:root{--navy:#052548;--blue:#075681;--ink:#142b3f;--muted:#536675;--paper:#fff;--wash:#f5f6f4;--line:#dce3e7;--a:#075681;--b:#c26932;--c:#708d83;--focus:#d77328;--side:282px}
*{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font-family:Arial,Helvetica,sans-serif;line-height:1.6}
a{color:var(--blue)}
button,input,select{font:inherit}
button,select{cursor:pointer}
button{border:1px solid var(--line);border-radius:5px;padding:.55rem .95rem;background:#fff;color:var(--navy);font-weight:600}
button:hover{background:#edf2f5}
button.primary{color:#fff;background:var(--navy);border-color:var(--navy)}
button:disabled{cursor:default;opacity:.45}
:focus-visible{outline:3px solid var(--focus);outline-offset:4px}
.skip-link{position:fixed;top:-100px;left:20px;background:#fff;padding:10px;z-index:10}.skip-link:focus{top:10px}
.topbar{height:82px;background:var(--navy);color:#fff;display:flex;align-items:center;justify-content:space-between;padding:0 34px;position:sticky;top:0;z-index:5}
.course{font-size:21px;text-decoration:none;color:#fff;letter-spacing:.03em}.course span{display:block;font-size:11px;letter-spacing:.02em;opacity:.75}
.header-actions{display:flex;align-items:center;gap:24px;font-size:13px}.header-actions a{color:#fff;text-decoration:none}.header-actions a:hover{text-decoration:underline}
#menu-toggle{display:none}
.page-layout{display:grid;grid-template-columns:var(--side) minmax(0,1fr);max-width:1700px;margin:auto}
.sidebar{position:sticky;top:82px;height:calc(100dvh - 82px);overflow:auto;padding:32px 20px 20px 28px;background:var(--wash);border-right:1px solid var(--line)}
.sidebar-heading{padding:0 10px 22px}.eyebrow{font-size:11px;letter-spacing:.15em;color:var(--muted);font-weight:700}
.sidebar h2{font-size:24px;margin:4px 0;color:var(--navy);line-height:1.3}.sidebar-heading p{font-size:12px;color:var(--muted);margin:4px 0}
.nav-group{font-size:10px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);padding:23px 10px 8px;font-weight:700}
.nav-link{display:flex;gap:12px;text-decoration:none;font-size:12px;line-height:1.45;padding:8px 10px;border-radius:4px;color:#435867;border-left:3px solid transparent}
.nav-link:hover{background:#e8edf0}.nav-link.active{background:#e3ebf0;border-left-color:var(--blue);color:var(--navy);font-weight:700}
.nav-link .nav-number{font-size:10px;min-width:17px;opacity:.65;padding-top:2px}.nav-link .lab-dot{margin-left:auto;color:var(--b);font-size:13px}
.sidebar-foot{font-size:11px;color:var(--muted);padding:26px 10px 0;border-top:1px solid var(--line);margin-top:28px}
main{padding:43px clamp(24px,5vw,80px) 24px;min-width:0;max-width:1170px;width:100%;margin:0 auto}
.slide-meta{display:flex;justify-content:space-between;font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);gap:18px;margin-bottom:30px}
.slide-copy h1{font-size:clamp(29px,3.4vw,46px);font-weight:700;line-height:1.2;letter-spacing:-.035em;color:var(--blue);margin:0 0 30px;max-width:950px}
.slide-copy p{font-size:clamp(19px,1.8vw,24px);line-height:1.6;margin:16px 0;color:var(--ink)}
.slide-copy .slide-footer{font-size:16px;line-height:1.5;color:var(--blue);margin-top:32px}
.slide-copy.cover{background:var(--navy);color:#fff;padding:clamp(30px,5vw,65px);border-radius:3px;min-height:410px;display:flex;flex-direction:column;justify-content:center}
.slide-copy.cover h1{color:#fff;font-size:clamp(35px,4vw,56px);max-width:700px}
.slide-copy.cover p{color:#e1ebf2;font-size:19px;margin:5px 0}
.slide-copy.section{min-height:285px;background:var(--navy);padding:45px;display:flex;align-items:center}.slide-copy.section h1{margin:0;color:#fff}
.slide-copy.references p{font-size:17px;margin-bottom:22px}
.slide-columns{display:grid;grid-template-columns:1fr 1fr;gap:50px}.slide-columns h2{font-size:21px;color:var(--blue)}
.equation{padding:24px 0 36px;overflow-x:auto}.equation math{font-size:clamp(25px,2.65vw,37px);white-space:nowrap}
math{font-family:"Cambria Math","STIX Two Math",math;line-height:1.2;color:inherit}
.table-wrap{overflow-x:auto}
table{border-collapse:collapse;width:100%;text-align:left}
.slide-table{font-size:clamp(14px,1.3vw,18px);margin:15px 0 28px}.slide-table th{background:var(--navy);color:#fff;padding:12px 14px;font-weight:600}.slide-table td{padding:13px 14px;border-bottom:1px solid var(--line)}.slide-table tr:nth-child(even){background:#f5f7f8}
