.react-flow{--xy-edge-stroke-default:#b1b1b7;--xy-edge-stroke-width-default:1;--xy-edge-stroke-selected-default:#555;--xy-connectionline-stroke-default:#b1b1b7;--xy-connectionline-stroke-width-default:1;--xy-attribution-background-color-default:#ffffff80;--xy-minimap-background-color-default:#fff;--xy-minimap-mask-background-color-default:#f0f0f099;--xy-minimap-mask-stroke-color-default:transparent;--xy-minimap-mask-stroke-width-default:1;--xy-minimap-node-background-color-default:#e2e2e2;--xy-minimap-node-stroke-color-default:transparent;--xy-minimap-node-stroke-width-default:2;--xy-background-color-default:transparent;--xy-background-pattern-dots-color-default:#91919a;--xy-background-pattern-lines-color-default:#eee;--xy-background-pattern-cross-color-default:#e2e2e2;background-color:var(--xy-background-color,var(--xy-background-color-default));--xy-node-color-default:inherit;--xy-node-border-default:1px solid #1a192b;--xy-node-background-color-default:#fff;--xy-node-group-background-color-default:#f0f0f040;--xy-node-boxshadow-hover-default:0 1px 4px 1px #00000014;--xy-node-boxshadow-selected-default:0 0 0 .5px #1a192b;--xy-node-border-radius-default:3px;--xy-handle-background-color-default:#1a192b;--xy-handle-border-color-default:#fff;--xy-selection-background-color-default:#0059dc14;--xy-selection-border-default:1px dotted #0059dccc;--xy-controls-button-background-color-default:#fefefe;--xy-controls-button-background-color-hover-default:#f4f4f4;--xy-controls-button-color-default:inherit;--xy-controls-button-color-hover-default:inherit;--xy-controls-button-border-color-default:#eee;--xy-controls-box-shadow-default:0 0 2px 1px #00000014;--xy-edge-label-background-color-default:#fff;--xy-edge-label-color-default:inherit;--xy-resize-background-color-default:#3367d9;direction:ltr}.react-flow.dark{--xy-edge-stroke-default:#3e3e3e;--xy-edge-stroke-width-default:1;--xy-edge-stroke-selected-default:#727272;--xy-connectionline-stroke-default:#b1b1b7;--xy-connectionline-stroke-width-default:1;--xy-attribution-background-color-default:#96969640;--xy-minimap-background-color-default:#141414;--xy-minimap-mask-background-color-default:#3c3c3c99;--xy-minimap-mask-stroke-color-default:transparent;--xy-minimap-mask-stroke-width-default:1;--xy-minimap-node-background-color-default:#2b2b2b;--xy-minimap-node-stroke-color-default:transparent;--xy-minimap-node-stroke-width-default:2;--xy-background-color-default:#141414;--xy-background-pattern-dots-color-default:#555;--xy-background-pattern-lines-color-default:#333;--xy-background-pattern-cross-color-default:#333;--xy-node-color-default:#f8f8f8;--xy-node-border-default:1px solid #3c3c3c;--xy-node-background-color-default:#1e1e1e;--xy-node-group-background-color-default:#f0f0f040;--xy-node-boxshadow-hover-default:0 1px 4px 1px #ffffff14;--xy-node-boxshadow-selected-default:0 0 0 .5px #999;--xy-handle-background-color-default:#bebebe;--xy-handle-border-color-default:#1e1e1e;--xy-selection-background-color-default:#c8c8dc14;--xy-selection-border-default:1px dotted #c8c8dccc;--xy-controls-button-background-color-default:#2b2b2b;--xy-controls-button-background-color-hover-default:#3e3e3e;--xy-controls-button-color-default:#f8f8f8;--xy-controls-button-color-hover-default:#fff;--xy-controls-button-border-color-default:#5b5b5b;--xy-controls-box-shadow-default:0 0 2px 1px #00000014;--xy-edge-label-background-color-default:#141414;--xy-edge-label-color-default:#f8f8f8}.react-flow__background{background-color:var(--xy-background-color-props,var(--xy-background-color,var(--xy-background-color-default)));pointer-events:none;z-index:-1}.react-flow__container{width:100%;height:100%;position:absolute;top:0;left:0}.react-flow__pane{z-index:1;touch-action:none}.react-flow__pane.draggable{cursor:grab}.react-flow__pane.dragging{cursor:grabbing}.react-flow__pane.selection{cursor:pointer}.react-flow__viewport{transform-origin:0 0;z-index:2;pointer-events:none}.react-flow__renderer{z-index:4}.react-flow__selection{z-index:6}.react-flow__nodesselection-rect:focus,.react-flow__nodesselection-rect:focus-visible{outline:none}.react-flow__edge-path{stroke:var(--xy-edge-stroke,var(--xy-edge-stroke-default));stroke-width:var(--xy-edge-stroke-width,var(--xy-edge-stroke-width-default));fill:none}.react-flow__connection-path{stroke:var(--xy-connectionline-stroke,var(--xy-connectionline-stroke-default));stroke-width:var(--xy-connectionline-stroke-width,var(--xy-connectionline-stroke-width-default));fill:none}.react-flow .react-flow__edges{position:absolute}.react-flow .react-flow__edges svg{pointer-events:none;position:absolute;overflow:visible}.react-flow__edge{pointer-events:visibleStroke}.react-flow__edge.selectable{cursor:pointer}.react-flow__edge.animated path{stroke-dasharray:5;animation:.5s linear infinite dashdraw}.react-flow__edge.animated path.react-flow__edge-interaction{stroke-dasharray:none;animation:none}.react-flow__edge.inactive{pointer-events:none}.react-flow__edge.selected,.react-flow__edge:focus,.react-flow__edge:focus-visible{outline:none}.react-flow__edge.selected .react-flow__edge-path,.react-flow__edge.selectable:focus .react-flow__edge-path,.react-flow__edge.selectable:focus-visible .react-flow__edge-path{stroke:var(--xy-edge-stroke-selected,var(--xy-edge-stroke-selected-default))}.react-flow__edge-textwrapper{pointer-events:all}.react-flow__edge .react-flow__edge-text{pointer-events:none;-webkit-user-select:none;user-select:none}.react-flow__arrowhead polyline{stroke:var(--xy-edge-stroke,var(--xy-edge-stroke-default))}.react-flow__arrowhead polyline.arrowclosed{fill:var(--xy-edge-stroke,var(--xy-edge-stroke-default))}.react-flow__connection{pointer-events:none}.react-flow__connection .animated{stroke-dasharray:5;animation:.5s linear infinite dashdraw}svg.react-flow__connectionline{z-index:1001;position:absolute;overflow:visible}.react-flow__nodes{pointer-events:none;transform-origin:0 0}.react-flow__node{-webkit-user-select:none;user-select:none;pointer-events:all;transform-origin:0 0;box-sizing:border-box;cursor:default;position:absolute}.react-flow__node.selectable{cursor:pointer}.react-flow__node.draggable{cursor:grab;pointer-events:all}.react-flow__node.draggable.dragging{cursor:grabbing}.react-flow__nodesselection{z-index:3;transform-origin:0 0;pointer-events:none}.react-flow__nodesselection-rect{pointer-events:all;cursor:grab;position:absolute}.react-flow__handle{pointer-events:none;background-color:var(--xy-handle-background-color,var(--xy-handle-background-color-default));border:1px solid var(--xy-handle-border-color,var(--xy-handle-border-color-default));border-radius:100%;width:6px;min-width:5px;height:6px;min-height:5px;position:absolute}.react-flow__handle.connectingfrom{pointer-events:all}.react-flow__handle.connectionindicator{pointer-events:all;cursor:crosshair}.react-flow__handle-bottom{top:auto;bottom:0;left:50%;transform:translate(-50%,50%)}.react-flow__handle-top{top:0;left:50%;transform:translate(-50%,-50%)}.react-flow__handle-left{top:50%;left:0;transform:translate(-50%,-50%)}.react-flow__handle-right{top:50%;right:0;transform:translate(50%,-50%)}.react-flow__edgeupdater{cursor:move;pointer-events:all}.react-flow__pane.selection .react-flow__panel{pointer-events:none}.react-flow__panel{z-index:5;margin:15px;position:absolute}.react-flow__panel.top{top:0}.react-flow__panel.bottom{bottom:0}.react-flow__panel.top.center,.react-flow__panel.bottom.center{left:50%;transform:translate(-15px)translate(-50%)}.react-flow__panel.left{left:0}.react-flow__panel.right{right:0}.react-flow__panel.left.center,.react-flow__panel.right.center{top:50%;transform:translateY(-15px)translateY(-50%)}.react-flow__attribution{background:var(--xy-attribution-background-color,var(--xy-attribution-background-color-default));margin:0;padding:2px 3px;font-size:10px}.react-flow__attribution a{color:#999;text-decoration:none}@keyframes dashdraw{0%{stroke-dashoffset:10px}}.react-flow__edgelabel-renderer{pointer-events:none;-webkit-user-select:none;user-select:none;width:100%;height:100%;position:absolute;top:0;left:0}.react-flow__viewport-portal{-webkit-user-select:none;user-select:none;width:100%;height:100%;position:absolute;top:0;left:0}.react-flow__minimap{background:var(--xy-minimap-background-color-props,var(--xy-minimap-background-color,var(--xy-minimap-background-color-default)))}.react-flow__minimap-svg{display:block}.react-flow__minimap-mask{fill:var(--xy-minimap-mask-background-color-props,var(--xy-minimap-mask-background-color,var(--xy-minimap-mask-background-color-default)));stroke:var(--xy-minimap-mask-stroke-color-props,var(--xy-minimap-mask-stroke-color,var(--xy-minimap-mask-stroke-color-default)));stroke-width:var(--xy-minimap-mask-stroke-width-props,var(--xy-minimap-mask-stroke-width,var(--xy-minimap-mask-stroke-width-default)))}.react-flow__minimap-node{fill:var(--xy-minimap-node-background-color-props,var(--xy-minimap-node-background-color,var(--xy-minimap-node-background-color-default)));stroke:var(--xy-minimap-node-stroke-color-props,var(--xy-minimap-node-stroke-color,var(--xy-minimap-node-stroke-color-default)));stroke-width:var(--xy-minimap-node-stroke-width-props,var(--xy-minimap-node-stroke-width,var(--xy-minimap-node-stroke-width-default)))}.react-flow__background-pattern.dots{fill:var(--xy-background-pattern-color-props,var(--xy-background-pattern-color,var(--xy-background-pattern-dots-color-default)))}.react-flow__background-pattern.lines{stroke:var(--xy-background-pattern-color-props,var(--xy-background-pattern-color,var(--xy-background-pattern-lines-color-default)))}.react-flow__background-pattern.cross{stroke:var(--xy-background-pattern-color-props,var(--xy-background-pattern-color,var(--xy-background-pattern-cross-color-default)))}.react-flow__controls{box-shadow:var(--xy-controls-box-shadow,var(--xy-controls-box-shadow-default));flex-direction:column;display:flex}.react-flow__controls.horizontal{flex-direction:row}.react-flow__controls-button{background:var(--xy-controls-button-background-color,var(--xy-controls-button-background-color-default));border:none;border-bottom:1px solid