[hidden]{display:none!important}header{height:82px}.brand-sub{max-width:65px;letter-spacing:1.6px}.intro{margin-bottom:30px}.intro h1{font-size:clamp(27px,3vw,42px)}.workspace{grid-template-columns:190px minmax(320px,560px) minmax(245px,300px);gap:25px}.session-stats{display:flex;gap:35px;padding:6px 0 6px 28px;border-left:1px solid var(--line)}.session-stats>div{display:flex;flex-direction:column;gap:5px}.session-stats b{font-size:29px;font-family:Manrope,Arial;font-weight:700}.session-stats span{font-size:10px;color:var(--muted)}.session-stats i{font-style:normal;color:#a3b774;font-size:24px}.category{padding:12px;margin:4px 0}.category strong{font-size:12px}.category small{font-size:10px}.category>span{font-size:25px}.category.active{background:#294b38;color:#f8fbed;box-shadow:0 4px 10px #204f3412}.category.active small{color:#bdcbb3}.category.active>span{color:#d0e6a5}.settings{padding-top:22px;margin-top:20px;border-top:1px solid var(--line)}.settings 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small{font-size:9px;line-height:1.7;color:var(--muted);display:block}.player-bar{display:flex;align-items:center;gap:10px;height:45px;margin:0 0 11px}.avatar{height:36px;width:36px;display:grid;place-items:center;border-radius:7px;font-size:28px}.rival{background:#e7ebdf;color:#45543f}.you{background:#2c4d3b;color:#f6f8ea}.player-bar>div:nth-child(2){display:flex;flex-direction:column;gap:4px;flex:1}.player-bar strong{font-size:12px;font-weight:600}.player-bar small{font-size:10px;color:var(--muted)}.rating-badge{font-size:11px;padding:7px 9px;background:#e9eddf;border-radius:5px;color:#587341;font-weight:600}.board-shell{position:relative;border-width:6px;overflow:visible;border-radius:6px;transition:box-shadow .25s,border-color .25s}.board-shell.correct{border-color:#76a641;box-shadow:0 0 0 4px #a3cc6d33,0 10px 25px #243a2620}.board-shell.wrong{border-color:#c25b47;animation:shake .35s}.board-shell.complete{border-color:#79a74a;box-shadow:0 0 0 5px #a9c57c40,0 12px 30px #223a2620}#board{overflow:hidden;border-radius:1px;touch-action:none;user-select:none}#board .piece-image{width:89%;height:89%;object-fit:contain;pointer-events:none;filter:drop-shadow(0 2px 1px #14271e35);position:relative;z-index:2}.square{cursor:pointer;transition:background-color .12s}.square.dark{background:#7e9975}.square{background:#eef0d8}.square.last{background:#dbda83}.square.dark.last{background:#b2b568}.square.selected{background:#edcf6c!important}.square.target:after{z-index:3;background:#24402f45;width:23%;height:23%;pointer-events:none}.square.capture:after{background:none;width:90%;height:90%;border:5px solid #27433055;box-sizing:border-box}.square.correct{background:#afd26b!important}.square.wrong{background:#dd8773!important}.square.hinted{box-shadow:inset 0 0 0 4px #e7b145}.move-badge{position:absolute;z-index:6;right:-3px;top:-5px;width:24px;height:24px;background:#76a73c;color:white;border:2px solid #f6f8ee;border-radius:50%;display:grid;place-items:center;font-weight:800;font-size:16px;line-height:1;box-shadow:0 2px 5px #0002;animation:pop .2s ease-out;pointer-events:none}.move-badge.bad{background:#c85b48}.bottom-player{margin:13px 0 0}.timer{font-family:Manrope;font-size:15px;letter-spacing:1px;color:#68755f}.board-toolbar{border-top:1px solid var(--line);margin-top:10px;padding-top:8px;gap:7px}.board-toolbar #puzzleId{margin-left:auto;font-size:10px}.board-toolbar button{font-size:11px!important}.keyboard-note{color:#929a89;font-size:9px;line-height:1.7;margin:4px 7px}.lesson{margin-top:0;padding:23px;border-radius:10px;box-shadow:0 6px 22px #293d2405}.lesson h2{font-size:24px;margin:18px 0 8px}.lesson-description{font-size:11px;margin:0 0 20px;line-height:1.7}.lesson-top>#moveCount{font-size:10px;color:var(--muted)}#feedback.feedback{display:flex;gap:11px;align-items:center;padding:15px 12px;border:1px solid #e0e6d6;border-radius:8px;background:#f1f4eb;min-height:85px;margin-bottom:22px;transition:background .2s,border .2s;color:#53644b}#feedbackIcon{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;font-size:22px;flex-shrink:0;color:#728a5b}#feedbackTitle{display:block;font-size:12px;line-height:1.5}#feedbackText{font-size:10px;line-height:1.7;margin:4px 0 0;color:inherit;opacity:.85}#feedback.feedback.correct,#feedback.feedback.complete{background:#e8f2d9;border-color:#b6d493;color:#3c651e}.feedback.correct #feedbackIcon,.feedback.complete #feedbackIcon{background:#7daa43;color:white}.feedback.complete #feedbackIcon{animation:pop .3s}#feedback.feedback.wrong{background:#fbece5;border-color:#e8b5a5;color:#974a36}.feedback.wrong #feedbackIcon{background:#bf614d;color:white}#feedback.feedback.replay{background:#eef0fa;border-color:#cbd4e4;color:#556888}.sequence-label{display:flex;justify-content:space-between;align-items:center;font-size:10px;color:var(--muted)}.steps{display:flex;gap:5px;margin:10px 0 16px}.step{height:5px;border-radius:4px;background:#e5e9df;flex:1}.step.finished{background:#83a94f}.step.current{background:#bccb9f}.move-list{display:flex;gap:5px;flex-wrap:wrap;min-height:40px;margin-bottom:16px}.move-chip{padding:6px 8px;background:#f2f3ed;border-radius:4px;border:0;color:#64705a;font-family:Arial;font-size:12px}.move-chip.player{background:#eaf0df;color:#43602f}.move-chip.current{box-shadow:inset 0 0 0 1px #809c5c}.move-placeholder{font-size:11px;color:#9ba38f;line-height:2}#replayControls{display:flex;justify-content:space-between;align-items:center;background:#f3f4ee;border-radius:5px;margin-bottom:15px}#replayControls button{border:0;background:none;padding:9px 20px;color:var(--ink)}#replayIndex{font-size:11px;color:var(--muted)}.primary{font-size:12px;padding:15px;box-shadow:0 3px 0 #173b29}.primary:hover{background:#365d45}.secondary-actions{display:flex;gap:8px;margin-top:13px}.secondary{font-size:10px;padding:11px 4px}button:disabled{opacity:.45;cursor:default}.lesson-footer{font-size:9px;margin-top:18px}.lesson .tip{margin-top:15px}#themeTags{display:flex;flex-wrap:wrap;gap:4px;margin-top:8px}#themeTags>span{font-size:9px;padding:4px 6px;background:#e2e9d6;border-radius:3px;color:#61734c}#sourceLink{display:block;text-align:center;font-size:10px;text-decoration:underline;text-underline-offset:3px;color:#6e7e5f;margin-top:14px}#arrows{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;z-index:7}#hintArrow{display:none}.loading-overlay{position:absolute;inset:0;display:grid;place-items:center;background:#eff2e7cc;z-index:10;border-radius:1px}.spinner{width:34px;height:34px;border:3px solid #afc095;border-top-color:#345436;border-radius:50%;animation:spin 1s linear infinite}#promotion{padding:15px;border:2px solid #9dbb6c;border-radius:8px;background:#f5f8ed;margin-bottom:12px}#promotion>strong{font-size:12px}#promotionOptions{display:flex;gap:6px;margin:12px 0}#promotionOptions button{border:1px solid #cad8b9;border-radius:5px;background:#e7eddd;padding:4px;flex:1;min-width:0}#promotionOptions img{width:100%;display:block}#cancelPromotion{background:none;border:0;font-size:11px;text-decoration:underline}.drag-ghost{position:fixed;z-index:100;pointer-events:none;filter:drop-shadow(0 9px 5px #0003)}.dragging-origin .piece-image{opacity:.25}.bottom-note{margin-top:30px}.support{white-space:nowrap}.square:focus-visible,button:focus-visible,select:focus-visible,input:focus-visible{outline:3px solid #c6a44c;outline-offset:-3px}@keyframes spin{to{transform:rotate(360deg)}}@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}@keyframes pop{from{transform:scale(.5);opacity:.5}to{transform:scale(1);opacity:1}}@media(max-width:1150px){main{padding:30px 3% 0}.workspace{grid-template-columns:160px minmax(300px,1fr) 260px;gap:18px}.lesson{padding:18px}.category{padding:12px 8px;gap:8px}.session-stats{gap:22px}.intro p{font-size:12px}}@media(max-width:950px){.workspace{grid-template-columns:minmax(320px,1fr) 