/* Learning map: connected lesson paths and a focused teaching surface. */
.academy{--ac-blue:#196b5c;background:#f7f6ee}.ac-header{max-width:none;background:#fff;padding:20px max(24px,calc((100vw - 1248px)/2));border-bottom:1px solid #dbe2ee}.ac-header nav button{font-size:15px}.ac-header nav button.active{background:#173352;color:#fff}.ac-shell{max-width:1320px}.sk-tabs{display:flex;gap:8px;margin-bottom:26px}.sk-tabs .ac-button{border-radius:24px;padding:10px 22px}.sk-home-top,.sk-map-heading{display:flex;align-items:center;justify-content:space-between;gap:30px;margin:10px 0 28px}.sk-home-top h1,.sk-map-heading h1{font-size:clamp(30px,3vw,43px);letter-spacing:-1.4px;line-height:1.2;margin-bottom:12px}.sk-home-top p,.sk-map-heading p{color:#536577;font-size:17px}.sk-home-grid{display:grid;grid-template-columns:1.6fr 1fr;gap:24px}.sk-next{background:#173352;color:#fff;border-radius:20px;padding:32px;position:relative;overflow:hidden}.sk-next .ac-kicker{color:#b5c9fe;font-size:13px}.sk-next h2{font-size:31px;line-height:1.25;margin:15px 0}.sk-next p{font-size:18px;max-width:650px;margin-bottom:25px;color:#e6edfa}.sk-next .ac-button.primary{background:#cfed7d;border-color:#cfed7d;color:#173352}.sk-next-foot{margin-top:22px;color:#c6d5e9;font-size:14px}.sk-home-progress{background:white;border:1px solid #d7dfeb;border-radius:20px;padding:25px 30px}.sk-home-progress h2{font-size:20px;margin-bottom:12px}.sk-home-progress>div{display:flex;gap:20px;align-items:center;padding:12px 0;border-bottom:1px solid #e6ebf3}.sk-home-progress strong{font-size:28px;min-width:100px;letter-spacing:-1px}.sk-home-progress small{font-size:16px;font-weight:400;color:#61728a}.sk-home-progress span{font-size:15px;color:#536577}.sk-branch-shortcuts{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.sk-branch-shortcuts button{background:white;border:1px solid #d7dfeb;border-radius:14px;padding:23px;text-align:left;color:#173352;border-top:4px solid var(--branch);display:flex;flex-direction:column;align-items:start;gap:12px}.sk-branch-shortcuts button:hover{box-shadow:0 5px 16px #18335010;transform:translateY(-2px)}.sk-branch-shortcuts button>span{font-size:28px;color:var(--branch);font-weight:700}.sk-branch-shortcuts h3{font-size:20px;line-height:1.3}.sk-branch-shortcuts p{font-size:15px;color:#536577;flex:1}.sk-branch-shortcuts b{font-size:14px;color:var(--branch)}.sk-quick{display:flex;justify-content:space-between;align-items:center;gap:24px;background:#e8eef7;border-radius:16px;padding:24px;margin-top:32px}.sk-quick h2{font-size:23px}.sk-quick p{max-width:540px;color:#536577;margin-top:8px}.sk-quick .ac-actions{margin:0}.sk-map-count{text-align:right;min-width:180px}.sk-map-count>strong{font-size:38px;display:block;line-height:1.15}.sk-map-count>strong>span{font-size:22px;color:#748397;font-weight:400}.sk-map-count>span{color:#536577;font-size:14px}.sk-recommend{background:#fff;border:1px solid #c4d1e9;border-left:5px solid #3059cd;padding:20px 24px;border-radius:12px;display:flex;align-items:center;justify-content:space-between;gap:20px}.sk-recommend>div{display:flex;gap:15px;align-items:center;font-size:15px}.sk-recommend strong{font-size:18px}.sk-dot{width:13px;height:13px;border:3px solid #3059cd;border-radius:50%;flex-shrink:0}.sk-filter{display:flex;flex-wrap:wrap;gap:8px;margin:26px 0 20px}.sk-filter .ac-button{font-size:14px;border-radius:24px;padding:9px 