@font-face{font-family:Atkinson;src:url(/seked/fonts/AtkinsonHyperlegibleNext.ttf)format("truetype");font-weight:100 900;font-display:swap}@font-face{font-family:Noto;src:url(/seked/fonts/NotoSerif-Regular.ttf)format("truetype");font-display:swap}:root{color:#242c2a;font-synthesis:none;--paper:#f7f5ef;--ink:#242c2a;--red:#9b3d2f;--blue:#286477;--muted:#62645b;--line:#c9c9bd;--wash:#ebece3;font-variant-numeric:tabular-nums;background:#f7f5ef;scroll-padding-top:22px;font-family:Atkinson,Arial,sans-serif;font-size:17px;line-height:1.55}*{box-sizing:border-box}body{margin:0}a{color:var(--red);text-underline-offset:4px}button,input{font:inherit}button{cursor:pointer;color:var(--ink);background:0 0;border:1px solid #90988d;border-radius:0;min-height:44px;padding:10px 15px;line-height:1.25}button:hover{background:var(--wash)}button[aria-pressed=true]{background:var(--ink);color:var(--paper);border-color:var(--ink)}button:disabled{opacity:.5;cursor:default}input{background:#fff;border:1px solid #90988d;border-radius:0;max-width:100%;min-height:44px;padding:9px 12px}input[aria-invalid=true]{border:2px solid var(--red)}:focus-visible{outline:3px solid var(--blue);outline-offset:4px}[hidden]{display:none!important}h1,h2,h3,p,figure{margin:0}p+p{margin-top:14px}h1,h2{font-family:Noto,Georgia,serif;font-weight:400;line-height:1.18}h1{letter-spacing:-.045em;font-size:clamp(43px,5.5vw,82px)}h2{letter-spacing:-.025em;font-size:clamp(29px,3vw,43px)}h3{font-size:24px;line-height:1.3}header,main,footer{max-width:1360px;margin:auto;padding-left:48px;padding-right:48px}header{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;gap:30px;padding-top:27px;padding-bottom:27px;display:flex}.wordmark{letter-spacing:.12em;color:var(--ink);align-items:center;gap:26px;font-size:27px;font-weight:650;text-decoration:none;display:flex}.wordmark span{letter-spacing:.04em;color:var(--muted);font-size:12px;font-weight:400}nav{flex-wrap:wrap;gap:26px;display:flex}nav a{color:var(--ink);font-size:14px;text-decoration:none}.skip{opacity:0;pointer-events:none;z-index:5;background:#fff;padding:12px;position:fixed;top:-80px}.skip:focus{opacity:1;pointer-events:auto;top:8px}.introduction{grid-template-columns:1.2fr 1fr;gap:80px;padding:66px 0 62px;display:grid}.eyebrow{letter-spacing:.12em;text-transform:uppercase;color:var(--red);margin-bottom:18px;font-size:11px;font-weight:650}.intro-copy{max-width:420px;padding-top:32px;font-size:18px}.text-link{margin-top:24px;display:inline-block}.section-heading{border-top:2px solid var(--red);justify-content:space-between;gap:20px;margin-bottom:25px;padding-top:15px;display:flex}.section-heading .eyebrow{margin:0}.section-heading>p+p{color:var(--muted);margin:0;font-size:12px}.problem-choices{grid-template-columns:repeat(6,1fr);gap:0;display:grid}.problem-choices button{text-align:left;border-right:none;flex-direction:column;gap:5px;padding:13px 16px;font-size:12px;display:flex}.problem-choices button:last-child{border-right:1px solid #90988d}.problem-choices span{font-family:Noto,serif;font-size:28px}.reader-heading{grid-template-columns:1.2fr 1fr;align-items:center;gap:50px;padding:35px 0 25px;display:grid}.reader-heading p{max-width:520px;font-size:18px}.reading-switch{flex-wrap:wrap;align-items:center;gap:10px;padding:14px 