@import url('./fonts.css');
:root{color-scheme:dark;--bg:#101114;--panel:#17191e;--panel2:#1e2128;--line:#2d3038;--muted:#a0a5b2;--ink:#f0f2f7;--blue:#b5d8ff;--pink:#efb8d3;--purple:#c8b9f4;--radius:18px;font-family:'DM Sans',sans-serif;font-size:16px}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink)}button,input,select,textarea{font:inherit}button,a,input,select,summary{touch-action:manipulation}button{cursor:pointer;border:1px solid var(--line);background:var(--panel2);color:var(--ink);border-radius:10px;padding:11px 16px;transition:background .15s,border-color .15s}button:hover{background:#2b303b;border-color:#6f7b8c}button:disabled{opacity:.45;cursor:not-allowed}button.primary{background:var(--blue);color:#111a25;border-color:var(--blue);font-weight:700}button.active{background:#29384c;border-color:var(--blue);color:var(--blue)}a{color:var(--blue);text-decoration:none}input,select,textarea{background:#111318;border:1px solid #444a57;color:var(--ink);border-radius:8px;padding:10px;max-width:100%}input[type=range]{accent-color:var(--blue);padding:0;width:100%}input[type=checkbox]{accent-color:var(--blue)}:focus-visible{outline:2px solid var(--pink);outline-offset:4px}.skip{position:fixed;left:8px;top:-80px;background:var(--blue);color:#111;padding:12px;z-index:99}.skip:focus{top:8px}.shell{display:grid;grid-template-columns:248px 1fr;min-height:100vh}.sidebar{border-right:1px solid var(--line);padding:34px 22px;position:sticky;top:0;height:100vh;display:flex;flex-direction:column;background:#131418}.brand{display:flex;align-items:center;gap:10px;font-family:Manrope,sans-serif;font-weight:800;font-size:25px;letter-spacing:-1px}.brand-mark{width:34px;height:34px;border:1px solid var(--blue);color:var(--blue);display:grid;place-items:center;border-radius:10px;font-size:25px}.brand small{font-size:13px;font-weight:500;letter-spacing:0;color:var(--muted);display:block}.side-caption{font-size:12px;letter-spacing:1.7px;color:#7f8593;margin:40px 12px 14px}.nav{display:grid;gap:7px}.nav button{border:0;background:none;text-align:left;color:#adb2bf;display:flex;align-items:center;gap:13px;padding:13px}.nav button.active{background:#232832;color:var(--blue)}.nav-icon{font-size:20px;width:22px}.course-tree{border-top:1px solid var(--line);margin-top:28px;padding:22px 12px;color:var(--muted);font-size:14px;line-height:2}.course-tree strong{color:var(--ink);font-weight:500}.side-bottom{margin-top:auto;border-top:1px solid var(--line);padding:20px 10px 0;font-size:13px;color:var(--muted)}.side-bottom b{display:block;color:var(--pink);font-size:14px;margin-bottom:5px}.workspace{min-width:0}.topbar{height:82px;padding:0 44px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:16px;font-size:14px;color:var(--muted)}.breadcrumb{display:flex;gap:12px;align-items:center}.breadcrumb b{font-weight:500;color:#e4e7ee}.saved{font-size:12px;border:1px solid var(--line);border-radius:30px;padding:7px 12px}.main{padding:36px 44px 50px;max-width:1500px;margin:auto}.eyebrow{color:var(--blue);font-size:12px;letter-spacing:2px;font-weight:700;text-transform:uppercase}h1,h2,h3{font-family:Manrope,sans-serif;line-height:1.25;margin:0}h1{font-size:34px;letter-spacing:-1.2px;margin:12px 0}h2{font-size:24px;letter-spacing:-.6px}h3{font-size:18px}.subtitle{color:var(--muted);line-height:1.65;margin:10px 0 25px;max-width:760px}.page-head{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:26px}.lesson-layout{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(290px,1fr);gap:22px}.panel{border:1px solid var(--line);border-radius:var(--radius);background:var(--panel);overflow:hidden}.panel-head{padding:21px 24px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:12px}.panel-body{padding:24px}.diagram{background:#13161c;position:relative;min-height:300px}.diagram svg{width:100%;display:block}.plot-label{font-size:15px;fill:var(--muted)}.plot-math{font-size:18px;fill:var(--blue)}.diagram-toolbar{display:flex;gap:8px;align-items:center;padding:12px 20px;flex-wrap:wrap;border-bottom:1px solid var(--line)}.diagram-toolbar button{font-size:13px;padding:7px 12px}.legend{display:flex;gap:20px;flex-wrap:wrap;color:var(--muted);font-size:13px;padding:14px 22px}.legend span:before{content:'';display:inline-block;width:9px;height:9px;border-radius:3px;background:var(--blue);margin-right:8px}.legend .pink:before{background:var(--pink)}.legend .purple:before{background:var(--purple)}.slider-row{padding:14px 22px 22px;display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:15px;color:var(--muted);font-size:14px}.pill{display:inline-block;padding:6px 10px;border:1px solid var(--line);border-radius:30px;font-size:12px;color:var(--muted)}.question-number{color:var(--pink);font-size:12px;letter-spacing:1.6px;margin-bottom:18px}.question-title{font-size:22px;line-height:1.4}.question-copy{color:var(--muted);line-height:1.6}.options{display:grid;gap:10px;margin:24px 0}.option{text-align:left;padding:14px 16px;display:flex;gap:12px;align-items:center;background:#1d2027}.option .letter{font-size:12px;border:1px solid #4a4e59;border-radius:6px;padding:3px 6px;color:var(--muted)}.option.selected{border-color:var(--blue);background:#253447}.option.correct{border-color:var(--blue)}.button-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.button-row .primary{flex:1}.feedback{border-left:3px solid var(--pink);padding:14px 16px;background:#29212b;border-radius:0 10px 10px 0;margin:16px 0;line-height:1.6}.feedback.success{border-color:var(--blue);background:#202d3b}.quiet{font-size:13px;color:var(--muted);line-height:1.6}.lesson-footer{display:flex;justify-content:space-between;gap:14px;align-items:center;margin:24px 0}.step-track{display:flex;gap:6px}.step-track span{height:4px;width:28px;background:var(--line);border-radius:4px}.step-track span.done{background:var(--blue)}.key-idea{display:flex;gap:16px;align-items:flex-start;padding:22px;border:1px solid var(--line);border-radius:14px;margin-top:22px;color:var(--muted);line-height:1.6}.key-idea b{color:var(--ink);display:block;margin-bottom:3px;font-size:14px}.key-icon{color:var(--pink);font-size:25px}.math{overflow-x:auto;padding:8px 0;color:#f1f3fa}.math .katex{font-size:1.12em}.math.block{padding:16px;background:#11141a;border-radius:10px;text-align:center}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:23px}.card p{color:var(--muted);line-height:1.6}.course-path{display:grid;gap:13px}.path-unit{display:grid;grid-template-columns:50px 1fr auto;gap:20px;align-items:center;border:1px solid var(--line);border-radius:14px;background:var(--panel);padding:19px 22px}.path-unit .number{width:44px;height:44px;display:grid;place-items:center;border:1px solid #53617a;color:var(--blue);border-radius:50%}.path-unit p{color:var(--muted);font-size:14px;margin:6px 0}.path-unit.locked{opacity:.6}.section-label{margin:30px 0 15px;color:var(--pink);font-size:12px;letter-spacing:1.8px;text-transform:uppercase}.progressbar{height:6px;background:var(--line);border-radius:8px;overflow:hidden}.progressbar i{display:block;height:100%;background:var(--blue)}.stat{font-family:Manrope,sans-serif;font-size:32px;color:var(--blue);margin:10px 0}.builder-fields{display:grid;gap:12px}.bound-row{display:grid;grid-template-columns:1fr 28px 1fr;align-items:center;gap:9px}.bound-row input{width:100%;font-family:monospace}.field-label{display:block;color:var(--muted);font-size:13px;margin:10px 0 7px}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:20px}.solid-canvas{width:100%;height:420px;display:block;touch-action:none}.toggles{display:flex;flex-wrap:wrap;gap:13px;padding:14px 20px;border-top:1px solid var(--line);font-size:13px;color:var(--muted)}.toggles label{display:flex;gap:6px;align-items:center}.question-list{display:grid;gap:12px}.source-card{display:flex;justify-content:space-between;gap:20px;align-items:center}.source-card p{margin:8px 0}.badge{background:#262431;color:var(--purple);padding:5px 8px;border-radius:6px;font-size:12px}.filters{display:flex;gap:10px;margin-bottom:20px;flex-wrap:wrap}.hint-box{padding:16px;background:#272430;border:1px solid #4a405d;border-radius:10px;line-height:1.6;margin-top:15px}.hint-box p{margin:8px 0}.notice{padding:16px 20px;background:#252130;border:1px solid #51475f;border-radius:12px;line-height:1.6;margin-bottom:22px}.hidden{display:none!important}.wide{grid-column:1/-1}dialog{background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:20px;width:min(700px,92vw);max-height:85vh;padding:28px}dialog::backdrop{background:#000b}dialog h2{margin-bottom:16px}dialog p{line-height:1.7;color:var(--muted)}.text-answer{width:100%;min-height:92px;resize:vertical}.answer-input{width:100%;margin:14px 