/* Business explainers. Original School Launch styles; palette and header/footer from courses/shared/course.css. */
:root{
  --ground:#F5F0E6; --paper:#FFFDF8; --linen:#EDE4D3; --ink:#1F1B16; --muted:#5A5247; --line:#D9CFBC;
  --forge:#8C3A1F; --forge-ink:#FFFFFF; --brass:#B08A3E; --focus:#1F4E5A;
  --plot-bg:#FFFDF8; --grid:#ECE4D4; --axis:#8A7F6E; --field:#7A6E5E;
  --c1:#1F5F8B; --c2:#C0392B; --c3:#2F6B3A; --band:rgba(47,107,58,.13); --hi:#F3DFA9;
  --f1:rgba(31,95,139,.30); --f2:rgba(192,57,43,.30); --f3:rgba(47,107,58,.30); --mono:ui-monospace,'SF Mono',Menlo,Consolas,monospace;
  --display:'Cinzel','Trajan Pro',Georgia,serif;
  --serif:'Source Serif 4',Georgia,'Times New Roman',serif;
  --sans:'Source Sans 3','Segoe UI',system-ui,-apple-system,sans-serif;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    color-scheme:dark;
    --ground:#17130F; --paper:#211C17; --linen:#2B241D; --ink:#EFE7D8; --muted:#B8AC98; --line:#3E352B;
    --forge:#E08A5F; --forge-ink:#17130F; --brass:#C9A55E; --focus:#8FC3CF;
    --plot-bg:#1B1713; --grid:#2E2720; --axis:#8C8170; --field:#9C907C;
    --c1:#8FC3E8; --c2:#FF8A7A; --c3:#9BD3A3; --band:rgba(155,211,163,.13); --hi:#5A4A22;
    --f1:rgba(143,195,232,.30); --f2:rgba(255,138,122,.30); --f3:rgba(155,211,163,.30);
  }
}
:root[data-theme="dark"]{
  color-scheme:dark;
  --ground:#17130F; --paper:#211C17; --linen:#2B241D; --ink:#EFE7D8; --muted:#B8AC98; --line:#3E352B;
  --forge:#E08A5F; --forge-ink:#17130F; --brass:#C9A55E; --focus:#8FC3CF;
  --plot-bg:#1B1713; --grid:#2E2720; --axis:#8C8170; --field:#9C907C;
  --c1:#8FC3E8; --c2:#FF8A7A; --c3:#9BD3A3; --band:rgba(155,211,163,.13); --hi:#5A4A22;
    --f1:rgba(143,195,232,.30); --f2:rgba(255,138,122,.30); --f3:rgba(155,211,163,.30);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
html,body{margin:0;background:var(--ground);color:var(--ink)}
body{font-family:var(--sans);font-size:17px;line-height:1.5;overflow-x:hidden}
a{color:var(--forge)}
:focus-visible{outline:3px solid var(--focus);outline-offset:2px}
[hidden]{display:none!important}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.skip{position:absolute;left:-999px;top:0;background:var(--ink);color:var(--ground);padding:.5rem .8rem;z-index:30}
.skip:focus{left:.5rem;top:.5rem}
.m{font-family:var(--serif);font-style:italic}
.mf{font-family:var(--serif)}

/* site header and footer */
.site-head .wrap,.site-foot .wrap{max-width:1120px;margin:0 auto;padding-inline:20px}
.site-head{background:var(--ground);border-bottom:1px solid var(--line)}
.site-head .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;padding-block:12px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand span{font-family:var(--display);font-weight:700;font-size:22px;color:var(--forge);letter-spacing:.03em}
.nav{display:flex;gap:4px;flex-wrap:wrap}
.nav a{text-decoration:none;color:var(--ink);font-weight:600;font-size:15px;padding:8px 12px;border-radius:6px}
.nav a:hover{background:var(--linen)}
.site-foot{border-top:1px solid var(--line);padding-block:28px;font-size:17px}
.site-foot .wrap{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;align-items:baseline}
.site-foot p{margin:0}
.eyebrow{font-size:13px;letter-spacing:.14em;text-transform:uppercase;font-weight:700;color:var(--muted)}
.muted{color:var(--muted)}
.foot-links{display:flex;flex-wrap:wrap;gap:4px 18px;margin:0 0 10px;padding:0;list-style:none;font-size:15px;font-weight:600}
.foot-links a{text-decoration:none}
.foot-links a:hover{text-decoration:underline}