0 22px;display:flex}.reading-switch>span{margin-right:12px;font-size:14px}.reading-switch button{font-size:14px}.reading-desk{border:1px solid var(--line);background:#fffefa;grid-template-columns:1.15fr 1fr;display:grid}.drawing-board{border-right:1px solid var(--line);min-width:0;padding:15px 25px 22px}.caption{color:var(--muted);font-size:13px;line-height:1.55}.drawing-board>.caption{padding:0 18px}.miniature{border-top:1px solid var(--line);grid-template-columns:1.15fr 1fr;align-items:center;gap:15px;margin-top:20px;padding-top:10px;display:grid}.unit-note{font-size:15px}.unit-note .eyebrow{margin-bottom:10px}.unit-note strong{color:var(--red);font-size:20px}.unit-note .caption{margin-top:14px}.section-svg,.unit-svg,.plan-svg{width:100%;height:auto;display:block;overflow:visible}.section-svg text,.unit-svg text,.plan-svg text{fill:var(--ink);font-family:Atkinson,Arial,sans-serif;font-size:14px}.section-svg .plate-label,.unit-svg .plate-label,.plan-svg .plate-label{letter-spacing:.04em;fill:var(--muted);font-size:10px}svg .outline{fill:none;stroke:var(--ink);stroke-width:1.8px}svg .half-shape{fill:#e8ece4;stroke:none}svg .height{stroke:var(--blue);stroke-width:2px}svg .run{stroke:var(--red);stroke-width:2px}svg .height-label{fill:var(--blue)}svg .run-label{fill:var(--red)}svg .emphasized{stroke-width:4px}svg .right-angle,svg .base-rule{fill:none;stroke:var(--muted);stroke-width:1px}svg .construction{fill:none;stroke:var(--line);stroke-width:1px;stroke-dasharray:4 4}svg .unit-tick{stroke:var(--blue);stroke-width:1px}svg circle{fill:var(--ink)}.calculation{min-width:0;padding:30px 32px}.step-heading{justify-content:space-between;align-items:center;gap:15px;display:flex}.step-heading .eyebrow{margin:0}.step-buttons{gap:4px;display:flex}.step-buttons button{width:32px;min-height:36px;padding:6px;font-size:13px}.calculation h3{margin-top:28px;margin-bottom:15px}.equation{color:var(--red);border-left:3px solid var(--red);overflow-wrap:anywhere;padding:10px 0 10px 18px;font-size:21px;line-height:1.5;margin-top:22px!important}.previous-next{justify-content:space-between;gap:15px;margin-top:22px;display:flex}.previous-next button{font-size:14px}.source-note{border-top:1px solid var(--line);margin-top:28px;padding-top:24px;font-size:14px}.source-note .eyebrow{margin-bottom:10px}.text-button{text-align:left;text-underline-offset:4px;color:var(--red);border:0;padding:8px 0;font-size:14px;text-decoration:underline;display:block;background:0 0!important}.reader-actions{flex-wrap:wrap;gap:12px;padding:24px 0 10px;display:flex}.reader-actions button{font-size:14px}.reader-actions p{color:var(--muted);flex-basis:100%;font-size:14px}.numbers{border-bottom:1px solid var(--line);padding:16px 0 25px}.numbers summary{cursor:pointer;padding:8px 0;font-size:15px}.numbers>div{max-width:780px;margin-top:20px}.numbers>p{max-width:780px;margin-top:16px}table{border-collapse:collapse;width:100%;font-size:14px}th,td{text-align:left;border-bottom:1px solid var(--line);padding:12px 14px 12px 0}th{font-weight:600}td{font-variant-numeric:tabular-nums}thead th{color:var(--muted);font-size:12px}#workshop,#words,#evidence{margin-top:70px}.workshop-intro{grid-template-columns:1.1fr 1fr;gap:60px;display:grid}.workshop-intro