0}.mini-label{font-size:12px;color:var(--muted)}.mobile-menu{display:none}.proof-steps{padding-left:20px;line-height:1.9;color:var(--muted)}.atlas-toolbar{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:18px}.atlas-toolbar select{min-width:190px}.boundary-button{cursor:pointer}.boundary-button:hover{stroke-width:6}.status-label{color:var(--pink);font-size:13px}.review-list{display:grid;gap:12px}footer{font-size:12px;color:#787f8c;padding-top:30px}.lesson-actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.hint-details{line-height:1.8}.compact{padding:12px}.numbered{color:var(--blue);font-family:monospace}.nav-count{margin-left:auto;font-size:12px}.region-grid{cursor:crosshair}.grid-legend{font-size:13px;color:var(--muted);line-height:1.6}.confidence{display:flex;gap:10px;margin:15px 0}.confidence button{flex:1;font-size:14px}.source-link{font-size:13px;color:var(--purple)}@media(min-width:1600px){.main{padding-top:48px}.diagram svg{max-height:470px}}@media(max-width:1150px){.shell{grid-template-columns:210px 1fr}.sidebar{padding:28px 14px}.main{padding:28px 24px}.topbar{padding:0 24px}.lesson-layout{grid-template-columns:1fr}.grid{grid-template-columns:repeat(2,1fr)}.question-title{font-size:21px}.diagram svg{max-height:410px}}@media(max-width:700px){.shell{display:block}.sidebar{position:relative;height:auto;padding:18px;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:22px}.side-caption,.course-tree,.side-bottom{display:none}.nav{display:flex;overflow-x:auto;margin-top:16px;gap:5px}.nav button{white-space:nowrap;font-size:13px;padding:9px 11px}.nav-icon{display:none}.topbar{height:64px;padding:12px 18px;font-size:12px}.breadcrumb{gap:6px;flex-wrap:wrap}.saved{display:none}.main{padding:25px 18px}.page-head{display:block}h1{font-size:28px}.grid,.two-col{grid-template-columns:1fr}.panel-body{padding:20px}.panel-head{padding:18px}.path-unit{grid-template-columns:36px 1fr;gap:14px;padding:16px}.path-unit button{grid-column:2}.path-unit .number{width:34px;height:34px}.solid-canvas{height:340px}.source-card{display:block}.source-card button{margin-top:10px}.legend{gap:12px}.lesson-footer{flex-wrap:wrap}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
.bound-row{grid-template-columns:minmax(0,1fr) 70px minmax(0,1fr)}.bound-row span{text-align:center;font-size:13px}.builder-fields+.builder-fields{margin-top:22px;padding-top:10px;border-top:1px solid var(--line)}.solid-canvas canvas{display:block;width:100%;height:100%}.katex-display{margin:.5em 0}.question-title{overflow-wrap:anywhere}.source-card h3{font-size:16px;line-height:1.5;max-width:650px}.options .option{line-height:1.55}.path-unit button:disabled{opacity:1;color:#989eaa}.card p{overflow-wrap:anywhere}

.diagram svg{max-height:390px}.brand{color:var(--ink)}
/* KISO / FIELD NOTES — shared design system, reference-derived edition */
:root{--bg:#050505;--panel:#0b0c0e;--panel2:#141517;--line:#2e3033;--muted:#a4a6ad;--ink:#f3f2ef;--blue:#b8d7f4;--pink:#e9b9d0;--purple:#c5b8dd;--radius:7px;--display:'Barlow Condensed',Impact,sans-serif;--mono:'IBM Plex Mono',monospace;font-family:Inter,Arial,sans-serif}
body{background-color:var(--bg);background-image:radial-gradient(circle at 1px 1px,#ffffff0c 1px,transparent 1.5px);background-size:18px 18px;background-attachment:fixed;line-height:1.55}
.shell{display:block;position:relative;max-width:1552px;min-height:calc(100vh - 48px);margin:24px auto 85px;border:1px solid #454545;border-radius:12px;background:#050505ef;overflow:clip}.shell:before{content:'';position:absolute;pointer-events:none;right:0;top:0;width:45%;height:360px;background-image:linear-gradient(45deg,transparent 48.8%,#ffffff06 49.5%,#ffffff06 50.5%,transparent 51.2%),linear-gradient(0deg,transparent 97%,#ffffff06 99%);background-size:20px 20px;mask-image:linear-gradient(150deg,black,transparent 75%)}
