="file"],
.form-group select,
.form-row-select {
  display: block;
  width: 100%;
  padding: 0.6rem 0.7rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  font-size: 0.92rem;
  font-family: var(--font-body);
  background: var(--surface);
  color: var(--ink);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.form-group input:focus,
.form-group select:focus,
.form-row-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

/* ---- Convert page: the form is itself a from -> to ---- */
.convert-page {
  max-width: 620px;
  margin: 0 auto;
}

.convert-page > p {
  color: var(--muted);
  margin-bottom: 1.5rem;
}

.convert-form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow);
}

/* From/To selects flank a gold arrow, echoing the hero. Labels live on their
   own grid row so the arrow centres against the selects, not the whole stack. */
.form-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  grid-template-areas:
    "from-label .     to-label"
    "from-sel   arrow to-sel";
  align-items: center;
  column-gap: 1rem;
  row-gap: 0.45rem;
  margin-bottom: 1.25rem;
}

.form-row-label--from { grid-area: from-label; }
.form-row-label--to { grid-area: to-label; }
.form-row-select--from { grid-area: from-sel; }
.form-row-select--to { grid-area: to-sel; }

.form-row .convert-arrow {
  grid-area: arrow;
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  text-align: center;
}

.convert-form .btn {
  width: 100%;
  justify-content: center;
  margin-top: 0.5rem;
}

.convert-error {
  background: var(--danger-soft);
  border: 1px solid color-mix(in srgb, var(--danger) 40%, transparent);
  border-left: 3px solid var(--danger);
  border-radius: var(--radius);
  padding: 0.9rem 1rem;
  margin-bottom: 1.5rem;
  color: var(--danger);
  font-size: 0.92rem;
}

.convert-error code {
  font-family: var(--font-mono);
}

/* ---- Documentation ---- */
.docs-page {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 2.5rem;
  max-width: 1140px;
  margin: 0 auto;
}

.docs-sidebar {
  position: sticky;
  top: 5rem;
  height: fit-content;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.1rem;
}

.docs-sidebar h3 {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-bottom: 0.75rem;
}

.docs-sidebar ul { list-style: none; padding: 0; margin: 0; }
.docs-sidebar li { margin-bottom: 0.15rem; }

.docs-sidebar a {
  display: block;
  padding: 0.4rem 0.65rem;
  color: var(--muted);
  text-decoration: none;
  border-radius: var(--radius);
  font-size: 0.88rem;
  border-left: 2px solid transparent;
}

.docs-sidebar a:hover {
  background: var(--surface-2);
  color: var(--primary);
  border-left-color: var(--accent);
}

.docs-content { min-width: 0; }

.docs-hero {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.docs-hero h1 {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}

.docs-hero .tagline { color: var(--muted); }

.docs-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.6rem 1.75rem;
  margin-bottom: 1.5rem;
}

.docs-section h2 {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.docs-section h3 {
  font-family: var(--font-mono);
  font-size: 1.02rem;
  margin-top: 1.5rem;
  margin-bottom: 0.6rem;
  color: var(--ink);
}

.docs-section h3:first-of-type { margin-top: 1rem; }
.docs-section p { margin-bottom: 1rem; color: var(--muted); }
.docs-section ul { margin-bottom: 1rem; padding-left: 1.4rem; }
.docs-section li { margin-bottom: 0.45rem; color: var(--muted); }

.docs-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.docs-table th, .docs-table td {
  padding: 0.65rem 0.9rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.docs-table th {
  background: var(--surface-2);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.8rem;
}

.docs-table td { font-size: 0.9rem; color: var(--muted); }

.docs-table code,
.docs-section :not(pre) > code {
  font-family: var(--font-mono);
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--ink);
  padding: 0.08rem 0.35rem;
  border-radius: 4px;
  font-size: 0.84rem;
}

.docs-cta {
  background: var(--primary);
  color: var(--on-primary);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  margin-top: 2rem;
}

