@font-face{font-family:Erode;src:url(erode-400.woff2) format('woff2');font-weight:400;font-display:swap}
@font-face{font-family:Erode;src:url(erode-500.woff2) format('woff2');font-weight:500;font-display:swap}
@font-face{font-family:Erode;src:url(erode-600.woff2) format('woff2');font-weight:600;font-display:swap}
:root{color-scheme:light;--bg:#fff;--surface:#f2f2f2;--ink:#0a0a0a;--muted:#595959;--accent:#d92b21;--accent-ink:#fff;--field:#0a0a0a;--field-ink:#fff;--gutter:32px;--small:16px;--body:20px;--lead:28px;--head:64px;--display:clamp(80px,9.5vw,150px);--ease:cubic-bezier(.16,1,.3,1)}
[data-theme=dark]{color-scheme:dark;--bg:#141414;--surface:#222;--ink:#f3f3f3;--muted:#bbb;--accent:#ec6258;--accent-ink:#0a0a0a;--field:#e6e6e6;--field-ink:#141414}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--bg);color:var(--ink);font:400 var(--body)/1.5 Erode,Georgia,serif}h1,h2,h3,p,figure{margin:0}h1,h2,h3{font-weight:500;letter-spacing:-.025em;text-wrap:balance}h1{font-size:var(--display);line-height:.95}h2{font-size:var(--head);line-height:1}h3{font-size:var(--lead);line-height:1.2}p{max-width:65ch;text-wrap:pretty}a{color:inherit;text-decoration-thickness:.06em;text-underline-offset:.2em}button,input{font:inherit}button,a,input,summary{-webkit-tap-highlight-color:transparent}button,summary{cursor:pointer}button{border:0;color:var(--ink);background:var(--surface)}a,button{transition:transform .18s var(--ease),opacity .18s}a:hover,button:hover{opacity:.75}a:active,button:active{transform:translateY(2px)}:focus-visible{outline:3px solid var(--accent);outline-offset:5px}img{display:block;width:100%;height:auto}button,.button{min-height:48px;padding:12px 24px}.button{display:inline-flex;align-items:center;justify-content:center;background:var(--accent);color:var(--accent-ink);text-decoration:none}.button.ink{background:var(--ink);color:var(--bg)}.site-nav{display:flex;align-items:center;justify-content:space-between;gap:32px;padding:24px var(--gutter)}.brand{font-size:var(--lead);font-weight:500;letter-spacing:-.025em;text-decoration:none;white-space:nowrap}.nav-links{display:flex;align-items:center;gap:30px;font-size:var(--small)}.nav-links a{text-decoration:none}.theme-toggle{font-size:var(--small);padding:10px 16px;min-height:44px}.hero{display:grid;grid-template-columns:38% 62%;padding:32px var(--gutter) 0;gap:0}.hero h1{grid-column:2;grid-row:1 / span 2;margin:6px 0 50px}.hero-copy{grid-column:1;grid-row:2;align-self:start;padding:0 50px 0 0}.hero-copy p{font-size:var(--lead);line-height:1.3;max-width:23ch;margin-bottom:32px}.hero-figure{grid-column:2;grid-row:3;background:var(--surface);padding:32px;min-width:0;overflow:hidden}.hero-meta{grid-column:1;grid-row:3;align-self:end;padding:32px 48px 0 0}.hero-meta strong{font-size:var(--head);line-height:1;font-weight:500;display:block}.hero-meta p{font-size:var(--small);margin-top:18px}.lab-title{display:flex;justify-content:space-between;gap:24px;align-items:center}.lab-title h2{font-size:var(--lead);letter-spacing:-.02em}.live-svg{width:100%;height:auto;display:block;max-height:270px;margin:14px 0 20px}.live-svg text{font:18px Erode,Georgia,serif;fill:var(--ink)}.live-svg .axis{stroke:var(--muted);stroke-width:1}.live-svg .projection{stroke:var(--muted);stroke-width:2;stroke-dasharray:5 5}.live-svg .vector{stroke:var(--accent);stroke-width:5}.lab-controls{display:flex;align-items:center;gap:22px;font-size:var(--small)}input[type=range]{accent-color:var(--accent);min-height:44px;width:100%}.lab-controls label{flex:1}.lab-controls label span{display:flex;justify-content:space-between}.readouts{display:flex;gap:26px;font-size:var(--body);font-variant-numeric:tabular-nums;margin-top:14px}.lab-link{font-size:var(--small);margin-top:22px;display:inline-block}.section{padding:140px var(--gutter) 0}.intro{display:grid;grid-template-columns:38% 62%;row-gap:48px}.intro h2{padding-right:60px}.intro>.lead{font-size:var(--lead);line-height:1.35}.explain-grid{grid-column:1/-1;display:grid;grid-template-columns:repeat(4,1fr);gap:32px}.explain-grid p{font-size:var(--body)}.explain-grid strong{display:block;font-weight:600;margin-bottom:12px}.course-band{margin-top:140px;padding:64px var(--gutter);background:var(--field);color:var(--field-ink)}.course-band .section-heading{display:flex;justify-content:space-between;align-items:end;gap:32px;margin-bottom:56px}.course-band .section-heading p{max-width:30ch}.course-row{display:grid;grid-template-columns:38% 1fr auto;gap:24px;padding:22px 