.site-foot .foot-base{margin-top:24px;padding-top:20px;border-top:1px solid var(--line)}
.motto{font-family:var(--serif);font-style:italic}
.network{display:flex;flex-direction:column;gap:12px;width:100%}
.network h2{margin:0}
.network-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.network-list li{display:flex;flex-direction:column;gap:2px;font-size:15px}
.network-list a{font-family:var(--serif);font-weight:600;font-size:18px}
.network-list span{color:var(--muted)}
.sl-foot-line{font-size:15px}
.sl-foot-legal{font-size:13px;margin-top:6px}
@media (max-width:700px){.network-list{grid-template-columns:minmax(0,1fr);gap:12px}}

/* explainer */
.app{max-width:1200px;margin:0 auto;padding:14px 16px 28px}
.top h1{margin:4px 0 2px;font-family:var(--serif);font-size:30px;line-height:1.2;color:var(--forge)}
.top .sub{margin:0 0 4px;color:var(--muted);max-width:75ch}
.top .meta{margin:0 0 12px;font-size:14px;color:var(--muted)}
.noscript{padding:12px 16px;background:var(--paper);border:1px solid var(--line);border-radius:8px}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 370px;gap:18px;align-items:start}
.stage{min-width:0}
.stage canvas{display:block;width:100%;aspect-ratio:16/10;height:auto;background:var(--plot-bg);border:1px solid var(--line);border-radius:8px;touch-action:pan-y;cursor:crosshair}
.hint{margin:6px 2px 0;font-size:14px;color:var(--muted)}
.key{display:flex;flex-wrap:wrap;gap:4px 16px;margin:6px 2px 0;padding:0;list-style:none;font-size:14px;color:var(--muted)}
.key li{display:flex;align-items:center;gap:6px}
.key i{display:inline-block;width:22px;height:0;border-top:3px solid}
.key i.k1{border-color:var(--c1)}
.key i.k2{border-color:var(--c2)}
.key i.k3{border-color:var(--c3)}
.key i.kf{border-color:var(--field);border-top-width:2px}
.key i.dash{border-top-style:dashed}
.key i.kb{height:12px;border:0;background:var(--band);border-left:2px solid var(--c3);border-right:2px solid var(--c3)}
.side{display:flex;flex-direction:column;gap:12px;min-width:0}
.card{background:var(--paper);border:1px solid var(--line);border-radius:8px;padding:12px 14px;min-width:0}
.card h2{margin:0 0 8px;font-size:18px;font-family:var(--serif);color:var(--forge)}
fieldset{border:0;margin:0;padding:0;min-width:0}
legend{padding:0;font-weight:700;font-family:var(--serif);font-size:18px;color:var(--forge);margin-bottom:6px}
.choices{display:grid;grid-template-columns:1fr 1fr;gap:4px 10px}
.choices label{display:flex;align-items:center;gap:8px;min-height:36px;cursor:pointer;font-family:var(--serif);font-size:17px}
input[type=radio],input[type=checkbox]{width:18px;height:18px;margin:0;accent-color:var(--forge);flex:0 0 auto}
.check{display:flex;align-items:center;gap:8px;min-height:36px;cursor:pointer;font-size:15.5px}
.row{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:6px 0}
.row label{font-weight:600;font-size:15px}
.num{font:inherit;font-size:16px;width:6.2em;min-height:40px;padding:4px 6px;border:1px solid var(--muted);border-radius:6px;background:var(--plot-bg);color:var(--ink)}
select{font:inherit;font-size:16px;min-height:40px;padding:4px 6px;border:1px solid var(--muted);border-radius:6px;background:var(--plot-bg);color:var(--ink)}
.slider{margin:8px 0}
.slider .sl-row{display:flex;justify-content:space-between;align-items:baseline;gap:8px;font-weight:600;font-size:15px}
.slider output{font-weight:700;color:var(--forge);font-variant-numeric:tabular-nums;font-family:var(--serif)}
input[type=range]{width:100%;min-height:36px;accent-color:var(--forge);margin:0}
