:root{color-scheme:dark;--bg:#11151e;--panel:#1c2230;--line:#3a4354;--text:#f5f6fc;--muted:#bbc3d5;--purple:#9872df;--cyan:#81e7ce}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.6 'Segoe UI',system-ui,sans-serif}button,input,select,textarea{font:inherit}button,a,summary,select{touch-action:manipulation}button{padding:10px 16px;border:1px solid #566078;border-radius:9px;background:#2b3445;color:var(--text);cursor:pointer;transition:background .15s}button:hover{background:#3c4860}button:disabled{opacity:.5;cursor:wait}.primary{background:#7850ba;border-color:#b299e8;font-weight:600}.primary:hover{background:#8e60d7}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #9eeedb;outline-offset:3px}a{color:#d4baff;text-decoration:none}a:hover{text-decoration:underline}h1,h2,p{margin:0 0 12px}h1{font-size:30px;line-height:1.25;font-weight:650}h2{font-size:21px;line-height:1.4}small,.muted{font-size:14px;color:var(--muted)}[hidden]{display:none!important}summary{cursor:pointer;font-weight:600;min-height:30px}details[open]>summary{margin-bottom:16px}label{font-size:15px;color:var(--muted)}input,select,textarea{background:#141b28;color:var(--text);border:1px solid #667088;border-radius:7px;padding:10px 12px;min-width:0;max-width:100%}select{cursor:pointer}input[type=range]{accent-color:#b398e8;padding:0}input[type=number]{width:100%}
.sidebar{position:fixed;inset:0 auto 0 0;width:202px;background:#171c27;border-right:1px solid var(--line);padding:25px 16px;display:flex;flex-direction:column;z-index:10;overflow:auto}.brand{display:flex;gap:8px;align-items:center;color:white;font-size:21px;font-weight:700}.brand-icon{font-size:39px;color:#c5a5ff}.brand-sub{display:block;font-size:13px;letter-spacing:2px;color:#c7b3ec}.brand-sub i{display:none}.new-game{margin:25px 0;display:flex;gap:10px;justify-content:center}.nav-label{color:#bac1d0;font-size:13px;margin:0 10px 8px}nav{display:flex;flex-direction:column;gap:7px}nav button{text-align:left;background:transparent;border-color:transparent;padding:11px 12px;display:flex;gap:10px;align-items:center;width:100%;font-size:16px}nav button span{font-size:21px;width:24px;text-align:center}nav button.active{background:#423355;border-color:#8465a8;color:#f4eaff}nav .tools-menu{margin-top:20px;color:var(--muted)}.tools-menu summary{padding:8px 12px;font-size:15px}.tools-menu button{font-size:14px;padding:10px 8px}.sidebar-bottom{margin-top:auto;padding-top:26px}.model-mini{border-top:1px solid var(--line);padding-top:16px;font-size:13px}.model-mini strong{display:inline;font-weight:500}.model-mini small{display:block;font-size:12px;margin-top:6px}.pulse{display:inline-block;background:var(--cyan);width:7px;height:7px;border-radius:50%;margin-right:5px}.local-label,.sidebar-bottom>p{display:none}.shell{margin-left:202px;padding:0 26px;max-width:1750px}.topbar{display:flex;align-items:center;justify-content:space-between;padding:23px 0 12px;gap:16px}.breadcrumb{font-size:15px;color:#c6b5e8;display:block;margin-bottom:6px}.topbar h1{margin:0}.experimental-badge{padding:5px 10px;border:1px solid #7e659e;color:#d2b6f1;border-radius:20px;font-size:13px}.notice{margin:5px 0 20px;color:#c5cad8;max-width:920px}.notice p{font-size:14px;margin:0;line-height:1.6}#error{position:sticky;top:10px;z-index:11;background:#642c3c;border:1px solid #dc879a;border-radius:8px;padding:14px;color:#fff3f6;margin-bottom:20px}.workspace{display:grid;grid-template-columns:minmax(330px,660px) minmax(360px,460px);gap:26px;align-items:start;margin:0 