.lab{border-top:2px solid var(--navy);background:var(--wash);padding:28px clamp(18px,3vw,36px) 25px;margin-top:46px;border-radius:0 0 5px 5px}
.lab-head{display:flex;justify-content:space-between;gap:15px;align-items:baseline;margin-bottom:14px}
.lab-kicker{color:var(--b);font-size:10px;letter-spacing:.13em;text-transform:uppercase;font-weight:700}
.lab h2{font-size:24px;line-height:1.2;margin:7px 0 14px;letter-spacing:-.025em;color:var(--navy)}
.lab p{font-size:15px;line-height:1.65;margin:12px 0}
.lab .demo-note{font-size:12px;color:var(--muted);margin-top:20px}
.lab .hint{font-size:13px;color:var(--muted)}
.demo-layout{display:grid;grid-template-columns:minmax(200px,.8fr) minmax(260px,1.2fr);gap:36px;margin-top:23px}
.controls{min-width:0}.controls label{display:block;font-size:13px;font-weight:600;margin:0 0 22px}
.control-heading{display:flex;justify-content:space-between;align-items:center;gap:10px}
output{font-variant-numeric:tabular-nums;font-weight:700;color:var(--navy)}
input[type=range]{display:block;width:100%;accent-color:var(--blue);margin-top:10px;cursor:pointer;min-height:25px}
input[type=checkbox],input[type=radio]{accent-color:var(--blue);width:17px;height:17px;margin:0 8px 0 0;vertical-align:middle}
select{background:#fff;border:1px solid #becbd3;border-radius:4px;padding:8px 12px;max-width:100%;color:var(--ink)}
.check-label{display:flex!important;align-items:center}
.result{border-left:1px solid #cbd6dc;padding-left:28px;min-width:0}
.result h3{font-size:13px;text-transform:uppercase;letter-spacing:.07em;margin:0 0 20px;color:var(--muted)}
.bar-row{display:grid;grid-template-columns:58px 1fr 58px;gap:12px;align-items:center;font-size:13px;margin:13px 0}
.bar-track{height:17px;background:#dfe6e9;overflow:hidden;border-radius:2px}.bar-fill{height:100%;min-width:0;background:var(--a);transition:width .15s ease}.bar-value{text-align:right;font-variant-numeric:tabular-nums}
.bar-row:nth-of-type(2) .bar-fill{background:var(--b)}.bar-row:nth-of-type(3) .bar-fill{background:var(--c)}
.metric{font-size:36px;line-height:1.2;color:var(--navy);font-weight:700;font-variant-numeric:tabular-nums}.metric-label{font-size:12px;color:var(--muted)}
.small-table{font-size:12px}.small-table th,.small-table td{padding:7px 8px;border-bottom:1px solid #d1dbe0;font-variant-numeric:tabular-nums}.small-table th{font-weight:600;color:var(--muted)}
.actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:16px 0}
.calculation{background:#fff;padding:13px 16px;font-size:14px;line-height:1.7;margin:16px 0;overflow-x:auto;border-left:3px solid var(--blue)}
.chart{width:100%;height:auto;display:block;margin:18px 0}.chart text{fill:var(--muted);font:11px Arial,Helvetica,sans-serif}
.legend{display:flex;gap:18px;font-size:12px;color:var(--muted);flex-wrap:wrap}
.legend span:before{content:"";display:inline-block;width:9px;height:9px;margin-right:7px;background:var(--a)}.legend span:nth-child(2):before{background:var(--b)}.legend span:nth-child(3):before{background:#a9b4bc}
.history{display:flex;gap:2px;align-items:center;margin:6px 0;flex-wrap:wrap;font-size:11px}.household-id{width:32px;color:var(--muted)}.purchase{display:inline-flex;align-items:center;justify-content:center;width:22px;height:23px;color:#fff;background:var(--a);border-radius:2px}.purchase.b{background:var(--b)}
.quiz fieldset{border:0;border-top:1px solid var(--line);padding:17px 0;margin:0}.quiz legend{float:left;width:100%;font-weight:700;font-size:14px;padding:0 0 10px}.quiz label{display:block;clear:both;font-size:13px;margin:8px 0;cursor:pointer}.feedback{font-size:13px;color:var(--blue);padding:10px 0}
.pager{display:flex;justify-content:space-between;gap:20px;border-top:1px solid var(--line);padding-top:25px;margin-top:46px}.pager a{font-size:14px;min-height:44px;display:flex;align-items:center;gap:14px;text-decoration:none;font-weight:600}.pager a[aria-disabled=true]{opacity:.3;pointer-events:none}
.page-foot{font-size:11px;color:var(--muted);display:flex;justify-content:space-between;gap:20px;padding:25px 0 0}
.noscript{padding:40px}
.exercise-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px 24px;margin:24px 0}
.exercise-controls label{display:flex;flex-direction:column;gap:8px;font-size:13px;font-weight:600}
.exercise-controls input{width:100%;min-width:0;padding:8px 12px;border:1px solid #becbd3;border-radius:4px;background:#fff;color:var(--ink)}
