/*
  Design tokens.

  Neutral-forward and deliberately not Material's baseline purple, which is what made the site read
  as an unmodified template. The primary action is near-black in light and near-white in dark; the
  one accent is reserved for links, focus rings and the active nav item, so colour always means
  something rather than decorating.

  Every colour is defined once on :root. The dark values are applied twice: scoped to
  :not([data-theme='light']) under the system preference, so an explicit light override wins, and
  again under [data-theme='dark'] so the in-app toggle wins in both directions.
*/
:root {
  color-scheme: light;

  --ground: #f6f6f7;
  --surface: #ffffff;
  --surface-sunken: #f1f1f3;
  --ink: #16161a;
  --ink-soft: #5a5a66;
  --ink-faint: #8b8b96;
  --line: #e4e4e8;
  --line-strong: #d0d0d7;

  --accent: #2f5bd7;
  --accent-soft: #eaf0fe;
  --accent-ink: #1e3f9e;

  --danger: #b3261e;
  --warn-ink: #7c4a03;
  --warn-bg: #fdf3e3;

  /* Solid, so a QR code always sits on true white regardless of theme. */
  --qr-paper: #ffffff;

  --radius: 10px;
  --radius-lg: 14px;
  --radius-pill: 999px;

  --shadow-sm: 0 1px 2px rgb(16 16 24 / 6%);
  --shadow-md: 0 4px 16px -4px rgb(16 16 24 / 10%), 0 1px 3px rgb(16 16 24 / 6%);

  --sans: ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    color-scheme: dark;

    --ground: #0c0c0f;
    --surface: #151519;
    --surface-sunken: #1d1d22;
    --ink: #ecedf1;
    --ink-soft: #a6a7b2;
    --ink-faint: #74757f;
    --line: #26262d;
    --line-strong: #3a3a44;

    --accent: #8fabff;
    --accent-soft: #1a2340;
    --accent-ink: #b9caff;

    --danger: #ff9d94;
    --warn-ink: #f0c48a;
    --warn-bg: #2a1f0f;

    --shadow-sm: 0 1px 2px rgb(0 0 0 / 40%);
    --shadow-md: 0 4px 16px -4px rgb(0 0 0 / 50%), 0 1px 3px rgb(0 0 0 / 40%);
  }
}

:root[data-theme='dark'] {
  color-scheme: dark;

  --ground: #0c0c0f;
  --surface: #151519;
  --surface-sunken: #1d1d22;
  --ink: #ecedf1;
  --ink-soft: #a6a7b2;
  --ink-faint: #74757f;
  --line: #26262d;
  --line-strong: #3a3a44;

  --accent: #8fabff;
  --accent-soft: #1a2340;
  --accent-ink: #b9caff;

  --danger: #ff9d94;
  --warn-ink: #f0c48a;
  --warn-bg: #2a1f0f;

  --shadow-sm: 0 1px 2px rgb(0 0 0 / 40%);
  --shadow-md: 0 4px 16px -4px rgb(0 0 0 / 50%), 0 1px 3px rgb(0 0 0 / 40%);
}

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

/*
  The `hidden` attribute carries only the UA stylesheet's display: none, which any `display` rule
  here outranks. Everything the page shows and hides is toggled through that attribute, so it is
  enforced once rather than guarded at each rule.
*/
[hidden] {
  display: none !important;
}

body {
  margin: 0;
  min-height: 100dvh;
  background: var(--ground);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* ---------- shell ---------- */

.page {
  width: min(100% - 32px, 1140px);
  margin-inline: auto;
  padding-block: max(14px, env(safe-area-inset-top)) 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-block: 10px 14px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: inherit;
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand svg {
  width: 20px;
  height: 20px;
  color: var(--accent);
}

.icon-button {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink-soft);
  cursor: pointer;
  transition: color 120ms ease, border-color 120ms ease;
}

.icon-button:hover,
.icon-button:focus-visible {
  color: var(--ink);
  border-color: var(--line-strong);
}

.icon-button svg {
  width: 17px;
  height: 17px;
}

/* ---------- type navigation ---------- */

/*
  A single scrolling row rather than wrapped pills: nine items wrapped to three ragged lines, and
  the count only grows. Overflow scrolls horizontally on narrow screens and simply fits on wide.
*/
.types {
  display: flex;
  gap: 4px;
  padding: 4px;
  margin-bottom: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--surface);
  overflow-x: auto;
  scrollbar-width: none;
}

.types::-webkit-scrollbar {
  display: none;
}

.type {
  flex: 0 0 auto;
  padding: 7px 14px;
  border-radius: var(--radius-pill);
  color: var(--ink-soft);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 120ms ease, color 120ms ease;
}

.type:hover {
  background: var(--surface-sunken);
  color: var(--ink);
}

.type[aria-current='page'] {
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-weight: 600;
}