.btn{font:inherit;font-size:15.5px;font-weight:700;min-height:44px;padding:6px 14px;border-radius:6px;border:2px solid var(--forge);background:transparent;color:var(--forge);cursor:pointer}
.btn.primary{background:var(--forge);color:var(--forge-ink)}
.btn:disabled{opacity:.45;cursor:default}
.btn.sq{min-width:48px;font-size:22px;line-height:1;padding:4px 10px}
.btns{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:6px}
.chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:6px}
.chip{font:inherit;font-size:14.5px;min-height:40px;padding:4px 12px;border-radius:20px;border:1.5px solid var(--forge);background:transparent;color:var(--forge);cursor:pointer;text-align:left}
.chip:hover,.btn:hover{background:var(--linen)}
.btn.primary:hover{background:var(--forge)}
.readout{font-size:15.5px;font-variant-numeric:tabular-nums}
.readout p{margin:4px 0}
.readout dl{display:grid;grid-template-columns:auto minmax(0,1fr);gap:3px 12px;margin:6px 0 0}
.readout dt{color:var(--muted)}
.readout dd{margin:0;font-weight:700;text-align:right;font-family:var(--serif)}
.formula{font-family:var(--serif);font-size:18px;line-height:1.6;overflow-wrap:anywhere;background:var(--linen);border-left:4px solid var(--forge);border-radius:0 6px 6px 0;padding:6px 10px;margin:6px 0}
.formula sup{font-size:.72em}
.note{font-size:14.5px;border-radius:6px;padding:6px 10px;margin:8px 0 0;background:var(--hi);color:var(--ink)}
.tablebox{max-height:260px;overflow:auto;border:1px solid var(--line);border-radius:6px;margin-top:6px}
table.steps{width:100%;border-collapse:collapse;font-size:14.5px;font-variant-numeric:tabular-nums}
table.steps th,table.steps td{padding:3px 6px;text-align:right;border-bottom:1px solid var(--line);white-space:nowrap}
table.steps th{position:sticky;top:0;background:var(--linen);font-family:var(--serif);font-weight:700}
table.steps caption{text-align:left;font-size:14px;color:var(--muted);padding:4px 6px}
.guide{margin-top:22px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;align-items:start}
.guide article{background:var(--paper);border:1px solid var(--line);border-radius:8px;padding:12px 16px}
.guide h2{font-family:var(--serif);color:var(--forge);font-size:21px;margin:0 0 6px}
.guide h3{font-family:var(--serif);font-size:18px;margin:14px 0 4px}
.guide p,.guide li{font-size:16px}
.guide .eq{font-family:var(--serif);font-size:18px;text-align:center;margin:8px 0;overflow-wrap:anywhere}
.guide .qs li{margin:0 0 10px}
details summary{cursor:pointer;font-weight:700;color:var(--forge);min-height:32px}
.verse{font-style:italic}
.foot{margin-top:18px;font-size:13px;color:var(--muted);border-top:1px solid var(--line);padding-top:8px}
@media (max-width:920px){.layout{grid-template-columns:minmax(0,1fr)}.guide{grid-template-columns:minmax(0,1fr)}}
@media (max-width:560px){
  .app{padding:10px 12px 22px}.top h1{font-size:24px}
  .site-head .wrap,.site-foot .wrap{padding-inline:16px}
  .choices{grid-template-columns:1fr 1fr}
  .stage canvas{aspect-ratio:4/3}
  .card{padding:10px 12px}
}
@media (prefers-reduced-motion:no-preference){.btn,.chip{transition:background-color .15s}}
@media print{.site-head,.site-foot,.skip,.side .btns{display:none!important}}
/* thumbnail mode (#thumb): only the drawing, 16:9 */
body.thumbmode .site-head,body.thumbmode .site-foot,body.thumbmode .top,body.thumbmode .side,body.thumbmode .guide,
body.thumbmode .foot,body.thumbmode .hint,body.thumbmode .key,body.thumbmode .skip{display:none!important}
