:root{--ink:#101316;--paper:#f3f5f3;--accent:#ff9b45;--cyan:#62d8ef;--muted:#b6bfc6;--rule:#34414a}html{scroll-behavior:smooth;scroll-padding-top:110px}.lecture-page{background:var(--ink);color:var(--paper);font-family:Arial,Helvetica,sans-serif;font-size:18px;line-height:1.7}.lecture-page a:focus-visible,.deck a:focus-visible,button:focus-visible{outline:3px solid var(--accent);outline-offset:5px}.skip{position:absolute;top:-100px;left:20px;z-index:200;background:white;padding:12px;color:black}.skip:focus{top:10px}.lecture-page .site-nav .nav-inner{max-width:1320px}.lecture-page .nav-links a{font-size:14px}.lecture-hero{max-width:1280px;margin:0 auto;padding:72px 36px 0}.eyebrow{font-size:14px;letter-spacing:.1em;text-transform:uppercase;font-weight:700;color:var(--accent);margin:0 0 22px}.lecture-hero h1{font-size:clamp(3.5rem,8.5vw,7.5rem);line-height:.98;letter-spacing:-.055em;margin:30px 0 38px}.lecture-hero h1 span{color:var(--cyan)}.hero-bottom{display:flex;align-items:center;justify-content:space-between;gap:30px;padding-bottom:48px}.hero-bottom p{font-size:25px;line-height:1.45;max-width:630px}.muted{color:var(--muted)}.download{display:inline-block;border-bottom:2px solid var(--accent);padding:14px 0;color:var(--paper);font-size:16px;font-weight:700;white-space:nowrap}.translation-strip{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule);padding:26px 0;font-size:20px}.translation-strip b{color:var(--accent);font-size:14px;margin-right:8px}.reading-layout{display:grid;grid-template-columns:220px minmax(0,880px);gap:60px;max-width:1280px;margin:0 auto;padding:65px 36px 70px}.lecture-nav{position:sticky;top:106px;align-self:start;display:flex;flex-direction:column;gap:12px}.lecture-nav .eyebrow{margin-bottom:10px}.lecture-nav a{font-size:15px;color:var(--muted);line-height:1.5;padding:4px 0}.lecture-nav a:hover{color:var(--cyan)}.intro-note{border-left:4px solid var(--cyan);padding:0 0 0 26px;margin-bottom:80px}.intro-note h2{font-size:34px;line-height:1.2;margin-bottom:18px}.intro-note p{font-size:21px;color:var(--muted)}.chapter{margin:0 0 80px;scroll-margin-top:20px}.chapter>header{display:flex;gap:28px;align-items:start;border-top:1px solid var(--rule);padding-top:32px;margin-bottom:44px}.chapter-number{color:var(--accent);font-size:45px;font-weight:700;line-height:1.2}.chapter h2{font-size:38px;line-height:1.15;letter-spacing:-.025em;margin:0 0 14px}.chapter>header p:not(.chapter-number){color:var(--muted)}.concept{position:relative;margin:0 0 52px;padding-bottom:42px;border-bottom:1px solid #243039;scroll-margin-top:24px}.concept h3{font-size:27px;line-height:1.25;margin:0 0 13px;letter-spacing:-.012em}.slide-ref{font-size:13px;letter-spacing:.07em;text-transform:uppercase;color:var(--muted);margin-bottom:12px}.concept .concept-lead{font-size:21px;color:var(--cyan);margin-bottom:18px;line-height:1.4}.key-points{list-style:none;margin:0 0 22px;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px 26px}.key-points li{border-left:2px solid var(--rule);padding-left:14px;font-size:17px;line-height:1.5}.concept>p:not(.concept-lead):not(.slide-ref){color:#c6cdd1}.concept blockquote{margin:25px 0 0;padding:18px 22px;background:#192228;font-size:19px;border-left:3px solid var(--accent);line-height:1.5}.concept blockquote span{display:block;color:var(--accent);text-transform:uppercase;letter-spacing:.08em;font-size:12px;font-weight:700;margin-bottom:5px}.demo{margin:0 0 60px;padding:28px;background:var(--paper);color:#142027;border-radius:3px;overflow:hidden}.demo figcaption{margin-bottom:28px;line-height:1.35}.demo figcaption b{font-size:23px;display:block;margin-bottom:7px}.demo figcaption span{font-size:14px;color:#46545f}.bar-row{display:grid;grid-template-columns:90px 1fr;gap:18px;align-items:center;margin-bottom:18px;font-size:16px}.track{width:100%;background:#dee5e7;height:46px}.bar{background:#19788d;height:100%;min-width:70px;display:flex;align-items:center;padding-left:12px;color:white;font-weight:700}.orange{background:#ac4e04!important;color:white}.scale{margin-left:108px;display:flex;justify-content:space-between;border-top:1px solid #74858e;padding-top:10px;font-size:13px}.diagram-takeaway{font-weight:700;font-size:22px;line-height:1.35;margin:25px 0 0}.demo button,.deck button{font:inherit;cursor:pointer;border:1px solid currentColor;background:transparent;padding:10px 16px;border-radius:3px;color:inherit;min-height:44px}.demo button:hover{background:#dae4e8}.demo button:disabled{opacity:.5;cursor:default}.demo-caption{font-size:16px;margin-top:20px;line-height:1.6}.area-stage{min-height:260px;display:flex;gap:80px;align-items:end;justify-content:center;margin-bottom:30px;padding-top:30px}.area-stage>div{text-align:center;min-width:190px}.area-stage