auto;max-width:1160px}.board-column{min-width:0}.turn-banner{padding:16px 18px;border:1px solid #7a69a0;border-radius:12px;background:#29263a;margin-bottom:14px}.game-strip{display:flex;align-items:center;gap:10px}.game-strip strong{font-size:24px;line-height:1.3;color:#fff}.game-strip>span:last-child{margin-left:auto;color:#cfbfec;font-size:13px}.turn-dot{width:9px;height:9px;flex-shrink:0;background:#82e6ce;border-radius:50%}#move-help{font-size:16px;color:#f1e8ff;margin:8px 0;line-height:1.55}.last-move-status{font-size:14px;color:#c7c9d9}.position-summary{display:flex;align-items:center;justify-content:space-between;gap:16px;border:1px solid var(--line);background:var(--panel);padding:14px 16px;border-radius:10px;margin-bottom:14px}.stat-label{display:block;color:#c7cad9;font-size:14px}.position-summary strong{display:block;font-size:18px;line-height:1.5}.position-summary small{display:block;font-size:13px;line-height:1.5;margin-top:3px}.material-scores{display:flex;gap:20px;text-align:center}.material-scores span{font-size:13px;color:#d0d4df}.material-scores strong{font-size:23px}.board-toolbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:14px 0}.board-toolbar>label{display:flex;align-items:center;gap:10px;font-size:14px}.board-toolbar select{font-size:14px;padding:6px 8px}.icon-button{background:transparent;padding:7px 10px;font-size:14px}.player{display:flex;gap:10px;align-items:center;margin:12px 0}.avatar{display:grid;place-items:center;width:34px;height:34px;border:1px solid #6c5c84;border-radius:8px;background:#3a2b4d;font-size:24px;color:#d3b0ff}.human-avatar{font-size:16px;background:#293b43;color:#b9e2dc;border-color:#42636a}.player strong{font-size:16px}.player small{display:block;font-size:13px}.player-right{margin-left:auto;display:flex;gap:10px;align-items:center}.color-tag{font-size:12px;letter-spacing:.6px;color:#c7c6d9}.captured{font-size:23px;line-height:1;color:#d3c0e3}.board-wrap{position:relative;border-radius:8px;overflow:hidden;border:2px solid #8a7a9f;box-shadow:0 8px 28px #0004}.board{display:grid;grid-template-columns:repeat(8,1fr);width:100%;aspect-ratio:1}.square{position:relative;aspect-ratio:1;display:flex;align-items:center;justify-content:center;border:0;border-radius:0;padding:0;min-width:0;touch-action:manipulation}.square.light{background:#ded7e8}.square.dark{background:#776786}.square.light:hover{background:#eae4f0}.square.dark:hover{background:#9380a4}.square.last.light{background:#ded5a3}.square.last.dark{background:#a89b62}.square.movable{cursor:grab}.square.movable:after{content:'';position:absolute;bottom:7%;left:44%;width:12%;height:5%;background:#224b43a0;border-radius:3px}.square.selected{background:#ad8cd0!important;box-shadow:inset 0 0 0 4px #573179}.square.hint{box-shadow:inset 0 0 0 4px #13a58b}.square.check{background:radial-gradient(circle,#f27e8f,#b23d56)!important}.piece{width:85%;height:85%;display:block;object-fit:contain;pointer-events:none;user-select:none;-webkit-user-drag:none;z-index:2;filter:drop-shadow(0 2px 1px #0003)}.square .coord{position:absolute;z-index:4;font-size:12px;font-weight:700;pointer-events:none}.rank-label{left:4px;top:0}.file-label{right:4px;bottom:0}.light .coord{color:#42324e}.dark .coord{color:#f5eaff}.legal-dot{width:31%;height:31%;border:3px solid #124d43;background:#4ce9b8ad;border-radius:50%;z-index:3;position:absolute;box-shadow:0 0 0 5px #d9fff466;pointer-events:none}.legal-capture{position:absolute;inset:4%;border:5px