:root {
  --bg: #f6f5f1;
  --card: #ffffff;
  --ink: #1d2126;
  --muted: #68707a;
  --rule: #dcdad2;
  --accent: #2f6f5e;
  --sq-light: #e8ebe4;
  --sq-dark: #7f9c8c;
  --sq-last: rgba(236, 201, 75, 0.55);
  --sq-pick: rgba(47, 111, 94, 0.55);
  --w: #ffffff;
  --d: #a9afb6;
  --b: #2b2f35;
  --bad: #c2452f;
  --good: #2f8f5b;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15181b;
    --card: #1e2226;
    --ink: #e7e9ea;
    --muted: #98a0a8;
    --rule: #30363c;
    --accent: #6fc3a9;
    --sq-light: #c9d1c8;
    --sq-dark: #5f7c6d;
    --w: #f1f1ee;
    --d: #7b838b;
    --b: #0c0d0f;
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.top, main, .block, footer { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
.top { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; padding-top: 28px; }
h1 { font-size: 30px; line-height: 1.2; margin: 0; letter-spacing: -0.01em; }
h2 { font-size: 17px; margin: 0 0 10px; }
.muted { color: var(--muted); }
#subtitle { margin: 6px 0 0; }

main { display: grid; grid-template-columns: minmax(0, 480px) minmax(0, 1fr); gap: 28px; margin-top: 22px; }
@media (max-width: 860px) { main { grid-template-columns: minmax(0, 1fr); } }

button, .chip {
  font: inherit; font-size: 14px; color: var(--ink);
  background: var(--card); border: 1px solid var(--rule); border-radius: 8px;
  padding: 6px 12px; cursor: pointer;
}
button:hover, .chip:hover { border-color: var(--accent); }
button:disabled { opacity: 0.45; cursor: default; border-color: var(--rule); }
.chip[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.lang { display: flex; gap: 6px; }

/* Bàn cờ */
.board-wrap { position: relative; width: 100%; aspect-ratio: 1; border-radius: 6px; overflow: hidden; }
.board { display: grid; grid-template-columns: repeat(8, 1fr); grid-template-rows: repeat(8, 1fr); width: 100%; height: 100%; }
.sq { position: relative; background: var(--sq-light); cursor: pointer; }
.sq.dark { background: var(--sq-dark); }
.sq.last::before, .sq.pick::before { content: ""; position: absolute; inset: 0; background: var(--sq-last); }
.sq.pick::before { background: var(--sq-pick); }
.sq.target::after {
  content: ""; position: absolute; left: 36%; top: 36%; width: 28%; height: 28%;
  border-radius: 50%; background: rgba(20, 30, 25, 0.28);
}
.sq img { position: absolute; inset: 4%; width: 92%; height: 92%; pointer-events: none; }
.sq .coord { position: absolute; font-size: 10px; font-weight: 600; opacity: 0.6; color: #26332d; pointer-events: none; }
.sq .coord.file { right: 3px; bottom: 1px; }
.sq .coord.rank { left: 3px; top: 1px; }
.arrows { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.board-bar { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.line { margin: 12px 0 0; font-variant-numeric: tabular-nums; line-height: 1.9; }
.line .mv { padding: 2px 5px; border-radius: 5px; cursor: pointer; white-space: nowrap; }
.line .mv:hover { background: var(--rule); }
.line .mv.fixed { color: var(--muted); }
.line .mv.cur { background: var(--accent); color: var(--bg); }
.line .num { color: var(--muted); margin-left: 4px; }

.guide {
  margin-top: 12px; padding: 12px 14px; background: var(--card);
  border: 1px solid var(--rule); border-radius: 10px;
}
.guide p { margin: 0 0 10px; }
.guide .row { display: flex; flex-wrap: wrap; gap: 8px; }
.guide .ok { color: var(--good); font-weight: 600; }
.guide .no { color: var(--bad); font-weight: 600; }

/* Bảng thống kê */
.filters { margin-bottom: 16px; }
table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
th { text-align: left; font-weight: 500; font-size: 13px; color: var(--muted); padding: 4px 8px 6px 0; }
td { padding: 7px 8px 7px 0; border-top: 1px solid var(--rule); vertical-align: middle; }
td.num, th.num { text-align: right; white-space: nowrap; }
td.bar { width: 46%; min-width: 110px; }
.results { margin-bottom: 26px; }
.results td.band { font-weight: 600; white-space: nowrap; }
.results tr.total td { border-top: 2px solid var(--rule); }
.moves-head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 8px; margin-bottom: 4px; }
.moves tbody tr { cursor: pointer; }
.moves tbody tr:hover td { background: color-mix(in srgb, var(--accent) 9%, transparent); }
.moves td.san { font-weight: 700; white-space: nowrap; }
.moves td.san .name { display: block; font-size: 13px; font-weight: 400; color: var(--muted); white-space: normal; }
.moves tr.more td { color: var(--accent); font-weight: 600; }
.share { display: inline-block; min-width: 46px; }

