:root{--ink:#172b3d;--muted:#4d6577;--paper:#f6f9fb;--blue:#145c91;--deep:#102f4b;--line:#ccdbe4;--soft:#edf4f8;color-scheme:light}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:110px}body{margin:0;background:var(--paper);color:var(--ink);font:17px/1.72 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}button,input,select,textarea{font:inherit}button{cursor:pointer;border:1px solid #b3cbd9;border-radius:7px;padding:9px 14px;background:#fff;color:var(--deep);font-size:.88rem;font-weight:650}button:hover{background:#e9f4f8}button:disabled{cursor:default;opacity:.55}a{color:var(--blue)}button,input,select,textarea,summary,a,[tabindex]{outline-offset:4px}:focus-visible{outline:3px solid #bf7208!important;outline-offset:4px}button:focus-visible{position:relative;z-index:2}[hidden]{display:none!important}.skip-link{position:fixed;top:-90px;left:16px;background:white;padding:12px;z-index:20}.skip-link:focus{top:10px}.sr-only{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.site-header{background:var(--deep);color:#fff;border-bottom:1px solid #34637b;position:sticky;top:0;z-index:9}.topbar{max-width:1450px;margin:auto;padding:15px 30px;display:flex;align-items:center;gap:26px;justify-content:space-between}.back{color:#c2e9f5;text-decoration:none;font-size:.78rem}.course-mark{font-weight:800;font-size:1rem;letter-spacing:.05em;margin:3px 0}.course-mark span{font-weight:400;font-size:.78rem;letter-spacing:0;margin-left:9px;color:#dfedf2}.mode-control{display:flex;padding:4px;border:1px solid #5b8198;border-radius:9px;gap:4px}.mode{color:#e1f1f5;border:0;background:transparent;white-space:nowrap}.mode.active{background:#fff;color:var(--blue)}.reference-actions{display:flex;gap:5px}.reference-actions button{background:transparent;color:#e1f1f5;border-color:#577c92}.reference-actions button:hover{background:#234b63}
.hero{padding:47px max(28px,calc((100% - 1260px)/2)) 42px;background:linear-gradient(120deg,#102f4b,#176b8e);color:white}.eyebrow{font-size:.72rem;font-weight:750;letter-spacing:.12em;line-height:1.6;text-transform:uppercase;color:#3c7188;margin:0 0 12px}.hero .eyebrow{color:#bde6ef}.hero h1{font:700 clamp(2.4rem,4.8vw,4.4rem)/1.07 Georgia,"Times New Roman",serif;max-width:950px;margin:0 0 22px}.dek{max-width:830px;font-size:1.25rem;line-height:1.6;color:#e5f5f9;margin:0 0 22px}.byline{color:#d3e9f0;font-size:.86rem}.byline span{padding:0 9px}
.lesson-layout{display:grid;grid-template-columns:230px minmax(0,950px);gap:52px;max-width:1290px;padding:38px 30px 0;margin:auto}.section-nav{position:sticky;top:125px;align-self:start;max-height:calc(100vh - 145px);overflow:auto}.section-nav summary{font-size:.8rem;font-weight:750;cursor:pointer;list-style:none}.section-nav ol{list-style:none;padding:0;margin:15px 0}.section-nav li{margin:7px 0}.section-nav a{display:grid;grid-template-columns:22px 1fr auto;gap:8px;align-items:baseline;text-decoration:none;border-left:3px solid transparent;border-radius:0 5px 5px 0;padding:8px 6px;color:#425e72;font-size:.82rem;line-height:1.4}.section-nav a[aria-current]{border-color:var(--blue);background:#e3eff5;color:var(--deep);font-weight:700}.section-nav a>span:first-child{font-weight:750;color:#638195}.section-nav small{font-size:.64rem;white-space:nowrap}.section-nav>p{border-top:1px solid var(--line);padding-top:15px;font-size:.75rem;color:var(--muted)}main{min-width:0;max-width:100%}.lesson-section{padding:30px 0 60px;border-top:1px solid var(--line);scroll-margin-top:110px}.lesson-section:first-child{border-top:0;padding-top:0}.lesson-section h2{font:700 clamp(1.7rem,2.8vw,2.55rem)/1.17 Georgia,"Times New Roman",serif;letter-spacing:-.02em;margin:0 0 18px}.question{color:var(--blue);font-size:1.14rem;line-height:1.55;font-weight:650;max-width:780px}.thesis{color:var(--muted);font-size:.92rem;border-left:3px solid #73a9bb;padding-left:15px;margin:22px 0 28px}.narrative p,.study-content>p{max-width:800px;margin:20px 0}.study-content h3{margin:30px 0 8px;font:700 1.3rem/1.3 Georgia,serif;color:var(--blue)}