280px}.sidebar{grid-column:1/-1;display:block}.sidebar>.section-label,.library-note{display:none}.themes{display:flex;gap:5px}.category{flex:1;width:auto;display:flex;padding:9px;justify-content:center}.category small{display:none}.category strong{font-size:10px}.category>span{font-size:21px;width:auto}.settings{display:flex;align-items:center;gap:14px;margin:10px 0 0;padding:0;border:0}.settings select{width:auto;margin:0;max-width:220px}.toggle-row{margin:0;font-size:10px}.settings>.section-label{display:none}.session-stats{gap:20px}.intro h1{font-size:33px}.intro{gap:12px}.keyboard-note{font-size:9px}}@media(max-width:670px){main{padding:22px 4% 0}.intro{align-items:flex-start;gap:8px}.intro h1{font-size:28px;line-height:1.2;letter-spacing:-1px}.intro p{font-size:11px;max-width:290px}.eyebrow{font-size:8px;letter-spacing:1.2px}.session-stats{border:0;padding:6px 0;gap:13px}.session-stats b{font-size:22px}.session-stats span{font-size:8px;max-width:60px}.session-stats i{font-size:16px}.workspace{display:flex;gap:18px}.sidebar{width:100%}.themes{overflow:auto;gap:4px;padding-bottom:4px}.category{min-width:66px;display:flex;flex-direction:column;gap:3px;padding:9px 5px}.category>span{height:23px}.category strong{font-size:9px;white-space:nowrap}.settings{flex-wrap:wrap;gap:10px 14px;margin-top:9px}.settings select{font-size:10px;padding:8px;max-width:145px}.toggle-row{font-size:10px;flex:1;min-width:90px}.toggle-row input{width:27px;height:16px}.toggle-row input:before{width:10px;height:10px}.toggle-row input:checked:before{transform:translateX(11px)}.board-area{width:100%}.player-bar{height:38px;margin-bottom:8px}.avatar{height:32px;width:32px;font-size:24px}.board-shell{border-width:4px}.move-badge{width:22px;height:22px;font-size:14px;right:-2px;top:-3px}.lesson{width:100%;padding:20px;margin-top:0}.lesson h2{font-size:25px}.lesson-description{font-size:12px}.feedback{min-height:75px!important}#feedbackTitle{font-size:14px}#feedbackText{font-size:12px}.lesson-footer{font-size:10px}.keyboard-note{display:none}.board-toolbar{margin-top:7px}.bottom-player{margin-top:10px}.support{font-size:0}.support:before{content:'♡';font-size:25px}.header-actions{gap:12px}.intro-note{display:none}.primary{padding:16px}.secondary{font-size:12px}.text-button{font-size:11px}.lesson .tip p{font-size:12px}.steps{margin-bottom:12px}.move-list{margin-bottom:12px;min-height:25px}.bottom-note{margin-top:25px}.brand-sub{display:none}}@media(max-width:380px){.session-stats{display:none}.settings .toggle-row{font-size:9px}.category{min-width:61px}}

/* Roomier desktop studio and touch-first responsive layout. */
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}body{font-size:16px}header{padding-inline:clamp(20px,3vw,64px);height:88px}.brand{font-size:30px}.brand-sub{font-size:10px}.header-actions select{min-height:44px;font-size:14px}.support{font-size:14px}main{width:calc(100% - 64px);max-width:1600px;padding:32px 0 0}.intro{margin-bottom:28px;gap:24px}.intro h1{font-size:clamp(32px,2.7vw,46px)}.intro p{font-size:15px}.eyebrow{font-size:11px}.session-stats b{font-size:34px}.session-stats span{font-size:12px;max-width:none}.workspace{display:grid;grid-template-columns:240px minmax(0,1fr) 360px;gap:28px;align-items:start}.workspace>*{min-width:0}.sidebar{display:block}.sidebar>.section-label{display:block;font-size:12px;margin:12px 0 20px}.themes{display:block}.category{display:flex;width:100%;min-height:66px;padding:13px 14px;gap:12px;text-align:left;justify-content:flex-start;flex-direction:row}.category strong{font-size:15px;line-height:1.4;white-space:normal}.category small{display:block;font-size:12px;line-height:1.5}.category>span{font-size:28px;width:28px;flex-shrink:0}.section-label{font-size:11px;line-height:1.6}.settings{display:block;border-top:1px solid var(--line);padding-top:20px;margin-top:20px}.settings>.section-label{display:block}.settings