/* ==========================================================================
   Feature Extraction from Ancient Script
   Dark manuscript-ink palette, single restrained ochre accent.
   ========================================================================== */

:root {
  /* --- dark (default): warm near-black ground, aged parchment ink --- */
  --bg:            #0d0b09;
  --bg-veil:       rgba(13, 11, 9, 0.92);
  --surface:       #16130f;
  --surface-2:     #1e1a14;
  --surface-3:     #262019;
  --rule:          #2c2519;
  --rule-soft:     #201b14;

  --ink:           #ece2ce;
  --ink-dim:       #a3947a;
  --ink-faint:     #6d6252;

  --accent:        #d59a30;
  --accent-bright: #eab455;
  --accent-veil:   rgba(213, 154, 48, 0.14);
  --accent-line:   rgba(213, 154, 48, 0.42);

  --ok:            #86a06a;
  --miss:          #b8735c;

  --focus:         #eab455;

  /* heatmap ramp stops, reused by app.js via getComputedStyle-free constants */
  --tile-bg:       #12100c;

  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
          "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;

  --r: 6px;
  --pad: clamp(1rem, 3vw, 2rem);
  --maxw: 1240px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg:            #f5efe3;
    --bg-veil:       rgba(245, 239, 227, 0.93);
    --surface:       #fffcf5;
    --surface-2:     #efe7d7;
    --surface-3:     #e5dbc7;
    --rule:          #dbcfb6;
    --rule-soft:     #e8dfcc;

    --ink:           #201b13;
    --ink-dim:       #5d5343;
    --ink-faint:     #857a66;

    --accent:        #9c6a11;
    --accent-bright: #7d5409;
    --accent-veil:   rgba(156, 106, 17, 0.12);
    --accent-line:   rgba(156, 106, 17, 0.38);

    --ok:            #4d6b33;
    --miss:          #9c4a30;

    --focus:         #7d5409;
    --tile-bg:       #ded3bd;
  }
}

/* --------------------------------------------------------------- base ---- */

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }

h1, h2 { font-weight: 600; letter-spacing: -0.01em; margin: 0; }

a { color: var(--accent-bright); text-underline-offset: 3px; }
a:hover { color: var(--ink); }

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 3px;
}

.pixelated {
  image-rendering: pixelated;
  image-rendering: -moz-crisp-edges;
  image-rendering: crisp-edges;
}

/* ------------------------------------------------------------ loading ---- */

.loader {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  background: var(--bg-veil);
  backdrop-filter: blur(2px);
}
.loader[hidden] { display: none; }
.loader__inner { width: min(280px, 70vw); text-align: center; }
.loader__bar {
  height: 2px;
  background: var(--rule);
  overflow: hidden;
  border-radius: 2px;
}
.loader__bar span {
  display: block;
  height: 100%;
  width: 40%;
  background: var(--accent);
  animation: slide 1.15s ease-in-out infinite;
}
@keyframes slide {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(350%); }
}
.loader__msg {
  margin: 1rem 0 0;
  font-size: 0.78rem;
  color: var(--ink-dim);
  letter-spacing: 0.06em;
  text-transform: lowercase;
}
.loader--error .loader__bar span { animation: none; width: 100%; background: var(--miss); }

/* --------------------------------------------------------------- page ---- */

.page {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(2rem, 6vw, 4.5rem) var(--pad) 3rem;
}

.masthead { margin-bottom: clamp(2rem, 5vw, 3.5rem); max-width: 62ch; }
.masthead h1 {
  font-size: clamp(1.75rem, 5vw, 2.9rem);
  line-height: 1.12;
  text-wrap: balance;
}
.pitch {
  margin: 0.9rem 0 0;
  color: var(--ink-dim);
  font-size: clamp(1rem, 2.2vw, 1.1rem);
  max-width: 54ch;
}

main { display: grid; gap: clamp(1rem, 2.5vw, 1.6rem); }

/* -------------------------------------------------------------- panel ---- */

.panel {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  padding: clamp(1.1rem, 2.5vw, 1.75rem);
}

.panel__head { margin-bottom: 1.15rem; }
.panel__head h2 {
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
}
.panel__note {
  margin: 0.45rem 0 0;
  color: var(--ink-faint);
  font-size: 0.85rem;
  max-width: 68ch;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: clamp(1rem, 2.5vw, 1.6rem);
  align-items: stretch;   /* equal-height cards read tidier than a ragged edge */
}