.math-spine{margin:24px 0 30px}.equation{background:var(--soft);border-left:3px solid #c89543;margin:14px 0;padding:15px 20px 10px;max-width:100%;overflow-x:auto;overscroll-behavior-x:contain}.equation math{font-size:1.12rem;min-width:max-content;margin:4px auto 9px}.equation-id{display:block;color:#536f80;font:600 .62rem/1.4 system-ui,sans-serif;letter-spacing:.05em;text-align:right}math{font-family:"STIX Two Math","Cambria Math",Georgia,serif;font-size:1.04em;vertical-align:baseline}math[display="block"]{margin:10px 0}mi[mathvariant="bold"]{font-weight:800}mtext{font-size:.9em}
.visual{margin:34px 0;background:#fff;border:1px solid var(--line);border-radius:12px;padding:22px;min-width:0;max-width:100%}.figure-heading{display:flex;align-items:baseline;gap:12px;margin:0 0 18px}.figure-heading>span{font-size:.62rem;font-weight:800;color:#5c7a8d;letter-spacing:.05em;white-space:nowrap}.figure-heading h3{font:700 1.22rem/1.3 Georgia,serif;margin:0;color:var(--deep)}.figure-scroll{overflow-x:auto;overscroll-behavior-x:contain;max-width:100%;padding:3px 0 8px}.figure-scroll>.diagram{min-width:600px}.diagram{width:100%;height:auto;display:block}.diagram text{font:14px system-ui,sans-serif;fill:var(--ink)}.diagram .diagram-heading{font-weight:750;font-size:16px}.diagram .small-label{font-size:14px}.diagram .axis-title{font-size:14px;font-weight:650}.diagram .tick{font-size:13px;fill:#465f70}.diagram .marker-label{font-size:12px;fill:#4d3d1f;font-weight:650;paint-order:stroke;stroke:#fff;stroke-width:3px;stroke-linejoin:round}.diagram .gridline{stroke:#dfe8ee;stroke-width:1}.diagram .axis{stroke:#5b7485;stroke-width:1.2}.panel-fill{fill:#f1f6f9;stroke:#d9e5ec}.visual figcaption{font-size:.78rem;line-height:1.65;color:var(--muted);margin-top:14px;max-width:850px}.plot-legend{list-style:none;padding:0;display:flex;flex-wrap:wrap;gap:8px 22px;margin:6px 0 18px;font-size:.75rem}.plot-legend li{display:flex;align-items:center;gap:7px}.plot-legend span{width:28px;border-top:3px solid var(--line-color);display:inline-block}.inset{border-top:1px solid var(--line);padding-top:12px;margin-top:15px}.inset p,.legend-copy{font-size:.78rem;color:var(--muted)}
.assumptions{font-size:.86rem;border-top:1px solid var(--line);padding-top:17px;margin-top:26px;color:var(--muted)}.assumptions h3,.interpretation h3,.check h3{font-size:.72rem;text-transform:uppercase;letter-spacing:.07em;margin:0 0 6px}.assumptions p,.interpretation p,.check p{margin:0}.interpretation{border-left:3px solid #ca9b4f;background:#fff7e8;padding:15px 20px;margin:22px 0;font-size:.91rem}.check{padding:14px 0 20px;font-size:.91rem}.check h3{color:var(--blue)}.source-anchor{font-size:.74rem;line-height:1.7;border-top:1px solid var(--line);padding-top:15px;color:var(--muted);margin-top:20px}.source-anchor>span{font-size:.65rem;text-transform:uppercase;font-weight:750;letter-spacing:.05em}.source-anchor p{margin:5px 0}.source-anchor details{margin-top:10px}.next-section{display:inline-block;margin-top:24px;text-decoration:none;font-weight:650;font-size:.8rem}details>summary{cursor:pointer;color:var(--blue);font-weight:650;padding:7px 1px}
.table-scroll{overflow-x:auto;overscroll-behavior-x:contain;max-width:100%;margin:16px 0;padding-bottom:5px}table{border-collapse:collapse;min-width:540px;width:100%;font-size:.8rem;line-height:1.6;text-align:left}caption{text-align:left;color:var(--muted);font-size:.75rem;font-weight:650;padding:6px 0 12px}td,th{padding:11px 13px;border-bottom:1px solid var(--line);vertical-align:top}thead th{background:#edf4f8;color:var(--deep)}tbody th{font-weight:650}tbody tr:nth-child(even){background:#f8fbfc}