solid #0af7be;border-radius:50%;z-index:3;box-shadow:inset 0 0 0 2px #124c41,0 0 0 2px #124c41;pointer-events:none}.move-legend{display:flex;flex-wrap:wrap;gap:8px 18px;color:#cfd6e5;font-size:13px;margin:14px 0}.move-legend>span{display:flex;align-items:center;gap:7px}.move-legend i{display:inline-block;width:12px;height:12px;border-radius:50%}.legend-dot{background:#6ee7bc}.legend-ring{border:3px solid #6ee7bc}.legend-selected{background:#bb94e8}.thinking{position:absolute;bottom:15px;left:50%;transform:translateX(-50%);background:#161d2cf5;border:1px solid #b3a1d9;border-radius:25px;padding:10px 16px;white-space:nowrap;display:flex;align-items:center;gap:10px;z-index:5;color:#fff}.spinner{width:14px;height:14px;border:2px solid #9c88b6;border-top-color:white;border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.game-controls{display:flex;flex-wrap:wrap;gap:10px;margin:16px 0}.game-controls>button{font-size:15px}.game-controls details{position:relative;font-size:14px}.game-controls summary{border:1px solid #566078;padding:10px 12px;border-radius:8px;font-weight:400}.option-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}.option-actions button,.option-actions a{font-size:14px}.option-actions a{padding:10px}.panel{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px;margin-bottom:16px}.panel-heading{display:flex;gap:14px;align-items:center;justify-content:space-between;margin-bottom:16px}.panel-heading h2{margin:0;font-size:19px}.history-panel summary{display:flex;justify-content:space-between;font-size:16px}.history-panel summary span{font-size:13px;color:var(--muted)}.history{max-height:230px;overflow:auto}.move-row{display:grid;grid-template-columns:40px 1fr 1fr;gap:8px;align-items:center}.move-row:nth-child(odd){background:#252e40}.move-row>span{padding-left:8px;font-size:14px;color:#c2c7d7}.move-row button{border:0;background:transparent;text-align:left;font-size:16px}.move-row .replay-active{background:#4c3a68}.empty{padding:18px;color:var(--muted);font-size:15px}.right-column{position:sticky;top:20px;min-width:0}.chat-panel{padding:0;overflow:hidden;display:flex;flex-direction:column;min-height:660px}.chat-heading{display:flex;gap:12px;align-items:center;padding:20px;border-bottom:1px solid var(--line)}.chat-heading h2{font-size:22px;margin-bottom:2px}.chat-heading small{font-size:14px}.chat-mark{width:38px;height:38px;display:grid;place-items:center;background:#44325b;border:1px solid #82679f;border-radius:10px;font-size:25px;color:#e2c6ff}.assistant-mode-row{padding:15px 18px 0;display:flex;flex-wrap:wrap;gap:10px;align-items:flex-end}.assistant-mode-row label{font-size:13px;flex:1;min-width:180px}.assistant-mode-row select{display:block;width:100%;font-size:14px;margin-top:5px}.assistant-mode-row button{font-size:13px;padding:10px}.assistant-readiness{padding:0 18px;margin:12px 0 0;font-size:14px;color:#d5cced;line-height:1.6}.chat-log{padding:20px;overflow:auto;min-height:240px;height:390px;max-height:55vh;scrollbar-width:thin;scrollbar-color:#7f6e9b transparent}.chat-bubble{padding:16px;background:#273147;border:1px solid #46536c;border-radius:12px;margin-bottom:16px;font-size:17px;line-height:1.75}.chat-bubble.user{background:#3c3052;border-color:#78618f;margin-left:30px}.chat-bubble p{margin:8px 0 0;white-space:pre-wrap;overflow-wrap:anywhere}.source{display:block;font-size:12px;font-weight:600;letter-spacing:.1px;color:#d5d1ec}.quick-prompts{display:flex;flex-wrap:wrap;gap:8px;padding:0 