/* ---------- headings ---------- */

.crumb {
  margin-bottom: 6px;
  font-size: 0.8125rem;
  color: var(--ink-faint);
}

.crumb a {
  color: inherit;
  text-decoration: none;
}

.crumb a:hover {
  color: var(--ink);
  text-decoration: underline;
}

h1 {
  margin: 0 0 8px;
  font-size: clamp(1.75rem, 1.3rem + 1.9vw, 2.5rem);
  font-weight: 680;
  line-height: 1.1;
  letter-spacing: -0.028em;
}

.lede {
  margin: 0 0 28px;
  max-width: 62ch;
  font-size: 1.0625rem;
  color: var(--ink-soft);
}

/* ---------- the tool ---------- */

/*
  Two columns on desktop: the form, and a result panel that stays in view while the form is filled.
  Below 900px it collapses to one column and the result follows the form.
*/
.tool {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 372px;
  gap: 20px;
  align-items: start;
}

@media (max-width: 900px) {
  .tool {
    grid-template-columns: minmax(0, 1fr);
  }
}

.panel {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.result {
  position: sticky;
  top: 16px;
  align-self: start;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}

@media (max-width: 900px) {
  .result {
    position: static;
  }
}

form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* ---------- fields ---------- */

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

.field-label {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink);
}

.optional {
  font-weight: 400;
  color: var(--ink-faint);
}

.field {
  width: 100%;
  padding: 10px 13px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  font-size: 0.9375rem;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

.field::placeholder {
  color: var(--ink-faint);
}

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

.field[aria-invalid='true'] {
  border-color: var(--danger);
}

textarea.field {
  resize: vertical;
  min-height: 68px;
}

select.field {
  appearance: none;
  padding-right: 34px;
  background-image: linear-gradient(45deg, transparent 50%, currentColor 50%),
    linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: right 16px center, right 11px center;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
}

.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

@media (max-width: 520px) {
  .field-grid {
    grid-template-columns: 1fr;
  }
}

.field-with-action {
  display: flex;
  gap: 8px;
}

.field-with-action .field {
  flex: 1;
  min-width: 0;
}

.checkbox {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 0.9375rem;
  color: var(--ink-soft);
  cursor: pointer;
}

.checkbox input {
  width: 17px;
  height: 17px;
  accent-color: var(--accent);
  cursor: pointer;
}

.field-error {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--danger);
}

/* ---------- buttons ---------- */

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 9px 15px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  font-size: 0.875rem;
  font-weight: 550;
  cursor: pointer;
  transition: background-color 120ms ease, border-color 120ms ease, opacity 120ms ease;
}

.button:hover:not(:disabled) {
  background: var(--surface-sunken);
  border-color: var(--line-strong);
}

.button-primary {
  border-color: transparent;
  background: var(--ink);
  color: var(--ground);
}

.button-primary:hover:not(:disabled) {
  background: var(--ink);
  opacity: 0.88;
}

.button-block {
  width: 100%;
  padding: 11px 15px;
  font-size: 0.9375rem;
}

.button-small {
  flex-shrink: 0;
  padding: 7px 12px;
  font-size: 0.8125rem;
}

.button:disabled {
  cursor: default;
  opacity: 0.45;
}

:where(a, button, input, select, textarea, summary):focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- the code itself ---------- */

.qr-frame {
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 1;
  margin: 0;
  padding: 16px;
  border-radius: var(--radius);
  background: var(--qr-paper);
  border: 1px solid var(--line);
}

#qr-canvas {
  display: block;
  max-width: 100%;
  max-height: 100%;
  /* Nearest-neighbour, so modules stay square-edged rather than blurring when scaled. */
  image-rendering: pixelated;
}

/* Shown before there is anything to render, so the panel has shape instead of a bare sentence. */
.qr-placeholder {
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 1;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface-sunken);
  color: var(--ink-faint);
}

.qr-placeholder svg {
  width: 64px;
  height: 64px;
  opacity: 0.35;
}

.status {
  margin: 0;
  min-height: 2.6em;
  font-size: 0.8125rem;
  line-height: 1.45;
  color: var(--ink-soft);
  text-wrap: pretty;
}

.status[data-error='true'] {
  color: var(--danger);
}

.status[data-warn='true'] {
  color: var(--warn-ink);
}

.actions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(84px, 1fr));
  gap: 8px;
  width: 100%;
}

.actions .button {
  width: 100%;
}

/* ---------- customisation ---------- */

.tune {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.tune > summary {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink-soft);
  cursor: pointer;
  list-style: none;
}

.tune > summary::-webkit-details-marker {
  display: none;
}

.tune > summary::before {
  content: '';
  width: 0;
  height: 0;
  border-left: 4px solid currentColor;
  border-block: 4px solid transparent;
  transition: rotate 140ms ease;
}