.interactive{background:#fff;border:1px solid #acc8d7;border-top:4px solid var(--blue);border-radius:9px;padding:25px;margin:30px 0}.interactive>h3{font:700 1.5rem/1.25 Georgia,serif;margin:0 0 15px}.interactive>p{font-size:.92rem}.interactive .eyebrow{font-size:.66rem}.prediction{background:#f0f6f9;padding:17px;border-radius:7px;margin:22px 0}.prediction p{margin:0 0 12px;font-size:.9rem}.prediction label{display:block;font-size:.8rem;margin-bottom:4px}.prediction select{max-width:100%;margin-bottom:12px;width:100%}.prediction button{font-size:.8rem}.prediction p[role]{margin:9px 0 0;font-size:.8rem;color:var(--blue)}fieldset{border:1px solid var(--line);border-radius:7px;min-width:0;padding:18px;margin:20px 0}fieldset:disabled{opacity:.65}legend{padding:0 8px;font-size:.83rem;font-weight:700}.control-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:20px 25px}.control-grid label{font-size:.82rem;display:block;min-width:0;line-height:1.6}.control-grid label>span{display:flex;flex-wrap:wrap;align-items:center;gap:10px}.control-grid output{font-variant-numeric:tabular-nums;font-size:.8rem;color:var(--blue);font-weight:700}.control-grid input[type=range]{width:100%;min-width:0;accent-color:var(--blue)}select,textarea{background:#fff;border:1px solid #9db7c7;border-radius:5px;padding:9px 10px;color:var(--ink);font-size:.84rem;max-width:100%}select{width:100%;margin-top:6px;min-height:42px}.control-grid select{font-size:.78rem}textarea{display:block;width:100%;margin:9px 0 12px;resize:vertical}.interactive>label{font-size:.86rem}.button-row{display:flex;flex-wrap:wrap;gap:10px;margin:18px 0}.readouts dl{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));margin:22px 0;background:#edf4f8;border-radius:7px;padding:15px;gap:15px}.readouts dt{font-size:.68rem;color:#4b6476;line-height:1.5;margin-bottom:6px}.readouts dd{font-size:.82rem;font-weight:700;line-height:1.5;margin:0;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.fineprint{font-size:.74rem!important;color:var(--muted)}.fixture-matrix{display:flex;justify-content:center;margin:18px 0;background:#f2f7fa;border-radius:7px}.visibility-example{border-top:1px solid var(--line);margin-top:25px;padding-top:10px}.visibility-example h4{font:700 1.12rem Georgia,serif}.visibility-example p,#mode-details p{font-size:.83rem}p[role=status]{font-size:.85rem;color:var(--blue)}
.state-flow h4,.mode-shape-inset h4{font-size:.94rem;color:var(--blue)}.state-flow table{font-size:.75rem;min-width:480px}.relationship-list{list-style:none;padding:0;border-top:1px solid var(--line)}.relationship-list li{border-bottom:1px solid var(--line);padding:15px 12px;font-size:.83rem}.relationship-list li strong{display:block;color:var(--blue)}.relationship-list li span{display:block;margin-top:5px}.mode-shape-inset{padding-top:12px;overflow-x:auto;overscroll-behavior-x:contain}.mode-shape-inset>p{font-size:.8rem}.mode-shape-inset .diagram{min-width:600px}
.mode-groups{display:grid;grid-template-columns:1fr 1fr;gap:22px}.mode-group{min-width:0}.mode-group>h4{font-size:.68rem;letter-spacing:.07em;color:var(--blue);border-bottom:2px solid #8ab3c6;padding-bottom:12px}.aircraft-mode{position:relative;padding:12px 0 20px;border-bottom:1px solid var(--line)}.aircraft-mode h5{font:700 1.06rem Georgia,serif;margin:0 0 12px}.aircraft-mode .diagram{min-width:0}.aircraft-mode .diagram text{font-size:15px}.aircraft-mode p{font-size:.76rem;margin:7px 0;padding-right:12px}.qualitative-roots{display:none}.mode-svg{width:100%;min-width:0}.mode-svg svg{width:100%}
