:root{color-scheme:dark;--bg:#11151a;--panel:#1b2129;--text:#ecede9;--muted:#9ba7b4;--white:#7ce1cb;--black:#ffb668}*{box-sizing:border-box}body{margin:0;background:radial-gradient(ellipse at 20% 0,#253036 0,transparent 50%),var(--bg);color:var(--text);font:15px/1.5 system-ui,sans-serif}.workspace{max-width:1120px;margin:auto;padding:40px 32px}header{margin-bottom:28px}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--white);font-weight:700}h1{font-size:clamp(26px,4vw,38px);letter-spacing:-1px;margin:10px 0 4px}.subtitle{color:var(--muted);margin:0}.toolbar{display:flex;gap:16px;margin-bottom:24px}label{display:flex;flex-direction:column;gap:6px;color:var(--muted);font-size:12px;font-weight:600}.game-label{flex:1}select,button{font:inherit;color:var(--text);background:var(--panel);border:1px solid #3a4551;border-radius:8px;padding:11px 14px}select{width:100%;min-width:130px}button{cursor:pointer;font-weight:600}button:hover:enabled{background:#303d47;border-color:var(--white)}button:disabled{opacity:.4;cursor:default}button:focus-visible,select:focus-visible{outline:2px solid var(--white);outline-offset:3px}.replay-layout{display:grid;grid-template-columns:minmax(0,640px) minmax(240px,1fr);gap:28px}.player-line{display:flex;justify-content:space-between;gap:12px;padding:10px 0;font-size:13px;color:var(--muted)}.player-line span:first-child{color:var(--text);font-weight:600}.board-frame{position:relative;border:7px solid #303a42;border-radius:8px;overflow:hidden;box-shadow:0 14px 45px #0005}.board{display:grid;grid-template-columns:repeat(8,1fr);aspect-ratio:1}.square{position:relative;display:flex;align-items:center;justify-content:center;background:#b8b8a5;aspect-ratio:1}.square.dark{background:#596b68}.piece{font-family:"DejaVu Sans","Arial Unicode MS",serif;font-size:clamp(25px,5.5vw,64px);line-height:1;z-index:2}.piece.white{color:#fffaf0;text-shadow:0 2px 2px #000b,-1px 0 #303b36,0 -1px #303b36,1px 0 #303b36}.piece.black{color:#192321;text-shadow:0 1px #d9e4d2}.coordinate{position:absolute;font-size:10px;line-height:1;color:#22362e;z-index:4;font-weight:700}.dark .coordinate{color:#e1e4d7}.rank{top:4px;left:4px}.file{bottom:3px;right:4px}.mark{position:absolute;inset:3px;border:3px solid var(--white);z-index:3;pointer-events:none}.mark.black{border-color:var(--black);inset:8px}.mark.source{border-style:dashed;background:#7ce1cb22}.mark.black.source{background:#ffb66822}.arrows{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;z-index:5}.controls{display:flex;gap:12px;margin-top:12px}.controls button{flex:1}kbd{font:11px monospace;border:1px solid #60716f;border-radius:4px;padding:1px 5px;margin-left:7px;color:var(--muted)}.status{min-height:45px;color:var(--muted);font-size:13px;margin:14px 0 8px}.legend{display:flex;gap:12px;flex-wrap:wrap;font-size:11px;color:var(--muted)}.legend span{display:flex;align-items:center;gap:5px}.legend i{width:10px;height:10px;border:2px solid var(--white)}.legend .black-mark{border-color:var(--black)}.moves-panel{background:var(--panel);border:1px solid #303b46;border-radius:12px;overflow:hidden;align-self:start}.panel-heading{display:flex;align-items:center;justify-content:space-between;padding:18px 20px}.panel-heading h2{font-size:16px;margin:0}.panel-heading span{font-size:11px;color:var(--muted)}.move-columns,.move-row{display:grid;grid-template-columns:36px 1fr 1fr;gap:8px;align-items:center}.move-columns{padding:8px 20px;color:var(--muted);font-size:11px;background:#151b21}#move-list{list-style:none;padding:8px 12px;margin:0;max-height:490px;overflow:auto}.move-row{padding:3px 8px;border-radius:5px;font-size:14px}.move-number{color:var(--muted);font-size:12px}.san{padding:5px 8px;border-radius:4px;min-height:31px}.san.current{background:#7ce1cb24;color:var(--white);font-weight:700;box-shadow:inset 2px 0 var(--white)}.san.recent{background:#ffffff08}.empty{padding:16px 20px;color:var(--muted);font-size:13px}.errors{background:#4d2828;border:1px solid #9a5656;border-radius:8px;padding:12px 16px;margin-bottom:20px;font-size:13px;white-space:pre-wrap}footer{margin-top:32px;color:#75818b;font-size:11px}@media(min-width:1100px){.piece{font-size:64px}}@media(max-width:760px){.workspace{padding:24px 16px}.replay-layout{grid-template-columns:1fr;gap:20px}.toolbar{flex-wrap:wrap}.game-label{flex-basis:100%}.piece{font-size:9vw}#move-list{max-height:280px}.legend{gap:9px}.board-frame{border-width:5px}}@media(prefers-reduced-motion:no-preference){button{transition:background .15s}}