18px 16px}.quick-prompts button{font-size:14px;padding:8px 10px;background:#292c3d}.chat-panel form{display:flex;gap:10px;align-items:flex-end;padding:16px;border-top:1px solid var(--line);background:#171e2b}.chat-panel textarea{flex:1;font-size:17px;line-height:1.6;resize:vertical;min-height:100px;max-height:240px;width:100%}.chat-panel form button{font-size:15px;padding:12px 16px}.chat-footnote{padding:12px 18px;font-size:13px;color:#c4c8d7}.opponent-panel summary{font-size:14px}.opponent-details{display:flex;justify-content:space-between;font-size:14px}.opponent-panel p{font-size:14px;margin-top:12px}.lesson-panel h2{font-size:19px}.pill{font-size:12px;color:var(--cyan);white-space:nowrap}.lesson-list{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:16px 0}.lesson-list button{text-align:left;font-size:15px;line-height:1.5}.fen-row{margin-top:16px}.fen-row label{display:block;margin-bottom:8px}.fen-row>div{display:flex;gap:8px}.fen-row input{width:100%;font:13px/1.6 Consolas,monospace}.fen-row button{font-size:13px;padding:8px}.replay{display:flex;gap:8px;align-items:center;margin:16px 0 0}.replay>span{font-size:13px}.replay input{flex:1;width:0}.replay button{padding:5px 10px;font-size:14px}.analysis-summary{background:#312c43;padding:14px;border-radius:8px;overflow-wrap:anywhere;font-size:15px}.candidate{display:grid;grid-template-columns:70px 1fr 55px;gap:12px;align-items:center;border-bottom:1px solid var(--line);padding:12px 0;font-size:15px}.candidate progress{width:100%;height:10px;accent-color:#b18adb}.mono{font:14px/1.7 Consolas,monospace;margin:16px 0}.dashboard,.settings{padding:15px 0;max-width:1200px}.section-heading{display:flex;justify-content:space-between;gap:20px;align-items:center;margin-bottom:24px}.section-heading h2{font-size:26px}.section-heading p{color:var(--muted)}.metric-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:18px 0}.metric{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:18px}.metric small{display:block;font-size:14px}.metric strong{display:block;font-size:27px;margin:10px 0}.metric span{font-size:13px;color:var(--muted)}canvas{display:block;width:100%;height:280px}.settings-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.settings label,.assistant-training>label{display:block;margin:18px 0}.settings label input,.settings label select,.assistant-training>label select{display:block;width:100%;margin-top:8px}.settings dl{display:grid;grid-template-columns:1fr 2fr;gap:12px;font-size:15px}.settings dt{color:var(--muted)}.settings dd{margin:0;overflow-wrap:anywhere}.data-row{display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;align-items:center;padding:16px 0;border-bottom:1px solid var(--line);font-size:15px;overflow-wrap:anywhere}.data-row small{display:block}.training-controls{display:flex;align-items:flex-end;gap:15px;flex-wrap:wrap;margin-top:18px}.training-controls label{max-width:180px}.training-controls input,.training-controls select{display:block;margin-top:7px;width:100%}#assistant-training-status{padding:15px;background:#2b3145;border-radius:8px;white-space:pre-wrap}.assistant-training p{font-size:15px;color:#d4d9e5}.chess-training-details{margin-top:25px}.chess-training-details>summary{font-size:21px;padding:15px}.assistant-focus .board-column{display:none}.workspace.assistant-focus{display:block;max-width:900px}.assistant-focus .right-column{position:static}.assistant-focus .chat-log{height:50vh;max-height:none}.assistant-focus .opponent-panel{display:none}.overline{font-size:14px;color:#c6b4e4}.analysis-panel p{font-size:15px}footer{padding:30px 0;color:#b6bdce;font-size:13px;display:flex;gap:20px;justify-content:space-between}dialog{background:#1e2636;color:var(--text);border:1px solid #9b80bb;border-radius:16px;padding:30px;width:min(480px,94vw)}dialog::backdrop{background:#080b13ba;backdrop-filter:blur(4px)}dialog h2{font-size:26px}dialog p{color:#d5d9e6}dialog label{display:block;margin:20px 0}dialog select{display:block;width:100%;margin-top:8px}.dialog-actions{display:flex;justify-content:flex-end;gap:12px;margin-top:24px}#promotion-options{display:flex;gap:10px}#promotion-options button{font-size:36px;flex:1}
@media(max-width:1200px){.sidebar{width:175px;padding:20px 12px}.shell{margin-left:175px;padding:0 20px}.brand{font-size:18px}.brand-icon{font-size:31px}.workspace{gap:20px;grid-template-columns:minmax(300px,1fr) minmax(330px,390px)}.position-summary{padding:12px}.material-scores{gap:12px}.position-summary strong{font-size:16px}.position-summary small{font-size:12px}.chat-log{padding:16px}.chat-heading{padding:16px}.chat-bubble{padding:13px;font-size:16px}.chat-panel form{flex-wrap:wrap}.chat-panel textarea{flex-basis:100%}.chat-panel form button{margin-left:auto}}
@media(max-width:1000px){.sidebar{position:static;width:100%;height:auto;padding:13px 18px;border-right:0;border-bottom:1px solid var(--line);display:flex;flex-direction:row;flex-wrap:wrap;gap:12px;align-items:center;overflow:visible}.brand{margin-right:auto}.brand-sub{font-size:11px;letter-spacing:1px}.brand-icon{font-size:28px}.new-game{margin:0;padding:8px 14px}.nav-label,.sidebar-bottom{display:none}nav{flex-direction:row;flex-wrap:wrap;width:100%;gap:5px}nav button{width:auto;font-size:15px;padding:8px 11px}nav button span{font-size:18px;width:auto}.tools-menu summary{font-size:14px;padding:9px 13px}nav .tools-menu{margin:0 0 0 auto;position:relative}.tools-menu[open]{background:#202938;border:1px solid #5d6580;border-radius:8px}.tools-menu[open] button{width:100%}.shell{margin:0;padding:0 22px}.workspace{grid-template-columns:minmax(330px,1fr) minmax(330px,1fr);gap:20px}.turn-banner{padding:14px}.game-strip strong{font-size:22px}.chat-panel{min-height:650px}.position-summary{flex-wrap:wrap}.position-summary>div:first-child{flex:1}.material-scores{gap:20px}.board-toolbar>label{font-size:13px;gap:6px}.board-toolbar select{max-width:130px}.icon-button{font-size:13px}.player small{font-size:12px}}
@media(max-width:760px){.shell{padding:0 16px}.topbar{padding-top:20px}h1{font-size:27px}.notice{margin-bottom:18px}.workspace{display:flex;flex-direction:column;gap:20px;max-width:620px}.board-column,.right-column{width:100%}.right-column{position:static}.chat-panel{min-height:0}.chat-panel form{flex-wrap:nowrap}.chat-panel textarea{flex-basis:auto;font-size:17px}.chat-panel form button{margin:0}.chat-log{height:330px;max-height:60vh}.chat-bubble{font-size:17px}.board-toolbar>label{font-size:14px}.board-toolbar select{font-size:14px;max-width:none}.position-summary strong{font-size:18px}.position-summary small{font-size:13px}.turn-banner{padding:16px}.game-strip strong{font-size:24px}.settings-grid{grid-template-columns:1fr}.metric-cards{grid-template-columns:1fr 1fr}.section-heading{flex-wrap:wrap}.settings dl{grid-template-columns:1fr 1fr}.game-controls>button{flex:1}.game-controls details{flex-basis:100%}.game-controls summary{padding:9px 12px}.legend-ring{border-width:2px}.move-legend{gap:8px 