:root{--ink:#18191b;--muted:#64666c;--hair:#d9dadd;--quiet:#f3f3f4;--paper:#fff;--accent:#232426;--stroke:var(--hair);--wash:var(--quiet);--mono:ui-monospace,SFMono-Regular,Consolas,"Liberation Mono",monospace;--serif:Arial,Helvetica,sans-serif;font-family:Arial,Helvetica,sans-serif;color:var(--ink);background:white;font-synthesis:none;-webkit-font-smoothing:antialiased}
*{box-sizing:border-box}body{margin:0}button,a,input,select{font:inherit}button{border:0;color:inherit;background:none;cursor:pointer}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,#figure:focus-visible,select:focus-visible{outline:2px solid #30343a;outline-offset:4px}button:disabled{opacity:.45;cursor:default}
.sr,.skip:not(:focus){position:absolute;width:1px;height:1px;clip-path:inset(50%);overflow:hidden}.skip:focus{position:fixed;z-index:99;background:white;padding:12px}.wrap{width:min(calc(100% - clamp(36px,9vw,160px)),1550px);margin-inline:auto}.masthead{border-bottom:1px solid var(--hair)}.bar{height:65px;display:flex;align-items:center;justify-content:space-between}.brand{display:inline-flex;gap:10px;align-items:center;font-size:23px;font-weight:650;letter-spacing:-1.2px;text-decoration:none}.brand img{width:31px;height:33px}.bar nav{display:flex;gap:28px}.bar nav button,.crumb button,footer button{display:inline-flex;align-items:center;gap:8px;font-size:13px;min-height:38px;padding:4px 0}.bar nav button:hover,.crumb button:hover,footer button:hover{text-decoration:underline;text-underline-offset:4px}[data-icon]{display:inline-flex;align-items:center;justify-content:center;flex-shrink:0}svg.ico{width:17px;height:17px;display:block;fill:none;stroke:currentColor;stroke-width:1.55;stroke-linecap:round;stroke-linejoin:round}
.contextbar{padding:17px 0 8px;display:flex;justify-content:space-between;align-items:center;gap:12px}.crumb{display:flex;align-items:center;gap:10px;font-size:13px;color:#73757a}.crumb span{color:#aaa}.crumb button{min-height:26px;color:#64666b}.crumb #crumb-robot{color:#292a2b}.tabs{display:flex;gap:3px;border:1px solid var(--hair);padding:3px;border-radius:6px}.tabs button{display:flex;align-items:center;gap:6px;font-size:12px;font-weight:500;color:#5e6065;min-width:84px;min-height:29px;justify-content:center;border-radius:3px}.tabs button.active{color:white;background:#252628}.tabs button:not(.active):hover{background:var(--quiet)}.tabs .ico{width:15px;height:15px}
.workspace{display:grid;grid-template-columns:minmax(250px,.76fr) minmax(0,1.48fr);grid-template-rows:auto 1fr;column-gap:clamp(30px,5%,86px);align-items:start;padding:27px 0 31px}.subject{grid-column:1;grid-row:1;min-width:0}.smallcap,.kicker,.section-label,.stage-info{font:500 10px/1.5 var(--mono);text-transform:uppercase;letter-spacing:1.2px;color:#72747a}.subject h1{font-size:clamp(69px,7.4vw,118px);line-height:.94;letter-spacing:-.082em;font-weight:590;margin:11px 0 27px;overflow-wrap:break-word}.subject h1.compact{font-size:clamp(44px,4.8vw,77px);line-height:1;letter-spacing:-.075em}.guide{grid-column:1;grid-row:2;min-width:0;outline:0}.guide h2,.dialog-top+h2,#dialog-content h2{font-weight:600;letter-spacing:-.045em;font-size:clamp(25px,2.25vw,36px);line-height:1.08;margin:0 0 12px}.guide p,dialog p{font-size:15px;line-height:1.55;color:#53555b;margin:0 0 14px;overflow-wrap:break-word}.guide .overview p{font-size:clamp(15px,1.24vw,20px);line-height:1.53;max-width:36ch}.overview