.docs-cta h2 {
  font-family: var(--font-mono);
  color: var(--on-primary);
  margin-bottom: 1rem;
  border-bottom: none;
  padding-bottom: 0;
}

.docs-cta .btn-primary {
  background: var(--accent);
  color: #1c1408;
}

.docs-cta .btn-primary:hover {
  background: color-mix(in srgb, var(--accent) 85%, #fff);
}

/* ---- Code blocks + tabs ---- */
.code-tabs { margin-top: 1rem; }

.code-tabs-nav {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
}

.code-tab {
  padding: 0.5rem 1rem;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--muted);
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  transition: color 0.15s, border-color 0.15s;
}

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

.code-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.code-tabs-content {
  background: var(--code-bg);
  border-radius: 0 0 var(--radius) var(--radius);
}

.code-tab-panel { display: none; }
.code-tab-panel.active { display: block; }
.code-tab-panel .code-block { margin: 0; border-radius: 0 0 var(--radius) var(--radius); }

.code-block-wrapper { position: relative; margin-bottom: 1rem; }

.code-block {
  background: var(--code-bg);
  color: var(--code-ink);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  overflow-x: auto;
}

/* Syntax highlighting: skylighting token classes, coloured for the dark code
   panel (which stays dark in both themes). */
.code-block .kw, .code-block .cf, .code-block .bu, .code-block .ex { color: #7cc4d0; } /* keywords, control flow, builtins */
.code-block .dt { color: #9db8dd; } /* types */
.code-block .fu { color: #8fd0b8; } /* functions */
.code-block .st, .code-block .ss, .code-block .vs, .code-block .ch { color: #d8b878; } /* strings */
.code-block .dv, .code-block .bn, .code-block .fl, .code-block .cn, .code-block .sc { color: #d99a62; } /* numbers, constants */
.code-block .co, .code-block .do, .code-block .an, .code-block .cv, .code-block .in { color: #7e8d89; font-style: italic; } /* comments */
.code-block .im, .code-block .pp, .code-block .ot { color: #6fb3a2; } /* imports, preprocessor */
.code-block .va, .code-block .at { color: #c9d6d2; } /* variables, attributes */
.code-block .op { color: #a4b3af; } /* operators */
.code-block .er, .code-block .al, .code-block .wa { color: var(--danger); } /* errors */

.copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius);
  padding: 0.25rem 0.5rem;
  cursor: pointer;
  color: #cdd5d2;
  font-size: 0.85rem;
  opacity: 0;
  transition: opacity 0.2s, background-color 0.2s;
  z-index: 1;
}

.code-block-wrapper:hover .copy-btn { opacity: 1; }
.copy-btn:hover { background: rgba(255, 255, 255, 0.16); color: #fff; }
.copy-icon { line-height: 1; }
.copy-icon.copied { display: none; color: var(--success); }
.show-copied .copy-icon.default { display: none; }
.show-copied .copy-icon.copied { display: inline; }

/* ---- Sign in ---- */
.sign-in-page {
  max-width: 400px;
  margin: 3rem auto;
  text-align: center;
}

.sign-in-page h1 {
  font-family: var(--font-mono);
  margin-bottom: 1rem;
}

.sign-in-page p { color: var(--muted); }

.auth-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

/* ---- Error pages ---- */
.error-page {
  max-width: 600px;
  margin: 3rem auto;
  text-align: center;
}

.error-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 1.5rem;
}

.error-card h1 { font-family: var(--font-mono); margin-bottom: 1rem; }
.error-reference { color: var(--muted); font-size: 0.9rem; font-family: var(--font-mono); }

/* ---- Policy content ---- */
.policy-content { max-width: 800px; margin: 0 auto; }
.policy-content h1 { font-family: var(--font-mono); }

/* ---- Footer ---- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer a {
  color: var(--muted);
  text-decoration: none;
}