select{display:block;max-width:none;width:100%;font-size:14px;min-height:46px;margin:12px 0}.toggle-row{font-size:13px;min-height:44px;margin:4px 0;gap:10px}.toggle-row input{width:38px;height:23px}.toggle-row input:before{width:17px;height:17px}.toggle-row input:checked:before{transform:translateX(15px)}.library-note{display:block;padding:19px}.library-note p{font-size:13px}.library-note small{font-size:11px}.library-note b{font-size:26px}.player-bar{height:48px;margin-bottom:12px}.avatar{width:42px;height:42px;font-size:30px}.player-bar strong{font-size:15px}.player-bar small{font-size:12px}.rating-badge{font-size:14px;padding:9px 11px}.board-area{width:100%}.board-shell{width:100%}.coord{font-size:12px}.move-badge{width:30px;height:30px;font-size:20px}.bottom-player{margin:14px 0 0}.timer{font-size:18px}.board-toolbar{margin-top:12px;gap:10px}.board-toolbar button,.board-toolbar #flip{font-size:13px!important;min-height:44px;padding:10px}.board-toolbar #puzzleId{font-size:12px}.keyboard-note{font-size:11px}.lesson{padding:25px;margin-top:0}.pill{font-size:11px;padding:8px 10px}.lesson-top>#moveCount{font-size:12px}.lesson h2{font-size:29px}.lesson-description{font-size:14px;line-height:1.7}#feedback.feedback{min-height:100px;padding:17px 14px;gap:12px}#feedbackIcon{width:36px;height:36px;font-size:25px}#feedbackTitle{font-size:16px}#feedbackText{font-size:13px;line-height:1.65}.sequence-label{font-size:12px}.steps{margin-top:12px;margin-bottom:18px}.step{height:6px}.move-chip{font-size:15px;min-height:40px;padding:10px}.move-placeholder{font-size:13px}.primary{font-size:15px;min-height:52px;padding:15px 12px}.secondary{font-size:13px;min-height:46px;padding:12px 5px}.text-button{font-size:12px;min-height:44px;padding:10px}.tip>div{font-size:13px}.tip p,.lesson .tip p{font-size:13px;line-height:1.75}#themeTags>span{font-size:11px}#sourceLink{font-size:12px;padding:12px 0;min-height:44px}.lesson-footer{font-size:12px}.bottom-note{font-size:13px;line-height:1.7;margin-top:32px}.bottom-note a{min-height:44px;display:flex;align-items:center}footer{font-size:12px;padding:24px 3%;gap:16px;flex-wrap:wrap}#replayControls button{min-height:44px;min-width:54px;font-size:18px}#replayIndex{font-size:13px}#promotion>strong{font-size:14px}#promotionOptions button{min-height:48px}#cancelPromotion{min-height:44px;font-size:14px}
@media(min-width:1600px){main{width:calc(100% - 96px)}}
@media(max-width:1279px){main{width:calc(100% - 40px);padding-top:26px}.workspace{grid-template-columns:minmax(0,1fr) 330px;gap:22px}.sidebar{grid-column:1/-1}.sidebar>.section-label,.library-note{display:none}.themes{display:flex;gap:7px;overflow-x:auto;padding:0 0 6px;scrollbar-width:thin}.category{width:auto;flex:1;min-width:110px;min-height:57px;justify-content:center;padding:10px 8px;gap:7px}.category strong{font-size:12px}.category small{display:none}.category>span{width:auto;font-size:24px}.settings{display:flex;flex-wrap:wrap;align-items:center;gap:8px 24px;padding:10px 0 0;margin:0;border:0}.settings>.section-label{display:none}.settings select{width:240px;margin:0;font-size:14px}.toggle-row{margin:0;font-size:13px;gap:14px}.intro h1{font-size:36px}.intro p{font-size:14px}.lesson{padding:22px}.lesson h2{font-size:27px}.lesson-description{font-size:13px}.session-stats{gap:24px;padding-left:22px}.player-bar strong{font-size:14px}.coord{font-size:11px}}