h2{max-width:19ch}.actions{display:flex;flex-wrap:wrap;align-items:center;gap:17px;margin:21px 0}.primary,.secondary,.text-action{display:inline-flex;align-items:center;justify-content:center;gap:8px;font-size:13px;font-weight:600;min-height:39px;padding:9px 14px;border-radius:4px;text-decoration:none;line-height:1.25}.primary{background:var(--ink);color:white;border:1px solid var(--ink)}.primary:hover{background:#383a3d}.secondary{background:white;border:1px solid var(--hair)}.secondary:hover{border-color:#777}.text-action{padding-inline:0;font-weight:500}.text-action:hover{text-decoration:underline;text-underline-offset:4px}.actions svg{width:15px;height:15px}.specs{display:flex;gap:26px;margin:27px 0 0;border-top:1px solid var(--hair);padding-top:15px;max-width:345px}.specs div{flex:1}.specs strong{display:block;font-size:28px;line-height:1.05;font-weight:560;letter-spacing:-1.5px}.specs small{display:block;margin-top:6px;font:10px/1.4 var(--mono);letter-spacing:.5px;text-transform:uppercase;color:#696c72}
.stage{grid-column:2;grid-row:1 / span 2;min-width:0;align-self:start;position:relative}.stage-info{display:flex;justify-content:space-between;gap:12px;min-height:18px;line-height:1.25;font-size:9px}.stage-info span:last-child{color:#8b8c91}.figure-area{height:clamp(425px,55vh,660px);position:relative;isolation:isolate}#figure{position:absolute;inset:0;width:100%;height:100%;cursor:grab;touch-action:pan-y}#figure:active{cursor:grabbing}#callouts{position:absolute;inset:0;pointer-events:none}.callout{position:absolute;transform:translate(-50%,-50%);pointer-events:auto;background:#202123;color:#fff;border:1.5px solid white;box-shadow:0 0 0 .6px #3335;border-radius:100%;width:23px;height:23px;display:grid;place-items:center;font:600 11px/1 Arial,sans-serif;padding:0;transition:background .15s}.callout:before{content:"";position:absolute;inset:-5px}.callout:hover,.callout.chosen{outline:1px solid #333}.callout span{display:none;position:absolute;bottom:calc(100% + 6px);left:50%;transform:translateX(-50%);padding:5px 8px;font:12px/1.3 Arial,sans-serif;white-space:nowrap;background:var(--ink);color:white;border-radius:3px;pointer-events:none}.callout:hover span,.callout:focus-visible span{display:block}.view-toolbar{display:flex;justify-content:center;align-items:center;gap:15px;margin-top:6px}.mode-switch,.turn-tools{display:flex;align-items:center;gap:3px}.mode-switch{border:1px solid var(--hair);padding:2px;border-radius:5px}.mode-switch button,.turn-tools button{min-height:30px;display:inline-flex;align-items:center;justify-content:center;gap:5px;line-height:1;padding:6px 10px;font-size:11px;border-radius:3px}.mode-switch .selected{background:#e9e9eb;font-weight:600}.turn-tools{border-left:1px solid var(--hair);padding-left:10px}.turn-tools button{padding:5px 8px}.turn-tools button:hover,.mode-switch button:hover{background:var(--quiet)}.mode-switch .ico,.turn-tools .ico{width:15px;height:15px}.caption{text-align:center;color:#71747a;font-size:11px;line-height:1.5;margin:8px 0 0}.legend{border-top:1px solid #232426;padding:19px 0 26px}.legend-title{display:flex;justify-content:space-between;align-items:baseline;gap:16px;margin-bottom:17px}.legend h2{margin:0;font-size:22px;font-weight:550;letter-spacing:-1px}.legend-title>span{font-size:11px;color:var(--muted)}.legend-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px clamp(18px,3vw,52px)}.legend-item{display:grid;grid-template-columns:22px 1fr;text-align:left;gap:0 