.wdl { display: flex; height: 22px; border-radius: 5px; overflow: hidden; border: 1px solid var(--rule); font-size: 12px; line-height: 20px; }
.wdl span { overflow: hidden; text-align: center; white-space: nowrap; }
.wdl .w { background: var(--w); color: #1d2126; }
.wdl .d { background: var(--d); color: #14171a; }
.wdl .b { background: var(--b); color: #f1f1ee; }
.wdl.thin { opacity: 0.45; }
.legend { display: flex; gap: 14px; font-size: 13px; color: var(--muted); margin: -4px 0 8px; }
.legend i { display: inline-block; width: 11px; height: 11px; border-radius: 3px; border: 1px solid var(--rule); margin-right: 5px; vertical-align: -1px; }

/* Bẫy và thế cờ */
.block { margin-top: 40px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 12px; }
.cards.puzzles { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.card {
  background: var(--card); border: 1px solid var(--rule); border-radius: 10px;
  padding: 14px 16px; cursor: pointer; text-align: left; font: inherit; color: inherit;
}
.card:hover { border-color: var(--accent); }
.card h3 { font-size: 15px; margin: 0 0 4px; }
.card .seq { font-variant-numeric: tabular-nums; margin: 0 0 8px; }
.card .seq b.bad { color: var(--bad); }
.card .seq b.good { color: var(--good); }
.card dl { display: grid; grid-template-columns: auto 1fr; gap: 2px 10px; margin: 0; font-size: 14px; }
.card dt { color: var(--muted); }
.card dd { margin: 0; font-weight: 600; }
.card .rating { font-size: 22px; font-weight: 700; }
.card .tags { font-size: 13px; color: var(--muted); margin: 2px 0 0; }

footer { margin-top: 44px; padding-bottom: 40px; font-size: 13px; }

@media (max-width: 520px) {
  .top { flex-direction: column; }
  h1 { font-size: 26px; }
  .legend { flex-wrap: wrap; gap: 4px 10px; }
  .cards.puzzles { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  td.bar { width: 40%; min-width: 96px; }
}

/* Trang bẫy */
.nav { margin-bottom: 6px; font-size: 14px; }
.nav a { color: var(--accent); text-decoration: none; }
.nav a:hover { text-decoration: underline; }
.sq.bad::before { content: ""; position: absolute; inset: 0; background: color-mix(in srgb, var(--bad) 60%, transparent); }
.sq.good::before { content: ""; position: absolute; inset: 0; background: color-mix(in srgb, var(--good) 60%, transparent); }
.board-bar .play { min-width: 112px; font-weight: 600; background: var(--accent); border-color: var(--accent); color: var(--bg); }
.line .mv.bad { color: var(--bad); font-weight: 700; }
.line .mv.good { color: var(--good); font-weight: 600; }
.line .mv.cur.bad, .line .mv.cur.good { color: var(--bg); }
.line .mv.cur.bad { background: var(--bad); }
.line .mv.cur.good { background: var(--good); }
.kicker { margin: 0 0 2px; font-size: 14px; }
h2.big { font-size: 26px; line-height: 1.2; margin: 0 0 8px; }
.tiles { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin: 18px 0 26px; }
main > section { min-width: 0; }
.tile { min-width: 0; background: var(--card); border: 1px solid var(--rule); border-radius: 10px; padding: 12px 14px; }
.tile b { display: block; font-size: 26px; line-height: 1.2; font-variant-numeric: tabular-nums; }
.tile span { font-size: 14px; color: var(--muted); }
.tile.bad b { color: var(--bad); }
.tile.good b { color: var(--good); }
.rank tbody tr { cursor: pointer; }
.rank tbody tr:hover td, .rank tr.cur td { background: color-mix(in srgb, var(--accent) 9%, transparent); }
.rank td.name b { display: block; }
.rank td.name span { font-size: 13px; color: var(--muted); }
.rank td.meter { width: 30%; }
.rank td.meter i { display: block; height: 10px; min-width: 2px; border-radius: 5px; background: var(--bad); }
.rank th.num:first-child, .rank td.num:first-child { text-align: left; width: 34px; color: var(--muted); }
@media (max-width: 520px) { .rank td.meter, .rank th:last-child { display: none; } }