var(--xy-controls-button-border-color-props,var(--xy-controls-button-border-color,var(--xy-controls-button-border-color-default)));width:26px;height:26px;color:var(--xy-controls-button-color-props,var(--xy-controls-button-color,var(--xy-controls-button-color-default)));cursor:pointer;-webkit-user-select:none;user-select:none;justify-content:center;align-items:center;padding:4px;display:flex}.react-flow__controls-button svg{fill:currentColor;width:100%;max-width:12px;max-height:12px}.react-flow__edge.updating .react-flow__edge-path{stroke:#777}.react-flow__edge-text{font-size:10px}.react-flow__node.selectable:focus,.react-flow__node.selectable:focus-visible{outline:none}.react-flow__node-input,.react-flow__node-default,.react-flow__node-output,.react-flow__node-group{border-radius:var(--xy-node-border-radius,var(--xy-node-border-radius-default));width:150px;color:var(--xy-node-color,var(--xy-node-color-default));text-align:center;border:var(--xy-node-border,var(--xy-node-border-default));background-color:var(--xy-node-background-color,var(--xy-node-background-color-default));padding:10px;font-size:12px}.react-flow__node-input.selectable:hover,.react-flow__node-default.selectable:hover,.react-flow__node-output.selectable:hover,.react-flow__node-group.selectable:hover{box-shadow:var(--xy-node-boxshadow-hover,var(--xy-node-boxshadow-hover-default))}.react-flow__node-input.selectable.selected,.react-flow__node-input.selectable:focus,.react-flow__node-input.selectable:focus-visible,.react-flow__node-default.selectable.selected,.react-flow__node-default.selectable:focus,.react-flow__node-default.selectable:focus-visible,.react-flow__node-output.selectable.selected,.react-flow__node-output.selectable:focus,.react-flow__node-output.selectable:focus-visible,.react-flow__node-group.selectable.selected,.react-flow__node-group.selectable:focus,.react-flow__node-group.selectable:focus-visible{box-shadow:var(--xy-node-boxshadow-selected,var(--xy-node-boxshadow-selected-default))}.react-flow__node-group{background-color:var(--xy-node-group-background-color,var(--xy-node-group-background-color-default))}.react-flow__nodesselection-rect,.react-flow__selection{background:var(--xy-selection-background-color,var(--xy-selection-background-color-default));border:var(--xy-selection-border,var(--xy-selection-border-default))}.react-flow__nodesselection-rect:focus,.react-flow__nodesselection-rect:focus-visible,.react-flow__selection:focus,.react-flow__selection:focus-visible{outline:none}.react-flow__controls-button:hover{background:var(--xy-controls-button-background-color-hover-props,var(--xy-controls-button-background-color-hover,var(--xy-controls-button-background-color-hover-default)));color:var(--xy-controls-button-color-hover-props,var(--xy-controls-button-color-hover,var(--xy-controls-button-color-hover-default)))}.react-flow__controls-button:disabled{pointer-events:none}.react-flow__controls-button:disabled svg{fill-opacity:.4}.react-flow__controls-button:last-child{border-bottom:none}.react-flow__controls.horizontal .react-flow__controls-button{border-bottom:none;border-right:1px solid var(--xy-controls-button-border-color-props,var(--xy-controls-button-border-color,var(--xy-controls-button-border-color-default)))}.react-flow__controls.horizontal .react-flow__controls-button:last-child{border-right:none}.react-flow__resize-control{position:absolute}.react-flow__resize-control.left,.react-flow__resize-control.right{cursor:ew-resize}.react-flow__resize-control.top,.react-flow__resize-control.bottom{cursor:ns-resize}.react-flow__resize-control.top.left,.react-flow__resize-control.bottom.right{cursor:nwse-resize}.react-flow__resize-control.bottom.left,.react-flow__resize-control.top.right{cursor:nesw-resize}.react-flow__resize-control.handle{background-color:var(--xy-resize-background-color,var(--xy-resize-background-color-default));border:1px solid #fff;border-radius:1px;width:5px;height:5px;translate:-50% -50%}.react-flow__resize-control.handle.left{top:50%;left:0}.react-flow__resize-control.handle.right{top:50%;left:100%}.react-flow__resize-control.handle.top{top:0;left:50%}.react-flow__resize-control.handle.bottom{top:100%;left:50%}.react-flow__resize-control.handle.top.left,.react-flow__resize-control.handle.bottom.left{left:0}.react-flow__resize-control.handle.top.right,.react-flow__resize-control.handle.bottom.right{left:100%}.react-flow__resize-control.line{border-color:var(--xy-resize-background-color,var(--xy-resize-background-color-default));border-style:solid;border-width:0}.react-flow__resize-control.line.left,.react-flow__resize-control.line.right{width:1px;height:100%;top:0;transform:translate(-50%)}.react-flow__resize-control.line.left{border-left-width:1px;left:0}.react-flow__resize-control.line.right{border-right-width:1px;left:100%}.react-flow__resize-control.line.top,.react-flow__resize-control.line.bottom{width:100%;height:1px;left:0;transform:translateY(-50%)}.react-flow__resize-control.line.top{border-top-width:1px;top:0}.react-flow__resize-control.line.bottom{border-bottom-width:1px;top:100%}.react-flow__edge-textbg{fill:var(--xy-edge-label-background-color,var(--xy-edge-label-background-color-default))}.react-flow__edge-text{fill:var(--xy-edge-label-color,var(--xy-edge-label-color-default))}:root{--bg:#f5f6f8;--panel:#fff;--border:#d5d9e0;--text:#1f2430;--muted:#667085;--accent:#3b6fe0;--success:#1f9d55;--error:#d92d20;--variable:#ffe9a8;--scalar:#d9e6ff;--array:#dff5e3;--object:#f1e1fb;--pet:#ffe3d3;--code-bg:#1f2430;--tap:44px;color:var(--text);-webkit-text-size-adjust:100%;-moz-text-size-adjust:100%;text-size-adjust:100%;font-family:system-ui,-apple-system,Segoe