/* ------------------------------------------------------------ gallery ---- */

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(74px, 1fr));
  gap: 0.5rem;
  /* Tall enough that all 47 glyphs fit without scrolling on a desktop layout,
     but still capped so the strip never dominates a short viewport. */
  max-height: min(60vh, 440px);
  overflow-y: auto;
  padding: 2px;
  scrollbar-width: thin;
  scrollbar-color: var(--rule) transparent;
}
.gallery::-webkit-scrollbar { width: 8px; }
.gallery::-webkit-scrollbar-thumb { background: var(--rule); border-radius: 4px; }

.glyph {
  display: block;
  width: 100%;
  padding: 5px 5px 3px;
  background: var(--surface-2);
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  cursor: pointer;
  font: inherit;
  color: var(--ink-faint);
  transition: border-color 0.15s, background 0.15s, transform 0.15s;
}
.glyph:hover { border-color: var(--accent-line); transform: translateY(-1px); }
.glyph canvas {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  border-radius: 2px;
  background: #fff;
}
.glyph__name {
  display: block;
  margin-top: 4px;
  font-family: var(--mono);
  font-size: 0.66rem;
  text-align: center;
  letter-spacing: 0.02em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.glyph[aria-checked="true"] {
  background: var(--accent-veil);
  border-color: var(--accent);
  color: var(--accent-bright);
}

/* -------------------------------------------------------------- stage ---- */

.stage { display: flex; justify-content: center; }
.stage__frame {
  position: relative;
  width: min(240px, 68vw);
  aspect-ratio: 1;
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
  background: #fff;
}
.stage__frame > canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
.heat { opacity: 0; transition: opacity 0.35s ease; pointer-events: none; }
.heat.on { opacity: 1; }

/* ---------------------------------------------------------- occlusion ---- */

.occl { margin-top: 1.25rem; display: grid; gap: 0.7rem; justify-items: start; }

.btn {
  font: inherit;
  font-size: 0.87rem;
  padding: 0.55rem 1rem;
  border-radius: 4px;
  border: 1px solid var(--accent-line);
  background: var(--accent-veil);
  color: var(--accent-bright);
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.btn:hover:not(:disabled) { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.btn:disabled { opacity: 0.45; cursor: default; }
.btn--quiet {
  border-color: var(--rule);
  background: var(--surface-2);
  color: var(--ink-dim);
}
.btn--quiet:hover:not(:disabled) { background: var(--surface-3); border-color: var(--ink-faint); color: var(--ink); }

.occl__status { font-size: 0.76rem; color: var(--ink-faint); min-height: 1.2em; }
.occl__explain { margin-top: 0.15rem; }

.progress {
  width: min(240px, 100%);
  height: 2px;
  background: var(--rule);
  border-radius: 2px;
  overflow: hidden;
}
.progress[hidden] { display: none; }
.progress span {
  display: block;
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.12s linear;
}

.legend { display: flex; align-items: center; gap: 0.5rem; }
.legend[hidden] { display: none; }
.legend__label { font-size: 0.68rem; color: var(--ink-faint); letter-spacing: 0.04em; }
.legend__ramp {
  display: block;
  width: 96px;
  height: 8px;
  border-radius: 2px;
  border: 1px solid var(--rule);
  background: linear-gradient(90deg, #2b3346 0%, #7a5a24 45%, #d59a30 75%, #f2c877 100%);
}

/* ---------------------------------------------------------- prediction --- */

.bars { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.55rem; }
.bar {
  display: grid;
  grid-template-columns: 5.5rem minmax(0, 1fr) 4rem;
  align-items: center;
  gap: 0.75rem;
}
.bar__name {
  font-family: var(--mono);
  font-size: 0.83rem;
  color: var(--ink-dim);
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bar__track {
  height: 20px;
  background: var(--surface-2);
  border-radius: 3px;
  overflow: hidden;
}
.bar__fill {
  /* A span defaults to display:inline, on which width and height do not apply -
     without this the fill renders 0x0 and every bar looks empty. */
  display: block;
  height: 100%;
  width: 0;
  background: var(--accent);
  opacity: 0.42;
  border-radius: 3px;
  transition: width 0.4s cubic-bezier(0.22, 0.8, 0.3, 1);
}
.bar__pct {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}
.bar--top .bar__name { color: var(--ink); }
.bar--top .bar__fill { opacity: 1; }
.bar--top .bar__pct { color: var(--accent-bright); }

