#caissa-subtitle{text-align:center;pointer-events:none;z-index:10;padding:0 8px;font-family:IRANSansX,Vazirmatn,sans-serif;transition:bottom .25s;position:absolute;bottom:calc(4.5em + 10px);left:0;right:0;container-type:inline-size}.video-js.vjs-has-started.vjs-user-inactive.vjs-playing #caissa-subtitle{bottom:max(8px,3%)}#caissa-subtitle .sub-text{-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);color:#f3f4f6;direction:rtl;background-color:#0000009e;border-radius:6px;max-width:88%;padding:2px 10px;font-size:clamp(12px,2.2cqw,26px);font-weight:500;line-height:1.65;display:inline-block}@container (width<=480px){#caissa-subtitle .sub-text{border-radius:6px;max-width:96%;padding:2px 8px;line-height:1.6}}@media (width<=639px){#video-box.has-subs{overflow:visible;margin-bottom:72px!important}#video-box.has-subs .video-js:not(.vjs-fullscreen) #caissa-subtitle{background:#020617;justify-content:center;align-items:flex-start;height:72px;padding:7px 10px 0;transition:none;display:flex;top:100%;bottom:auto}#video-box.has-subs .video-js:not(.vjs-fullscreen) #caissa-subtitle .sub-text{-webkit-backdrop-filter:none;backdrop-filter:none;color:#e5e7eb;background:0 0;max-width:100%;padding:0;font-size:13px;font-weight:400;line-height:1.6}}[data-modern] #caissa-subtitle{font-family:Vazirmatn,IRANSansX,sans-serif}[data-modern] #caissa-subtitle .sub-text{color:#e2e4e9;background-color:#0000007a;font-weight:500}[data-modern] #caissa-subtitle :is(.eng,b){color:#f2d58a;font-weight:500}@media (width<=639px){[data-modern] #video-box.has-subs .video-js:not(.vjs-fullscreen) #caissa-subtitle .sub-text{color:#d6d9de;font-weight:500}}#caissa-subtitle .eng,#caissa-subtitle b{color:#fbbf24;direction:ltr;padding:0 2px;font-weight:700;display:inline-block}.video-js .vjs-control-bar{z-index:11}.pgn-load-btn{color:#b45309;background-color:#d9770612;border-color:#d9770659}.pgn-load-btn:hover{background-color:#d9770629}.pgn-load-btn.is-active{color:#fff;background-color:#d97706;border-color:#d97706}.dark .pgn-load-btn{color:#fbbf24}.dark .pgn-load-btn.is-active{color:#fff}.video-js .vjs-big-play-button{color:#f59e0b!important;background-color:#0f172ad9!important;border:2px solid #ffffff1a!important;border-radius:50%!important;width:80px!important;height:80px!important;margin:0!important;line-height:80px!important;transition:all .2s ease-in-out!important;top:50%!important;left:50%!important;transform:translate(-50%,-50%)!important;box-shadow:0 10px 25px -5px #00000080!important}.video-js .vjs-big-play-button:hover{color:#0f172a!important;background-color:#f59e0b!important;transform:translate(-50%,-50%)scale(1.1)!important}.video-js video{object-fit:contain!important}.video-js .vjs-control-bar{padding-inline:10px;background:linear-gradient(#0000,#0f172a99,#0f172af2)!important;height:4.5em!important}.video-js .vjs-caissa-quality .vjs-button{justify-content:center;align-items:flex-start;display:flex}.video-js .vjs-caissa-quality .vjs-icon-placeholder{white-space:nowrap;font-size:1.3em;font-weight:700;line-height:2.30769em}.video-js .vjs-caissa-quality{min-width:4em;width:auto!important}.video-js .vjs-volume-panel{margin-inline-start:10px!important}#lesson-toolbar{background:#fff;border:1px solid #94a3b859;border-radius:12px;align-items:center;gap:2px;width:max-content;margin-inline-start:auto;padding:3px;display:flex;box-shadow:0 1px 3px #0000000f}html.dark #lesson-toolbar{background:#111827;border-color:#94a3b838}#lesson-toolbar .lt-seg{color:#64748b;cursor:pointer;background:0 0;border:0;border-radius:9px;justify-content:center;align-items:center;width:34px;height:34px;font-size:17px;line-height:1;text-decoration:none;transition:background-color .15s,color .15s;display:inline-flex;position:relative}#lesson-toolbar .lt-seg:hover{color:#334155;background:#64748b1f}html.dark #lesson-toolbar .lt-seg{color:#94a3b8}html.dark #lesson-toolbar .lt-seg:hover{color:#e2e8f0;background:#94a3b824}#lesson-toolbar .lt-seg.is-off{color:#b45309}html.dark #lesson-toolbar .lt-seg.is-off{color:#fbbf24}#lesson-toolbar .lt-seg.is-off:after{content:"";pointer-events:none;background:currentColor;border-radius:1px;width:20px;height:1.5px;position:absolute;transform:rotate(-45deg)}#lesson-toolbar .lt-report:hover{color:#b91c1c;background:#ef44441a}html.dark #lesson-toolbar .lt-report:hover{color:#fca5a5}@media (width<=1023px){#lesson-toolbar{display:none}}@media (width>=1024px){#lesson-grid:not(.board-focus):not(.video-focus) #lesson-toolbar{margin-inline:0 auto}#lesson-grid:not(.board-focus):not(.video-focus) #video-box{margin-block-end:8px!important}}#lesson-grid:not(.video-focus) #video-box{max-height:68vh;margin-inline:auto}#lesson-grid.board-focus .lt-report-m,#lesson-grid.video-focus .lt-report-m{order:3}#lesson-grid.board-focus #lesson-nav,#lesson-grid.video-focus #lesson-nav{order:4}#lesson-grid.video-focus #lesson-nav{width:100%;max-width:min(100%, calc((100vh - var(--caissa-stick-h,4rem) - 3rem) * 16 / 9));margin-inline:auto}.lesson-nav-btn{white-space:nowrap;border-radius:.875rem;justify-content:center;align-items:center;gap:.375rem;height:2.75rem;padding-inline:1.25rem;font-size:13px;font-weight:700;transition:background-color .15s;display:flex}.lesson-nav-btn .ui-icon{flex-shrink:0;width:1rem;height:1rem}@media (width>=1024px){.lesson-nav-btn{min-width:9.5rem}}#lesson-menu-btn{inset-inline-start:0;top:calc(var(--caissa-stick-h,4rem) - .5rem);z-index:45;color:#b45309;cursor:pointer;background:#fff;border:1px solid #00000014;border-top:0;border-start-start-radius:0;border-start-end-radius:0;border-end-end-radius:1rem;border-end-start-radius:0;justify-content:center;align-items:center;width:5.5rem;height:2.25rem;padding-top:.5rem;transition:background .15s,height .15s,box-shadow .15s;display:flex;position:fixed;box-shadow:0 8px 20px -10px #00000059}#lesson-menu-btn svg{width:1.35rem;height:1.35rem}#lesson-menu-btn:hover{background:#fffbeb;height:2.55rem;box-shadow:0 12px 24px -10px #00000073}#lesson-menu-btn:focus-visible{outline-offset:-3px;outline:2px solid #d97706}html.dark #lesson-menu-btn{color:#fbbf24;background:#1f2937;border-color:#ffffff14}html.dark #lesson-menu-btn:hover{background:#374151}.lesson-drawer{z-index:60;display:flex;position:fixed;inset:0}.lesson-drawer[hidden]{display:none}.lesson-drawer-veil{-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);background:#00000073;position:absolute;inset:0}.lesson-drawer-panel{border-inline-start:1px solid #00000014;width:min(22rem,88vw);height:100%;margin-inline-end:auto;animation:.18s ease-out lesson-drawer-in;position:relative;overflow-y:auto;box-shadow:-18px 0 45px -12px #00000059}html.dark .lesson-drawer-panel{border-inline-start-color:#ffffff14;box-shadow:-18px 0 45px -12px #000000bf}@keyframes lesson-drawer-in{0%{opacity:0;transform:translate(1.5rem)}to{opacity:1;transform:translate(0)}}@media (prefers-reduced-motion:reduce){.lesson-drawer-panel{animation:none}#lesson-menu-btn{transition:none}}.lesson-drawer-panel .lesson-title{text-overflow:clip;white-space:normal;overflow:visible}.lesson-drawer-panel h2{-webkit-line-clamp:unset;height:auto}.cg-wrap{aspect-ratio:1;width:100%;max-width:520px;height:auto;margin-inline:auto;position:relative}.cg-wrap cg-board{width:100%;height:100%;position:absolute;top:0;left:0}#lesson-grid{--board-max:clamp(280px, min(max(calc(36vw - 172px), calc(100vw - 120.9vh - 390px)), calc(68vh - 42px)), 560px);column-gap:1rem}@media (width<=639px){#lesson-grid:not(.board-focus){--board-max:min(560px, calc(100vw - 76px))}}@media (width>=640px) and (width<=1023px){#lesson-grid:not(.board-focus){--board-max:clamp(280px, min(calc(100vw - 88px), calc(100vh - 8rem)), 560px)}}@media (width>=1024px) and (width<=1249px){#lesson-grid:not(.board-focus){--board-max:clamp(280px, min(calc(100vw - 392px), calc(100vh - 8rem)), 560px)}}@media (width<=1023px){#lesson-grid:not(.board-focus):not(.video-focus) :is(#lesson-left,#board-stack){display:contents}#lesson-grid:not(.board-focus):not(.video-focus){grid-auto-rows:max-content}#lesson-grid:not(.board-focus):not(.video-focus)>*{order:6}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-left>*{order:5;margin-block:0}#lesson-grid:not(.board-focus):not(.video-focus) #video-box{order:1;width:min(100%,120.889vh)}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-toolbar{order:2}#lesson-grid:not(.board-focus):not(.video-focus) #chess-card{order:3}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-pgn-box{order:4}#study-column .nav-side [data-video-toggle]{display:none}#caissa-moves-box{min-height:clamp(8rem, calc(100vh - var(--caissa-stick-h,4rem) - var(--caissa-board-h,20rem) - 10rem), 280px);min-height:clamp(8rem, calc(100dvh - var(--caissa-stick-h,4rem) - var(--caissa-board-h,20rem) - 10rem), 280px)}#lesson-grid:not(.board-focus):not(.video-focus) #video-box{width:calc(100% + 2rem);max-height:none;box-shadow:none;border:0;border-radius:0;margin:-2.75rem -1rem 0}body:has(#lesson-grid:not(.board-focus):not(.video-focus) #video-box) #lesson-menu-btn{display:none}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-left>#lesson-about{box-shadow:none;border-width:0 0 1px;border-radius:0;order:2;margin:-1.5rem -1rem 0;padding:1rem}#caissa-moves-box{min-height:clamp(18rem,55dvh,30rem)}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-left>.lesson-menu-m{order:2;margin:-1.5rem -1rem 0}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-left:has(>.lesson-menu-m)>#lesson-about h1{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:0;padding:0;position:absolute;overflow:hidden}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-left:has(>.lesson-menu-m)>#lesson-about:not(:has(p)){clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:0;padding:0;position:absolute;overflow:hidden}#lesson-grid:not(.board-focus):not(.video-focus) #lesson-left:has(>.lesson-menu-m)>#lesson-about>div{margin-top:0}#lesson-grid:is(.board-focus,.video-focus) .lesson-menu-m{display:none}[data-modern] #lesson-grid.video-focus #lesson-left{flex-direction:column;display:flex}[data-modern] #lesson-grid.video-focus #lesson-left>*{order:3}[data-modern] #lesson-grid.video-focus #lesson-left>#video-box{width:calc(100% + 2rem);max-height:none;box-shadow:none;border:0;border-radius:0;order:1;margin:-2.75rem -1rem 0}body:has([data-modern] #lesson-grid.video-focus #video-box) #lesson-menu-btn{display:none}[data-modern] #lesson-grid:not(.board-focus):not(.video-focus) #lesson-left>.lm-info{order:2;margin:-1.5rem -1rem 0}[data-modern] #lesson-grid.video-focus #lesson-left>.lm-info{order:2;margin:0 -1rem 1.5rem}[data-modern] #lesson-grid.board-focus .lm-info{display:none}[data-modern] #lesson-grid:not(.board-focus) #lesson-left:has(>.lm-info)>#lesson-about{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:0;padding:0;position:absolute;overflow:hidden}[data-modern] #lesson-grid:has(.lm-info) .lt-report-m{display:none}.lm-info{flex-direction:column;gap:.3rem;padding:1.25rem 1rem 