.tune[open] > summary::before {
  rotate: 90deg;
}

.tune-body {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-top: 12px;
}

.tune-row {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 10px;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.tune-row output {
  min-width: 4.5ch;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.75rem;
  text-align: right;
}

.tune-row input[type='range'] {
  grid-column: 1 / -1;
  width: 100%;
  accent-color: var(--accent);
}

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

.swatch {
  width: 30px;
  height: 30px;
  padding: 2px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: var(--surface);
  cursor: pointer;
}

.tune select.field,
.tune input[type='text'].field {
  padding: 7px 11px;
  font-size: 0.8125rem;
}

.tune-note {
  margin: 0;
  font-size: 0.75rem;
  color: var(--ink-faint);
}

.tune-reset {
  align-self: flex-start;
}

/* ---------- map picker ---------- */

.map-panel {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-sunken);
}

.map-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.map-search-row {
  display: flex;
  flex: 1;
  min-width: 200px;
  gap: 8px;
}

.map-search-row .field {
  flex: 1;
  min-width: 0;
}

.map {
  height: 300px;
  border-radius: 8px;
  overflow: hidden;
  /* The tile layer is a light raster in both themes, so it needs a light ground beneath it. */
  background: #e7e6ea;
}

.map-status {
  margin: 0;
  min-height: 1.2em;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.map-status[data-error='true'] {
  color: var(--danger);
}

.map .leaflet-control-attribution {
  background: rgb(255 255 255 / 88%);
  color: #3a3a44;
  font-size: 10px;
}

.map .leaflet-control-attribution a {
  color: #2f5bd7;
}

.map .leaflet-bar a {
  color: #16161a;
  background: #fff;
}

/* ---------- long-form content ---------- */

.article {
  max-width: 68ch;
  margin-top: 56px;
}

.article section + section {
  margin-top: 36px;
}

.article h2 {
  margin: 0 0 10px;
  font-size: 1.1875rem;
  font-weight: 650;
  letter-spacing: -0.015em;
}

.article p {
  margin: 0 0 14px;
  color: var(--ink-soft);
}

.article p:last-child {
  margin-bottom: 0;
}

.article strong {
  color: var(--ink);
  font-weight: 600;
}

.article a {
  color: var(--accent);
}

code {
  padding: 1.5px 5px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--surface-sunken);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.8125em;
  overflow-wrap: anywhere;
}

/* FAQ as disclosures: nine pages of stacked Q&A is a wall, and this makes it scannable.
   The answers stay in the HTML, so they are still indexed. */
.faq {
  margin-top: 12px;
  border-top: 1px solid var(--line);
}

.faq-item {
  border-bottom: 1px solid var(--line);
}

.faq-item > summary {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 13px 0;
  font-size: 0.9375rem;
  font-weight: 550;
  cursor: pointer;
  list-style: none;
}

.faq-item > summary::-webkit-details-marker {
  display: none;
}

.faq-item > summary::after {
  content: '+';
  margin-left: auto;
  color: var(--ink-faint);
  font-weight: 400;
  font-size: 1.125rem;
  line-height: 1.2;
}

.faq-item[open] > summary::after {
  content: '\2212';
}

.faq-item p {
  margin: 0;
  padding: 0 0 15px;
  color: var(--ink-soft);
  font-size: 0.9375rem;
}

/* ---------- link cards ---------- */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.cards a {
  display: block;
  height: 100%;
  padding: 13px 15px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: inherit;
  text-decoration: none;
  transition: border-color 120ms ease, background-color 120ms ease;
}

.cards a:hover {
  border-color: var(--accent);
  background: var(--surface-sunken);
}

.cards strong {
  display: block;
  margin-bottom: 3px;
  font-size: 0.9375rem;
  font-weight: 600;
}

.cards span {
  font-size: 0.875rem;
  color: var(--ink-soft);
}

/* ---------- footer ---------- */

.footer {
  max-width: 68ch;
  margin-top: 56px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 0.8125rem;
  color: var(--ink-faint);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  margin-bottom: 12px;
}

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

.footer-links a:hover {
  color: var(--ink);
  text-decoration: underline;
}

.footer p {
  margin: 3px 0;
}

/* ---------- toast ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: max(22px, env(safe-area-inset-bottom));
  translate: -50% 0;
  max-width: calc(100% - 32px);
  padding: 10px 18px;
  border-radius: var(--radius-pill);
  background: var(--ink);
  color: var(--ground);
  font-size: 0.875rem;
  box-shadow: var(--shadow-md);
  animation: toast-in 150ms ease;
}

@keyframes toast-in {
  from {
    opacity: 0;
    translate: -50% 6px;
  }
}

.sprite {
  display: none;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}