6px;align-content:start;padding:8px 4px 10px 1px;border-radius:3px;min-height:56px}.legend-item:hover,.legend-item.current{background:#f5f5f6}.legend-item .num{font:11px/1.65 var(--mono);color:#83858a}.legend-item strong{font-size:14px;line-height:1.35;font-weight:600}.legend-item .job{grid-column:2;font-size:13px;line-height:1.4;color:#686a70;margin-top:3px}.guide .back{font-size:12px;color:#595c62;display:flex;align-items:center;gap:6px;padding:0;margin:0 0 12px}.guide .detail-tabs,.dialog-tabs{display:flex;flex-wrap:wrap;gap:14px;border-bottom:1px solid var(--hair);margin:17px 0}.detail-tabs button,.dialog-tabs button{font-size:12px;padding:7px 0;border-bottom:2px solid transparent}.detail-tabs button.active,.dialog-tabs button.active{font-weight:600;border-color:var(--ink)}.detail-copy h3,.how strong{font-size:14px;font-weight:600;line-height:1.4;margin:10px 0 3px}.guide .detail-copy p,.how p{font-size:13px;line-height:1.55;margin:3px 0 12px}.linkline{display:flex;gap:6px;align-items:center;font-size:13px;line-height:1.4;margin:12px 0;text-underline-offset:3px}.linkline svg{width:12px;height:12px}details{border-bottom:1px solid var(--hair);padding:12px 0}summary{cursor:pointer;font-size:14px;line-height:1.4;font-weight:550}details p{margin:8px 0!important}.workspace[data-mode=build]{grid-template-columns:minmax(0,1.12fr) minmax(0,1fr);grid-template-rows:auto 1fr;gap:0 clamp(27px,4vw,70px)}.workspace[data-mode=build] .subject,.workspace[data-mode=build] .guide{grid-column:2}.workspace[data-mode=build] .subject h1{font-size:clamp(35px,4.2vw,66px);margin-bottom:11px}.workspace[data-mode=build] .stage{grid-column:1;position:sticky;top:16px}.workspace[data-mode=build] .figure-area{height:clamp(390px,53vh,570px)}.workspace[data-mode=teach]{grid-template-columns:minmax(350px,1.02fr) minmax(0,1.22fr)}.workspace[data-mode=teach] .stage{position:sticky;top:15px}.workspace[data-mode=teach] .subject h1{font-size:clamp(42px,4.8vw,72px);margin-bottom:13px}.section-label{display:flex;justify-content:space-between;margin:20px 0 8px}.progress{height:3px;background:#e8e8ea;border-radius:2px;overflow:hidden}.progress i{display:block;height:100%;background:#343539}footer{border-top:1px solid var(--hair);display:flex;align-items:center;justify-content:space-between;padding:16px 0 24px;color:#66686e;font-size:12px}footer button{font-size:12px}footer .ico{width:13px}.sr:focus{clip-path:none}
dialog{position:fixed;inset:0 auto 0 0;margin:0;height:100dvh;max-height:100dvh;width:min(440px,100%);max-width:100%;padding:22px clamp(20px,3vw,34px) 35px;background:white;color:var(--ink);border:0;border-right:1px solid var(--hair);overflow:auto;overscroll-behavior:contain}dialog::backdrop{background:#1c1e223d}.dialog-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:27px}.icon-button{width:34px;height:34px;display:grid;place-items:center;border-radius:4px}.icon-button:hover{background:var(--quiet)}dialog h2{font-size:33px!important}dialog h3{font-size:16px;letter-spacing:-.4px;margin:22px 0 8px}dialog p{font-size:14px}.search-box{display:flex;align-items:center;gap:9px;border:1px solid #999ba1;border-radius:4px;padding:0 12px;margin:18px 0 10px}.search-box input{padding:11px 0;width:100%;border:none;background:transparent;font-size:15px;color:var(--ink)}.search-box:focus-within{outline:1px solid #343539}.search-box input:focus{outline:0}.filters{display:flex;flex-wrap:wrap;gap:6px;margin:8px 0 