/* Self-contained: no CDN, no webfonts, no external anything. Pieces are Unicode
   glyphs, so the whole viewer ships zero image assets — which also sidesteps the
   CC0 asset rule entirely (there are no assets to license). */

:root {
  color-scheme: light dark;
  --bg: #14151a;
  --panel: #1c1e26;
  --line: #2c2f3a;
  --text: #e8e8ee;
  --dim: #9a9db0;
  --accent: #c9a227;
  --light-sq: #b9b3a6;
  --dark-sq: #6d6a63;
  --hl: #c9a22766;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
}

header {
  display: flex;
  align-items: baseline;
  gap: .6rem;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--line);
}
.brand {
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--accent);
  text-decoration: none;
}
.sub { color: var(--dim); font-size: .85rem; }
.spacer { flex: 1; }
.who { color: var(--dim); font-size: .8rem; font-variant-numeric: tabular-nums; }
.linkish {
  background: none;
  border: none;
  color: var(--dim);
  font-size: .8rem;
  cursor: pointer;
  padding: .2rem .4rem;
}
.linkish:hover { color: var(--accent); }

main { max-width: 60rem; margin: 0 auto; padding: 1.5rem 1.25rem 3rem; }

#signin { text-align: center; padding: 3rem 1rem; }
#signin h2 { font-size: 1.3rem; }
.lede { color: var(--dim); max-width: 30rem; margin: 0 auto 1.5rem; }
.steam {
  display: inline-block;
  padding: .7rem 1.4rem;
  background: var(--accent);
  color: #14151a;
  font-weight: 600;
  border-radius: 6px;
  text-decoration: none;
}
.steam:hover { filter: brightness(1.1); }

button {
  font: inherit;
  border-radius: 6px;
  border: 1px solid var(--line);
  padding: .55rem .9rem;
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
}
button:hover { border-color: var(--accent); }
button:disabled { opacity: .4; cursor: default; border-color: var(--line); }

.status { padding: .7rem .9rem; border: 1px solid var(--line); border-radius: 6px; color: var(--dim); }
.status.err { border-color: #7a3a3a; color: #e6a3a3; }

h2 { font-size: 1.05rem; margin: 0 0 .75rem; font-weight: 600; }

/* Wide content scrolls inside its own box; the page body never scrolls sideways. */
table { width: 100%; border-collapse: collapse; display: block; overflow-x: auto; }
thead th {
  text-align: left;
  font-size: .72rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--dim);
  font-weight: 600;
  padding: .4rem .6rem;
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
tbody td { padding: .55rem .6rem; border-bottom: 1px solid var(--line); white-space: nowrap; }
tbody tr { cursor: pointer; }
tbody tr:hover td { background: var(--panel); }
.r { text-align: right; }
.result { font-variant-numeric: tabular-nums; color: var(--accent); }
.tc { color: var(--dim); font-variant-numeric: tabular-nums; }

.back { color: var(--dim); text-decoration: none; font-size: .85rem; }
.back:hover { color: var(--accent); }
.meta { color: var(--dim); font-size: .85rem; margin-bottom: 1rem; }

.viewer { display: flex; gap: 1.25rem; flex-wrap: wrap; align-items: flex-start; }

.board {
  display: grid;
  /* minmax(0, 1fr), NOT 1fr: a bare 1fr means minmax(auto, 1fr), and that auto floor
     stops a track shrinking below its content's min-content size. The glyphs have
     different advance widths (the queen is wider than the pawn), so bare 1fr let a
     square resize to fit whichever piece was standing on it. Rows are declared for the
     same reason — implicit rows default to auto, i.e. sized to content. */
  grid-template-columns: repeat(8, minmax(0, 1fr));
  grid-template-rows: repeat(8, minmax(0, 1fr));
  width: min(28rem, 100%);
  aspect-ratio: 1;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  flex: 1 1 20rem;
}
.sq {
  display: flex;
  align-items: center;
  justify-content: center;
  /* Sized off the square, so the board scales without a font-size table. */
  font-size: clamp(1rem, 6.5cqw, 2.4rem);
  line-height: 1;
  user-select: none;
  /* Belt and braces: a grid item's default min-width/height is auto, so a stubborn
     glyph could still push its cell out even with minmax(0, 1fr) tracks. */
  min-width: 0;
  min-height: 0;
  overflow: hidden;
}
.board { container-type: inline-size; }
.sq.light { background: var(--light-sq); }
.sq.dark { background: var(--dark-sq); }
.sq.hl { background-image: linear-gradient(var(--hl), var(--hl)); }
/* Both colours are drawn as the SOLID glyphs and recoloured. The outline glyphs
   (♔♕♖) render at a different weight to the solid ones (♚♛♜) in most fonts, so
   using each set for its own colour makes white pieces look spindly next to
   black. One glyph set + fill/stroke keeps them identical. */
.pc { color: #111; text-shadow: 0 0 1px #111; }
.pc.w { color: #f6f4ee; text-shadow: 0 0 1px #111, 0 0 2px #111; }

.side { flex: 1 1 14rem; min-width: 12rem; }

.moves {
  list-style: none;
  margin: 0 0 .75rem;
  padding: .5rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  max-height: 20rem;
  overflow-y: auto;
  display: flex;
  flex-wrap: wrap;
  gap: .15rem .35rem;
  font-variant-numeric: tabular-nums;
}
.moves li { padding: .1rem .3rem; border-radius: 3px; cursor: pointer; }
.moves li.num { color: var(--dim); cursor: default; }
.moves li.on { background: var(--accent); color: #14151a; }
.moves li:not(.num):hover { background: var(--line); }
.moves li.on:hover { background: var(--accent); }
/* {[%clk]} beside its move. Tabular figures so the column doesn't jitter as the
   digits change, and dimmed so the SAN stays the thing you read. */
.moves .clk {
  margin-left: .35rem;
  color: var(--dim);
  font-size: .75em;
  font-variant-numeric: tabular-nums;
}
.moves li.on .clk { color: #14151a; opacity: .7; }

.controls { display: flex; gap: .35rem; }
.controls button { flex: 1; padding: .4rem; }
.ply { color: var(--dim); font-size: .8rem; margin-top: .5rem; font-variant-numeric: tabular-nums; }
.replay-error { margin-top: .5rem; color: #e6a3a3; font-size: .8rem; }

.pgn { margin-top: 1.5rem; }
.pgn summary { cursor: pointer; color: var(--dim); font-size: .85rem; }
.pgn pre {
  margin: .5rem 0 0;
  padding: .75rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow-x: auto;
  font-size: .8rem;
  white-space: pre-wrap;
  word-break: break-word;
}

footer {
  border-top: 1px solid var(--line);
  padding: 1.25rem;
  color: var(--dim);
  font-size: .8rem;
  text-align: center;
}
footer p { margin: .2rem 0; }

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f5f2; --panel: #fff; --line: #ddd9d0; --text: #22232a; --dim: #6b6d7c;
    --light-sq: #e8e2d4; --dark-sq: #9a9384;
  }
  .pc.w { color: #fff; text-shadow: 0 0 1px #333, 0 0 2px #333; }
}