15px}.sk-tree{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px;align-items:start}.sk-tree.single{grid-template-columns:minmax(0,700px);justify-content:center}.sk-branch{min-width:0;background:#ebeff5;border-radius:16px;padding:20px 12px 6px}.sk-branch>header{padding:0 8px 18px;min-height:151px;border-bottom:1px solid #cdd7e4}.sk-branch-icon{display:inline-flex;align-items:center;justify-content:center;width:43px;height:43px;border-radius:12px;background:var(--branch);color:#fff;font-size:23px;font-weight:700;margin-bottom:12px}.sk-branch h2{font-size:19px;line-height:1.3;margin-bottom:8px}.sk-branch header p{font-size:14px;color:#536577}.sk-branch ol{list-style:none;padding:16px 0 0;margin:0}.sk-branch li{padding:0 0 24px;position:relative}.sk-branch li:not(:last-child):after{content:'';position:absolute;left:29px;top:calc(100% - 24px);height:24px;width:2px;background:#aebed2}.sk-node{width:100%;display:flex;align-items:flex-start;gap:11px;text-align:left;background:white;border:1px solid #cdd7e4;border-radius:12px;padding:15px 12px;color:#173352;min-height:101px}.sk-node:hover{border-color:var(--branch);box-shadow:0 3px 12px #152e4910}.sk-node-marker{display:inline-flex;width:33px;height:33px;align-items:center;justify-content:center;border:1px solid #d0dce9;border-radius:50%;font-size:14px;color:#61738c;flex-shrink:0;font-weight:700}.sk-node strong{font-size:16px;line-height:1.3;display:block;margin:2px 0 7px}.sk-node small{display:block;color:#61738c;font-size:13px}.sk-node em{font-size:12px;line-height:1.4;color:#63748a;font-style:normal;display:block;margin-top:9px}.sk-branch li.suggested .sk-node{border:2px solid var(--branch);padding:14px 11px}.sk-branch li.complete .sk-node-marker{background:var(--branch);color:#fff;border-color:var(--branch)}.sk-map-help{border-top:1px solid #d2dce8;margin-top:35px;padding-top:28px;max-width:900px}.sk-map-help h2{font-size:22px;margin-bottom:12px}.sk-map-help p{font-size:15px;line-height:1.75;color:#536577;margin-bottom:12px}.sk-lesson-top{display:flex;gap:15px;align-items:center;flex-wrap:wrap;margin-bottom:23px;color:#536577;font-size:14px}.sk-lesson-top .sk-state{margin-left:auto;background:#e6edf8;border-radius:20px;padding:6px 12px}.sk-lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 290px;gap:26px;align-items:start}.sk-lesson-main,.sk-check{background:white;border:1px solid #d4deeb;border-radius:18px;padding:32px;min-width:0}.sk-lesson-main h1,.sk-check h1{font-size:32px;letter-spacing:-.7px;line-height:1.25;margin:10px 0 22px}.sk-original{background:#f0f4fb;border-left:4px solid #3059cd;padding:15px 18px;margin-bottom:22px}.sk-original span{display:block;color:#566b87;font-size:13px;margin-bottom:5px}.sk-original strong{font-size:18px;line-height:1.5}.sk-explanation{font-size:18px;line-height:1.8}.sk-example-equation{font-size:19px;font-weight:700;padding:17px 20px;margin:23px 0;background:#e8f3ee;border-radius:10px;line-height:1.6}.sk-experiment{border:1px solid #d6e1ef;background:#f6f8fc;border-radius:14px;padding:22px}.sk-experiment-heading{display:flex;align-items:center;justify-content:space-between;gap:15px;flex-wrap:wrap}.sk-experiment h2{font-size:19px}.sk-experiment>p{font-size:14px;color:#61738b;margin-top:5px}.sk-model{padding:28px 0 20px;text-align:center;min-height:200px}.sk-model p{font-size:14px;color:#526782;margin-top:16px;line-height:1.6}.sk-model-equation{font-size:21px;font-weight:700;line-height:1.5;margin-top:20px;overflow-wrap:anywhere}.sk-slider{display:block;border-top:1px