p{max-width:540px}.lab-controls{flex-wrap:wrap;align-items:end;gap:16px;margin-top:28px;display:flex}.lab-controls label{margin-bottom:8px;font-size:13px;display:block}.lab-controls input{width:160px}.lab-controls button{font-size:14px}.lab-controls+p{max-width:870px;margin-top:14px}#dimension-error{color:var(--red);font-size:14px}#dimension-error:empty{display:none}.section-choices{flex-wrap:wrap;gap:8px;margin-top:25px;display:flex}.section-choices button{font-size:14px}.lab-drawings{grid-template-columns:1.3fr 1fr;align-items:start;gap:40px;margin-top:20px;display:grid}.lab-drawings>div:first-child{border:1px solid var(--line);background:#fffefa;padding:15px 25px}#section-summary{margin-top:12px;font-size:14px}.plan-panel{grid-template-columns:1fr 1fr;align-items:center;gap:10px;display:grid}.plan-panel>.caption{font-size:14px}#lab-unit{grid-column:1/-1;justify-self:center;max-width:320px}.lab-comparison{grid-template-columns:1.3fr 1fr;align-items:center;gap:40px;margin:25px 0;display:grid}.lab-comparison p{font-size:15px}.measure{max-width:820px;margin-top:20px}.word-grid{grid-template-columns:repeat(4,1fr);gap:30px;margin-top:30px;display:grid}.word-grid article{border-top:1px solid var(--line);padding-top:22px;font-size:15px}.word-grid h3{color:var(--blue);margin-bottom:12px;font-family:Noto,Georgia,serif;font-size:32px}.word-grid p+p{font-size:14px}.word-grid button{margin-top:12px}.source-choices{flex-wrap:wrap;gap:8px;margin:24px 0 20px;display:flex}.source-choices button{font-size:13px}.source-figure{margin:0}#scan-window{border:1px solid var(--line);background:#e5e1d6;max-width:100%;height:650px;overflow:auto}#scan-window img{width:100%;max-width:1100px;height:auto;margin:auto;display:block}#scan-window.enlarged img{width:2200px;max-width:none;margin:0}.source-figure figcaption{color:var(--muted);max-width:900px;margin-top:14px;font-size:14px}.scan-controls{flex-wrap:wrap;align-items:center;gap:20px;margin:20px 0;display:flex}.scan-controls button,.scan-controls a{font-size:14px}#evidence>.caption{max-width:980px}.limits{border-top:1px solid var(--line);grid-template-columns:1.1fr 1fr 1fr;gap:35px;margin:65px 0 55px;padding-top:30px;display:grid}.limits h2{font-size:28px}.limits p{margin:0;font-size:14px}footer{border-top:1px solid var(--line);color:var(--muted);justify-content:space-between;gap:20px;padding-top:22px;padding-bottom:26px;font-size:12px;display:flex}@media (width<=1100px){header,main,footer{padding-left:28px;padding-right:28px}.introduction{gap:40px}.reader-heading{gap:30px}.reading-desk{grid-template-columns:1fr 1fr}.drawing-board{padding-left:12px;padding-right:12px}.calculation{padding:24px}.step-heading{flex-direction:column;align-items:start}.miniature{grid-template-columns:1fr}.unit-note{padding:0 15px}.miniature .unit-svg{max-height:240px}.word-grid,.limits{grid-template-columns:1fr 1fr}.limits h2{grid-column:1/-1}}@media (width<=760px){header{flex-direction:column;align-items:start;gap:18px}.introduction{grid-template-columns:1fr;gap:12px;padding:38px 0}.intro-copy{max-width:580px;padding:0}.reader-heading,.workshop-intro{grid-template-columns:1fr;gap:18px}.reader-heading{padding:28px 0 22px}.reading-desk{grid-template-columns:1fr}.drawing-board{border-right:0;border-bottom:1px solid var(--line)}.miniature{grid-template-columns:1fr 