.topbar{height:108px;padding:0 38px;position:relative;z-index:1;border-bottom:1px solid #252525}.brand{font:700 35px/1 var(--display);letter-spacing:-.5px;gap:12px}.brand-mark{border:1px solid #eee;border-radius:2px;width:32px;height:38px;font:600 31px var(--display);color:#eee}.brand small{font:400 10px/1.6 var(--mono);letter-spacing:1.1px;margin-top:5px;max-width:210px}.breadcrumb{font:400 12px var(--mono);letter-spacing:.2px}.saved{font:400 10px var(--mono);border-radius:2px;letter-spacing:.6px;background:#0b0b0b;padding:7px 10px}.main{padding:36px 38px 54px;max-width:none}.eyebrow,.question-number,.section-label{font-family:var(--mono);font-size:11px;letter-spacing:1.7px;font-weight:400;color:#a5a6aa}.eyebrow:before{content:'[ ';color:#62646a}.eyebrow:after{content:' ]';color:#62646a}h1{font-family:var(--display);text-transform:uppercase;font-weight:600;font-size:56px;letter-spacing:-.7px;line-height:1;margin:15px 0 17px;max-width:1120px}h2,h3{font-family:Inter,sans-serif;font-weight:500;letter-spacing:-.4px}h2{font-size:24px}h3{font-size:17px}.subtitle{font-size:15px;line-height:1.75;max-width:810px;margin-bottom:27px;color:#adaeb5}.page-head{margin-bottom:20px}.page-head h1{margin-bottom:5px}.lesson-layout{grid-template-columns:minmax(0,1.3fr) minmax(340px,1fr);gap:18px;align-items:start}.panel{border-radius:7px;border-color:#353535;background:#0b0b0c}.panel-head{padding:17px 22px;min-height:66px;border-bottom:1px solid #29292a}.panel-head h3{font-family:var(--mono);font-size:12px;letter-spacing:.3px}.pill{border-radius:2px;font-family:var(--mono);font-size:10px;padding:4px 8px;color:#a6a7ad;border-color:#39393b}.panel-body{padding:27px}.question-number{color:var(--pink);margin-bottom:20px}.question-title{font-size:22px;line-height:1.55;font-weight:500;letter-spacing:-.5px}.question-copy{font-size:15px;line-height:1.75}.options{gap:9px;margin:24px 0 20px}.option{border:1px solid #323235;background:#151517;border-radius:3px;min-height:57px;padding:12px 15px;font-size:15px}.option .letter{border-radius:1px;font:11px var(--mono);border-color:#4b4b50}.option:hover{background:#1d1d20;border-color:#85858b}.option.selected{background:#20252b;border-color:var(--blue)}button{border-radius:3px;background:#171719;padding:10px 15px;font-size:14px;line-height:1.55}button:hover{border-color:#929399;background:#252529}button.primary{background:#eeede9;color:#101011;border-color:#eeede9;font-size:14px;font-weight:600}button.primary:hover{background:white;border-color:white}button.active{color:#f1f0ed;background:#252528;border-color:#a0a1a7}input,select,textarea{border-radius:3px;background:#0d0d0f;border-color:#454549;font-size:14px}input[type=range]{accent-color:#dddddf}input[type=checkbox]{accent-color:#d6d6da}.button-row{gap:9px}.simple-button{display:flex;width:100%;justify-content:space-between;align-items:center;margin:12px 0 0;text-align:left;border:1px solid #404044;background:transparent;color:#c7c6cc;font:12px var(--mono);padding:12px 14px}.simple-button:hover{color:var(--ink);background:#19171c}.simple-button span{color:var(--pink);font-size:18px}.simple-explanation{border-left:2px solid var(--pink);padding:17px 19px;background:#171316;margin-top:10px;font-size:15px;line-height:1.8}.simple-explanation .eyebrow{color:var(--pink);font-size:10px}.simple-explanation p{margin:10px 0 0}.feedback{border-radius:0;border-left-width:2px;background:#1c1318;border-color:var(--pink);font-size:14px;line-height:1.8}.feedback b{font-weight:500;color:#f5d4e3}.feedback.success{background:#12191f;border-color:var(--blue)}.feedback.success b{color:var(--blue)}.hint-box{background:#16131b;border:1px solid #493d53;border-radius:3px;font-size:14px;line-height:1.8}.hint-box b{font:12px var(--mono);color:var(--purple)}.key-idea{border-radius:3px;padding:20px 22px;font-size:14px;background:#0b0b0d}.key-idea b{font:12px var(--mono);color:#dad9de}.key-icon{font-size:20px;color:#c8c7ce}.diagram{background:#08090b}.diagram svg{max-height:365px}.diagram-toolbar{padding:12px 18px;gap:8px;background:#0e0e10}.diagram-toolbar button{border-radius:2px;font:11px var(--mono);padding:7px 10px}.diagram-toolbar .mini-label{font-size:11px}.legend{font:11px var(--mono);padding:14px 20px;gap:16px}.legend span:before{width:7px;height:7px;border-radius:0}.slider-row{font:12px var(--mono);padding:16px 20px}.slider-row output{font-size:12px;color:#e5e4e9}.math.block{border-radius:0;margin:0;background:#08090b;padding:13px;border-bottom:1px solid #242428}.solid-canvas{height:385px}.quiet{font-size:12px;line-height:1.75}.toggles{font:11px var(--mono);padding:13px 18px;gap:16px}.toggles label{gap:4px}.card{border-radius:4px;background:#0b0b0d;border-color:#353538}.card p{font-size:14px;line-height:1.8}.stat{font-family:var(--display);font-size:48px;color:#eeede9;font-weight:500}.progressbar{height:3px;border-radius:0;background:#2d2d30}.progressbar i{background:#e1e0df}.step-track