UI,sans-serif}*{box-sizing:border-box}html,body,#root{background:var(--bg);height:100%;margin:0}button{font:inherit;cursor:pointer;-webkit-tap-highlight-color:transparent}button:disabled{cursor:default}input,select,textarea{font-size:16px}.primary-button,.secondary-button{min-height:var(--tap);border:1px solid var(--accent);border-radius:10px;padding:0 16px;font-weight:600}.primary-button{background:var(--accent);color:#fff}.secondary-button{background:var(--panel);color:var(--accent)}.secondary-button[aria-pressed=true]{background:#e7eefc}.primary-button:disabled,.secondary-button:disabled{opacity:.55}.text-button{min-height:var(--tap);color:var(--accent);background:0 0;border:none;padding:0 8px;font-weight:600}.text-button:disabled{color:var(--muted)}.icon-button{min-width:var(--tap);min-height:var(--tap);border:1px solid var(--border);background:var(--panel);color:var(--accent);border-radius:10px;place-items:center;font-size:1.3rem;line-height:1;display:inline-grid}.icon-button:disabled{color:var(--muted);opacity:.5}.language-select{border:1px solid var(--border);background:var(--panel) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%23667085' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat right 10px center;min-height:36px;color:var(--text);cursor:pointer;appearance:none;border-radius:10px;flex-shrink:0;padding:0 28px 0 10px;font-weight:600}.language-select:focus-visible{outline:2px solid var(--accent);outline-offset:1px}.segmented-control{border:2px solid var(--accent);border-radius:10px;display:flex;overflow:hidden}.segmented-option{background:var(--panel);min-height:50px;color:var(--accent);border:none;flex:1;padding:0 16px;font-size:.95rem;font-weight:600}.segmented-option+.segmented-option{border-left:1px solid var(--accent)}.segmented-option.active{background:var(--accent);color:#fff;font-weight:700}@media (width<=600px){.segmented-control{width:100%}}@media (width<=480px){.segmented-option{padding:0 8px}}.progress-meter{background:#00000014;border-radius:999px;height:8px;margin-top:8px;overflow:hidden}.progress-meter-fill{background:var(--accent);border-radius:999px;height:100%;transition:width .3s}.level-card.complete .progress-meter-fill{background:var(--success)}.home-screen{max-width:760px;padding:20px 16px calc(36px + env(safe-area-inset-bottom));margin:0 auto}.hero-card{color:#fff;background:linear-gradient(145deg,#181c25 0%,#1e283d 55%,#233968 100%);border-radius:16px;flex-direction:column;gap:16px;padding:24px 20px 20px;display:flex;position:relative;overflow:hidden;box-shadow:0 4px 20px #00000026}@media (width>=680px){.hero-card{flex-direction:row;justify-content:space-between;align-items:center;padding:28px 24px}.hero-content{flex:1;max-width:340px}}.hero-title{letter-spacing:-.02em;color:#fff;margin:0 0 6px;font-size:1.85rem;font-weight:800}.hero-tagline{color:#c4d3eb;margin:0;font-size:1.05rem;line-height:1.45}.hero-diagram-wrap{justify-content:center;align-items:center;display:flex}.hero-diagram{width:100%;max-width:330px;height:auto;display:block}.hero-node{animation:.45s cubic-bezier(.16,1,.3,1) backwards hero-pop}.hero-var-a{animation-delay:50ms}.hero-var-b{animation-delay:.15s}.hero-array{animation-delay:.35s}.hero-scalar-1{animation-delay:.65s}.hero-scalar-2{animation-delay:.75s}.hero-arrow{stroke-dasharray:200;stroke-dashoffset:200px;animation:.55s ease-out forwards hero-draw}.hero-arrow-1{animation-delay:.2s}.hero-arrow-2{animation-delay:.25s}.hero-arrow-3{animation-delay:.5s}.hero-arrow-4{animation-delay:.55s}@keyframes hero-pop{0%{opacity:0;transform-origin:50%;transform:scale(.85)}to{opacity:1;transform:scale(1)}}@keyframes hero-draw{to{stroke-dashoffset:0}}@media (prefers-reduced-motion:reduce){.hero-node{opacity:1!important;animation:none!important;transform:none!important}.hero-arrow{stroke-dashoffset:0!important;animation:none!important}}.home-action-bar{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;margin:18px 0 24px;display:flex}.home-primary-action{flex:1;min-width:220px}.home-continue-button{text-align:left;flex-direction:column;justify-content:center;align-items:flex-start;gap:2px;width:100%;min-height:50px;padding:8px 18px;display:flex}.home-continue-label{font-size:1.05rem;font-weight:700}.home-continue-subtext{opacity:.9;white-space:nowrap;text-overflow:ellipsis;max-width:100%;font-size:.8rem;font-weight:400;overflow:hidden}.all-solved-banner{color:var(--success);background:#1f9d551f;border:1px solid #1f9d554d;border-radius:10px;align-items:center;gap:8px;padding:10px 16px;font-size:.95rem;font-weight:600;display:flex}.all-solved-icon{font-size:1.1rem}.home-levels{margin-top:8px}.home-levels-header{justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:12px;display:flex}.home-levels-title{margin:0;font-size:1.25rem;font-weight:700}.home-levels-progress{color:var(--muted);font-size:.85rem}.level-cards-list{flex-direction:column;gap:10px;margin:0;padding:0;list-style:none;display:flex}.level-card{background:var(--panel);border:1px solid var(--border);text-align:left;width:100%;color:var(--text);border-radius:12px;padding:14px 16px;transition:border-color .15s,box-shadow .15s}.level-card:hover{border-color:var(--accent)}.level-card.current{border-color:var(--accent);box-shadow:0 0 0 2px #3b6fe040}.level-card.complete{border-color:#a8dfbe}.level-card-main{align-items:center;gap:12px;display:flex}.level-card-badge{background:var(--bg);border-radius:50%;flex-shrink:0;place-items:center;width:34px;height:34px;font-size:.95rem;font-weight:700;display:grid}.level-card.complete .level-card-badge{color:var(--success);background:#1f9d5526}.level-card-info{flex:1;justify-content:space-between;align-items:baseline;gap:8px;min-width:0;display:flex}.level-card-title{margin:0;font-size:1.05rem;font-weight:600}.level-card-count{color:var(--muted);white-space:nowrap;font-size:.85rem}.home-footer{flex-wrap:wrap;justify-content:center;align-items:center;gap:4px 20px;margin-top:24px;padding-top:12px;display:flex}.home-reset,.home-feedback{padding:4px 8px;font-size:.85rem}.home-feedback{min-height:var(--tap);color:var(--accent);align-items:center;font-weight:600;text-decoration:none;display:inline-flex}.home-feedback:hover{text-decoration:underline}.level-screen{background:var(--bg);flex-direction:column;min-height:100dvh;display:flex}.level-screen-header{padding:8px 16px;padding-top:max(8px, env(safe-area-inset-top));background:var(--panel);border-bottom:1px solid var(--border);flex-shrink:0;justify-content:space-between;align-items:center;gap:12px;display:flex}.level-screen-back{padding-left:0;font-size:1rem}.level-screen-body{width:100%;max-width:760px;padding:20px 16px calc(36px + env(safe-area-inset-bottom));flex:1;margin:0 auto}.level-hero{align-items:center;gap:14px;margin-bottom:12px;display:flex}.level-hero-badge{background:var(--accent);color:#fff;border-radius:50%;flex-shrink:0;place-items:center;width:44px;height:44px;font-size:1.25rem;font-weight:800;display:grid}.level-hero-info{flex:1;min-width:0}.level-hero-title{margin:0;font-size:1.35rem;font-weight:700;line-height:1.25}.level-hero-count{color:var(--muted);margin:4px 0 0;font-size:.9rem}.level-continue-button{width:100%;min-height:46px;margin-top:16px;font-size:1rem}.level-problem-section{margin-top:24px}.level-section-heading{color:var(--text);margin:0 0 10px;font-size:1rem;font-weight:700}.challenge-heading-row{justify-content:space-between;align-items:baseline;gap:8px;margin:20px 0 10px;display:flex}.challenge-heading-row .challenge-heading{margin:0}.challenge-heading-note{color:var(--muted);font-size:.8rem;font-style:italic}.level-footer-nav{border-top:1px solid var(--border);justify-content:space-between;align-items:center;gap:12px;margin-top:36px;padding-top:16px;display:flex}.problem-list{grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:8px;margin:0;padding:0;list-style:none;display:grid}.challenge-heading{color:var(--muted);text-transform:uppercase;letter-spacing:.04em;margin:14px 0 8px;font-size:.8rem;font-weight:600}.problem-chip{width:100%;min-height:var(--tap);background:var(--panel);border:1px solid var(--border);color:var(--text);text-align:left;border-radius:10px;align-items:center;gap:10px;padding:8px 12px;display:flex}.problem-chip:hover{border-color:var(--accent)}.problem-chip.done{border-color:var(--success);background:#1f9d550a}.problem-chip-number{color:var(--muted);font-weight:600}.problem-chip-title{flex:1;font-size:.95rem}.hidden-title{color:var(--muted);font-style:italic;font-weight:400}.problem-chip-check{color:var(--success);font-weight:700}.problem-screen{flex-direction:column;height:100dvh;display:flex;overflow:hidden}.problem-header{padding:4px 8px;padding-top:max(4px, env(safe-area-inset-top));background:var(--panel);border-bottom:1px solid var(--border);flex-shrink:0;align-items:center;gap:4px;display:flex}.header-back{white-space:nowrap;padding-left:4px}.header-stepper{flex:1;justify-content:center;align-items:center;gap:4px;min-width:0;display:flex}.header-position{min-width:56px;color:var(--muted);text-align:center;white-space:nowrap;font-size:.85rem}.header-stepper .icon-button{background:0 0;border:none;min-width:36px}.problem-panel{background:var(--panel);border-bottom:1px solid var(--border);flex-shrink:0;max-height:38dvh;padding:8px 12px 10px;overflow-y:auto}.problem-panel:has(.problem-about[open]){max-height:none;overflow-y:visible}.problem-title-row{justify-content:space-between;align-items:center;gap:8px;display:flex}.problem-title{margin:2px 0;font-size:1.1rem;line-height:1.25}.problem-title:focus{outline:none}.problem-title-row .text-button{flex-shrink:0;min-height:36px;font-size:.85rem}.code-snippet{background:var(--code-bg);color:#f2f4f8;border-radius:8px;margin:6px 0;padding:10px 12px;font-size:.9rem;line-height:1.4;overflow-x:auto}.problem-constraints{background:#fff6e0;border-left:4px solid #e0a020;border-radius:6px;margin:6px 0;padding:8px 12px;font-size:.9rem;line-height:1.45}.problem-tip{background:#e8f6ec;border-left:4px solid #3a9a5b;border-radius:6px;margin:6px 0;padding:8px 12px;font-size:.9rem;line-height:1.45}.problem-tip-heading{text-transform:uppercase;letter-spacing:.04em;margin:0 0 2px;font-size:.8rem;font-weight:700}.problem-tip p{margin:0}.problem-constraints-heading{text-transform:uppercase;letter-spacing:.04em;margin:0 0 2px;font-size:.8rem;font-weight:700}.problem-constraints ul{margin:0;padding:0;list-style:none}.problem-constraints li+li{margin-top:4px}.curriculum-html code{background:#0000000f;border-radius:4px;padding:1px 4px;font-family:monospace;font-size:.9em}.problem-about{color:var(--muted);margin-top:4px;font-size:.9rem}.problem-about summary{min-height:32px;color:var(--accent);cursor:pointer;align-items:center;font-weight:600;list-style:none;display:flex}.problem-about summary::-webkit-details-marker{display:none}.problem-about-chevron{margin-right:6px;transition:transform .15s;display:inline-block}.problem-about[open] .problem-about-chevron{transform:rotate(90deg)}.problem-about-toggle{color:var(--accent);margin-left:auto;font-size:.85rem}.problem-feedback{font-size:.85rem}.problem-feedback a{color:var(--accent);font-weight:600}.problem-about-done{margin-top:4px;padding-left:0}.level-heading{color:var(--text);margin:4px 0;font-size:.95rem}.level-description,.level-instructions{margin:4px 0 8px;line-height:1.45}.workspace{flex-direction:column;flex:1;min-height:0;display:flex}.canvas{flex:1;min-height:120px;position:relative}.editor-panel{background:var(--panel);border-top:1px solid var(--border);flex-direction:column;flex-shrink:0;max-height:40dvh;padding:8px 12px;display:flex;overflow-y:auto}.editor-caption{color:var(--muted);margin:0;font-size:.8rem}.editor-hint{opacity:.85;font-style:italic}.given-code{margin:4px 0 8px}.then-caption{margin-top:8px}.then-code{margin:4px 0 0}.code-editor{border:1px solid var(--border);resize:vertical;background:#fbfbfd;border-radius:8px;min-height:112px;margin-top:4px;padding:10px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;line-height:1.4}.canvas-toolbar{background:var(--panel);border-bottom:1px solid var(--border);flex-shrink:0;padding:8px 8px 6px}.toolbar{flex-wrap:nowrap;gap:4px;display:flex}.toolbar-button{min-width:0;min-height:40px;color:var(--text);white-space:nowrap;text-overflow:ellipsis;border:1px solid #555b6b;border-radius:10px;flex:auto;padding:0 6px;font-size:.8rem;font-weight:600;overflow:hidden;box-shadow:0 1px 2px #0000001f}.toolbar-variable{background:var(--variable)}.toolbar-scalar{background:var(--scalar)}.toolbar-array{background:var(--array)}.toolbar-object{background:var(--object)}.toolbar-pet{background:var(--pet)}.canvas-actions{flex-direction:column;align-items:center;gap:8px;display:flex}.canvas-actions .react-flow__controls{margin:0;position:static}.canvas-delete,.canvas-duplicate,.canvas-multiselect{border:1px solid var(--border);background:var(--panel);cursor:pointer;border-radius:4px;justify-content:center;align-items:center;width:26px;height:26px;min-height:26px;padding:4px;display:flex;box-shadow:0 1px 3px #00000026}.canvas-delete{color:var(--error)}.canvas-delete:hover{border-color:var(--error);background:#fee4e2}.canvas-duplicate,.canvas-multiselect{color:var(--text)}.canvas-duplicate:hover,.canvas-multiselect:hover{background:var(--bg);border-color:var(--accent)}.canvas-multiselect.active{background:var(--accent);border-color:var(--accent);color:#fff}.canvas-delete svg,.canvas-duplicate svg,.canvas-multiselect svg{width:14px;height:14px;display:block}.multi-select-banner{gap:8px}.connect-banner{background:var(--text);color:#fff;white-space:nowrap;border-radius:999px;align-items:center;gap:4px;padding:4px 4px 4px 12px;font-size:.85rem;display:flex;box-shadow:0 2px 6px #00000040}.connect-banner .text-button{color:#a9c2ff;min-height:36px}.react-flow__controls{box-shadow:0 1px 3px #00000026}.mem-node{background:var(--panel);border:2px solid #555b6b;border-radius:8px;min-width:120px;padding:10px 10px 8px;font-size:.9rem;position:relative}.mem-node.selected{box-shadow:0 0 0 3px #3b6fe066}.mem-node.flagged{border-color:var(--error);box-shadow:0 0 0 3px #d92d204d}.react-flow__node.connect-target .mem-node{border-style:dashed;border-color:var(--accent)}.variable-node{background:var(--variable);border-radius:4px}.variable-node.read-only{padding-top:8px}.scalar-node{background:var(--scalar);border-radius:4px}.array-node{background:var(--array)}.object-node{background:var(--object)}.pet-node{background:var(--pet);border-radius:4px}.pet-field{align-items:center;gap:6px;display:flex}.pet-field-label{white-space:nowrap;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.pet-node.read-only{padding-top:8px}.mem-node-header{cursor:grab;align-items:center;gap:6px;min-height:28px;display:flex}.mem-node-title{letter-spacing:.06em;text-transform:uppercase;color:var(--muted);flex:1;font-size:.7rem;font-weight:700}.mem-grip{color:#00000059;letter-spacing:-1px;font-size:.9rem}.scalar-kind{color:inherit;letter-spacing:.06em;text-transform:uppercase;background:#fff9;border:1px