:root {
  --bg: #f7f3ec;
  --ink: #2b2b2b;
  --muted: #6d6d6d;
  --card: #ffffff;
  --line: #e6dccb;
  --light: #f0d9b5;
  --dark: #b58863;
  --good: #3f8f2f;
  --bad: #c33;
  --accent: #8b5a2b;
  --easy: #6aa832; --medium: #e0a000; --hard: #d9542b; --expert: #7b3a96;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
html[data-lang="zh"] .en { display: none; }
html[data-lang="en"] .zh { display: none; }
a { color: #1a5fa8; }
.wrap { max-width: 980px; margin: 0 auto; padding: 0 16px; }

header.top { background: #fff; border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 8px; min-height: 52px; flex-wrap: wrap; }
header.top h1 { font-size: 18px; margin: 0; white-space: nowrap; }
header.top h1 a { color: var(--ink); text-decoration: none; }
nav { display: flex; align-items: center; gap: 2px; flex-wrap: wrap; }
nav a { color: #555; text-decoration: none; padding: 6px 8px; border-radius: 6px; font-size: 15px; }
nav a:hover, nav a.on { background: #f1e6d3; color: var(--ink); }
#lang-toggle { font: inherit; font-size: 13px; color: #555; background: #f4f4f4; border: 1px solid #ddd; border-radius: 4px; padding: 3px 8px; cursor: pointer; margin-left: 4px; }

main { padding: 18px 0 40px; }
.head { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; flex-wrap: wrap; }
.head h2 { margin: 0; font-size: 22px; }
.badge { display: inline-block; color: #fff; font-size: 13px; font-weight: 600; padding: 1px 9px; border-radius: 99px; vertical-align: middle; }
.lv-easy { background: var(--easy); } .lv-medium { background: var(--medium); } .lv-hard { background: var(--hard); }
.lv-expert { background: var(--expert); } .lv-famous { background: var(--accent); } .lv-free { background: #777; }
.sub { color: var(--muted); font-size: 14px; margin: 4px 0 12px; }
.tag { display: inline-block; font-size: 12px; background: #efe6d6; color: #6b5433; border-radius: 4px; padding: 0 6px; margin: 0 4px 4px 0; }

/* ── board & layout ─────────────────────────────────────────── */
.play { display: grid; grid-template-columns: minmax(0, 520px) minmax(0, 1fr); gap: 22px; align-items: start; }
@media (max-width: 820px) { .play { grid-template-columns: minmax(0, 1fr); } }
.board-col { width: 100%; max-width: 520px; margin: 0 auto; }
.board-wrap { position: relative; width: 100%; aspect-ratio: 1 / 1; box-shadow: 0 4px 14px rgba(80, 50, 20, .25); }
#board { position: absolute; inset: 0; }
#board .cg-wrap, #board cg-container { width: 100%; height: 100%; }
cg-board { border-radius: 2px; }
.msg { min-height: 30px; margin: 10px 0 6px; padding: 6px 10px; border-radius: 6px; background: #fff; border: 1px solid var(--line); font-size: 15px; }
.msg.good { border-color: #b5d8a6; background: #f1faec; color: var(--good); }
.msg.bad { border-color: #efb4b4; background: #fdf0f0; color: var(--bad); }
.msg.big { font-weight: 700; font-size: 17px; }
.btns { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; margin: 8px 0; }
button { font: inherit; font-size: 14px; background: #fff; border: 1px solid #cdbfa8; border-radius: 6px; padding: 5px 12px; cursor: pointer; color: var(--ink); }
button:hover { background: #f6efe2; }
button.primary { background: var(--dark); border-color: #9a6f4c; color: #fff; }
button.primary:hover { background: #a47552; }
button.ok::after { content: " ✓"; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 16px; margin-bottom: 14px; }
.panel h3 { margin: 4px 0 8px; font-size: 16px; }
.hint { color: var(--muted); font-size: 14px; }
code { font-size: 13px; background: #f4efe6; padding: 1px 4px; border-radius: 3px; word-break: break-all; }
.fenrow { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }

/* move lists */
.moves { display: flex; flex-wrap: wrap; gap: 2px 4px; align-items: baseline; max-height: 260px; overflow-y: auto; font-size: 14px; }
.moves .mvno { color: var(--muted); font-size: 12px; margin-left: 4px; }
.moves .mv { border: 0; background: none; padding: 1px 5px; border-radius: 4px; font-weight: 600; }
.moves .mv:hover { background: #f1e6d3; }
.moves .mv.on { background: var(--dark); color: #fff; }
.moves .mv.key { color: #b0540f; }
.moves .mv.key.on { color: #fff; background: #b0540f; }
.nav { display: flex; gap: 6px; justify-content: center; margin: 8px 0 2px; }
.nav button { min-width: 44px; }

/* engine table */
table.eng { border-collapse: collapse; width: 100%; font-size: 14px; }
table.eng td { padding: 4px 6px; border-top: 1px solid #f0e8da; vertical-align: top; }
table.eng td.ev { font-weight: 700; white-space: nowrap; font-variant-numeric: tabular-nums; }
table.eng td.pv { color: var(--muted); font-size: 13px; }
table.eng tr.best td:first-child { color: var(--good); font-weight: 700; }

/* analysis article */
.article h3 { font-size: 17px; margin: 18px 0 6px; }
.article p { margin: 6px 0 10px; }
.article .lead { font-size: 16px; font-weight: 500; }
blockquote { margin: 10px 0 14px; padding: 8px 14px; border-left: 4px solid var(--dark); background: #faf6ef; }
blockquote p { margin: 0 0 4px; font-style: italic; }
blockquote cite { font-size: 13px; color: var(--muted); font-style: normal; }

/* archive */
.dlist { list-style: none; padding: 0; margin: 0; }
.dlist li { display: flex; justify-content: space-between; gap: 8px; padding: 7px 4px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.dlist li span { color: var(--muted); font-size: 14px; }
.dlist li.done a::after, .cards a.done h4::after { content: " ✓"; color: var(--good); }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; }
.cards a { display: block; background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; text-decoration: none; color: var(--ink); }
.cards a:hover { border-color: var(--dark); }
.cards h4 { margin: 0 0 2px; font-size: 15px; }
.cards small { color: var(--muted); font-size: 13px; }
.pager { display: flex; justify-content: space-between; gap: 8px; margin-top: 8px; font-size: 14px; }

form#fenform { display: flex; gap: 6px; }
#fenin { flex: 1; min-width: 0; font: 13px monospace; padding: 5px 8px; border: 1px solid #cdbfa8; border-radius: 6px; }
.err { color: var(--bad); font-size: 13px; min-height: 1em; margin: 4px 0; }
#log { font-size: 14px; }

footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; padding: 14px 0 30px; }
footer p { margin: 4px 0; }