span{border-radius:0;width:32px;height:3px}.step-track span.done{background:#e1e0df}.section-label{border-top:1px solid #303033;padding-top:24px;margin-top:25px}.path-unit{border-radius:4px;background:#0a0a0c;border-color:#303033}.path-unit .number{border-radius:2px;width:38px;height:38px;border-color:#45454a;font:12px var(--mono);color:#d2d1d7}.path-unit p{font-family:var(--mono);font-size:11px}.path-unit.locked{opacity:.64}.notice{border-radius:3px;border-color:#453e48;background:#151217;font-size:14px}.source-link{font:11px var(--mono);color:#c2bbc9}.badge{border-radius:2px;font:10px var(--mono);background:#211d27}.field-label{font:11px var(--mono);color:#aeb0b8;margin:17px 0 9px}.answer-input{font-size:17px;min-height:49px}.text-answer{font-size:14px}.bound-row{gap:10px}.bound-row span{font:11px var(--mono)}.builder-fields{gap:5px}.atlas-toolbar{gap:12px;margin-bottom:18px}.workspace-footnote{border-top:1px solid #272729;padding:20px 38px;display:flex;justify-content:space-between;gap:16px;font:10px var(--mono);letter-spacing:1px;color:#77777f}.workspace-footnote a{color:#9a9aa2}.sidebar{position:fixed;top:auto;left:auto;right:32px;bottom:84px;width:305px;height:auto;max-height:calc(100vh - 110px);overflow:auto;z-index:40;border:1px solid #777;border-radius:6px;padding:12px;background:#111112f7;box-shadow:0 10px 50px #000b;backdrop-filter:blur(12px);display:block}.menu-heading{display:flex;justify-content:space-between;padding:7px 4px 17px;font-family:var(--mono);font-size:13px}.menu-heading .mini-label{font-size:10px;color:#818189}.nav{display:grid;gap:6px}.nav button{border:1px solid #303033;background:#1a1a1c;border-radius:2px;padding:12px;font:12px var(--mono);color:#d8d7dc;gap:13px;display:flex;align-items:center;text-align:left}.nav button:hover{border-color:#79797e;background:#252528}.nav button.active{color:#fff;background:#2b2b2e;border-color:#747477}.nav-index{font-size:10px;color:#87878e}.nav-arrow{margin-left:auto;color:#6b6b72}.nav-count{font-size:10px}.menu-path{font:10px/1.9 var(--mono);padding:17px 7px 5px;color:#82828a}.menu-path strong{font-weight:400;color:#d0ced7}.workspace-menu{position:fixed;z-index:41;bottom:24px;right:32px;display:flex;align-items:center;gap:13px;background:#151515f5;border:1px solid #777;border-radius:5px;padding:8px 10px;font:12px var(--mono);letter-spacing:.7px;box-shadow:0 5px 25px #0009}.menu-symbol{height:29px;width:29px;border-radius:2px;background:#efeee9;color:#121212;font-size:23px;display:grid;place-items:center;line-height:1}.current-view{border-left:1px solid #444;margin-left:10px;padding:0 7px 0 15px;font-size:10px;color:#a7a6af;letter-spacing:0}.workspace-menu[aria-expanded=true]{border-color:#eee}.side-caption,.course-tree,.side-bottom{display:none}.brand:hover{color:white}.lesson-footer{margin:21px 0}.lesson-footer>a{font-family:var(--mono);font-size:11px;color:#c8c7ce}a:hover{text-decoration:underline;text-underline-offset:4px}.brand:hover{text-decoration:none}.topbar .brand small{color:#9e9ea6}.grid-legend{font:11px var(--mono)}
@media(max-width:1600px){.shell{margin:22px 24px 86px}.main{padding:32px 34px 45px}.topbar{padding:0 34px}}
@media(max-width:1150px){.shell{display:block;margin:16px 16px 84px}.lesson-layout{grid-template-columns:minmax(0,1fr) minmax(300px,1fr)}h1{font-size:47px}.main{padding:30px 26px}.topbar{padding:0 26px}.brand{font-size:31px}.brand small{font-size:9px}.breadcrumb{font-size:10px}.saved{display:none}.panel-body{padding:22px}.question-title{font-size:20px}.diagram-toolbar .mini-label{display:none}}
@media(max-width:850px){.lesson-layout{grid-template-columns:1fr}.diagram svg{max-height:325px}.solid-canvas{height:345px}.topbar{height:96px}.breadcrumb{max-width:210px;flex-wrap:wrap;justify-content:flex-end}.page-head{align-items:flex-start}.page-head .pill{white-space:nowrap}.subtitle{font-size:14px}}