12px}.filters button{padding:6px 10px;font-size:12px;border-radius:30px;border:1px solid var(--hair)}.filters button.active{background:#242527;border-color:#242527;color:white}.catalog-count{font:10px var(--mono);color:var(--muted);text-transform:uppercase;letter-spacing:.6px;margin:19px 0 7px}.catalog-row{display:flex;align-items:center;width:100%;gap:16px;border-top:1px solid var(--hair);padding:9px 0;text-align:left}.catalog-row canvas{width:57px;height:59px;flex:0 0 57px}.catalog-row strong{display:block;font-size:18px;font-weight:550;letter-spacing:-.5px}.catalog-row small{font-size:12px;color:var(--muted);display:block;margin-top:3px}.catalog-row>.ico,.catalog-row>[data-icon]{margin-left:auto}.catalog-row:hover{background:#f7f7f8}.progress-row{display:grid;grid-template-columns:1fr auto;align-items:center;gap:6px 12px;padding:12px 0;border-top:1px solid var(--hair)}.progress-row button{text-align:left;font-size:14px;font-weight:600;padding:4px 0}.progress-row span{font:11px var(--mono);color:var(--muted)}.progress-row .progress{grid-column:span 2}.equip{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px}.equip button{text-align:left;display:flex;align-items:center;gap:8px;min-height:43px;padding:8px 9px;border:1px solid var(--hair);border-radius:3px;font-size:12px}.equip button.active{border-color:#252628;background:#f3f3f4}.equipment-note{margin:13px 0;font-size:13px}.device-kit{padding:12px 0;border-top:1px solid var(--hair);font-size:13px}.device-kit output{display:block;font-size:12px;color:var(--muted);line-height:1.5;overflow-wrap:anywhere}.device-kit li{margin-bottom:5px}.device-kit ol{padding-left:18px;line-height:1.45}.device-kit label{display:inline-block;font-size:12px}.device-kit select{padding:5px;margin-left:5px}.device-kit input[type=file]{max-width:100%;font-size:12px;margin:10px 0}.guide code,dialog code{font-size:.92em;color:#323337}
@media(min-width:1500px){.workspace{padding-top:40px}.figure-area{height:clamp(540px,58vh,760px)}}
@media(max-width:900px){.wrap{width:calc(100% - 46px)}.workspace{grid-template-columns:minmax(220px,.83fr) minmax(0,1.3fr);column-gap:22px}.subject h1{font-size:72px}.guide h2{font-size:26px}.figure-area{height:430px}.workspace[data-mode=build]{grid-template-columns:minmax(0,.9fr) minmax(0,1fr);gap:15px}.legend-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.bar nav{gap:18px}}
@media(max-width:730px){.wrap{width:calc(100% - 34px)}.bar{height:54px}.brand{font-size:19px;letter-spacing:-.8px;gap:6px}.brand img{width:25px;height:27px}.bar nav{gap:13px}.bar nav button{font-size:12px;gap:4px}.bar nav button:last-child{font-size:0;gap:0;min-width:29px}.bar nav .ico{width:19px;height:19px}.contextbar{padding:11px 0 2px}.crumb{font-size:11px;gap:7px}.crumb button{font-size:11px;min-height:22px}.tabs{position:fixed;z-index:8;left:0;bottom:0;right:0;justify-content:center;border:0;border-top:1px solid #cccdd0;border-radius:0;gap:3px;padding:4px 6px max(4px,env(safe-area-inset-bottom));background:rgba(255,255,255,.98)}.tabs button{flex:1;min-height:42px;font-size:11px;gap:3px;flex-direction:column}.tabs button.active{background:#f2f2f3;color:var(--ink);font-weight:bold}.workspace,.workspace[data-mode=build],.workspace[data-mode=teach]{display:flex;flex-direction:column;gap:0;padding:13px 0 22px}.subject,.stage,.guide{width:100%}.subject{order:0}.stage,.workspace[data-mode=build] .stage,.workspace[data-mode=teach] .stage{order:1;position:relative;top:auto}.guide{order:2;margin-top:19px;scroll-margin-top:8px}.subject