1rem;display:flex}.lm-info-title{-webkit-line-clamp:2;color:var(--color-gray-900);-webkit-box-orient:vertical;font-size:15px;font-weight:700;line-height:1.6;display:-webkit-box;overflow:hidden}.lm-info-desc{-webkit-line-clamp:2;color:var(--color-gray-600);-webkit-box-orient:vertical;margin-top:.2rem;font-size:13px;line-height:1.85;display:-webkit-box;overflow:hidden}.lm-info-desc.is-open{-webkit-line-clamp:unset;display:block}.lm-info-more{color:var(--color-gray-900);align-self:flex-start;font-size:12px;font-weight:700}html.dark .lm-info-title,html.dark .lm-info-more{color:#fff}html.dark .lm-info-desc{color:var(--color-gray-400)}.lesson-menu-m{color:#b45309;text-align:start;background:#fff;border-block:1px solid #0000000f;align-items:center;gap:.75rem;padding:.75rem 1rem;font-size:13px;line-height:1.5rem;display:flex}.lesson-menu-m>svg{flex-shrink:0;width:1.35rem;height:1.35rem}html.dark .lesson-menu-m{color:#fbbf24;background:#111827;border-color:#ffffff0f}}.lm-info-actions{scrollbar-width:none;gap:.5rem;margin-top:.7rem;display:flex;overflow-x:auto}.lm-info-actions::-webkit-scrollbar{display:none}.lm-chip{border:1px solid var(--color-gray-200);height:2rem;color:var(--color-gray-800);white-space:nowrap;background:#fff;border-radius:9999px;flex-shrink:0;align-items:center;gap:.4rem;padding:0 .9rem;font-size:12.5px;font-weight:600;display:inline-flex}.lm-chip>svg,.lm-chip>.ui-icon,.lm-chip>i{flex-shrink:0;width:1rem;height:1rem;font-size:1rem}.lm-chip-count{color:var(--color-gray-500);font-weight:500}html.dark .lm-chip-count{color:var(--color-gray-400)}html.dark .lm-chip{color:var(--color-gray-200);background:#ffffff14;border-color:#0000}.lm-about-actions,.lm-pgn-report,.lm-board-actions{display:none}@media (width>=1024px){.lm-about-actions{gap:.5rem;margin-top:1rem;display:flex}}@media (width<=639px){#lesson-grid:not(.board-focus){--board-max:100vw}#lesson-grid:not(.video-focus) #chess-card{width:calc(100% + 2rem);box-shadow:none;border:0;border-radius:0;margin-inline:-1rem;padding:1rem 0 0}#lesson-grid:not(.video-focus) #caissa-board{box-shadow:none;border:0}#lesson-grid:not(.video-focus) #study-column{border-inline:0;border-bottom:0;border-radius:0}}#lesson-grid{height:auto;overflow-y:visible}@media (width>=1024px){#lesson-grid.board-focus #lesson-pgn-box{scrollbar-width:none}#lesson-grid.board-focus #lesson-pgn-box::-webkit-scrollbar{display:none}}@media (width<=639px){#lesson-grid:not(.video-focus){--board-max:min(100vw, calc(100dvh - var(--caissa-stick-h,4rem) - 20rem))}#lesson-grid:not(.video-focus) #chess-card{height:calc(100vh - var(--caissa-stick-h,4rem));height:calc(100dvh - var(--caissa-stick-h,4rem))}#lesson-grid:not(.video-focus) #board-row{flex:auto;min-height:0}#lesson-grid:not(.video-focus) #board-column{flex:none}#lesson-grid:not(.video-focus) #study-column{flex:auto;min-height:0}#lesson-grid:not(.video-focus) #caissa-moves-box{flex:auto;order:1;min-height:0}#lesson-grid:not(.video-focus) #engine-panel{border-top:1px solid var(--color-gray-200);border-bottom:0;order:2}#lesson-grid:not(.video-focus) #study-column>:first-child{border-top:1px solid var(--color-gray-200);border-bottom:0;order:3;padding-block:.25rem}#lesson-grid:not(.video-focus) #study-column>:last-child{order:4}html.dark #lesson-grid:not(.video-focus) :is(#engine-panel,#study-column>:first-child){border-top-color:var(--color-gray-800)}}@media (width>=1250px){#lesson-grid:not(.board-focus):not(.video-focus){max-width:min(2200px, calc(var(--board-max) + 384px + 120.9vh));grid-template-columns:minmax(0,1fr) auto;margin-inline:auto}}#lesson-grid{scrollbar-gutter:stable}#lesson-left{min-width:0}#lesson-toolbar .lt-seg>span{text-overflow:ellipsis;min-width:0;overflow:hidden}@media (width>=2400px){#lesson-grid{max-width:2200px;margin-inline:auto}}#lesson-grid.board-focus{--board-max:min(1100px, calc(100vh - 8rem))}@media (width<=639px){#lesson-grid.board-focus{--board-max:min(100vw, calc(100dvh - var(--caissa-stick-h,4rem) - 20rem))}}#caissa-board.cg-wrap{max-width:var(--board-max,520px)}.board-col-w{width:100%;max-width:var(--board-max,520px);margin-inline:auto}#board-column>*{flex-shrink:0}@media (width>=1024px){#board-row{align-items:flex-start}#study-column{width:17rem;height:var(--caissa-board-h,auto);align-self:stretch}#study-column .nav-ico{width:1.75rem;height:1.75rem}#study-column .nav-side{width:3.625rem}#board-row{justify-content:center}#board-column{width:var(--board-max);flex:0 auto;min-width:0}#lesson-grid:not(.board-focus) #board-stack{width:fit-content;margin-inline:auto}#lesson-grid:not(.board-focus) #lesson-pgn-box{width:0;min-width:100%}#lesson-grid.board-focus #study-column{width:28rem}}#lesson-grid.board-focus #lesson-pgn-box{box-shadow:none;border-radius:.75rem}#lesson-grid.board-focus #lesson-pgn-box>summary{padding:.625rem 1rem}@media (width>=1024px){#lesson-grid.board-focus:has(#lesson-pgn-box){--board-max:min(1000px, calc(100vh - 11rem));grid-template-columns:minmax(0,auto) 17rem;grid-auto-rows:max-content;justify-content:center;column-gap:2rem}#lesson-grid.board-focus:has(#lesson-pgn-box.is-collapsed){grid-template-columns:minmax(0,auto) 2.75rem}#lesson-grid.board-focus:has(#lesson-pgn-box) :is(#board-stack,#lesson-left){display:contents}#lesson-grid.board-focus:has(#lesson-pgn-box) #lesson-left>*{margin-block:0}#lesson-grid.board-focus:has(#lesson-pgn-box) #lesson-left>*{grid-column:1/-1}#lesson-grid.board-focus:has(#lesson-pgn-box)>*{grid-column:1/-1}#lesson-grid.board-focus:has(#lesson-pgn-box) #chess-card{grid-area:1/1}#lesson-grid.board-focus:has(#lesson-pgn-box) #lesson-toolbar{grid-area:2/1}#lesson-grid.board-focus #lesson-pgn-box{contain:size;grid-area:1/2/span 2;align-self:stretch;overflow-y:auto}#lesson-grid.board-focus #lesson-pgn-box>summary{pointer-events:none;z-index:2;background:#fff;justify-content:flex-start;gap:.5rem;position:sticky;top:0}.dark #lesson-grid.board-focus #lesson-pgn-box>summary{background:var(--color-gray-900)}#lesson-grid.board-focus #lesson-pgn-box>summary>h3{white-space:nowrap;min-width:0}#lesson-grid.board-focus #lesson-pgn-box>summary>span[aria-hidden]{display:none}#lesson-grid.board-focus .pgn-collapse-btn{pointer-events:auto;flex-shrink:0;order:-1;display:inline-flex}#lesson-grid.board-focus #lesson-pgn-box.is-collapsed .pgn-collapse-btn svg{transform:rotate(180deg)}#lesson-grid.board-focus #lesson-pgn-box.is-collapsed>div,#lesson-grid.board-focus #lesson-pgn-box.is-collapsed>summary>h3{display:none}#lesson-grid.board-focus #lesson-pgn-box.is-collapsed>summary{justify-content:center;padding-inline:0}#lesson-grid.board-focus #lesson-pgn-box>div{padding:.25rem 1rem 1rem}#lesson-grid.board-focus .pgn-card:first-child{border-top:0;border-start-start-radius:.5rem;border-start-end-radius:.5rem}#lesson-grid.board-focus .pgn-card:last-child{border-end-end-radius:.5rem;border-end-start-radius:.5rem}#lesson-grid.board-focus .pgn-card{background:var(--color-gray-100);border:0;border-top:1px solid #fff;border-radius:0;margin:0;padding:.625rem .875rem;transition:background-color .15s}#lesson-grid.board-focus .pgn-card:hover{background:var(--color-gray-200)}#lesson-grid.board-focus .pgn-card.is-current{background:color-mix(in oklab, var(--color-primary) 10%, #fff)}#lesson-grid.board-focus .pgn-card>div,#lesson-grid.board-focus .pgn-card>summary>span:first-child>span[aria-hidden]{display:none}.dark #lesson-grid.board-focus .pgn-card{background:var(--color-gray-800);border-top-color:var(--color-gray-900)}.dark #lesson-grid.board-focus .pgn-card:hover{background:var(--color-gray-700)}.dark #lesson-grid.board-focus .pgn-card.is-current{background:#fbbf241f}#lesson-grid.board-focus .pgn-lang-pair{display:none}#lesson-grid.board-focus .pgn-split{border-radius:var(--radius-field,.5rem);background:color-mix(in oklab, var(--color-primary) 40%, transparent);padding:1px;display:inline-flex}#lesson-grid.board-focus .pgn-split>.btn{--btn-color:#fff;--btn-fg:var(--color-primary);box-shadow:none;border:0;min-width:2.4rem;font-weight:900}#lesson-grid.board-focus .pgn-split>.btn.is-active{--btn-color:var(--color-primary);--btn-fg:var(--color-primary-content)}.dark #lesson-grid.board-focus .pgn-split{background:#fbbf2473}.dark #lesson-grid.board-focus .pgn-split>.btn{--btn-color:var(--color-gray-900);--btn-fg:#fbbf24}.dark #lesson-grid.board-focus .pgn-split>.btn.is-active{--btn-color:#fbbf24;--btn-fg:#111827}#lesson-grid.board-focus .pgn-split>.btn:first-child:not(:last-child){clip-path:polygon(0 0,100% 0,calc(100% - 8px) 100%,0 100%)}#lesson-grid.board-focus .pgn-split>.btn:last-child:not(:first-child){clip-path:polygon(8px 0,100% 0,100% 100%,0 100%);margin-inline-start:-6px}}.pgn-split,.pgn-collapse-btn{display:none}#lesson-grid.board-focus{grid-template-columns:minmax(0,1fr)}#lesson-grid.board-focus #board-stack{order:1}#lesson-grid.board-focus #lesson-left{order:2}#lesson-grid.board-focus #video-box,#lesson-grid.video-focus #board-stack{display:none}#lesson-grid.video-focus{grid-template-columns:minmax(0,1fr)}#lesson-grid.video-focus #lesson-left{width:100%;max-width:min(100%, calc((100vh - var(--caissa-stick-h,4rem) - 3rem) * 16 / 9));margin-inline:auto}#lesson-grid.video-focus #video-box{max-height:calc(100vh - var(--caissa-stick-h,4rem) - 3rem);margin-inline:auto}#lesson-grid.board-focus .cg-movelist{font-size:17px;line-height:1.5}#lesson-grid.board-focus .cg-mvnum{font-size:13px}#lesson-grid.board-focus .cg-mvrow{grid-template-columns:2.6rem 1fr 1fr}#lesson-grid.board-focus .cg-var{font-size:14px;line-height:1.6}#lesson-grid.board-focus .cg-cmt{font-size:14px;line-height:1.9}.cg-book{color:#1f2937;direction:rtl;padding:6px 16px 20px}.dark .cg-book{color:#d1d5db}.cg-bk-p{text-align:start;margin:0 0 12px;font-size:13.5px;line-height:1.85}#lesson-grid.board-focus .cg-bk-p{margin-bottom:14px;font-size:15px}.cg-bk-mainp{background:#f1f2f4;border-radius:8px;margin-top:14px;padding:6px 10px}.dark .cg-bk-mainp{background:#ffffff0f}#lesson-grid.board-focus .cg-book .cg-bk-p:not(.cg-bk-mainp):not(.cg-bk-varp){color:#374151}.dark #lesson-grid.board-focus .cg-book .cg-bk-p:not(.cg-bk-mainp):not(.cg-bk-varp){color:#d1d5db}#lesson-grid.board-focus .cg-book .cg-bk-varp{color:#4b5563;border-inline-start:2px solid #e5e7eb;padding-inline-start:10px;font-size:14px}.dark #lesson-grid.board-focus .cg-book .cg-bk-varp{color:#b9bfc8;background:#ffffff09;border-inline-start-color:#ffffff2e;border-start-end-radius:6px;border-end-end-radius:6px;padding-block:4px}.cg-bk-run{unicode-bidi:isolate}.cg-bk-shared{opacity:.55}.cg-bk-shared-tgl{color:#6b7280;cursor:pointer;margin:-4px 0 12px;font-size:12px;font-weight:600;display:block}.cg-bk-shared-tgl:hover{color:#111827;text-underline-offset:3px;text-decoration:underline}.dark .cg-bk-shared-tgl{color:#9ca3af}.dark .cg-bk-shared-tgl:hover{color:#fff}.cg-train-here{cursor:pointer;background:var(--color-amber-600);color:#fff;text-align:center;border:0;border-radius:10px;width:100%;margin:16px 0 4px;padding:8px 12px;font-family:inherit;font-size:13px;font-weight:800;display:block}.cg-train-here:hover{background:var(--color-amber-700)}#lesson-grid:not(.board-focus) .cg-book .cg-bk-p:not(.cg-bk-mainp) .cg-bk-run{-webkit-box-decoration-break:clone;box-decoration-break:clone;background:#f4f5f7;border-radius:5px;padding:1px 4px}.dark #lesson-grid:not(.board-focus) .cg-book .cg-bk-p:not(.cg-bk-mainp) .cg-bk-run{background:#ffffff0b}.cg-book .cg-bk-run.cg-bk-own{margin:4px 0;display:table}.cg-bk-mv{cursor:pointer;white-space:nowrap;border-radius:4px;padding:1px 3px;font-weight:700}.cg-bk-main{color:#1f2937;font-size:14.5px}#lesson-grid.board-focus .cg-bk-main{font-size:16px}.dark .cg-bk-main{color:#f3f4f6}.cg-bk-var{color:#2f7fc8}.dark .cg-bk-var{color:#7db8f0}.cg-bk-mv:hover{background:#2f7fc81a}.cg-bk-mv.is-cur{color:#1f2937;background:#d6e8fb}.dark .cg-bk-mv.is-cur{color:#fff;background:#60a5fa52}.cg-book #cg-cur{font-weight:700}.cg-book #cg-cur .cg-pc[data-s=w]:before{content:var(--pc-line)}.cg-book #cg-cur .cg-pc[data-s=b]:before,.dark .cg-book #cg-cur .cg-pc[data-s=w]:before{content:var(--pc-solid)}.dark .cg-book #cg-cur .cg-pc[data-s=b]:before{content:var(--pc-line)}#lesson-grid .cg-bk-txt{color:inherit;font-weight:400}#lesson-grid .cg-book .cg-cmt-inline .eng,#lesson-grid .cg-book .cg-cmt-inline b{color:#2f7fc8;background:0 0;padding:0;font-weight:700}.dark #lesson-grid .cg-book .cg-cmt-inline .eng,.dark #lesson-grid .cg-book .cg-cmt-inline b{color:#7db8f0}#lesson-grid.board-focus .cg-book .cg-cmt-inline .eng,#lesson-grid.board-focus .cg-book .cg-cmt-inline b,.dark #lesson-grid.board-focus .cg-book .cg-cmt-inline .eng,.dark #lesson-grid.board-focus .cg-book .cg-cmt-inline b{color:inherit;font-weight:600}#lesson-grid.board-focus .cg-book .cg-cmt-inline .eng.mv{font-size:.92em}#lesson-grid .cg-book .cg-cmt-mv{color:#2f7fc8;font-weight:700}.dark #lesson-grid .cg-book .cg-cmt-mv{color:#7db8f0}#lesson-grid .cg-book .cg-cmt-inline .eng:not(.mv){color:#475569;text-underline-offset:3px;font-family:inherit;font-weight:400;-webkit-text-decoration:underline dotted #64748b8c;text-decoration:underline dotted #64748b8c}.dark #lesson-grid .cg-book .cg-cmt-inline .eng:not(.mv){color:#cbd5e1;text-decoration-color:#cbd5e166}#lesson-grid.board-focus .pv-txt{font-size:14px}#lesson-grid.board-focus #pv-row-1,#lesson-grid.board-focus #pv-row-2,#lesson-grid.board-focus #pv-row-3{grid-template-columns:4rem 1fr}.pv-scroll{scrollbar-width:none;-ms-overflow-style:none}.pv-scroll::-webkit-scrollbar{display:none}html::-webkit-scrollbar{width:6px;height:6px}#lesson-grid::-webkit-scrollbar{width:6px;height:6px}#caissa-settings-body::-webkit-scrollbar{width:6px;height:6px}#caissa-scroll-wrapper::-webkit-scrollbar{width:6px;height:6px}#lesson-pgn-box pre::-webkit-scrollbar{width:6px;height:6px}html::-webkit-scrollbar-track{background:0 0}#lesson-grid::-webkit-scrollbar-track{background:0 0}#caissa-settings-body::-webkit-scrollbar-track{background:0 0}#caissa-scroll-wrapper::-webkit-scrollbar-track{background:0 0}#lesson-pgn-box pre::-webkit-scrollbar-track{background:0 0}html::-webkit-scrollbar-corner{background:0 0}#lesson-grid::-webkit-scrollbar-corner{background:0 0}#caissa-scroll-wrapper::-webkit-scrollbar-corner{background:0 0}#lesson-pgn-box pre::-webkit-scrollbar-corner{background:0 0}html::-webkit-scrollbar-thumb{background:#00000061;border-radius:999px}#lesson-grid::-webkit-scrollbar-thumb{background:#00000061;border-radius:999px}#caissa-settings-body::-webkit-scrollbar-thumb{background:#00000061;border-radius:999px}#caissa-scroll-wrapper::-webkit-scrollbar-thumb{background:#00000061;border-radius:999px}#lesson-pgn-box pre::-webkit-scrollbar-thumb{background:#00000061;border-radius:999px}html::-webkit-scrollbar-thumb:hover{background:#0000008c}#lesson-grid:hover::-webkit-scrollbar-thumb{background:#0000008c}#caissa-settings-body:hover::-webkit-scrollbar-thumb{background:#0000008c}#caissa-scroll-wrapper:hover::-webkit-scrollbar-thumb{background:#0000008c}#lesson-pgn-box pre:hover::-webkit-scrollbar-thumb{background:#0000008c}html.dark::-webkit-scrollbar-thumb{background:#ffffff4d}html.dark #lesson-grid::-webkit-scrollbar-thumb{background:#ffffff4d}html.dark #caissa-settings-body::-webkit-scrollbar-thumb{background:#ffffff4d}html.dark #caissa-scroll-wrapper::-webkit-scrollbar-thumb{background:#ffffff4d}html.dark #lesson-pgn-box pre::-webkit-scrollbar-thumb{background:#ffffff4d}html.dark::-webkit-scrollbar-thumb:hover{background:#ffffff73}html.dark #lesson-grid:hover::-webkit-scrollbar-thumb{background:#ffffff73}html.dark #caissa-settings-body:hover::-webkit-scrollbar-thumb{background:#ffffff73}html.dark #caissa-scroll-wrapper:hover::-webkit-scrollbar-thumb{background:#ffffff73}html.dark #lesson-pgn-box pre:hover::-webkit-scrollbar-thumb{background:#ffffff73}@supports not selector(::-webkit-scrollbar){html,#lesson-grid,#caissa-settings-body,#caissa-scroll-wrapper,#lesson-pgn-box pre{scrollbar-width:thin;scrollbar-color:#00000061 transparent}html.dark,html.dark #lesson-grid,html.dark #caissa-settings-body,html.dark #caissa-scroll-wrapper,html.dark #lesson-pgn-box pre{scrollbar-color:#ffffff4d transparent}}#lesson-sidebar::-webkit-scrollbar{width:6px;height:6px}#lesson-sidebar::-webkit-scrollbar-track{background:0 0}#lesson-sidebar::-webkit-scrollbar-corner{background:0 0}#lesson-sidebar::-webkit-scrollbar-thumb{background:#05164573;border-radius:999px}#lesson-sidebar:hover::-webkit-scrollbar-thumb{background:#051645ad}html.dark #lesson-sidebar::-webkit-scrollbar-thumb{background:#fbbf2480}html.dark #lesson-sidebar:hover::-webkit-scrollbar-thumb{background:#fbbf24bf}@supports not