solid #d6e0ed;padding-top:17px}.sk-slider>span{display:flex;justify-content:space-between;gap:10px;font-size:15px;font-weight:600}.sk-slider output{font-weight:800;color:#244bbe}.sk-slider input{width:100%;accent-color:#3059cd;min-height:35px;margin-top:10px;cursor:pointer}.sk-lesson-side{display:grid;gap:18px}.sk-lesson-side>section{border:1px solid #d4deeb;background:white;border-radius:13px;padding:22px}.sk-lesson-side h3{font-size:18px;margin-bottom:13px}.sk-lesson-side p{font-size:15px;color:#536577;line-height:1.7;margin-bottom:15px}.sk-lesson-side .ac-button{width:100%;font-size:14px}.sk-lesson-side details{padding:10px 0;border-top:1px solid #e1e7f0}.sk-lesson-side summary{cursor:pointer;font-size:15px;font-weight:600}.sk-lesson-side details p{margin:10px 0 0;font-size:14px}.sk-step-controls{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-top:27px}.sk-step-dots{display:flex;gap:6px}.sk-step-dots i{height:7px;width:7px;background:#cfd9e8;border-radius:50%}.sk-step-dots i.on{background:#3059cd}.sk-skip{display:flex;justify-content:space-between;gap:15px;border-top:1px solid #d9e3ef;margin-top:25px;padding-top:12px;flex-wrap:wrap}.sk-fraction-links{padding:18px;background:#eff3fd;border-radius:12px;margin-top:20px}.sk-fraction-links>div{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}.sk-unit-grid{display:grid;grid-template-columns:repeat(var(--cols),1fr);gap:2px;max-width:350px;margin:auto;border:2px solid #173352;padding:2px;background:white}.sk-unit-grid i{aspect-ratio:1;background:#e2eaf7}.sk-unit-grid[style*='--cols:4'] i{aspect-ratio:1.3}.sk-unit-grid i.filled{background:#3059cd}.sk-groups{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}.sk-groups>div{border:2px solid #3059cd;border-radius:10px;padding:10px 16px;background:#e7eeff;color:#3059cd;font-size:24px;letter-spacing:4px}.sk-price-bar{display:flex;max-width:480px;margin:20px auto;min-height:75px;gap:3px}.sk-price-bar span{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;background:#ccd9ee;padding:9px;font-size:14px;font-weight:700}.sk-price-bar span+span{background:#c3e5a3}.sk-calculation{display:grid;gap:10px;text-align:center;font-size:24px;margin-top:15px}.sk-balance{display:flex;align-items:center;justify-content:center;gap:20px;font-size:30px}.sk-balance>span{border-bottom:5px solid #8144a2;padding:18px 24px;background:#ece6f5;min-width:110px}.sk-rectangle{display:grid;grid-template-columns:repeat(var(--cols),1fr);border:4px solid #08786b;max-width:420px;margin:10px auto;gap:1px;background:#a1c5bc}.sk-rectangle>i{aspect-ratio:1;background:#d4eae1}.sk-vessels{display:flex;justify-content:center;gap:30px}.sk-vessels>div{flex:1;max-width:150px}.sk-vessels>div>span{font-size:14px}.sk-vessel{position:relative;height:165px;display:flex;align-items:center;justify-content:center;background:#eef4ff;border:2px solid #758eac;border-top-style:dashed;border-radius:0 0 14px 14px;margin-top:10px;overflow:hidden}.sk-vessel i{position:absolute;bottom:0;left:0;right:0;background:#92c6ea;transition:height .35s}.sk-vessel b{z-index:1;font-size:26px}.sk-bars{display:flex;justify-content:center;gap:22px;max-width:400px;margin:auto}.sk-bars>div{flex:1;min-width:25px}.sk-bars>div>div{height:150px;position:relative;background:#e5eaf3}.sk-bars i{position:absolute;bottom:0;left:0;right:0;background:#c38339;transition:height .3s}.sk-bars b{font-size:20px;display:inline-block;padding:4px 10px;margin-top:8px;border-radius:6px}.sk-bars