.verdict {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 1.15rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid var(--rule-soft);
  font-size: 0.83rem;
  color: var(--ink-faint);
  min-height: 1.5rem;
}
.verdict svg { flex: none; }
.verdict--ok svg { color: var(--ok); }
.verdict--miss svg { color: var(--miss); }

/* ----------------------------------------------------- feature explorer -- */

.panel--feature { padding-bottom: clamp(1.3rem, 3vw, 2rem); }

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--rule-soft);
}
.tab {
  font: inherit;
  font-size: 0.82rem;
  padding: 0.4rem 0.85rem;
  border-radius: 4px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--ink-faint);
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
}
.tab:hover { color: var(--ink); background: var(--surface-2); }
.tab[aria-selected="true"] {
  background: var(--accent-veil);
  border-color: var(--accent-line);
  color: var(--accent-bright);
}
.tab__count {
  font-family: var(--mono);
  font-size: 0.72rem;
  opacity: 0.65;
  margin-left: 0.4rem;
}

.feat__caption {
  margin: 1.1rem 0 0;
  font-size: 0.92rem;
  color: var(--ink-dim);
  max-width: 76ch;
}
.feat__meta {
  margin: 0.35rem 0 0;
  font-size: 0.73rem;
  color: var(--ink-faint);
  letter-spacing: 0.03em;
}

.tiles {
  margin-top: 1.25rem;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(52px, 1fr));
  gap: 6px;
  background: var(--surface-2);
  border: 1px solid var(--rule-soft);
  border-radius: 4px;
  padding: 10px;
}
.tiles--input {
  grid-template-columns: minmax(0, 220px);
  justify-content: center;
}
.tiles canvas {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  border-radius: 2px;
  background: var(--tile-bg);
  image-rendering: pixelated;
  image-rendering: -moz-crisp-edges;
  image-rendering: crisp-edges;
}
.tiles:focus-visible { outline-offset: 2px; }

/* ---------------------------------------------------------- draw mode ---- */

.panel--draw { padding: 0; }
.panel--draw summary {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: clamp(1rem, 2.2vw, 1.3rem) clamp(1.1rem, 2.5vw, 1.75rem);
  cursor: pointer;
  list-style: none;
  border-radius: var(--r);
}
.panel--draw summary::-webkit-details-marker { display: none; }
.summary__title {
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
}
.panel--draw[open] .summary__title { color: var(--accent); }
.summary__hint { font-size: 0.76rem; color: var(--ink-faint); }
.panel--draw summary::before {
  content: "+";
  font-family: var(--mono);
  color: var(--ink-faint);
  margin-right: 0.1rem;
}
.panel--draw[open] summary::before { content: "\2212"; }

.draw {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(1rem, 3vw, 2rem);
  padding: 0 clamp(1.1rem, 2.5vw, 1.75rem) clamp(1.3rem, 2.5vw, 1.75rem);
  align-items: start;
}
.draw__canvasWrap {
  position: relative;
  width: min(256px, 74vw);
  aspect-ratio: 1;
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
  background: #fff;
}
.draw__canvasWrap > canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
.draw__ghost { opacity: 0.16; }
.draw__pad { cursor: crosshair; touch-action: none; background: transparent; }
.draw__side { display: grid; gap: 0.8rem; justify-items: start; }
.caveat {
  margin: 0;
  font-size: 0.8rem;
  line-height: 1.65;
  color: var(--ink-faint);
  border-left: 2px solid var(--rule);
  padding-left: 0.85rem;
  max-width: 60ch;
}

/* ----------------------------------------------------------- colophon ---- */

.colophon {
  margin-top: clamp(2.5rem, 6vw, 4rem);
  padding-top: 1.5rem;
  border-top: 1px solid var(--rule-soft);
  color: var(--ink-faint);
  font-size: 0.82rem;
  max-width: 78ch;
}
.colophon p { margin: 0 0 0.5rem; }

/* --------------------------------------------------------- responsive ---- */

@media (max-width: 900px) {
  .draw { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .split { grid-template-columns: 1fr; }
  .gallery { grid-template-columns: repeat(auto-fill, minmax(66px, 1fr)); max-height: 260px; }
  .tiles { grid-template-columns: repeat(auto-fill, minmax(44px, 1fr)); }
  .bar { grid-template-columns: 4.5rem minmax(0, 1fr) 3.4rem; gap: 0.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .loader__bar span { width: 100%; }
}