selector(::-webkit-scrollbar){#lesson-sidebar{scrollbar-width:thin;scrollbar-color:#05164573 transparent}html.dark #lesson-sidebar{scrollbar-color:#fbbf2480 transparent}}#caissa-board cg-board{background-image:var(--board-bg)!important;background-color:#0000!important;background-size:100% 100%!important}#caissa-board[data-piece-set=staunton3d]{aspect-ratio:512/464.5;margin-top:1.81%;overflow:visible}#caissa-board[data-piece-set=staunton3d] coords coord{color:#fff!important;text-shadow:0 1px 2px #000!important}#caissa-board[data-piece-set=staunton3d] coords.files{bottom:calc(1px - 2.5%)}#caissa-board[data-piece-set=staunton3d] coords.files coord{padding-left:3px}#caissa-board[data-piece-set=staunton3d] cg-board{background-image:none!important}#caissa-board[data-piece-set=staunton3d] cg-board:before{content:"";background-repeat:no-repeat;background-size:100% 100%;height:103.2%;position:absolute;top:-.7307%;left:0;right:0}#caissa-board[data-piece-set=staunton3d] piece{width:16.741%;height:23.563%;top:-9.1%;left:-1.85%}#caissa-board square.light.check,#caissa-board square.dark.check{background-color:#dc262699!important;background-image:radial-gradient(#ff0000e6 0%,#c800001a 70%)!important;box-shadow:inset 0 0 25px 2px #f00c!important}.cg-wrap square{pointer-events:none;width:12.5%;height:12.5%;position:absolute}.cg-wrap piece{z-index:2;cursor:grab;background-size:cover;width:12.5%;height:12.5%;position:absolute}.cg-wrap piece.dragging{z-index:10;cursor:grabbing}.engine-switch{cursor:pointer;background:#d1d5db;border-radius:9999px;width:2.25rem;height:1.25rem;transition:background-color .15s;position:relative}html.dark .engine-switch{background:#4b5563}.engine-switch:hover{background:#9ca3af}html.dark .engine-switch:hover{background:#6b7280}.engine-switch:focus-visible{outline-offset:2px;outline:2px solid #059669}.engine-switch-knob{background:#fff;border-radius:9999px;width:.875rem;height:.875rem;transition:transform .15s;position:absolute;top:.1875rem;left:.1875rem;box-shadow:0 1px 2px #00000040}.engine-switch.is-on,html.dark .engine-switch.is-on{background:#059669}.engine-switch.is-on:hover{background:#047857}.engine-switch.is-on .engine-switch-knob{transform:translate(1rem)}.nav-ico{color:#6b7280;border-radius:.5rem;justify-content:center;align-items:center;width:2rem;height:2rem;font-size:.95rem;line-height:1;transition:background-color .15s,color .15s;display:flex}.nav-side{width:4.125rem}.nav-ico:hover{color:#111827;background:#0000000f}html.dark .nav-ico{color:#9ca3af}html.dark .nav-ico:hover{color:#fff;background:#ffffff14}.caissa-mat{pointer-events:none;-webkit-user-select:none;user-select:none;align-items:center;gap:.25rem;height:1rem;padding:0 .15rem;display:flex;position:absolute;left:0;right:0;overflow:hidden}#caissa-mat-top{bottom:100%}#caissa-mat-bottom{top:100%}.caissa-mat[hidden]{display:none}.mat-group{display:inline-flex}.mat-group+.mat-group{margin-inline-start:.3rem}.mat-ico{filter:grayscale();opacity:.55;background-position:50%;background-repeat:no-repeat;background-size:contain;width:.95rem;height:.95rem;display:block}.mat-ico+.mat-ico{margin-inline-start:-.42rem}html.dark .mat-ico{filter:grayscale()invert()brightness(.92);opacity:.8}.mat-edge{color:#6b7280;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.72rem;font-weight:700;line-height:1}html.dark .mat-edge{color:#9ca3af}@media (width>=1024px){#lesson-grid.board-focus:has(#lesson-pgn-box){grid-template-columns:minmax(1rem,.5fr) minmax(0,auto) minmax(20rem,1fr);grid-template-rows:calc(100vh - var(--caissa-stick-h,4rem) - 3rem);justify-content:stretch}#lesson-grid.board-focus:has(#lesson-pgn-box.is-collapsed){grid-template-columns:minmax(1rem,.5fr) minmax(0,auto) minmax(2.75rem,1fr)}#lesson-grid.board-focus:has(#lesson-pgn-box) #chess-card{grid-area:1/2;align-self:center}#lesson-grid.board-focus:has(#lesson-pgn-box) #lesson-toolbar{grid-area:2/2}#lesson-grid.board-focus #lesson-pgn-box{width:20rem;height:calc(100vh - var(--caissa-stick-h,4rem));border:0;border-inline-start:1px solid var(--color-gray-200);border-radius:0;grid-area:1/3;justify-self:end;margin-block-start:-1.5rem;margin-inline-end:-1.5rem}.dark #lesson-grid.board-focus #lesson-pgn-box{border-inline-start-color:var(--color-gray-800)}#lesson-grid.board-focus #lesson-pgn-box.is-collapsed{width:2.75rem}#lesson-grid.board-focus #lesson-pgn-box{transition:width .28s;overflow-x:hidden}#lesson-grid.board-focus #lesson-pgn-box>div{min-width:calc(20rem - 1px);transition:opacity .2s}#lesson-grid.board-focus #lesson-pgn-box.is-collapsed>div{opacity:0;visibility:hidden;pointer-events:none;display:block}@media (prefers-reduced-motion:reduce){#lesson-grid.board-focus #lesson-pgn-box,#lesson-grid.board-focus #lesson-pgn-box>div{transition:none}}:is(#lesson-grid.board-focus,#lesson-grid.board-focus:has(#lesson-pgn-box)){--board-max:min(800px, calc(100vh - var(--caissa-stick-h,4rem) - 7rem))}#lesson-grid.board-focus:has(#lesson-pgn-box){column-gap:2.5rem}#lesson-grid.board-focus #chess-card{box-shadow:none;background:0 0;border:0;border-radius:0;padding:0}#lesson-grid.board-focus #board-row{gap:1.75rem}#lesson-grid.board-focus #caissa-board{box-shadow:0 1px 3px #0000002e}#lesson-grid.board-focus #study-column{border-color:var(--color-gray-200);background:#fff;border-radius:0;width:27rem}.dark #lesson-grid.board-focus #study-column{background:var(--color-gray-900);border-color:var(--color-gray-800)}#lesson-grid.board-focus #study-column>div:first-child,#lesson-grid.board-focus #study-column>div:last-child{background:0 0}.dark #lesson-grid.board-focus #study-column>div:first-child,.dark #lesson-grid.board-focus #study-column>div:last-child{border-color:var(--color-gray-800)}#lesson-grid.board-focus #study-column .nav-side{width:auto}#lesson-grid.board-focus #study-column{flex-shrink:100;min-width:17rem}#lesson-grid.board-focus .cg-movelist{font-size:15px}#lesson-grid.board-focus .cg-cmt{font-size:13px;line-height:1.9}#lesson-grid.board-focus .cg-var{font-size:13px}#lesson-grid.board-focus #study-column:has(#btn-toggle-engine[aria-pressed=false]) :is(#engine-score,#engine-meta){visibility:hidden}#lesson-grid.board-focus #lesson-pgn-box>summary{border-bottom:1px solid var(--color-gray-200);padding:.9rem 1.25rem}.dark #lesson-grid.board-focus #lesson-pgn-box>summary{border-bottom-color:var(--color-gray-800)}#lesson-grid.board-focus #lesson-pgn-box>summary>h3{font-size:15px}#lesson-grid.board-focus #lesson-pgn-box>div{padding:0;display:block}#lesson-grid.board-focus .pgn-card,#lesson-grid.board-focus .pgn-card:first-child,#lesson-grid.board-focus .pgn-card:last-child{border:0;border-bottom:1px solid var(--color-gray-200);background:0 0;border-radius:0;padding:.75rem 1.25rem}#lesson-grid.board-focus .pgn-card:hover{background:var(--color-gray-50)}#lesson-grid.board-focus .pgn-card.is-current,.dark #lesson-grid.board-focus .pgn-card.is-current{background:var(--color-primary)}#lesson-grid.board-focus .pgn-card.is-current .pgn-title{color:var(--color-primary-content)}.dark #lesson-grid.board-focus .pgn-card{border-bottom-color:var(--color-gray-800);background:0 0}.dark #lesson-grid.board-focus .pgn-card:hover{background:#ffffff0a}#lesson-grid.board-focus .pgn-card .pgn-title{text-align:start;unicode-bidi:plaintext;font-size:14px;font-weight:600}#lesson-grid.board-focus .pgn-split:not(:has(>.btn+.btn)){display:none}.dark #lesson-grid.board-focus .pgn-split{background:var(--color-gray-700)}.dark #lesson-grid.board-focus .pgn-split>.btn{--btn-color:var(--color-gray-900);--btn-fg:var(--color-gray-300)}.dark #lesson-grid.board-focus .pgn-split>.btn.is-active{--btn-color:var(--color-primary);--btn-fg:#fff}[data-modern] #lesson-grid.board-focus #lesson-pgn-box:has(>.lm-pgn-report){position:relative}[data-modern] #lesson-grid.board-focus #lesson-pgn-box:has(>.lm-pgn-report)>div{padding-bottom:3.25rem}[data-modern] #lesson-pgn-box>.lm-pgn-report{inset-inline:0;border-top:1px solid var(--color-gray-200);background:#fff;display:block;position:absolute;bottom:0}.dark [data-modern] #lesson-pgn-box>.lm-pgn-report{border-top-color:var(--color-gray-800);background:var(--color-gray-900)}[data-modern] #lesson-pgn-box>.lm-pgn-report>a{color:var(--color-gray-600);align-items:center;gap:.5rem;padding:.75rem 1.25rem;font-size:14px;font-weight:600;transition:background-color .15s,color .15s;display:flex}[data-modern] #lesson-pgn-box>.lm-pgn-report>a:hover{background:var(--color-gray-50);color:var(--color-red-700)}.dark [data-modern] #lesson-pgn-box>.lm-pgn-report>a{color:var(--color-gray-400)}.dark [data-modern] #lesson-pgn-box>.lm-pgn-report>a:hover{color:var(--color-red-300);background:#ffffff0a}[data-modern] #lesson-pgn-box>.lm-pgn-report>a>svg{flex:none;width:1rem;height:1rem}[data-modern] #lesson-pgn-box.is-collapsed>.lm-pgn-report{display:none}}@media (width<=1023px){body:has([data-modern] #lesson-grid[data-initial-focus=board]) #lesson-menu-btn{display:none}[data-modern] #lesson-grid[data-initial-focus=board]{padding-top:0}[data-modern] #lesson-grid[data-initial-focus=board] #board-column{top:var(--caissa-stick-h,0px);z-index:5;background:#fff;position:sticky}.dark [data-modern] #lesson-grid[data-initial-focus=board] #board-column{background:var(--color-gray-900)}}@media (width<=639px){[data-modern] #lesson-grid:not(.video-focus){--board-max:min(100vw, calc(100svh - var(--caissa-stick-h,4rem) - 12rem))}[data-modern] #lesson-grid:not(.video-focus) #chess-card{height:calc(100vh - var(--caissa-stick-h,4rem));height:calc(100svh - var(--caissa-stick-h,4rem))}}@media (width<=1023px){[data-modern] #lesson-grid .caissa-mat{display:none}[data-modern] #lesson-grid:not(.video-focus) #chess-card{padding-top:0}[data-modern] #lesson-grid #board-row{gap:0}[data-modern] #caissa-scroll-wrapper{scrollbar-width:none}[data-modern] #caissa-scroll-wrapper::-webkit-scrollbar{display:none}}@media (width<=639px){[data-modern] #lesson-grid:not(.video-focus) #study-column{grid-template:"moves moves"minmax(0,1fr)"panel panel""eng nav"/auto minmax(0,1fr);display:grid}[data-modern] #lesson-grid:not(.video-focus) #caissa-moves-box{grid-area:moves;min-height:0}[data-modern] #lesson-grid:not(.video-focus) #engine-panel{grid-area:panel}[data-modern] #lesson-grid:not(.video-focus) #study-column>:first-child{grid-area:eng;gap:.35rem;padding:.375rem .25rem .375rem .5rem}[data-modern] #lesson-grid:not(.video-focus) #study-column>:last-child{grid-area:nav;min-width:0;padding-inline-start:0}[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine,[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine:hover{width:2rem;height:2rem;color:var(--color-gray-500);background:0 0;border-radius:.5rem}[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine.is-on{color:#059669}html.dark [data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine{color:var(--color-gray-400)}html.dark [data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine.is-on{color:#34d399}[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine .engine-switch-knob{display:none}[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine:before{content:"";background:currentColor;position:absolute;inset:.3125rem;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M8.25 3v1.5M4.5 8.25H3m18 0h-1.5M4.5 12H3m18 0h-1.5m-15 3.75H3m18 0h-1.5M8.25 19.5V21M12 3v1.5m0 15V21m3.75-18v1.5m0 15V21m-9-1.5h10.5a2.25 2.25 0 0 0 2.25-2.25V6.75a2.25 2.25 0 0 0-2.25-2.25H6.75A2.25 2.25 0 0 0 4.5 6.75v10.5a2.25 2.25 0 0 0 2.25 2.25Zm.75-12h9v9h-9v-9Z'/%3E%3C/svg%3E") 50%/contain no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M8.25 3v1.5M4.5 8.25H3m18 0h-1.5M4.5 12H3m18 0h-1.5m-15 3.75H3m18 0h-1.5M8.25 19.5V21M12 3v1.5m0 15V21m3.75-18v1.5m0 15V21m-9-1.5h10.5a2.25 2.25 0 0 0 2.25-2.25V6.75a2.25 2.25 0 0 0-2.25-2.25H6.75A2.25 2.25 0 0 0 4.5 6.75v10.5a2.25 2.25 0 0 0 2.25 2.25Zm.75-12h9v9h-9v-9Z'/%3E%3C/svg%3E") 50%/contain no-repeat}[data-modern] #lesson-grid:not(.video-focus) #study-column>:first-child>:is(#engine-score,#engine-meta),[data-modern] #lesson-grid:not(.video-focus) #btn-flip-board{display:none}[data-modern] #lesson-grid:not(.video-focus) #study-column{grid-template-columns:auto minmax(0,1fr) auto;grid-template-areas:"moves moves moves""panel panel panel""eng nav gear"}[data-modern] #lesson-grid:not(.video-focus) #study-column>:first-child{display:contents}[data-modern] #lesson-grid:not(.video-focus) #study-column>:last-child{grid-area:3/1/auto/-1;padding-inline:2.75rem}[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine,[data-modern] #lesson-grid:not(.video-focus) #btn-engine-settings{z-index:1;grid-row:3;align-self:center}[data-modern] #lesson-grid:not(.video-focus) #btn-toggle-engine{grid-column:1;margin-inline-start:.5rem}[data-modern] #lesson-grid:not(.video-focus) #btn-engine-settings{grid-column:3;margin-inline-end:.5rem}[data-modern] #lesson-grid:not(.video-focus) #study-column{position:relative}[data-modern] #lesson-grid:not(.video-focus) #study-column>:last-child>:nth-child(2){position:absolute;bottom:.375rem;left:50%;transform:translate(-50%)}[data-modern] #lesson-grid:not(.video-focus) #btn-engine-settings{background:0 0;border:0;width:2rem;height:2rem}}@media (width<=1023px){[data-modern] #lesson-grid[data-initial-focus=board] #lesson-pgn-box{border:0;border-block:1px solid var(--color-gray-200);width:calc(100% + 2rem);box-shadow:none;border-radius:0;margin-inline:-1rem}[data-modern] #lesson-grid[data-initial-focus=board] #lesson-pgn-box>summary{pointer-events:none;border-bottom:1px solid var(--color-gray-200);padding:.85rem 1rem}[data-modern] #lesson-grid[data-initial-focus=board] #lesson-pgn-box>summary>span[aria-hidden]{display:none}[data-modern] #lesson-grid[data-initial-focus=board] #lesson-pgn-box>div{padding:0}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-card{border:0;border-bottom:1px solid var(--color-gray-200);background:0 0;border-radius:0;margin:0;padding:.7rem 1rem}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-card:last-child{border-bottom:0}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-card.is-current{background:var(--color-primary)}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-card.is-current .pgn-title{color:var(--color-primary-content)}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-card .pgn-title{font-size:13px;font-weight:600}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-lang-pair{display:none}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-split{border-radius:var(--radius-field,.5rem);background:color-mix(in oklab, var(--color-primary) 40%, transparent);padding:1px;display:inline-flex}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-split>.btn{--btn-color:#fff;--btn-fg:var(--color-primary);box-shadow:none;border:0;min-width:2.4rem;font-weight:900}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-split>.btn.is-active{--btn-color:var(--color-primary);--btn-fg:var(--color-primary-content)}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-split>.btn:first-child:not(:last-child){clip-path:polygon(0 0,100% 0,calc(100% - 8px) 100%,0 100%)}[data-modern] #lesson-grid[data-initial-focus=board] .pgn-split>.btn:last-child:not(:first-child){clip-path:polygon(8px 0,100% 0,100% 100%,0 100%);margin-inline-start:-6px}.dark [data-modern] #lesson-grid[data-initial-focus=board] #lesson-pgn-box,.dark [data-modern] #lesson-grid[data-initial-focus=board] #lesson-pgn-box>summary,.dark [data-modern] #lesson-grid[data-initial-focus=board] .pgn-card{border-color:var(--color-gray-800)}[data-modern] #lesson-grid:has(.lm-board-actions) .lt-report-m{display:none}[data-modern] #lesson-grid .lm-board-actions{order:3;justify-self:right;gap:.5rem;width:auto;display:flex}}.dark [data-modern] #lesson-grid.board-focus .pgn-split,.dark [data-modern] #lesson-grid[data-initial-focus=board] .pgn-split{background:#8ea6d459}.dark [data-modern] #lesson-grid.board-focus .pgn-split>.btn,.dark [data-modern] #lesson-grid[data-initial-focus=board] .pgn-split>.btn{--btn-color:var(--color-gray-900);--btn-fg:#a3b8df}.dark [data-modern] #lesson-grid.board-focus .pgn-split>.btn.is-active,.dark [data-modern] #lesson-grid[data-initial-focus=board] .pgn-split>.btn.is-active{--btn-color:#8ea6d4;--btn-fg:#0c1220}.dark [data-modern] #lesson-grid.board-focus .pgn-card.is-current,.dark [data-modern] #lesson-grid[data-initial-focus=board] .pgn-card.is-current{background:#1e2a42}.dark [data-modern] #lesson-grid.board-focus .pgn-card.is-current .pgn-title,.dark [data-modern] #lesson-grid[data-initial-focus=board] .pgn-card.is-current .pgn-title{color:#e2e4e8}