b.sk-middle{background:#173352;color:#fff}.sk-tokens{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}.sk-tokens i{display:flex;align-items:center;justify-content:center;width:48px;height:48px;border-radius:50%;font-style:normal;color:#fff;font-weight:700;border:2px solid #173352}.sk-tokens .blue{background:#3059cd}.sk-tokens .orange{background:#a95515}.sk-tokens .removed{background:#e6eaf1;border-style:dashed;color:#667990}.sk-light{margin:auto;width:110px;height:110px;display:flex;align-items:center;justify-content:center;background:#24324b;color:#c3cee2;border:5px solid #91a1bb;border-radius:50%;font-weight:700;font-size:25px;transition:background .2s}.sk-light.on{background:#fbd372;color:#4c3711;border-color:#dcab2a}.sk-network{max-width:400px;width:100%;font:16px 'DM Sans',sans-serif;fill:#173352}.sk-question{display:block;margin:26px 0;font-size:18px;line-height:1.6}.sk-question>span{font-weight:600}.sk-question>div{display:flex;align-items:center;gap:12px;margin-top:12px;font-size:15px}.sk-question input{max-width:200px;width:100%;padding:12px;border:1px solid #9bafcc;border-radius:9px;min-height:48px;font:inherit;background:#fff;color:#173352}.sk-question input:disabled{background:#edf4ef;opacity:1}.sk-answer-feedback{font-size:15px!important;padding:13px 16px;border-left:3px solid #bc8528;background:#fff5df;margin-top:12px!important}.sk-answer-feedback.correct{border-color:#358257;background:#ebf5ee}.sk-check-result{padding:20px;background:#eaf0fc;border-radius:12px;margin-top:23px}.sk-check-result p{font-size:15px;margin-top:9px}.sk-check>p{font-size:17px;line-height:1.75;color:#536577}.sk-notebook-link{background:#e9effb;padding:22px;border-radius:14px;margin:24px 0;display:flex;justify-content:space-between;align-items:center;gap:16px}.ac-game-card{box-shadow:0 3px 9px #142a4105}.ac-game-card h3{font-size:27px}.ac-game-icon{border-radius:12px}.ac-kicker{font-size:12px}.ac-level-row small,.ac-stat span{font-size:14px}
@media(max-width:1100px){.sk-tree{grid-template-columns:repeat(2,minmax(0,1fr))}.sk-branch-shortcuts{grid-template-columns:repeat(2,1fr)}.sk-branch>header{min-height:130px}.ac-header{padding:20px 25px;gap:15px}.sk-lesson-layout{grid-template-columns:minmax(0,1fr) 250px}.sk-lesson-main,.sk-check{padding:25px}.sk-quick{display:block}.sk-quick .ac-actions{margin-top:20px}}
@media(max-width:780px){.ac-header{display:block}.ac-header nav{margin-top:15px}.sk-home-grid,.sk-lesson-layout{grid-template-columns:1fr}.sk-home-top{align-items:flex-start;flex-direction:column;gap:20px}.sk-home-progress{padding:22px}.sk-lesson-side{grid-template-columns:1fr 1fr}.sk-lesson-side>section:last-child{grid-column:1/-1}.sk-map-count{min-width:100px}.sk-map-count>strong{font-size:32px}.sk-map-heading{gap:15px}.sk-recommend{align-items:flex-start;flex-direction:column}.sk-home-top .ac-button{width:auto}.sk-home-progress>div{display:inline-flex;margin-right:20px;gap:10px}.sk-home-progress strong{min-width:0}.sk-home-progress .ac-button{display:flex}}