solid #0003;border-radius:4px;padding:0 2px;font-size:.75rem;font-weight:700}.scalar-string{align-items:center;gap:2px;display:flex}.scalar-quote,.scalar-fixed{font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.scalar-quote{font-size:1.2rem;font-weight:700}.scalar-fixed{padding:3px 6px;display:block}.mem-input{background:#ffffffd9;border:1px solid #00000040;border-radius:4px;width:8.5em;min-width:0;padding:3px 6px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.mem-input-invalid{background:#fff5f5;border-color:#b42318}.quoted-literal-field{flex-direction:column;align-items:flex-start;gap:2px;display:flex}.mem-field-error{color:#b42318;max-width:14em;margin:0;font-size:.65rem;line-height:1.25}@supports (field-sizing:content){.mem-input{field-sizing:content;width:auto;min-width:7em;max-width:14em}}select.mem-input{width:auto}.mem-row{align-items:center;gap:6px;margin:4px 0;padding-right:4px;display:flex;position:relative}.mem-index{text-align:center;background:#fffc;border:1px solid #00000040;border-radius:4px;min-width:24px;padding:2px 6px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.mem-slot-cell{background:#ffffffd9;border:1px solid #00000040;border-radius:4px;flex:1;justify-content:center;align-items:center;min-width:36px;height:26px;display:flex;position:relative}.mem-slot-cell .react-flow__handle{cursor:crosshair;border-radius:4px;width:100%;min-width:0;height:100%;min-height:0;position:absolute;inset:0;transform:none}.mem-spacer{flex:1;min-width:24px}.mem-entry-key{text-align:left;width:5.5em;min-width:5.5em;max-width:9em}@supports (field-sizing:content){.mem-entry-key.mem-input{field-sizing:content;width:auto;min-width:4.5em;max-width:9em}}.mem-empty{color:var(--muted);font-size:.8rem;font-style:italic}.mem-icon-button{color:var(--muted);background:0 0;border:none;padding:0 6px;font-size:1.1rem;line-height:1}.mem-add-button{background:0 0;border:1px dashed #555b6b;border-radius:4px;margin-top:4px;padding:2px 8px;font-size:.8rem}.react-flow__node{pointer-events:none}.react-flow__node .mem-node-header,.react-flow__node .nodrag{pointer-events:all}.react-flow__node .react-flow__handle{pointer-events:none}.react-flow__node.connect-target{pointer-events:all}.react-flow__edges,svg.react-flow__connectionline{z-index:1001}.react-flow__edgelabel-renderer{z-index:1002}.react-flow__viewport-portal{z-index:1003;pointer-events:none}.mem-handle-hit{pointer-events:all;cursor:crosshair;background:0 0;position:absolute}.mem-edge-bend-handle{border:2px solid var(--accent);cursor:grab;touch-action:none;background:#fff;border-radius:100%;width:14px;height:14px;position:relative;box-shadow:0 1px 4px #0003}.mem-edge-bend-handle:before{content:"";position:absolute;inset:-10px}.mem-edge-bend-handle:active{cursor:grabbing}@media (pointer:coarse){.mem-edge-bend-handle{width:22px;height:22px}}.react-flow__handle{opacity:0;width:12px;height:12px}.mem-handle-visual{box-sizing:border-box;pointer-events:none;background:#555b6b;border:2px solid #fff;border-radius:100%;width:12px;height:12px;position:absolute;transform:translate(-50%,-50%)}@keyframes mem-handle-connect-pulse{0%,to{background:var(--accent);box-shadow:0 0 0 3px #3b6fe08c}50%{background:#7da3f5;box-shadow:0 0 0 9px #3b6fe01f}}.mem-handle-visual.clickconnecting{animation:1.75s ease-in-out infinite mem-handle-connect-pulse}@media (prefers-reduced-motion:reduce){.mem-handle-visual.clickconnecting{background:var(--accent);animation:none;box-shadow:0 0 0 4px #3b6fe066}}.mem-handle-visual.handle-error{background:var(--error);box-shadow:0 0 0 3px #d92d2059}.react-flow__handle.clickconnecting,.react-flow__handle.handle-error{opacity:0}.react-flow__edge.edge-error .react-flow__edge-path{stroke:var(--error);stroke-width:3px}@media (pointer:coarse){.react-flow__edge-path{stroke-width:2.5px}.mem-node{min-width:140px}.mem-node-header{min-height:32px}.react-flow__handle,.mem-handle-visual{width:22px;height:22px}.mem-icon-button{min-width:32px;min-height:32px}.mem-slot-cell{min-height:32px}.mem-add-button{min-height:32px;padding:0 12px}.react-flow__controls-button{width:36px;height:36px}.canvas-delete,.canvas-duplicate,.canvas-multiselect{width:36px;height:36px;min-height:36px}.canvas-delete svg,.canvas-duplicate svg,.canvas-multiselect svg{width:18px;height:18px}}.action-bar{background:var(--panel);border-top:1px solid var(--border);flex-direction:column;flex-shrink:0;display:flex;position:relative}.action-row{padding:8px;padding-bottom:max(8px, env(safe-area-inset-bottom));gap:6px;display:flex}.action-row .secondary-button{padding:0 10px}.action-primary{flex:1}.feedback-sheet{z-index:10;background:var(--panel);border-top:1px