@media(max-width:700px){.shell{margin:9px 9px 83px;border-radius:7px}.main{padding:26px 18px 32px}.topbar{padding:0 18px;height:86px;gap:10px}.brand{font-size:28px}.brand small{font-size:8px;max-width:150px;letter-spacing:.7px}.brand-mark{width:26px;height:32px;font-size:25px}.breadcrumb{font-size:9px;gap:5px;max-width:150px}.saved{display:none}h1{font-size:42px;line-height:1.04;letter-spacing:-.5px}.eyebrow{font-size:10px}.question-title{font-size:19px}.panel-head{padding:15px 17px}.panel-body{padding:21px 18px}.panel-head .pill{font-size:9px}.sidebar{position:fixed;bottom:80px;right:16px;width:min(305px,calc(100vw - 32px));padding:12px}.nav{display:grid;margin:0;overflow:visible}.nav button{font-size:12px;padding:12px}.workspace-menu{right:16px;bottom:20px}.current-view{max-width:130px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.workspace-footnote{padding:18px;font-size:8px;letter-spacing:.6px}.diagram svg{max-height:310px}.atlas-toolbar select{min-width:0;max-width:100%}.legend{font-size:10px}.path-unit{grid-template-columns:36px 1fr}.grid{grid-template-columns:1fr}.option{font-size:14px}.source-card{display:block}.source-card .button-row{margin-top:15px}.toggles{font-size:10px}}
/* Shared course library and Space Missions teaching surfaces */
.button{display:inline-block;padding:12px 18px;border:1px solid var(--line);border-radius:3px;text-decoration:none;font-weight:600}.space-diagram{max-width:620px;margin:auto}.space-diagram svg{width:100%;display:block}.space-readouts{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:22px 0}.space-readouts div{padding:14px;border:1px solid var(--line)}.space-readouts small{display:block;color:var(--muted);font-family:monospace;font-size:10px;margin-bottom:8px}.space-readouts b{font-size:22px;color:var(--blue)}.space-picks{display:flex;flex-wrap:wrap;gap:8px}.space-picks [aria-pressed=true]{background:#b8d7f4;color:#090a0c}.space-fact{min-height:310px;padding:30px 8px}.orbit-symbol{font-size:78px;color:#b8d7f4;line-height:1.1;margin-bottom:24px}.space-fact p{font-size:18px;line-height:1.7}.course-folder{margin-top:32px}input[type=range]{accent-color:#b8d7f4}.topbar{flex-wrap:wrap;gap:16px}@media(max-width:600px){.space-readouts b{font-size:18px}.space-fact{min-height:220px}.topbar .breadcrumb{font-size:10px}.space-picks button{font-size:12px}}
/* An interactive book: the scene is the answer surface. */
.book-main{padding:40px;min-height:70vh}.book-reading{max-width:900px;margin:auto}.book-reading h1{font-size:48px;margin:22px 0}.book-theory{max-width:760px;margin:0 0 24px;font-size:18px;line-height:1.75;color:#c4c4c8}.book-theory p+p{margin-top:12px}.book-breadcrumb,.book-next,.book-summary{display:flex;align-items:center;justify-content:space-between;gap:20px}.book-breadcrumb{font:11px monospace;color:#aaa;margin-bottom:32px}.book-next{margin:30px 0}.book-next .quiet{max-width:300px;font-size:12px}.book-step-track{display:flex;gap:10px;margin:24px 0}.book-step-track a{border:1px solid #444;width:34px;height:34px;display:grid;place-items:center;text-decoration:none;color:#aaa}.book-step-track .current{border-color:#b8d7f4;color:#b8d7f4}.book-step-track .done{background:#263746;color:white}.activity-intro{padding:28px 30px 12px}.activity-intro h2{font:600 23px/1.45 Inter,sans-serif;text-transform:none;margin:14px 0}.book-activity [data-work]{padding:0 30px 24px}.activity-svg{width:100%;display:block;max-height:490px;touch-action:manipulation;background:#0a0b0d}.activity-svg [role=button]{cursor:pointer}.activity-svg [role=button]:hover rect,.activity-svg [role=button]:focus rect{stroke:#e9b9d0;stroke-width:3}.activity-svg [role=button]:focus{outline:2px solid #e9b9d0}.activity-svg text{font-family:Inter,sans-serif}.activity-actions{padding:0 30px 24px}.book-activity [data-response],.book-activity [data-help]{margin:0 30px 22px}.match-row{display:grid;grid-template-columns:1fr 1fr;gap:18px;align-items:center;border-bottom:1px solid #303034;padding:18px 0}.match-row select{width:100%;min-width:0;white-space:normal;font-size:14px}.match-row span{font-size:16px;line-height:1.5}.sequence-slots{padding:24px;border:1px dashed #777;line-height:2;min-height:90px;margin:12px 0 24px}.sequence-slots span{display:inline-block;color:#b8d7f4;padding:0 7px}.tune-controls{padding-top:22px;display:grid;gap:18px}.activity-readout{display:flex;justify-content:space-between;align-items:center;padding:24px;background:#17191e;border-left:3px solid #b8d7f4;font-size:17px;margin-top:20px}.activity-readout strong{font:600 32px 'Barlow Condensed',sans-serif}.bound-inputs,.projection-task{display:grid;grid-template-columns:1fr 1fr;gap:16px;padding:24px 0}.projection-task p{grid-column:1/-1}.bound-inputs input,.projection-task input,.book-activity input:not([type=range]){display:block;width:100%;margin-top:8px;padding:14px;color:#eee;background:#101014;border:1px