12px;font-size:12px}.square .coord{font-size:11px}.legal-capture{border-width:4px}.lesson-list{grid-template-columns:1fr}.replay{flex-wrap:wrap}.replay input{min-width:80px}.fen-row>div{flex-wrap:wrap}.fen-row input{flex-basis:100%;font-size:13px}.color-tag{display:none}.player-right{max-width:45%}.captured{font-size:19px}.panel{padding:17px}.chat-panel{padding:0}footer{flex-direction:column;gap:4px;font-size:12px}.tools-menu[open]{position:absolute;right:16px;top:105px;z-index:20;width:210px}.tools-menu[open] button{font-size:16px}.chess-training-details>summary{font-size:18px}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* Keep the entire position visible in ordinary desktop windows. */
@media(min-width:761px){.topbar{padding-top:16px;padding-bottom:7px}.breadcrumb{font-size:13px;margin-bottom:3px}h1{font-size:27px}.notice{margin:3px 0 15px}.turn-banner{padding:12px 16px}.turn-banner #move-help{font-size:15px;margin:6px 0}.last-move-status{font-size:13px}.board-wrap{width:min(100%,calc(100dvh - 325px));margin-left:auto;margin-right:auto}.player{max-width:min(100%,calc(100dvh - 325px));margin-left:auto;margin-right:auto}.right-column .position-summary{margin-bottom:14px}.chat-panel{min-height:0}.chat-log{height:300px;min-height:150px}.assistant-focus .position-summary{display:none}.assistant-focus .chat-log{height:40vh}}
.status-flags{padding:13px 16px;margin:12px 0;border:1px solid #6d8f95;border-radius:9px;background:#243e43;font-size:16px;color:#ebffff}.status-flags.danger{border-color:#f193a5;background:#562c3e;color:#fff1f5}.mate-button{background:#285446;border-color:#8ce3c0;margin:0 0 12px;color:#f0fff8}.assistant-focus .position-summary{display:none}
/* Original, familiar chess symbols; scale changes the entire board. */
.piece{font-family:'Segoe UI Symbol','Cambria Math',serif;font-size:clamp(26px,4.8vw,65px);width:auto;height:auto;line-height:1;filter:drop-shadow(0 2px 1px #0005);transform:translateY(-2%)}.piece.white{color:#fff5e5;-webkit-text-stroke:1px #453b48}.piece.black{color:#24212a;-webkit-text-stroke:.5px #bbb0c4}.board-scale-control{display:flex;gap:9px;align-items:center;flex-wrap:wrap;margin:8px auto 14px;max-width:100%;font-size:14px}.board-scale-control label{color:#e6e5ee;font-size:14px}.board-scale-control input{flex:1;min-width:65px;width:0}.board-scale-control button{padding:3px 9px;min-height:32px;font-size:15px}.board-scale-control output{width:43px;font-size:14px;color:#dfcaff}.board-scale-control #board-scale-reset{font-size:13px}
.board-wrap{container-type:inline-size}.board .piece{font-size:clamp(22px,9.5cqw,76px)}
.workspace[data-board-scale="70"]{--board-factor:.7}.workspace[data-board-scale="80"]{--board-factor:.8}.workspace[data-board-scale="90"]{--board-factor:.9}.workspace[data-board-scale="100"]{--board-factor:1}.workspace[data-board-scale="110"]{--board-factor:1.1}.workspace[data-board-scale="120"]{--board-factor:1.2}.workspace[data-board-scale="130"]{--board-factor:1.3}.workspace[data-board-scale="140"]{--board-factor:1.4}.workspace[data-board-scale="150"]{--board-factor:1.5}
@media(min-width:761px){.board-wrap{width:min(100%,calc((100dvh - 350px)*var(--board-factor,1)))}.player{max-width:min(100%,calc((100dvh - 350px)*var(--board-factor,1)))}}
@media(max-width:760px){.board-wrap{width:min(100%,calc(100% * var(--board-factor,1)));margin-left:auto;margin-right:auto}.board-scale-control{gap:7px}.board-scale-control label{font-size:14px}.board .piece{font-size:clamp(22px,9.5cqw,70px)}}