solid var(--border);border-radius:14px 14px 0 0;max-height:45dvh;padding:12px 12px 10px;position:absolute;bottom:100%;left:0;right:0;overflow-y:auto;box-shadow:0 -4px 16px #0000001f}.feedback-close{color:var(--muted);background:0 0;border:none;position:absolute;top:2px;right:2px}.feedback-sheet>.check-result{margin-right:36px}.feedback-sheet>.check-result+.check-result{margin-top:10px}.error-list{color:var(--error);font-size:.95rem}.error-list ul{margin:6px 0 0;padding-left:20px}.error-list li+li{margin-top:4px}.hint-box{color:#5c4400;background:#fef8e7;border:1px solid #e6d38e;border-radius:8px;align-items:flex-start;gap:10px;padding:10px 12px;font-size:.95rem;line-height:1.4;display:flex}.hint-tag{color:#5c4400;letter-spacing:.05em;text-transform:uppercase;background:#f7e4a8;border-radius:4px;flex-shrink:0;padding:2px 6px;font-size:.7rem;font-weight:700}.answer-box{color:#1a3668;background:#edf3fc;border:1px solid #b7ccf0;border-radius:8px;padding:10px 12px;font-size:.95rem;line-height:1.4}.answer-box-header{justify-content:space-between;align-items:center;gap:8px;display:flex}.answer-tag{font-weight:700}.answer-note{color:#536b94;margin:6px 0 0;font-size:.85rem}.answer-box .code-snippet{margin:6px 0}.copy-solution-button{min-height:36px;padding:0 10px;font-size:.85rem}.success-message{color:var(--success);flex-wrap:wrap;align-items:center;gap:10px 12px;font-weight:600;animation:.5s ease-out success-pop;display:flex}.success-burst{background:var(--success);color:#fff;border-radius:50%;flex-shrink:0;place-items:center;width:28px;height:28px;animation:1.2s ease-out 2 success-pulse;display:grid}.success-text{flex:1;min-width:160px}@keyframes success-pop{0%{opacity:0;transform:scale(.95)}to{opacity:1;transform:scale(1)}}@keyframes success-pulse{0%{box-shadow:0 0 #1f9d5599}to{box-shadow:0 0 0 16px #1f9d5500}}@media (width>=900px){.problem-screen{grid-template:"header workspace""panel workspace"1fr"panel actions"/380px 1fr;display:grid}.problem-header{border-right:1px solid var(--border);grid-area:header}.problem-panel{border-right:1px solid var(--border);border-bottom:none;grid-area:panel;max-height:none;padding:12px 16px}.problem-title{font-size:1.3rem}.workspace{grid-area:workspace}.editor-panel{max-height:45vh}.action-bar{grid-area:actions}.action-row{order:0;max-width:640px}.feedback-sheet{max-height:40vh;box-shadow:none;border-radius:0;order:1;position:relative;inset:auto}}@media (width>=900px) and (pointer:fine){.code-editor,.mem-input,.scalar-kind{font-size:.9rem}}.debrief{flex:1;width:100%;max-width:760px;min-height:0;margin:0 auto;padding:20px;overflow-y:auto}.debrief-banner{color:var(--success);background:#1f9d551f;border-radius:999px;align-items:center;gap:10px;margin-bottom:16px;padding:6px 14px;font-size:.95rem;font-weight:600;display:inline-flex}.debrief-banner .success-burst{width:20px;height:20px;font-size:.8rem;animation:none}.debrief-heading{color:var(--text);margin:0 0 16px;font-size:1.25rem}.debrief-body{color:var(--text);flex-direction:column;gap:14px;line-height:1.55;display:flex}.debrief-html p{margin:0 0 10px}.debrief-html p:last-child{margin-bottom:0}.debrief-html pre{background:var(--code-bg);color:#f2f4f8;border-radius:8px;margin:8px 0 10px;padding:10px 12px;font-family:monospace;font-size:.9rem;line-height:1.4;overflow-x:auto}.debrief-html code{background:#0000000f;border-radius:4px;padding:1px 4px;font-family:monospace;font-size:.9em}.debrief-html pre code{color:inherit;background:0 0;padding:0}.debrief-html ol{margin:8px 0 10px 20px;padding:0}.debrief-html li{margin-bottom:4px}.debrief-figure{border:1px solid var(--border);background:var(--panel);border-radius:8px;margin:8px 0;position:relative;overflow:hidden}.debrief-canvas-wrapper{resize:vertical;width:100%;height:240px;min-height:160px;max-height:800px;position:relative;overflow:hidden}.debrief-canvas-wrapper .canvas{height:100%}.debrief-resize-handle{background:var(--panel);border-top:1px solid var(--border);cursor:ns-resize;touch-action:none;-webkit-user-select:none;user-select:none;justify-content:center;align-items:center;height:14px;transition:background .15s;display:flex}.debrief-resize-handle:hover,.debrief-resize-handle:focus-visible,.debrief-resize-handle.resizing{background:var(--bg);outline:none}.debrief-resize-grip{background:var(--muted);opacity:.45;border-radius:2px;width:36px;height:4px;transition:opacity .15s,width .15s}.debrief-resize-handle:hover .debrief-resize-grip,.debrief-resize-handle:focus-visible .debrief-resize-grip,.debrief-resize-handle.resizing .debrief-resize-grip{opacity:.85;width:48px}.debrief-caption{border-top:1px solid var(--border);background:var(--bg);color:var(--muted);padding:8px 14px;font-size:.85rem}.debrief-badge{z-index:5;letter-spacing:.02em;text-transform:uppercase;border-radius:4px;padding:2px 8px;font-size:.75rem;font-weight:600;position:absolute;top:8px;right:8px}.debrief-badge-correct{color:var(--success);background:#1f9d5526;border:1px solid #1f9d554d}.debrief-badge-incorrect{color:var(--error);background:#d92d2026;border:1px solid #d92d204d}