.next-section:hover,.back:hover{text-decoration:underline}footer{border-top:1px solid var(--line);max-width:1260px;margin:auto;padding:32px 30px 45px;color:var(--muted);font-size:.76rem}footer p{margin:8px 0}.noscript{padding:20px}dialog{position:fixed;margin:0 0 0 auto;inset:0;max-height:100dvh;height:100dvh;max-width:min(760px,100vw);width:760px;border:0;border-left:1px solid #9db7c7;padding:25px 30px;color:var(--ink);background:#fff;overflow:auto}dialog::backdrop{background:#102b3e99}.drawer-top{display:flex;align-items:center;justify-content:space-between;gap:15px;border-bottom:1px solid var(--line);padding:0 0 20px}.drawer-top .eyebrow{font-size:.64rem}.drawer-top h2{font:700 1.7rem Georgia,serif;margin:0}.drawer-top button{white-space:nowrap}.drawer-panel{font-size:.88rem}.drawer-panel section{padding:10px 0;border-bottom:1px solid var(--line)}.drawer-panel h3{font:700 1.15rem Georgia,serif;color:var(--blue)}.drawer-panel dt{font-size:.75rem;color:var(--blue);font-weight:750;margin-top:20px}.drawer-panel dd{margin:5px 0}.drawer-panel .equation{padding:12px}
@media(min-width:1600px){.lesson-layout{grid-template-columns:235px minmax(0,1000px);max-width:1380px;gap:65px}.narrative p,.study-content>p{max-width:850px}}@media(max-width:1050px){.topbar{flex-wrap:wrap;gap:12px}.reference-actions{margin-left:auto}.lesson-layout{grid-template-columns:180px minmax(0,1fr);gap:30px;padding-left:22px;padding-right:22px}.course-mark span{display:block;margin-left:0}.readouts dl{grid-template-columns:repeat(2,minmax(0,1fr))}.mode-groups{grid-template-columns:1fr}.mode-svg{max-width:430px}}
@media(max-width:800px){html{scroll-padding-top:12px}.site-header{position:static}.topbar{padding:16px 20px;gap:15px;align-items:flex-start}.topbar>div:first-child{width:100%}.course-mark span{display:inline;margin-left:8px}.mode-control{width:auto}.mode{font-size:.76rem;padding:8px}.reference-actions{width:100%;margin:0;justify-content:space-between;gap:7px}.reference-actions button{flex:1;font-size:.75rem;padding:8px}.hero{padding:32px 20px}.hero h1{font-size:2.45rem}.hero .eyebrow{font-size:.63rem}.dek{font-size:1.07rem}.byline{font-size:.75rem;line-height:1.8}.lesson-layout{display:block;padding:22px 20px 0}.section-nav{position:static;max-height:none;margin-bottom:32px}.section-nav summary{padding:10px 12px;background:#e7f1f6;border-radius:6px}.section-nav a{font-size:.85rem}.section-nav>p{font-size:.74rem;margin:12px 0}.lesson-section{padding-bottom:42px;scroll-margin-top:18px}.lesson-section h2{font-size:1.95rem}.question{font-size:1.08rem}.narrative p,.study-content>p{font-size:.96rem;line-height:1.78}.equation{padding:14px 14px 9px}.equation math{font-size:1.08rem}.visual{padding:14px;margin:26px 0}.figure-heading{display:block;margin-bottom:10px}.figure-heading h3{margin-top:6px;font-size:1.15rem}.figure-scroll>.diagram{min-width:600px}.plot-legend{display:block;font-size:.75rem}.plot-legend li{margin:8px 0}.visual figcaption{font-size:.74rem}.interactive{padding:16px;margin:25px 0}.interactive>h3{font-size:1.38rem}.control-grid{grid-template-columns:1fr;gap:17px}fieldset{padding:12px}.readouts dl{padding:12px;gap:15px 12px}.readouts dd{font-size:.77rem}.readouts dt{font-size:.66rem}.prediction{padding:13px}.button-row button{font-size:.76rem}.mode-groups{display:block}.mode-group{margin-top:20px}.aircraft-mode h5{font-size:1.12rem}.aircraft-mode .diagram text{font-size:16px}.mode-svg{max-width:440px}.aircraft-mode p{font-size:.82rem}.table-scroll table{font-size:.8rem}.source-anchor{font-size:.74rem}.assumptions{font-size:.82rem}.interpretation,.check{font-size:.86rem}dialog{padding:20px 18px}.drawer-top h2{font-size:1.4rem}.drawer-top{gap:8px}.drawer-top button{font-size:.75rem;padding:8px}.drawer-panel{font-size:.84rem}.drawer-panel h3{font-size:1.08rem}footer{padding-left:20px;padding-right:20px}}
html{scroll-behavior:auto;overflow-y:scroll;scrollbar-gutter:stable}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}@media print{.site-header,.section-nav,.next-section,.button-row{display:none}.lesson-layout{display:block;padding:0}.hero{background:white;color:#172b3d;padding:20px}.hero p{color:#172b3d}.visual,.interactive{break-inside:avoid}.figure-scroll,.equation,.table-scroll{overflow:visible}.diagram{min-width:0!important}.lesson-section{break-before:page}body{background:white}.study-content[hidden]{display:none!important}}