0;align-items:center;text-decoration:none;font-size:var(--lead)}.course-row:nth-child(even){background:color-mix(in srgb,var(--field-ink) 7%,var(--field));margin:0 calc(-1 * var(--gutter));padding-left:var(--gutter);padding-right:var(--gutter)}.course-row span:last-child{font-size:var(--small)}.course-row small{font-size:var(--small)}.course-band .button{margin-top:40px}.example{display:grid;grid-template-columns:38% 62%;align-items:start}.example h2{padding-right:48px}.example-panel{background:var(--surface);padding:32px}.example-panel p{margin:20px 0}.example-panel details{margin-top:20px}.example-panel summary{padding:12px 0;min-height:44px}.example-panel details p{margin-bottom:0}.formula-head{display:grid;grid-template-columns:38% 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@media(prefers-reduced-motion:no-preference){.hero h1 .line{display:block;overflow:hidden}.hero h1 .line span{display:block;animation:headline .9s var(--ease) both}.hero h1 .line:nth-child(2) span{animation-delay:.1s}@keyframes headline{from{transform:translateY(100%)}to{transform:translateY(0)}}.arrived{animation:arrive .8s var(--ease) both;animation-delay:var(--delay,0ms)}@keyframes arrive{from{opacity:.2;transform:translateY(24px)}to{opacity:1;transform:translateY(0)}}.arrived.picture{animation-name:picture}@keyframes picture{from{opacity:.4;transform:scale(.96)}to{opacity:1;transform:scale(1)}}}
@media(max-width:1000px){:root{--gutter:24px;--display:clamp(68px,10vw,100px);--head:48px;--lead:25px}.hero{grid-template-columns:36% 64%}.hero-copy{padding-right:28px}.hero-copy p{font-size:var(--body)}.hero-figure{padding:24px}.hero-meta{padding-right:24px}.explain-grid{grid-template-columns:repeat(2,1fr);gap:32px}.nav-links{gap:18px}.section{padding-top:100px}.course-band,.site-footer{margin-top:100px}.course-row{grid-template-columns:32% 1fr auto;font-size:var(--body)}}
@media(max-width:600px){:root{--gutter:20px;--body:18px;--lead:24px;--head:40px;--display:clamp(64px,17vw,90px)}.site-nav{padding-top:18px;padding-bottom:18px;align-items:start;gap:16px;flex-wrap:wrap}.brand{font-size:24px}.nav-links{width:100%;justify-content:space-between;gap:12px}.nav-links a{min-height:44px;display:flex;align-items:center}.theme-toggle{margin-left:auto}.hero{display:flex;flex-direction:column;padding-top:28px}.hero h1{order:0;margin:0 0 32px}.hero-copy{order:1;padding:0}.hero-copy p{font-size:var(--body);max-width:34ch;margin-bottom:26px}.hero-copy .button{width:100%}.hero-figure{order:2;margin-top:32px;padding:20px}.hero-meta{order:3;display:flex;gap:22px;align-items:center;padding:24px 0 0}.hero-meta p{margin:0}.hero-meta strong{font-size:var(--head);white-space:nowrap}.lab-title{display:block}.lab-title p{font-size:var(--small);margin-top:8px}.lab-title h2{font-size:var(--lead)}.live-svg{margin-top:24px}.lab-controls{display:block}.readouts{gap:20px;font-size:var(--body)}.section{padding-top:80px}.intro,.example,.formula-head{display:block}.intro h2,.example h2,.formula-head h2{padding:0;margin-bottom:28px}.intro>.lead,.formula-head p{font-size:var(--lead)}.explain-grid{margin-top:32px;gap:26px 22px}.explain-grid p{font-size:var(--body)}.course-band{margin-top:80px;padding-top:40px;padding-bottom:40px}.course-band .section-heading{display:block;margin-bottom:32px}.course-band .section-heading p{margin-top:20px;font-size:var(--body)}.course-row{grid-template-columns:1fr auto;gap:8px 16px;padding-top:20px;padding-bottom:20px}.course-row small{grid-column:1;grid-row:2}.course-row span:last-child{grid-row:1;grid-column:2}.example-panel{padding:24px}.formula-pages{grid-template-columns:1fr;padding:16px;gap:28px}.formula-head{margin-bottom:32px}.formula-links{gap:20px}.footer-top{grid-template-columns:1fr 1fr;gap:30px}.footer-top>p{grid-column:1/-1}.footer-wordmark{white-space:normal;font-size:17vw;line-height:.92;margin-top:64px;max-width:7ch}.site-footer{margin-top:80px;padding-top:36px}.footer-note{font-size:var(--small)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}}

.math-entry{display:grid;grid-template-columns:1.25fr 1fr;gap:64px;align-items:start}.math-entry h2{margin-bottom:28px}.math-entry>div>p{font-size:var(--lead);margin-bottom:28px}.math-entry-index{background:var(--surface);padding:32px}.math-entry-index p{font-size:18px!important;margin:0 0 24px!important}.math-entry-index strong{display:block;font-weight:500;font-size:24px;margin-bottom:4px}.math-entry-index a{font-size:16px}.nav-links{flex-wrap:wrap}@media(max-width:750px){.math-entry{grid-template-columns:1fr;gap:32px}.math-entry-index{padding:24px}.nav-links .theme-toggle{margin-left:0}}