:root {
  --bg: #f6f1e6;
  --surface: #fffdf8;
  --surface-2: #efe8d9;
  --ink: #26261f;
  --muted: #6a675a;
  --line: #d9d0bc;
  --accent: #2f6048;
  --accent-ink: #ffffff;
  --accent-soft: #dfeadf;
  --good: #2f6f46;
  --good-soft: #dcefdf;
  --bad: #a93c2a;
  --bad-soft: #f8e0da;
  --info: #7b5a12;
  --info-soft: #f5ebcd;
  --sq-light: #ebe3cf;
  --sq-dark: #6b9178;
  --radius: 10px;
  --result-white: #f4f1e8;
  --result-draw: #a7a595;
  --result-black: #3a3a33;
  font-family: ui-sans-serif, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #191b18;
    --surface: #23261f;
    --surface-2: #2d3029;
    --ink: #edeade;
    --muted: #a5a392;
    --line: #3d4037;
    --accent: #79b793;
    --accent-ink: #12211a;
    --accent-soft: #2a3a30;
    --good: #84c99a;
    --good-soft: #243a2b;
    --bad: #ec917f;
    --bad-soft: #452820;
    --info: #dfc173;
    --info-soft: #3b3219;
    --sq-light: #d9d2bd;
    --sq-dark: #5d8069;
    --result-black: #10110e;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.45;
  font-size: 16px;
}

h1, h2, p { margin: 0; }
a { color: var(--accent); }
button { font: inherit; color: inherit; cursor: pointer; }
button:focus-visible, a:focus-visible, input:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 16px;
  max-width: 1120px;
  margin: 0 auto;
  padding: 20px 16px 8px;
}
.brand {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
}
.tagline { color: var(--muted); }

main { max-width: 1120px; margin: 0 auto; padding: 8px 16px 32px; }

/* Setup */
.setup { display: grid; gap: 28px; padding-top: 12px; }
.step h2, .settings-grid h2 { font-size: 1.05rem; margin-bottom: 12px; font-weight: 650; }
.setup { counter-reset: step; }
.settings-grid h2 { margin-top: 0; }
.step { counter-increment: step; }
.step h2::before {
  content: counter(step);
  display: inline-grid;
  place-items: center;
  width: 1.6em;
  height: 1.6em;
  margin-right: 8px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: .85em;
}

.options { display: grid; gap: 10px; }
.options-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.options-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.options-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.option, .opening-card {
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-align: left;
  padding: 12px 14px;
  background: var(--surface);
  border: 1.5px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .12s, background-color .12s;
}
.option:hover, .opening-card:hover { border-color: var(--accent); }
.option.is-selected, .opening-card.is-selected {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: inset 0 0 0 1px var(--accent);
}
.option-label { font-weight: 650; }
.option-hint { color: var(--muted); font-size: .86rem; }
.options-compact .option { text-align: center; align-items: center; padding: 10px 6px; }

.color-option { display: grid; grid-template-columns: 52px 1fr; column-gap: 12px; align-items: center; }
.color-option .option-hint { grid-column: 2; }
.color-icon { width: 52px; height: 52px; grid-row: 1 / span 2; background: var(--sq-dark); border-radius: 8px; }

.opening-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 12px; }
.opening-card { gap: 6px; padding: 14px; }
.opening-head { display: flex; justify-content: space-between; gap: 8px; align-items: flex-start; }
.opening-name { font-weight: 650; }
.opening-moves { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .84rem; color: var(--accent); }
.opening-summary { color: var(--muted); font-size: .9rem; flex: 1; }
.badge { flex: none; font-size: .72rem; font-weight: 650; padding: 2px 8px; border-radius: 99px; }

.mastery { display: flex; align-items: center; gap: 8px; margin-top: 4px; }
.mastery-track { flex: 1; height: 6px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.mastery-fill { display: block; height: 100%; background: var(--accent); }
.mastery-label { font-size: .78rem; color: var(--muted); }

.note { color: var(--muted); font-size: .86rem; margin-top: 8px; }
.settings-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.check { display: flex; gap: 10px; align-items: center; cursor: pointer; }
.check input { width: 18px; height: 18px; accent-color: var(--accent); }