@media(max-width:800px){header{height:76px;padding-inline:16px;gap:12px}.brand{font-size:26px}.brand-sub{display:none}.header-actions{gap:14px}.header-actions select{font-size:14px;width:130px;max-width:140px}.support{font-size:0;min-width:44px;min-height:44px;display:grid;place-items:center}.support:before{content:'♡';font-size:29px}.support span{display:none}main{width:calc(100% - 24px);padding:20px 0 0;max-width:680px}.intro{align-items:flex-start;margin:0 4px 20px;gap:16px}.intro h1{font-size:31px;line-height:1.2;margin:12px 0}.intro p{font-size:13px;max-width:430px}.eyebrow{font-size:9px;letter-spacing:1.1px;line-height:1.6}.session-stats{border:0;padding:3px 0;gap:15px}.session-stats b{font-size:26px}.session-stats span{font-size:10px;max-width:75px}.workspace{display:flex;flex-direction:column;gap:18px}.sidebar{width:100%}.themes{gap:6px;padding-bottom:8px}.category{flex:0 0 auto;min-width:104px;min-height:64px;display:flex;flex-direction:column;gap:5px;padding:9px 10px;text-align:center}.category strong{font-size:12px;white-space:nowrap;margin:0}.category>span{height:24px;font-size:25px}.settings{display:grid;grid-template-columns:1fr 1fr;gap:2px 18px;padding:4px 4px 0}.settings select{grid-column:1/-1;width:100%;min-height:46px;font-size:16px}.toggle-row{font-size:13px;min-height:44px;justify-content:space-between;gap:10px}.board-area{width:100%}.player-bar{height:44px;margin-bottom:10px}.player-bar strong{font-size:14px}.player-bar small{font-size:11px}.avatar{width:38px;height:38px}.rating-badge{font-size:13px}.board-shell{border-width:4px}.coord{font-size:11px}.move-badge{width:25px;height:25px;font-size:17px;top:-2px;right:-2px}.bottom-player{margin:12px 0 0}.board-toolbar{margin-top:9px;gap:2px;flex-wrap:wrap}.board-toolbar button,.board-toolbar #flip{font-size:13px!important;padding:8px;min-height:44px}.board-toolbar #puzzleId{font-size:11px}.keyboard-note{display:none}.lesson{width:100%;padding:20px;margin:0;border-radius:10px}.lesson>.lesson-top,.lesson>h2,.lesson>.lesson-description{display:none}#feedback.feedback{min-height:90px;margin-bottom:20px;padding:16px}#feedbackTitle{font-size:17px}#feedbackText{font-size:14px}.primary{font-size:16px;min-height:54px}.secondary{font-size:14px;min-height:48px}.text-button{font-size:13px;min-height:44px}.lesson-footer{font-size:12px}.move-chip{min-height:44px;font-size:15px}.tip p,.lesson .tip p{font-size:14px}.bottom-note{font-size:12px;margin-top:26px;gap:10px;flex-wrap:wrap;padding-inline:5px}.bottom-note p{min-width:80%}.bottom-note a{margin-left:32px;font-size:13px}footer{font-size:11px;padding:20px 16px}.session-stats i{font-size:18px}}
@media(max-width:480px){main{width:calc(100% - 16px)}.intro{display:block;margin-inline:6px}.intro h1{font-size:29px;letter-spacing:-.8px}.intro p{font-size:13px;max-width:none}.session-stats{display:flex;flex-direction:row;gap:24px;margin-top:15px;padding:0}.session-stats>div{flex-direction:row;align-items:baseline;gap:7px}.session-stats b{font-size:22px}.session-stats span{font-size:11px;max-width:none}.eyebrow{font-size:8px;letter-spacing:1px}.category{min-width:97px}.category strong{font-size:11px}.settings{gap:2px 12px}.toggle-row{font-size:12px}.lesson{padding:17px}.header-actions{gap:5px}.header-actions select{width:115px;font-size:13px}.brand{font-size:24px}.brand-icon{font-size:32px}.coord{font-size:10px}.board-toolbar #puzzleId{flex-basis:100%;text-align:right;margin-top:-3px;padding-right:8px}.player-bar small{font-size:10px}.rating-badge{font-size:12px}.move-badge{width:22px;height:22px;font-size:15px}.bottom-note p{min-width:75%}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;scroll-behavior:auto!important}}
@media(max-width:380px){header{padding-inline:12px;gap:6px}.brand{font-size:22px}.brand-icon{font-size:28px}.header-actions select{width:100px;font-size:12px}.header-actions{gap:3px}.session-stats{gap:18px}}
.about-training{border-top:1px solid var(--line);padding:26px 0 32px;color:#68755f;max-width:100%}.about-training h2{font-size:22px;color:var(--ink);line-height:1.5}.about-training p{max-width:1000px;font-size:14px;line-height:1.9}.about-training nav{display:flex;gap:20px;flex-wrap:wrap;margin-top:15px}.about-training nav a{font-size:13px;text-decoration:underline;text-underline-offset:4px;min-height:44px;display:flex;align-items:center}@media(max-width:800px){.about-training{padding:20px 8px}.about-training h2{font-size:21px}.about-training p{font-size:13px}}