.scoring-panel{margin-top:28px;border:1px solid #303b46;border-radius:12px;background:var(--panel);padding:0 20px 20px}.scoring-panel .panel-heading{padding-left:0;padding-right:0}.scoring-controls{display:flex;gap:12px;align-items:end;flex-wrap:wrap}input{font:inherit;color:var(--text);background:#11151a;border:1px solid #3a4551;border-radius:8px;padding:11px 14px;width:140px}input:focus-visible{outline:2px solid var(--white);outline-offset:3px}#score-chart{display:block;width:100%;min-height:180px}.chart-caption{color:var(--muted);font-size:12px}.score-candidates{padding:0;list-style:none;display:grid;gap:8px}.score-candidates li{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:10px;background:#11151a;border-radius:6px;font-size:13px}.score-candidates span{flex:1;min-width:220px}.score-candidates button{font-size:12px;padding:6px 10px}.score-point{cursor:pointer}.score-point:focus{outline:none;stroke:white;stroke-width:3}.score-grid{stroke:#3a4551;stroke-width:1}.score-text{fill:var(--muted);font-size:12px}.score-line{fill:none;stroke:var(--white);stroke-width:2}.score-band{fill:#7ce1cb22;stroke:none}@media(max-width:760px){.scoring-panel{padding:0 12px 12px}.scoring-panel .panel-heading{display:block}}

.sync-toolbar{display:flex;align-items:end;gap:14px;flex-wrap:wrap;margin-bottom:20px}.sync-toolbar label{min-width:180px}.sync-toolbar p{font-size:12px;color:var(--muted);margin:0;align-self:center}.sync-toolbar .errors{flex-basis:100%;color:var(--text)}

/* Decision Impact is above the board; Move History aligns to the board itself. */
.replay-layout{grid-template-rows:400px 720px auto;align-items:stretch}
.scoring-panel{grid-column:1;grid-row:1;display:grid;grid-template-rows:auto auto minmax(0,1fr) auto;height:400px;margin:0;padding:0 14px 12px;overflow:hidden}
.scoring-panel .panel-heading{padding:12px 0 6px}
.scoring-panel .panel-heading h2{font-size:20px;letter-spacing:.1px}
.scoring-panel .panel-heading span{font-size:12px}
.chart-toolbar{display:flex;align-items:center;gap:6px;flex-wrap:wrap}
.chart-toolbar button{min-width:34px;padding:4px 10px;font-size:16px;line-height:1.2}
.chart-toolbar #score-zoom-reset,.chart-toolbar #score-refresh{font-size:12px}
.chart-toolbar #score-refresh{width:144px;flex-shrink:0}
.chart-toolbar span{margin-left:auto;color:var(--muted);font-size:11px}
#score-chart{width:100%;height:100%;min-height:0}
.score-selection{fill:#7ce1cb2b;stroke:var(--white);stroke-width:1;stroke-dasharray:5 4;pointer-events:none}
.score-text{font-size:16px}
.score-grid{stroke-width:1.3}
.score-line{stroke-width:3}
.chart-caption{display:block;margin:3px 0 8px;font-size:12px;line-height:1.35}
.score-candidates{max-height:none;min-height:0;overflow:auto;margin:0;align-content:start}
.score-candidates li{padding:7px;font-size:12px;gap:6px}
.score-candidates span{min-width:0}
.score-candidates button{font-size:11px;padding:5px 8px}
.impact-panel{grid-column:2;grid-row:1;display:grid;grid-template-rows:auto minmax(0,1fr);height:400px;min-height:0;overflow:hidden;border:1px solid #303b46;border-radius:12px;background:var(--panel)}
.impact-panel .panel-heading{padding:12px 14px}
.impact-panel .panel-heading h2{font-size:18px;margin:0}
.impact-panel .panel-heading span{font-size:11px;color:var(--muted)}
.impact-panel .impact-list{display:grid;align-content:start;gap:8px;min-height:0;overflow-y:auto;scrollbar-gutter:stable;padding:8px 12px;margin:0;list-style:none}
.impact-panel .impact-list li{display:flex;align-items:center;gap:6px;flex-wrap:wrap;padding:8px;background:#11151a;border-radius:6px;font-size:12px;cursor:pointer}
.impact-panel .impact-list li:hover{background:#26323a}
.impact-panel .impact-list li:focus-visible{outline:2px solid var(--white);outline-offset:1px}
.impact-panel .impact-list span{flex:1;min-width:0}
.impact-panel .impact-list button{font-size:11px;padding:5px 8px}
.board-panel{grid-column:1;grid-row:2;display:grid;grid-template-rows:40px 640px 40px;height:720px;overflow:hidden}
.board-panel .player-line{height:40px;padding:0;align-items:center}
.board-frame{width:100%;height:640px}
.board{width:100%;height:100%;aspect-ratio:auto}
.moves-panel{grid-column:2;grid-row:2;display:grid;grid-template-rows:auto auto minmax(0,1fr) auto;margin:40px 0;height:640px;min-height:0;overflow:hidden}
.moves-panel .panel-heading{padding:12px 14px}
.move-columns{padding:6px 14px}
#move-list{max-height:none;min-height:0;overflow-y:auto;scrollbar-gutter:stable}
.san[role="button"]{cursor:pointer}
.san[role="button"]:focus-visible{outline:2px solid var(--white);outline-offset:1px}
.below-board{grid-column:1;grid-row:3;min-width:0}
.scoring-controls-panel{margin-top:22px;padding:0 16px 14px;border:1px solid #303b46;border-radius:12px;background:var(--panel)}
.scoring-controls-panel .panel-heading{padding:14px 0 10px}
.scoring-controls-panel .panel-heading h2{font-size:16px;margin:0}
.scoring-controls-panel .panel-heading span{font-size:11px;color:var(--muted)}
.scoring-controls-panel .scoring-controls{gap:12px}
.scoring-controls-panel .scoring-controls label{min-width:135px}
.scoring-controls-panel #score-status{min-height:0;margin:12px 0 4px;font-size:13px}
.scoring-controls-panel #score-error{margin:8px 0 0}
@media(max-width:980px){
  .replay-layout{grid-template-columns:minmax(0,1fr);grid-template-rows:400px 400px auto auto 420px;gap:18px}
  .scoring-panel{grid-column:1;grid-row:1;width:100%;height:400px}
  .impact-panel{grid-column:1;grid-row:2;height:400px}
  .board-panel{grid-column:1;grid-row:3;grid-template-rows:40px auto 40px;height:auto}
  .board-frame{height:auto;aspect-ratio:1}
  .board{height:auto;aspect-ratio:1}
  .below-board{grid-column:1;grid-row:4}
  .moves-panel{grid-column:1;grid-row:5;margin:0;height:420px}
}
@media(max-width:760px){
  .scoring-controls-panel{padding:0 12px 12px}
  .scoring-controls-panel .scoring-controls{gap:8px}
  .scoring-controls-panel .scoring-controls label{flex:1;min-width:120px}
  .scoring-panel .panel-heading h2{font-size:19px}
}