body.thumbmode .app{max-width:none;padding:0}
body.thumbmode .layout{display:block}
body.thumbmode .stage canvas{aspect-ratio:16/9;border:0;border-radius:0}
.stage .tries{margin-top:12px}
.small{font-size:14px;margin:4px 0}
.lbl{font-weight:600;font-size:15px}
.bign{display:inline-block;min-width:2.2ch;text-align:center;font-family:var(--serif);font-size:26px;font-weight:700;color:var(--forge)}
#n{margin-top:4px}

/* lesson iframe: no site header or footer */
body.embedded{background:transparent}
body.embedded .site-head,body.embedded .site-foot{display:none}
/* business explainer additions */
.key i.k1f{height:12px;border:0;background:var(--f1);border-top:3px solid var(--c1)}
.key i.k2f{height:12px;border:0;background:var(--f2);border-top:3px solid var(--c2)}
.key i.k3f{height:12px;border:0;background:var(--f3);border-top:3px solid var(--c3)}
.seg{display:flex;flex-wrap:wrap;gap:6px}
.seg label{position:relative;display:flex;align-items:center;min-height:40px;padding:4px 12px;border:1.5px solid var(--forge);border-radius:20px;cursor:pointer;font-size:15px;font-weight:600;color:var(--forge)}
.seg input{position:absolute;opacity:0;width:1px;height:1px;margin:0}
.seg label:has(input:checked){background:var(--forge);color:var(--forge-ink)}
.seg label:has(input:focus-visible){outline:3px solid var(--focus);outline-offset:2px}
.field{margin:10px 0 4px}
.field .sl-row{display:flex;justify-content:space-between;align-items:center;gap:8px}
.field label{font-weight:600;font-size:15px}
.field .unit{display:flex;align-items:center;gap:4px;font-weight:700;color:var(--muted)}
.field .num{width:7.4em;text-align:right;font-variant-numeric:tabular-nums}
.field input[type=range]{margin-top:2px}
.stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin:12px 0 0}
.stat{background:var(--paper);border:1px solid var(--line);border-radius:8px;padding:8px 10px;min-width:0}
.stat .lab{display:block;font-size:13.5px;color:var(--muted);line-height:1.3}
.stat .val{display:block;font-family:var(--serif);font-weight:700;font-size:22px;color:var(--ink);font-variant-numeric:tabular-nums;overflow-wrap:anywhere;line-height:1.25}
.stat.big .val{color:var(--forge);font-size:26px}
.stat .sm{display:block;font-size:13.5px;color:var(--muted)}
.sheet{display:flex;align-items:flex-start;gap:8px;background:var(--linen);border-left:4px solid var(--c3);border-radius:0 6px 6px 0;padding:6px 8px 6px 10px;margin:6px 0}
.sheet code{flex:1;font-family:var(--mono);font-size:14.5px;overflow-wrap:anywhere;line-height:1.5;padding-top:6px}
.sheet .btn{min-height:36px;padding:2px 10px;font-size:14px}
.sheet + .small{margin-top:0}
.cursor{font-size:15px;margin:8px 2px 0;font-variant-numeric:tabular-nums}
.cursor b{font-family:var(--serif)}
.tablebox{max-height:340px}
table.steps td:first-child,table.steps th:first-child{text-align:center}
.stage .card{margin-top:12px}
.verse{font-style:italic}
@media (max-width:560px){.stats{grid-template-columns:repeat(2,minmax(0,1fr))}.stat .val{font-size:19px}.stat.big .val{font-size:22px}}
@media (max-width:360px){.stats{grid-template-columns:minmax(0,1fr)}}
body.thumbmode .stage > :not(#cv){display:none!important}
body.thumbmode .app > :not(main),body.thumbmode .sr-only{display:none!important}
/* phones and tablets: chart and results, then the controls, then the explanations */
@media (max-width:920px){.layout{display:flex;flex-direction:column;align-items:stretch;gap:0}.stage{display:contents}.stage > .card{order:2}.side{order:1;margin-top:12px}.stats.three .stat.big{grid-column:1/-1}}