solid #555;border-radius:3px;font:16px monospace}.projection-shadow svg{display:block;width:100%;max-height:320px}.projection-shadow{border:1px solid #444;margin:20px}.projection-buttons button.active{background:#b8d7f4;color:#111}.book-map{margin:34px 0}.book-chapter{display:flex;align-items:center;gap:25px;border-top:1px solid #303034;padding:23px 8px;text-decoration:none;color:#eee}.book-chapter>span{font:24px 'Barlow Condensed',sans-serif;color:#888;min-width:28px}.book-chapter>div{flex:1}.book-chapter h3{font:600 20px Inter,sans-serif;text-transform:none;margin:0 0 9px}.book-chapter p{font:12px/1.65 monospace;color:#aaa;margin:0}.book-chapter>small{font:12px monospace;color:#b8d7f4}.book-summary{border:1px solid #333;padding:22px}.book-summary b{font:36px 'Barlow Condensed',sans-serif}.book-summary span{font-size:13px;color:#aaa}.book-links{padding-bottom:24px}.book-activity .projection-buttons{padding:14px 0}.book-activity .field-label{line-height:1.6}@media(max-width:700px){.book-main{padding:24px 16px}.book-reading h1{font-size:36px}.book-theory{font-size:16px}.activity-intro{padding:20px 16px 8px}.activity-intro h2{font-size:19px}.book-activity [data-work]{padding:0 12px 16px}.activity-actions{padding:0 14px 20px;gap:8px}.book-activity [data-response],.book-activity [data-help]{margin:0 14px 18px}.match-row{grid-template-columns:1fr;gap:8px}.book-next,.book-summary{flex-wrap:wrap}.book-next .quiet{order:3;width:100%;max-width:none}.book-breadcrumb{font-size:9px;gap:8px}.book-chapter{gap:14px}.book-chapter h3{font-size:17px}.bound-inputs,.projection-task{grid-template-columns:1fr}.activity-readout{font-size:13px;padding:16px}.activity-readout strong{font-size:26px}}
/* Teaching colours have fixed meanings across every book. */
:root{--teach-concept:#b8dcfa;--teach-keyword:#f2bfd7;--teach-formula:#f5e7aa;--teach-definition:#d3c3f0;--teach-observation:#f9d0ab;--teach-exam:#b6e6d0;--teach-example:#c9ced9}
[hidden]{display:none!important}.book-reading{max-width:860px}.teaching-top{display:flex;justify-content:space-between;gap:20px;align-items:center;margin:26px 0 16px}.teaching-top small{font-size:13px;color:#aeb4bf;text-align:right}.phase-label{font:13px var(--mono);color:var(--teach-concept);letter-spacing:.08em}.teaching-title{font-family:Arial,sans-serif;font-size:clamp(27px,4vw,38px);line-height:1.18;letter-spacing:-.035em;text-transform:none;max-width:25ch;margin:18px 0 28px}.teaching-blocks{display:grid;gap:16px}.teaching-block{--accent:var(--teach-concept);padding:22px 25px;border-left:3px solid var(--accent);background:linear-gradient(100deg,color-mix(in srgb,var(--accent) 7%,#0b0c0f),#0b0c0f);border-radius:0 12px 12px 0}.teaching-block.definition{--accent:var(--teach-definition)}.teaching-block.formula{--accent:var(--teach-formula)}.teaching-block.observation{--accent:var(--teach-observation)}.teaching-block.exam{--accent:var(--teach-exam)}.teaching-block.example{--accent:var(--teach-example)}.teaching-label{display:block;color:var(--accent,var(--teach-concept));font:12px var(--mono);letter-spacing:.11em;margin-bottom:12px}.teaching-block p{font-size:18px;line-height:1.75;max-width:65ch;margin:0;color:#e0e2e7}.teaching-keyword{color:var(--teach-keyword);font-weight:650}.teaching-block.formula p{color:var(--teach-formula)}.colour-key{font-size:13px;color:#a6aab3;margin:24px 0}.colour-key summary{cursor:pointer;padding:12px 0}.colour-key>div{display:flex;flex-wrap:wrap;gap:14px;padding:12px 0}.legend-concept{color:var(--teach-concept)}.legend-keyword{color:var(--teach-keyword)}.legend-formula{color:var(--teach-formula)}.legend-definition{color:var(--teach-definition)}.legend-observation{color:var(--teach-observation)}.legend-exam{color:var(--teach-exam)}.teaching-continue{min-height:52px;min-width:210px;margin-bottom:24px}.diagram-guide{margin:24px 0;padding:24px;background:#0c1015;border:1px solid #293744;border-radius:12px}.teaching-svg,.experiment-svg{display:block;width:100%;max-height:330px}.diagram-copy{font-size:16px;line-height:1.65;padding:18px 0;color:var(--teach-concept)}.diagram-revealed .diagram-copy{color:var(--teach-observation)}.diagram-guide button{min-height:48px}.teaching-complete{margin-bottom:30px}.journey-progress{display:flex;gap:16px;align-items:center;margin:18px 0 28px}.journey-progress [role=progressbar]{height:5px;background:#252b33;border-radius:9px;flex:1;overflow:hidden}.journey-progress [role=progressbar] span{display:block;height:100%;background:var(--teach-concept)}.journey-progress small{font-size:12px;color:#b0b6c0}.book-step-track{flex-wrap:wrap}.tap-choices{display:grid;gap:12px;margin:16px 0}.tap-choices button{text-align:left;min-height:52px;font-size:16px;line-height:1.5;padding:16px 20px}.tap-choices button.chosen,.experiment-stages button.chosen{border-color:var(--teach-exam);background:#17251f;color:var(--teach-exam)}.tap-match{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:20px 0}.tap-match>div{display:flex;flex-direction:column;gap:12px}.tap-match button{min-height:64px;text-align:left;line-height:1.45;font-size:16px;padding:15px;overflow-wrap:anywhere}.tap-match button small{display:block;font-size:13px;margin-top:9px;color:#aeb7c5}.tap-match [aria-pressed=true]{border-color:var(--teach-concept);background:#18232c;box-shadow:0 0 0 1px var(--teach-concept)}.tap-match .matched{border-color:#537968}.tap-match .matched small{color:var(--teach-exam)}.space-picks{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.space-picks button{font-size:16px;min-height:56px;line-height:1.45;text-align:left;padding:16px}.sequence-slots{display:flex;flex-direction:column;gap:8px;min-height:55px}.sequence-slots span{display:flex;gap:15px;align-items:center}.sequence-slots b{background:#24333d;color:var(--teach-concept);padding:8px 12px;border-radius:6px}.direction-buttons{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.direction-buttons button{min-height:48px;font-size:16px}.prediction-card,.followup-card{padding:24px 30px;border-block:1px solid #30343b;background:#11161c}.followup-card{background:#111c18}.followup-card p,.prediction-card p{font-size:16px;line-height:1.6}.experiment-stages{display:grid;gap:10px}.experiment-stages button{min-height:54px;text-align:left;font-size:16px}.observation-note{padding:20px;margin-top:20px;border-left:3px solid var(--teach-observation);background:#241d17;color:#eee}.observation-note b{color:var(--teach-observation)}.observation-note p{font-size:16px;line-height:1.6}.coverage-ledger details{border-bottom:1px solid #333;padding:16px 0}.coverage-ledger summary{font-size:18px;cursor:pointer}.coverage-ledger a{display:block;padding:15px 10px}.coverage-ledger a span{display:block;font-size:13px;color:#aab2bf;margin-top:5px}.milestone{animation:milestone-glow .8s ease-out}@keyframes milestone-glow{50%{background:#19271f}}.tune-controls input[type=range]{min-height:44px}.book-activity{scroll-margin-top:20px}.book-next{align-items:center}.book-next button{min-height:52px}
@media(max-width:600px){.teaching-top{align-items:start}.teaching-top small{max-width:65%;line-height:1.5}.teaching-block{padding:18px}.teaching-block p{font-size:17px;line-height:1.65}.teaching-title{font-size:29px}.tap-match{gap:10px}.tap-match button{padding:12px 9px;font-size:14px;min-height:70px}.tap-match button small{font-size:12px}.direction-buttons{grid-template-columns:repeat(2,1fr)}.space-picks{grid-template-columns:1fr}.prediction-card,.followup-card{padding:20px}.diagram-guide{padding:15px}.teaching-svg,.experiment-svg{min-height:210px}.teaching-continue{width:100%}.journey-progress{flex-wrap:wrap}.book-next .quiet{order:3;width:100%}.book-next{flex-wrap:wrap}.activity-intro h2{font-size:22px}.book-breadcrumb{font-size:12px}}
@media(prefers-reduced-motion:reduce){.milestone{animation:none}}
.diagram-guide:not(.diagram-revealed) .teaching-svg path,.diagram-guide:not(.diagram-revealed) .teaching-svg circle,.diagram-guide:not(.diagram-revealed) .teaching-svg ellipse{opacity:.45}.diagram-guide .teaching-svg text{font-weight:600}.diagram-revealed .teaching-svg path,.diagram-revealed .teaching-svg circle{transition:opacity .3s}.diagram-toolbar [data-plane],.diagram-toolbar [data-mode-button],.diagram-toolbar [data-hide-projection]{min-height:44px}
.skip{top:8px;transform:translateY(-200%)}.skip:focus{transform:translateY(-200%)}.skip:focus-visible{transform:translateY(0)}
.skip{width:1px;height:1px;padding:0;overflow:hidden;clip-path:inset(50%)}.skip:focus-visible{width:auto;height:auto;padding:12px;overflow:visible;clip-path:none}.diagram-revealed .teaching-svg circle[fill="none"],.diagram-revealed .teaching-svg ellipse[fill="none"]{stroke:var(--teach-concept);stroke-width:2}