/* A grid that converges: ink for text, and whatever colours the user paints in. */
:root {
  --bg: #f7f4ee;
  --surface: #ffffff;
  --border: #ddd8cd;
  --text: #1c1b19;
  --muted: #6d6a62;
  --accent: #6a3fb0;
  --accent-soft: #ece3f9;
  --ok: #1f7a58;
  --danger: #b5462f;
  --radius: 10px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171a;
    --surface: #1f242a;
    --border: #333a42;
    --text: #edeff1;
    --muted: #9aa3ac;
    --accent: #b892ee;
    --accent-soft: #2a2340;
    --ok: #55c99b;
    --danger: #ff8566;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 2rem 1rem 4rem;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 ui-sans-serif, -apple-system, "Segoe UI", Roboto, sans-serif;
}

header, main, footer { max-width: 60rem; margin: 0 auto; }

h1 { font-size: 1.7rem; margin: 0 0 .2rem; }
.tagline { margin: 0 0 .9rem; font-size: .95rem; color: var(--accent); letter-spacing: .01em; }
h2 { font-size: 1.05rem; margin: 0 0 1rem; text-transform: uppercase; letter-spacing: .07em; color: var(--accent); }
.resultHead {
  font-size: .95rem;
  margin: 1.5rem 0 .6rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--accent);
  border-top: 1px solid var(--border);
  padding-top: 1.1rem;
}

.lede { color: var(--muted); margin: 0 0 1.1rem; }
header { border-bottom: 2px solid var(--accent-soft); margin-bottom: 1.5rem; padding-bottom: .3rem; }

.note {
  display: flex;
  gap: .7rem;
  align-items: flex-start;
  margin: 0 0 1.5rem;
  padding: .75rem .95rem;
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.note::before {
  content: "i";
  flex: none;
  width: 1.15rem;
  height: 1.15rem;
  margin-top: .12rem;
  display: grid;
  place-items: center;
  border-radius: 99px;
  background: var(--accent);
  color: #fff;
  font: italic 700 .78rem/1 Georgia, "Times New Roman", serif;
}
.note p { margin: 0; font-size: .9rem; color: var(--text); }

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.hint { display: block; font-weight: 400; font-size: .8rem; color: var(--muted); margin: .15rem 0 .6rem; }
.hint.inline { display: inline; margin: 0; }

.stagehead { display: flex; align-items: center; gap: .75rem; flex-wrap: wrap; }
.spacer { flex: 1 1 auto; }

button {
  font: inherit;
  font-size: .9rem;
  padding: .5rem .9rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
}
button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(106, 63, 176, .35);
}
button.primary:hover { filter: brightness(1.08); }
button.ghost:hover { border-color: var(--accent); color: var(--accent); }
button.icon { padding: .3rem .5rem; font-size: .85rem; line-height: 1; }

/* ---- palette ---- */

.palette { display: flex; flex-wrap: wrap; gap: .6rem; margin-bottom: .8rem; }
.swatch {
  display: flex;
  align-items: center;
  gap: .4rem;
  padding: .35rem .5rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
}
.swatch input[type="color"] {
  width: 1.6rem;
  height: 1.6rem;
  padding: 0;
  border: none;
  border-radius: 5px;
  background: none;
  cursor: pointer;
}
.swatch input[type="text"] {
  width: 6rem;
  font: inherit;
  font-size: .85rem;
  padding: .25rem .4rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  color: var(--text);
}
.swatch button { padding: .2rem .4rem; font-size: .8rem; }
.swatch label.inline {
  display: inline-flex;
  align-items: center;
  gap: .3rem;
  font-size: .75rem;
  color: var(--muted);
  white-space: nowrap;
}
.swatch input.min {
  width: 3rem;
  font: inherit;
  font-size: .8rem;
  padding: .2rem .3rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  color: var(--text);
}
.swatch .count { font-size: .72rem; color: var(--muted); }

.brush .swatch {
  cursor: pointer;
  user-select: none;
  gap: .5rem;
}
.brush .swatch .dot {
  width: 1.3rem;
  height: 1.3rem;
  border-radius: 5px;
  border: 1px solid rgba(0, 0, 0, .25);
}
.brush .swatch.active { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft); }
.brush .swatch span.label { font-size: .85rem; }

/* ---- grid ---- */

.gridSize {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: .9rem;
}
.gridSize label {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-size: .85rem;
  font-weight: 600;
}
.gridSize input[type="number"] {
  width: 3.6rem;
  font: inherit;
  padding: .3rem .4rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--bg);
  color: var(--text);
}
.gridSize .hint { margin: 0; flex: 1 1 14rem; }