.exercise-step{border-top:1px solid #cbd6dc;padding:28px 0 12px;margin-top:26px}
.step-number{color:var(--b);font-size:11px;font-weight:700;letter-spacing:.12em}
.calibration-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.exercise-method{font-size:13px;border-top:1px solid var(--line);padding-top:20px;margin-top:22px}
.exercise-method summary{cursor:pointer;font-weight:700;color:var(--blue)}
.fit-status{padding:12px 16px;background:#e7eeeb;border-left:3px solid var(--c)}
.fit-warning{background:#fff1e5;border-left-color:var(--b)}
 .joint-flow{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px;margin:24px 0;padding:23px;background:#fff;border:1px solid var(--line);border-radius:5px}
.joint-flow>div{position:relative;min-width:0}.joint-flow>div:not(:nth-child(4)):after{content:"→";position:absolute;right:-16px;top:12px;font-size:20px;color:#94a5b1}
.joint-flow h3{font-size:17px;line-height:1.3;margin:7px 0;color:var(--navy)}.joint-flow p{font-size:12px;color:var(--muted);margin:0;line-height:1.55}
.joint-flow .joint-loop{grid-column:1/-1;border-top:1px solid var(--line);padding-top:14px;color:var(--blue)}.story-number{font-size:11px;color:var(--b);font-weight:700}
.joint-chart text{font-size:14px}
.joint-parameter-tiles{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:18px 0}
.joint-parameter-tiles>div{background:#fff;padding:12px;border:1px solid var(--line);border-radius:4px}.joint-parameter-tiles span{font-size:11px;color:var(--muted);display:block}.joint-parameter-tiles strong{font-size:25px;line-height:1.3;color:var(--navy);font-variant-numeric:tabular-nums}
.calibration-metrics{display:grid;grid-template-columns:1fr 1fr;gap:18px;background:#fff;padding:16px;margin:18px 0}.calibration-metrics strong{display:block;font-size:20px;color:var(--navy);font-variant-numeric:tabular-nums}
@media(max-width:720px){.joint-flow{grid-template-columns:1fr;gap:14px;padding:18px}.joint-flow>div{padding-left:26px}.joint-flow>div:after{display:none}.joint-flow .story-number{position:absolute;left:0;top:4px}.joint-flow h3{margin-top:0;font-size:16px}.joint-parameter-tiles{grid-template-columns:1fr 1fr}.calibration-metrics{grid-template-columns:1fr}}
@media(max-width:720px){.exercise-controls,.calibration-grid{grid-template-columns:1fr}.exercise-step .small-table th,.exercise-step .small-table td{white-space:nowrap}}
[hidden]{display:none!important}
@media(max-width:1000px){:root{--side:235px}.sidebar{padding-left:14px;padding-right:12px}main{padding:35px 30px 24px}.demo-layout{grid-template-columns:1fr;gap:18px}.result{border-left:0;border-top:1px solid var(--line);padding:23px 0 0}.slide-copy p{font-size:21px}}
@media(max-width:720px){.topbar{height:72px;padding:0 20px}.course{font-size:19px}.course span{display:none}.header-actions{gap:16px}.header-actions a{font-size:12px}#menu-toggle{display:block;font-size:12px;background:transparent;color:#fff;border-color:#527089;padding:7px 10px}.page-layout{display:block}.sidebar{display:none;position:fixed;top:72px;left:0;width:min(340px,90vw);height:calc(100dvh - 72px);z-index:4;box-shadow:10px 0 35px #05254830}.sidebar.open{display:block}main{padding:29px 22px 20px}.slide-meta{margin-bottom:22px;font-size:10px}.slide-copy h1{font-size:32px;margin-bottom:23px}.slide-copy p{font-size:19px}.slide-copy.cover{min-height:370px;padding:28px}.slide-copy.cover h1{font-size:38px}.slide-copy.section{padding:28px;min-height:230px}.slide-columns{gap:20px}.slide-columns p{font-size:17px}.lab{margin-top:33px}.lab h2{font-size:22px}.slide-table th,.slide-table td{padding:10px 9px;white-space:nowrap}.slide-table{font-size:13px}.page-foot span{display:none}.equation math{font-size:27px}.bar-row{grid-template-columns:54px 1fr 52px;gap:9px}.small-table{font-size:11px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
@media print{.topbar,.sidebar,.lab,.pager,.page-foot{display:none!important}.page-layout{display:block}main{max-width:none;padding:0}.slide-copy{break-inside:avoid}.slide-copy.cover,.slide-copy.section{background:#fff!important}.slide-copy.cover h1,.slide-copy.cover p,.slide-copy.section h1{color:#000!important}}

.slide-columns>div{min-width:0}
.slide-columns .col-eq{display:block;margin-top:10px;max-width:100%;overflow-x:auto}
@media(max-width:720px){.slide-columns .col-eq math{font-size:15px}}