.site-footer a:hover { color: var(--primary); }

/* ---- Skip nav ---- */
.skip-nav {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--primary);
  color: var(--on-primary);
  padding: 0.5rem 1rem;
  z-index: 100;
}

.skip-nav:focus { top: 0; }

/* ---- Theme toggle ---- */
.theme-toggle {
  background: transparent;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 0.4rem 0.6rem;
  cursor: pointer;
  color: var(--muted);
  font-size: 1rem;
  transition: color 0.15s, border-color 0.15s;
  display: flex;
  align-items: center;
}

.theme-toggle:hover {
  color: var(--ink);
  border-color: var(--primary);
}

.theme-icon { font-size: 0.9rem; line-height: 1; }
.theme-icon-dark { display: none; }
:root[data-theme="dark"] .theme-icon-light { display: none; }
:root[data-theme="dark"] .theme-icon-dark { display: inline; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) .theme-icon-light { display: none; }
  :root:not([data-theme]) .theme-icon-dark { display: inline; }
}

/* ---- Focus visibility (quality floor) ---- */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---- Responsive ---- */
@media (max-width: 860px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 2rem 0;
  }

  .docs-page { grid-template-columns: 1fr; }
  .docs-sidebar { position: static; }
  .docs-sidebar ul { display: flex; flex-wrap: wrap; gap: 0.25rem; }
  .docs-sidebar li { margin-bottom: 0; }
}

@media (max-width: 560px) {
  .main-nav a { padding: 0.4rem 0.5rem; font-size: 0.85rem; }
  .transmute { grid-template-columns: 1fr; }
  .transmute-arrow { transform: rotate(90deg); animation: none; }
  .format-columns { grid-template-columns: 1fr; gap: 1.5rem; }
  .form-row {
    grid-template-columns: 1fr;
    grid-template-areas:
      "from-label"
      "from-sel"
      "arrow"
      "to-label"
      "to-sel";
  }
  .form-row .convert-arrow { transform: rotate(90deg); justify-self: center; }
}

/* ---- Reduced motion: hold the output pane still ---- */
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto; }
  .output-stack .doc-body {
    animation: none;
    opacity: 0;
  }
  .output-stack .doc-body:first-child { opacity: 1; }
  .transmute-arrow { animation: none; }
}

/* ---- Demo page: two panes, live conversion ---- */
.demo-page {
  max-width: 960px;
  margin: 0 auto;
}

.demo-page > p {
  color: var(--muted);
  margin-bottom: 1.5rem;
}

.demo-form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow);
}

.demo-panes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.demo-input,
.demo-output {
  min-height: 320px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 0.8rem 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.5;
}

.demo-input {
  width: 100%;
  resize: vertical;
  background: var(--surface);
  color: var(--ink);
}

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

.demo-output {
  overflow: auto;
  background: var(--code-bg);
  color: var(--code-ink);
}

.demo-output-pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: var(--font-mono);
  color: var(--code-ink);
}

.demo-output-error {
  color: var(--code-ink);
  font-family: var(--font-body);
  opacity: 0.85;
}

@media (max-width: 720px) {
  .demo-panes {
    grid-template-columns: 1fr;
  }
}

/* ---- Pricing + per-conversion landing pages ---- */
.pricing-page, .formats-index, .format-pair-page {
  padding: 3rem 0;
}

.pricing-page h1, .formats-index h1, .format-pair-page h1 {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  letter-spacing: -0.01em;
  margin-bottom: 0.4rem;
}

.pricing-page .tagline, .formats-index .tagline, .format-pair-page .tagline {
  color: var(--muted);
  max-width: 46rem;
}

.pricing-price {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  color: var(--ink);
  margin-bottom: 0.6rem;
}

.pricing-card ul {
  list-style: none;
  color: var(--muted);
  font-size: 0.94rem;
  margin-bottom: 1rem;
}

.pricing-card li {
  padding: 0.2rem 0;
}

.pricing-note {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 1.5rem;
  max-width: 46rem;
}