.gridWrap { position: relative; display: inline-block; }
.gridBoard {
  position: relative;
  display: grid;
  gap: 6px;
  margin-bottom: .5rem;
}
.gridHeader {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .78rem;
  font-weight: 700;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.arrows-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: visible;
}

/* While a search runs, nothing else on the page should react -- editing a
   colour or an instruction mid-search would race the search's own writes to
   the same grid. Opacity is left alone: the panel holding the grid also
   holds the overlay, and dimming it would dim the overlay along with it. */
main.searching > * { pointer-events: none; }
main.searching .searchOverlay { pointer-events: auto; }

.searchOverlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: .6rem;
  background: rgba(20, 23, 26, .88);
  border-radius: var(--radius);
  z-index: 5;
  text-align: center;
  padding: 1rem;
}
/* An element's own `display` always beats the browser's default [hidden]
   rule, so the hidden attribute needs restating here explicitly. */
.searchOverlay[hidden] { display: none; }
@media (prefers-color-scheme: light) {
  .searchOverlay { background: rgba(247, 244, 238, .92); }
}
.searchOverlay #searchProgress {
  margin: 0;
  font-size: .85rem;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}
.spinner {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.cell {
  position: relative;
  aspect-ratio: 1;
  border-radius: 7px;
  border: 2px solid rgba(0, 0, 0, .12);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  overflow: hidden;
}
.cell input {
  width: 92%;
  background: rgba(255, 255, 255, .82);
  color: #1c1b19;
  border: none;
  border-radius: 4px;
  text-align: center;
  font-size: 2.2rem;
  line-height: 1;
  padding: .1rem 0;
  cursor: text;
}
.cell.final { outline: 3px solid var(--accent); outline-offset: 1px; }
.cell.traced { outline: 3px dashed var(--accent); outline-offset: 1px; }
.cell.target { outline: 3px solid var(--ok); outline-offset: 1px; }
.cell .pin {
  position: absolute;
  bottom: 2px;
  right: 3px;
  font-size: .8rem;
}
button.ghost.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.gridBoard.picking .cell { cursor: crosshair; }
.cell .badge {
  position: absolute;
  top: 2px;
  right: 3px;
  font-size: .62rem;
  font-weight: 700;
  color: #fff;
  background: rgba(0, 0, 0, .55);
  border-radius: 99px;
  padding: 0 .35rem;
}
.cell .err {
  position: absolute;
  bottom: 2px;
  left: 3px;
  font-size: .7rem;
}

/* ---- steps ---- */

.step {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem;
  padding: .7rem .8rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  margin-bottom: .6rem;
}
.step select, .step .num {
  font: inherit;
  font-size: .85rem;
  padding: .3rem .4rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  color: var(--text);
}
.step label.inline { display: inline-flex; align-items: center; gap: .3rem; font-size: .8rem; }
.step .sentence { flex-basis: 100%; font-size: .85rem; color: var(--muted); font-style: italic; }
.step .move { display: flex; gap: .2rem; margin-left: auto; }

/* ---- verify ---- */

.funnel {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-wrap: wrap;
  font-variant-numeric: tabular-nums;
  font-size: .95rem;
  margin: .8rem 0;
}
.funnel .n {
  padding: .25rem .6rem;
  border-radius: 99px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
}
.funnel .arrow { color: var(--muted); }

.verdict {
  padding: .7rem .9rem;
  border-radius: var(--radius);
  font-weight: 600;
  margin: .3rem 0 .9rem;
}
.verdict.ok { background: rgba(31, 122, 88, .12); color: var(--ok); }
.verdict.bad { background: rgba(181, 70, 47, .12); color: var(--danger); }

.issues ul { margin: 0 0 .8rem; padding-left: 1.2rem; font-size: .88rem; }
.issues li { margin-bottom: .3rem; }

.trace {
  margin-top: .8rem;
  padding: .7rem .9rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  font-size: .88rem;
}
.trace ol { margin: .3rem 0 0; padding-left: 1.3rem; }
.trace li { margin-bottom: .2rem; }

footer p { color: var(--muted); font-size: .85rem; }

/* The site masthead, styled exactly as on the landing page. */
.sitebar {
  display: block;
  max-width: 60rem;
  margin: 0 auto 1.4rem;
  text-decoration: none;
  color: var(--text);
}
.sitebar-name { display: block; font-size: 1.25rem; font-weight: 700; margin: 0 0 .1rem; }
.sitebar-sub {
  display: block;
  font: italic 13px Georgia, "Times New Roman", serif;
  color: var(--muted);
  letter-spacing: 0;
}
.sitebar:hover .sitebar-name { color: var(--accent); }
.sitebar-horizon { display: block; width: 100%; height: auto; margin: .5rem 0 0; }
@media (prefers-color-scheme: dark) { .sitebar-horizon { filter: invert(1); } }