h1,.workspace[data-mode=teach] .subject h1{font-size:clamp(49px,13.5vw,67px);margin:5px 0 10px}.subject h1.compact,.workspace[data-mode=build] .subject h1{font-size:clamp(36px,10vw,48px);margin:4px 0 8px}.stage-info{font-size:8px;min-height:11px}.stage-info span:first-child{display:none}.stage-info span:last-child{margin-left:auto}.figure-area,.workspace[data-mode=build] .figure-area{height:clamp(278px,41svh,405px)}.workspace[data-mode=build] .figure-area,.workspace[data-mode=teach] .figure-area{height:clamp(217px,30svh,315px)}.callout{height:21px;width:21px;font-size:10px}.view-toolbar{margin-top:1px;gap:7px}.mode-switch button{min-height:32px;font-size:11px}.turn-tools{padding-left:5px}.turn-tools button{min-width:30px;min-height:32px}.caption{font-size:10px;margin-top:6px}.overview h2,.guide h2{font-size:26px;max-width:26ch}.guide .overview p{max-width:100%;font-size:15px}.actions{margin:15px 0;gap:14px}.specs{margin:18px 0 0;max-width:100%;padding-top:11px}.specs strong{font-size:23px}.legend{padding:14px 0 20px}.legend-grid{grid-template-columns:1fr;gap:2px}.legend-item{border-bottom:1px solid #ececee;min-height:56px}.legend-title{margin-bottom:7px}.legend h2{font-size:20px}.legend-title>span{font-size:10px}.legend-item strong{font-size:14px}.legend-item .job{font-size:13px}footer{padding-bottom:78px}.guide .detail-copy p{font-size:14px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
[hidden]{display:none!important}
.subject h1{letter-spacing:-.065em}.subject h1.compact{letter-spacing:-.055em}
.catalog-row img{width:57px;height:59px;object-fit:contain;flex-shrink:0}
.progress-row button{display:inline-flex;align-items:center;gap:6px}.progress-row button svg{width:13px;height:13px}
.file-receipt{display:block;margin:6px 0;color:#55585b;font-size:12px;line-height:1.45;overflow-wrap:anywhere}
@media(max-width:730px){.workspace[data-mode=build] .figure-area{height:clamp(180px,26svh,247px)}}

/* Direct manipulation belongs to the drawing. Prose and text fields stay selectable. */
:where(a, button, summary, label, input, select, [tabindex], .figure-area) {
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}
.figure-area, .figure-area *, button, button *, summary, select, input[type="range"] {
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  user-select: none;
}
#figure, #figure *, button img, button svg, .brand img {
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}
[tabindex]:focus-visible {
  outline: 2px solid #30343a;
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}
:is(button, a, summary, select, input[type="range"], [tabindex]):focus:not(:focus-visible),
html[data-input="pointer"] :is(#figure, button, a, summary, select, input[type="range"], [tabindex]):focus {
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}

#entry-page[hidden],#robot-page[hidden]{display:none!important}
footer>a{color:inherit;text-decoration:underline;text-underline-offset:3px}
footer>a:first-child{text-decoration:none}
#main-content:focus{outline:none}
@media(max-width:730px){.bar .brand{font-size:clamp(17px,4.5vw,20px)}#main-content>footer{gap:10px;justify-content:space-between;flex-wrap:wrap}}
@media(max-width:400px){.bar .brand{white-space:nowrap}.bar nav{gap:6px}.bar nav button:first-child{min-width:36px;font-size:0;gap:0}.bar nav button:last-child{min-width:36px}.bar nav .ico{flex-shrink:0}}