.formats-related, .formats-code, .formats-about, .formats-faq {
  margin-top: 2rem;
}

.formats-related h2, .formats-code h2, .formats-about h2, .formats-faq h2 {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  margin-bottom: 0.6rem;
}

.formats-about p, .formats-faq p {
  color: var(--muted);
  max-width: 46rem;
}

.formats-faq-entry {
  margin-top: 1.2rem;
}

.formats-faq-entry h3 {
  font-size: 1rem;
  margin-bottom: 0.4rem;
}

.formats-code > p {
  color: var(--muted);
  margin-bottom: 1rem;
  max-width: 46rem;
}

.formats-index-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.2rem;
}

.formats-index-links a {
  font-size: 0.92rem;
}

/* The from/to picker reuses the convert-form card; it just needs a width cap. */
.formats-picker {
  max-width: 640px;
  margin: 2rem 0 0.5rem;
}

.formats-note {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 0.9rem;
}

.formats-family {
  margin-top: 2.5rem;
}

.formats-family h2 {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
}

.formats-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 0.5rem;
  max-width: 640px;
}

.formats-group summary {
  cursor: pointer;
  padding: 0.55rem 0.9rem;
  font-size: 0.95rem;
}

.formats-group summary:hover {
  color: var(--primary);
}

.formats-group[open] summary {
  border-bottom: 1px solid var(--border);
}

.formats-group .formats-index-links {
  padding: 0.75rem 0.9rem;
}

.formats-count {
  color: var(--muted);
  font-size: 0.85rem;
}

/* ---- Guides: long-form advice pages ----
   The checklist is the reason anyone links to a page like this, so it gets the
   structure and the accent; the prose around it stays deliberately quiet. */
.guide {
  padding: 3rem 0;
  max-width: 46rem;
}

.guide h1 {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 4.5vw, 2.2rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0.3rem 0 0.6rem;
}

.guide-lede {
  font-size: 1.05rem;
  color: var(--muted);
}

.guide section {
  margin-top: 2.5rem;
}

.guide h2 {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  margin-bottom: 0.7rem;
}

.guide p {
  color: var(--muted);
}

.guide p + p {
  margin-top: 0.7rem;
}

/* The one loud element on the page: a federal warning, quoted as one. */
.guide-quote {
  background: var(--danger-soft);
  border-left: 3px solid var(--danger);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.1rem 1.3rem;
  margin-bottom: 1.2rem;
}

.guide-quote p {
  color: var(--ink);
  font-size: 1.05rem;
  line-height: 1.5;
}

.guide-quote cite {
  display: block;
  margin-top: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-style: normal;
  color: var(--muted);
}

/* One list treatment for the whole page. Every list here is genuinely ordered
   (the checks by how much they save you, the steps by what to do first), so a
   mono numeral in the accent does for all of them; three different markers read
   as three unrelated lists. */
.guide-list {
  list-style: none;
  counter-reset: item;
  margin-bottom: 0.9rem;
}

.guide-list li {
  counter-increment: item;
  display: grid;
  grid-template-columns: 1.9rem 1fr;
  gap: 0.2rem 0.6rem;
  padding: 0.7rem 0;
  border-top: 1px solid var(--border);
  color: var(--ink);
}

.guide-list li::before {
  content: counter(item);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--accent);
}

.guide-list strong {
  font-weight: 600;
}

.guide-list span {
  grid-column: 2;
  color: var(--muted);
  font-size: 0.94rem;
}

/* Three cards squeezed into the article measure wrap every title, so go two up
   and let the odd one out take the full width. */
.guide .feature-grid {
  grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr));
}

.guide .feature-grid > :last-child:nth-child(odd) {
  grid-column: 1 / -1;
}

.guide-sources {
  list-style: none;
  font-size: 0.92rem;
}

.guide-sources li {
  padding: 0.2rem 0;
}

@media (max-width: 560px) {
  .guide-list li {
    grid-template-columns: 1.4rem 1fr;
  }
}