.start-bar {
  position: sticky;
  bottom: 0;
  padding: 12px 0;
  background: linear-gradient(transparent, var(--bg) 30%);
}
.primary, .secondary, .ghost { padding: 10px 18px; border-radius: 8px; font-weight: 650; }
.primary { background: var(--accent); color: var(--accent-ink); border: 1.5px solid var(--accent); }
.primary:hover { filter: brightness(1.08); }
.primary:disabled { opacity: .6; cursor: wait; }
.secondary { background: var(--accent-soft); color: var(--accent); border: 1.5px solid transparent; }
.ghost { background: transparent; border: 1.5px solid var(--line); }
.ghost:hover, .secondary:hover { border-color: var(--accent); }
#start { width: 100%; padding: 14px; font-size: 1.05rem; }
.error { color: var(--bad); margin-top: 8px; }
.error:empty { display: none; }

/* Training layout */
.training {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 380px;
  gap: 24px;
  align-items: start;
  padding-top: 8px;
}
.board-column { position: sticky; top: 12px; }

.panel { display: grid; gap: 14px; min-width: 0; }
.panel-top { display: flex; justify-content: space-between; gap: 12px; align-items: flex-start; }
.panel-top h1 { font-family: Georgia, "Times New Roman", serif; font-size: 1.3rem; line-height: 1.2; }
.panel-top .ghost { padding: 6px 12px; flex: none; }
.muted { color: var(--muted); font-size: .88rem; }

.status {
  min-height: 72px;
  padding: 12px 14px;
  border-radius: var(--radius);
  background: var(--surface-2);
  border-left: 4px solid var(--line);
}
.status[data-tone="turn"] { background: var(--accent-soft); border-color: var(--accent); }
.status[data-tone="good"] { background: var(--good-soft); border-color: var(--good); }
.status[data-tone="bad"] { background: var(--bad-soft); border-color: var(--bad); }
.status[data-tone="info"] { background: var(--info-soft); border-color: var(--info); }
.status-title { font-weight: 700; }
.status-detail { font-size: .92rem; }

.actions { display: flex; flex-wrap: wrap; gap: 8px; }
.finish { display: grid; gap: 10px; padding: 14px; border-radius: var(--radius); background: var(--surface); border: 1.5px solid var(--accent); }

.panel-block { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px 14px; }
.panel-block h2 { font-size: .92rem; font-weight: 700; margin-bottom: 6px; }
#line-idea { font-size: .92rem; color: var(--muted); }

.moves {
  list-style: none;
  margin: 0 0 8px;
  padding: 0;
  max-height: 150px;
  overflow-y: auto;
  font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: .9rem;
  min-height: 1.4em;
}
.moves li { display: grid; grid-template-columns: 2.4em 1fr 1fr; padding: 1px 0; }
.move-num { color: var(--muted); }

.stats { display: grid; gap: 5px; font-size: .86rem; }
.stats-head, .stats-row { display: grid; grid-template-columns: 58px 1fr 84px; gap: 8px; align-items: center; }
.stats-head { color: var(--muted); font-size: .76rem; }
.stats-row { padding: 2px 4px; margin: 0 -4px; border-radius: 5px; }
.stats-row.is-played { background: var(--accent-soft); font-weight: 700; }
.stats-move { font-family: ui-monospace, Menlo, Consolas, monospace; }
.stats-share { display: flex; align-items: center; gap: 6px; }
.share-track { flex: 1; height: 7px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.share-fill { display: block; height: 100%; background: var(--accent); }
.share-value { width: 3.2em; text-align: right; font-variant-numeric: tabular-nums; }
.result-bar { display: flex; height: 10px; border-radius: 3px; overflow: hidden; border: 1px solid var(--line); }
.result-white { background: var(--result-white); }
.result-draw { background: var(--result-draw); }
.result-black { background: var(--result-black); }
.stats-foot { color: var(--muted); font-size: .76rem; margin-top: 2px; }

/* Board */
.board {
  position: relative;
  width: 100%;
  max-width: min(100%, calc(100vh - 96px));
  aspect-ratio: 1;
  margin: 0 auto;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 2px 14px rgb(0 0 0 / .18);
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}
.board.is-movable { cursor: pointer; }
.board.is-shaking { animation: shake .3s; }
@keyframes shake {
  25% { transform: translateX(-5px); }
  50% { transform: translateX(5px); }
  75% { transform: translateX(-3px); }
}
.board-squares { position: absolute; inset: 0; display: grid; grid-template: repeat(8, 1fr) / repeat(8, 1fr); }
.sq { position: relative; }
.sq-light { background: var(--sq-light); color: var(--sq-dark); }
.sq-dark { background: var(--sq-dark); color: var(--sq-light); }
.sq[data-file]::after { content: attr(data-file); position: absolute; right: 4%; bottom: 1%; font-size: clamp(9px, 1.5vw, 13px); font-weight: 700; }
.sq[data-rank]::before { content: attr(data-rank); position: absolute; left: 4%; top: 1%; font-size: clamp(9px, 1.5vw, 13px); font-weight: 700; }