1fr}.step-heading{flex-direction:row;align-items:center}.lab-drawings,.lab-comparison{grid-template-columns:1fr;gap:24px}.plan-panel{grid-template-columns:1fr 1fr}.plan-panel>#lab-unit{grid-area:1/auto/3}.plan-panel>.caption{grid-area:2/1}.lab-controls input{width:170px}.problem-choices{grid-template-columns:repeat(3,1fr)}.problem-choices button:nth-child(3){border-right:1px solid #90988d}.problem-choices button:nth-child(n+4){border-top:0}.section-heading>p+p{display:none}#scan-window{height:510px}.limits{gap:24px}.wordmark span{font-size:11px}#workshop,#words,#evidence{margin-top:48px}}@media (width<=480px){:root{font-size:16px}header,main,footer{padding-left:19px;padding-right:19px}header{padding-top:18px;padding-bottom:18px}nav{gap:12px 18px}.wordmark{gap:20px;font-size:24px}.introduction h1{font-size:46px}.intro-copy{font-size:17px}.problem-choices button{min-height:90px;padding:12px 10px;font-size:11px}.reader-heading p{font-size:17px}.calculation{padding:24px 19px}.step-heading{flex-direction:column;align-items:flex-start}.step-buttons button{width:42px;min-height:42px}.miniature{grid-template-columns:1fr;gap:0}.miniature .unit-svg{max-height:230px}.unit-note{padding:0 10px 12px}.drawing-board{padding:10px 9px 18px}.drawing-board>.caption{padding:0 10px}.section-svg text{font-size:15px}.section-svg .plate-label{font-size:10px}.equation{font-size:19px}.word-grid{grid-template-columns:1fr;gap:20px}.word-grid article{padding-top:15px}.word-grid h3{font-size:30px}.word-grid p+p{font-size:15px}.lab-controls{gap:14px}.lab-controls>div{width:calc(50% - 7px)}.lab-controls input{width:100%}.lab-controls button{flex:1}.lab-drawings>div:first-child{padding:8px 0 16px}#section-summary{padding:0 15px}.plan-panel{grid-template-columns:1fr 1fr}.plan-panel>.caption,.lab-comparison table{font-size:12px}th,td{padding-right:8px}.lab-comparison p{font-size:14px}.source-choices{gap:7px}.source-choices button{padding:9px 10px;font-size:12px}#scan-window{height:440px}.limits{grid-template-columns:1fr}.limits h2{grid-column:auto}.limits p{font-size:15px}footer{flex-direction:column;gap:10px}.reader-actions button{flex-grow:1}.source-note{font-size:15px}}@media print{header,footer,.skip,.introduction,.reader-actions,.previous-next,.step-buttons,#workshop,#words,#evidence,.limits,.numbers{display:none}main{padding:0}.reading-desk{border:0;display:block}.drawing-board{border:0}.calculation{padding:20px 0}.section-svg{max-height:320px}.unit-svg{max-height:180px}}.reckoning{border:1px solid var(--line);background:#efefe6;border-top:0;grid-template-columns:1.15fr 1fr;gap:40px;padding:28px 25px;display:grid}.reckoning .eyebrow{margin-bottom:12px}.reckoning h3{font-size:23px}.reckoning p{margin-top:15px;font-size:14px}.reckoning .equation{font-size:17px}.reckoning caption{text-align:left;margin-bottom:8px;font-size:13px}.reckoning input{width:20px;height:20px;min-height:0;accent-color:var(--red);cursor:pointer}.reckoning td:first-child{width:65px}.reckoning-actions{flex-wrap:wrap;gap:10px;margin-top:16px;display:flex}.reckoning-actions button{font-size:13px}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}@media (width<=760px){.reckoning{grid-template-columns:1fr;gap:20px;padding:25px 19px}}@media print{.reckoning{display:none}}