#suggest-status{font-size:13px;color:var(--muted);min-height:20px;margin:8px 0 14px}

/* Position alerts and observed captures never change the board/player row dimensions. */
.square.king-check{background:#c98b24}.square.king-checkmate{background:#b84765}
.king-check .coordinate,.king-checkmate .coordinate{color:#fff}
.player-line{min-width:0;overflow:hidden}
.player-identity{display:flex;align-items:center;gap:8px;flex-shrink:0;max-width:70%;min-width:0}
.player-identity>span:first-child{white-space:nowrap;color:var(--text);font-weight:600}
.player-line>span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;text-align:right}
.capture-strip{display:flex;align-items:center;gap:4px;min-width:0;overflow:hidden;white-space:nowrap}
.capture{font-family:"DejaVu Sans","Arial Unicode MS",serif;font-size:18px;line-height:1}
.capture.white{color:#fffaf0}.capture.black{color:#b4c8bd;text-shadow:0 1px #111}
.king-status{height:20px;margin:8px 0;font-size:12px;color:var(--muted);overflow:hidden;white-space:nowrap}
.below-board>#status,#suggest-status{height:4.5em;min-height:4.5em;overflow-y:auto}
.legend .check-mark{background:#c98b24;border-color:#c98b24}.legend .mate-mark{background:#b84765;border-color:#b84765}
@media(max-width:480px){.player-identity{gap:4px;max-width:100%}.capture-strip{gap:2px}.capture{font-size:13px}.player-line{gap:5px;font-size:11px}.stockfish-controls{gap:6px}.stockfish-controls button{min-width:0;padding:8px 4px;font-size:12px}}

/* Fork controls share the existing board and timeline shell. */
.fork-toolbar,.fork-controller-options{display:flex;flex-wrap:wrap;gap:.75rem;align-items:center;margin:1rem 0}
.fork-toolbar[hidden]{display:none}.fork-toolbar label,.fork-controller-options label{display:flex;flex-direction:column;gap:.3rem}
dialog{color:inherit;background:#162326;border:1px solid #46615f;border-radius:12px;padding:1.5rem;max-width:min(90vw,650px)}
dialog::backdrop{background:#000a}dialog form{display:grid;gap:1rem}dialog textarea{width:100%;font:inherit;background:#0e191c;color:inherit;border:1px solid #46615f;padding:.5rem}
.square.legal-target::after{content:'';position:absolute;width:24%;height:24%;border-radius:50%;background:#7ce1cb99;pointer-events:none;z-index:4}
.square.selected-piece{box-shadow:inset 0 0 0 4px #7ce1cb}.san.fork-boundary{border-bottom:3px solid #7ce1cb}
#fork-state{flex-basis:100%}#fork-promotion-choices{margin:1rem 0}#fork-list{max-width:20rem}
[hidden]{display:none!important}