.board-marks, .board-pieces { position: absolute; inset: 0; pointer-events: none; }
.mark, .piece { position: absolute; top: 0; left: 0; width: 12.5%; height: 12.5%; }
.piece { transition: transform .18s ease-out; }
.piece svg { display: block; width: 100%; height: 100%; }
.piece.is-dragging { transition: none; z-index: 5; filter: drop-shadow(0 4px 5px rgb(0 0 0 / .35)); }

.mark-last { background: rgb(232 196 76 / .5); }
.mark-selected { background: rgb(232 196 76 / .75); }
.mark-check { background: radial-gradient(circle, rgb(214 48 30 / .9) 15%, rgb(214 48 30 / 0) 72%); }
.mark-wrong { background: rgb(214 48 30 / .55); }
.mark-hint { background: rgb(55 130 215 / .6); }
.mark-dest::after { content: ""; position: absolute; inset: 36%; border-radius: 50%; background: rgb(24 40 30 / .35); }
.mark-capture::after { content: ""; position: absolute; inset: 4%; border-radius: 50%; border: 5px solid rgb(24 40 30 / .35); }

.board-arrows { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 4; }
.board-arrows line { stroke: rgb(208 92 38 / .85); stroke-width: .17; }
.board-arrows polygon { fill: rgb(208 92 38 / .85); }

/* Footer */
.site-footer {
  max-width: 1120px;
  margin: 0 auto;
  padding: 16px 16px 28px;
  color: var(--muted);
  font-size: .82rem;
  border-top: 1px solid var(--line);
}
.link { background: none; border: 0; padding: 0; margin-top: 6px; color: var(--muted); text-decoration: underline; font-size: inherit; }

@media (max-width: 900px) {
  .training { grid-template-columns: minmax(0, 1fr); gap: 14px; }
  .board-column { position: static; }
  .board { max-width: 100%; }
  .options-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .settings-grid { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 480px) {
  .options-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .option { padding: 10px; }
  .opening-grid { grid-template-columns: minmax(0, 1fr); }
}
@media (prefers-reduced-motion: reduce) {
  .piece { transition: none; }
  .board.is-shaking { animation: none; }
}

/* Header link, stats and filters */
.stats-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--muted);
  font-size: .92rem;
}
.stats-strip strong { color: var(--accent); font-size: 1.2rem; font-family: Georgia, "Times New Roman", serif; }

.filters { display: grid; gap: 12px; margin-bottom: 14px; }
.filter-title { margin: 0 0 6px; font-size: .84rem; font-weight: 650; color: var(--muted); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  padding: 6px 12px;
  background: var(--surface);
  border: 1.5px solid var(--line);
  border-radius: 99px;
  font-size: .88rem;
  font-weight: 600;
}
.chip:hover { border-color: var(--accent); }
.chip.is-selected { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }

.search-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.search-row .ghost { padding: 7px 14px; }
#search, #rating-input {
  font: inherit;
  color: var(--ink);
  background: var(--surface);
  border: 1.5px solid var(--line);
  border-radius: 8px;
  padding: 8px 12px;
}
#search { flex: 1 1 240px; min-width: 0; }
#rating-input { width: 110px; font-size: 1.15rem; font-weight: 700; }

.opening-tags { display: flex; flex-wrap: wrap; gap: 4px; }
.tag { padding: 1px 7px; font-size: .72rem; background: var(--surface-2); color: var(--muted); border-radius: 99px; }
.badge-easy { background: var(--good-soft); color: var(--good); }
.badge-medium { background: var(--info-soft); color: var(--info); }
.badge-hard { background: var(--bad-soft); color: var(--bad); }
.empty { padding: 16px 4px; }

.rating-row { display: flex; align-items: center; gap: 14px; margin-bottom: 10px; }
#rating-slider { flex: 1; min-width: 0; height: 28px; accent-color: var(--accent); cursor: pointer; }
.scale-chips { margin-bottom: 12px; }
.range-summary { margin-top: 12px; font-weight: 550; }

.start-note { margin-top: 6px; font-size: .84rem; color: var(--muted); text-align: center; }

@media (max-width: 640px) {
  .start-bar { padding-bottom: 6px; }
}