@media(max-width:560px){.sk-tree,.sk-branch-shortcuts{grid-template-columns:1fr}.sk-branch>header{min-height:0;padding-bottom:15px}.sk-branch{padding:18px 15px 0}.sk-node{min-height:85px}.sk-filter{gap:7px}.sk-filter .ac-button{font-size:14px;padding:8px 12px}.sk-map-heading{display:block}.sk-map-count{margin-top:15px;text-align:left;display:flex;align-items:center;gap:12px}.sk-map-count>span{font-size:14px}.sk-recommend{padding:18px}.sk-recommend .ac-button{width:100%}.sk-lesson-main,.sk-check{padding:22px 16px}.sk-lesson-main h1,.sk-check h1{font-size:27px}.sk-explanation{font-size:17px}.sk-experiment{padding:18px 12px}.sk-step-dots{display:none}.sk-step-controls .ac-button{font-size:14px;padding:10px 12px}.sk-lesson-side{grid-template-columns:1fr}.sk-lesson-top{gap:10px}.sk-lesson-top .sk-state{margin:0}.sk-home-progress>div{display:flex}.sk-home-progress strong{min-width:95px}.sk-skip{display:block}.sk-skip .ac-button{display:flex}.sk-bars{gap:12px}.sk-tokens i{width:40px;height:40px}.sk-next{padding:25px}.sk-notebook-link{display:block}.sk-notebook-link .ac-button{margin-top:15px}.ac-header nav{gap:3px}.ac-header nav button{font-size:14px;padding:9px 10px}}
@media(prefers-reduced-motion:reduce){.sk-vessel i,.sk-bars i,.sk-light{transition:none}}
.sk-rectangle{width:calc(var(--cols) * 48px);max-width:100%}
/* Algebra keeps letter tiles distinct from ordinary units. */
.ag-intro-actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-top:20px}.ag-substitution{display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap;margin-bottom:24px}.ag-substitution>div{background:#ede6f8;border-radius:10px;padding:16px}.ag-substitution b{display:block;font-size:23px}.ag-substitution span{display:block;font-size:14px;color:#526782;margin-top:8px}.ag-tile-row,.ag-group-row{display:flex;gap:10px;align-items:center;justify-content:center;flex-wrap:wrap}.ag-tile{display:inline-flex;justify-content:center;align-items:center;min-width:52px;min-height:46px;padding:9px 12px;background:#e7dcf7;border:2px solid #7050ac;color:#49316c;border-radius:7px;font-weight:700;font-style:normal;font-size:19px;white-space:nowrap}.ag-tile.unit{background:#f7e9cd;border-color:#b97e27;color:#6c470d;min-width:37px}.ag-tile.extra{background:#d5e9fa;border-color:#3a74a2;color:#254e77}.ag-bracket-group{display:flex;gap:5px;border:2px solid #a397b9;border-radius:9px;padding:12px 8px;background:#fff}.ag-bracket-group .ag-tile{min-width:34px;padding:7px}.ag-operation{background:#eee8f7;padding:14px;border-radius:9px;margin:0 0 20px!important;text-align:left;color:#49316c!important;font-size:16px!important}.ag-balance{flex-wrap:wrap}.ag-balance>span{font-size:clamp(20px,2.5vw,30px);padding:16px}.ag-pattern{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap}.ag-pairs{display:flex;align-items:center;gap:6px;flex-wrap:wrap;justify-content:center}.ag-pairs>span{display:grid;gap:4px;border:1px dashed #7c9bc1;padding:4px;border-radius:6px}.ag-tile.pattern,.ag-tile.fixed{min-width:24px;min-height:24px;padding:2px 5px;font-size:14px;background:#dce8fb;border-color:#3059cd;color:#173352;border-radius:3px}.ag-tile.fixed{background:#f6dda0;border-color:#a7731d}.ag-coordinate-scroll{overflow:auto;max-width:100%;border-radius:10px;background:#fff}.ag-graph{display:block;width:100%;min-width:340px;max-width:500px;margin:auto;font:16px 'DM Sans',sans-serif;fill:#173352}.sk-branch-shortcuts{grid-template-columns:repeat(auto-fit,minmax(190px,1fr))}
@media(min-width:1200px){.sk-tree:not(.single){grid-template-columns:repeat(5,minmax(0,1fr))}.sk-branch>header{min-height:170px}.sk-tree.single .sk-branch>header{min-height:0}}
@media(max-width:560px){.ag-intro-actions .ac-button{width:100%}.ag-substitution{gap:10px}.ag-tile{font-size:17px}.ag-bracket-group{padding:8px 6px}.ag-balance{gap:10px}.ag-balance>span{min-width:85px;padding:12px 8px}.ag-pairs{gap:3px}.sk-branch-shortcuts{grid-template-columns:1fr}}