p{margin-top:20px;font-size:15px;line-height:1.5}.square{width:80px;height:80px;background:#19788d;margin:auto}.compared{width:113.137px;height:113.137px;background:#ac4e04;transition:width .45s,height .45s}.compared.wrong{width:160px;height:160px}.concealed{visibility:hidden}.reveal-chart{min-height:200px}#reveal-status,#route-status,#baseline-note{font-size:16px;margin:18px 0;line-height:1.5}.route-row{margin:0 0 30px}.route-row>b{font-size:16px;display:block;margin-bottom:18px}.route-track{height:36px;position:relative;border-bottom:3px solid #778992;margin:0 20px}.traveler{position:absolute;bottom:-18px;left:0;display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:#19788d;color:white;transform:translateX(-50%);font-size:16px;font-weight:bold}.end-label{font-size:14px;text-align:center;margin-bottom:18px}.demo-controls{display:flex;gap:10px;flex-wrap:wrap}.baseline-chart{height:270px;display:flex;align-items:end;justify-content:center;gap:60px;padding:0 20px 20px;border-bottom:2px solid #6a7e88}.baseline-column{display:flex;align-items:center;flex-direction:column;gap:5px}.baseline-column>div{width:85px;background:#19788d;transition:height .4s}.baseline-column:nth-child(2)>div{background:#ac4e04}.baseline-column span,.baseline-column b{font-size:18px}.course-materials #assignment,.course-materials #checkpoint{scroll-margin-top:120px}.course-materials .goal-box{border-radius:3px;background:#172b33;border-color:#3b697c}.course-materials .goal-box h2{color:var(--cyan)}.course-materials .grid-2{gap:20px}.course-materials .card{border-radius:3px}.course-materials li{margin-bottom:10px}.reference-list{padding-left:24px;margin:24px 0}.reference-list li{margin-bottom:15px}.closing-note{margin-top:50px;border-top:1px solid var(--rule);padding-top:40px}.closing-note p{font-size:38px;font-weight:bold;line-height:1.2;color:var(--cyan)}.closing-note span{display:block;margin-top:20px;color:var(--muted)}
/* Classroom presentation */
.deck{margin:0;background:var(--ink);color:var(--paper);font-family:Arial,Helvetica,sans-serif}.deck *{box-sizing:border-box}.deck a{color:var(--cyan);text-decoration:none}.slide{min-height:calc(100dvh - 82px);padding:5vh 6vw 7vh;max-width:1600px;margin:auto}.slide[hidden],.notes[hidden]{display:none}.slide h1{font-size:clamp(2.2rem,4.1vw,4.6rem);line-height:1.08;letter-spacing:-.025em;margin:4vh 0}.slide-lead{font-size:clamp(1.4rem,2.7vw,2.6rem);line-height:1.25;color:var(--cyan);max-width:1300px;margin:4vh 0}.slide-content{display:flex;align-items:center;gap:6vw}.slide-content ul{list-style:none;margin:0;padding:0;flex:1;font-size:clamp(1.25rem,2.35vw,2.3rem);line-height:1.5}.slide-content li{margin-bottom:1.5vh}.slide-content .demo{flex:1.2;margin:0;font-size:18px}.slide-content svg{width:50%;min-width:0}.slide-content>.small{font-size:14px}.cover h1,.closing h1,.statement h1{font-size:clamp(3rem,7.8vw,7.5rem);max-width:1200px}.cover .slide-content,.closing .slide-content,.statement .slide-content{margin-top:8vh}.cover .slide-content ul,.closing .slide-content ul,.statement .slide-content ul{font-size:22px;display:flex;flex-wrap:wrap;gap:14px 32px;color:var(--muted)}.translation .slide-content ul{display:grid;grid-template-columns:repeat(4,1fr);gap:30px}.exercise .eyebrow{color:var(--cyan)}.exercise .slide-lead{color:var(--accent)}.big-equation{font-size:clamp(3rem,8vw,8rem);margin:0;color:var(--accent);font-weight:bold;white-space:nowrap}.deck-bars{display:flex;align-items:end;gap:50px}.deck-bars>div{display:flex;flex-direction:column;align-items:center;gap:8px}.deck-bars i{display:block;background:#25889e;width:90px}.deck-bars>div:nth-child(2) i{background:#ff9b45}.deck-controls{position:sticky;bottom:0;background:#172027;border-top:1px solid var(--rule);padding:12px 4vw;display:flex;align-items:center;justify-content:center;gap:16px;font-size:14px;flex-wrap:wrap}.deck button:hover{background:#2b3a44}.deck button:disabled{opacity:.35}.notes{margin-top:45px;border-top:1px solid var(--rule);padding-top:25px;font-size:18px;line-height:1.65;max-width:1100px;color:var(--muted)}.notes>b{color:var(--accent)}
@media(max-width:1000px){.reading-layout{grid-template-columns:170px minmax(0,1fr);gap:35px}.translation-strip{font-size:16px}.key-points{grid-template-columns:1fr}.hero-bottom{align-items:start;flex-direction:column}.slide-content{gap:24px}.slide-content .demo{padding:20px}.slide-content .demo figcaption{display:none}.slide-content .bar-row{grid-template-columns:60px 1fr}.slide-content .scale{margin-left:78px}.slide-content .demo .diagram-takeaway{font-size:20px}.slide-content .demo .bar{font-size:14px}}
@media(max-width:720px){html{scroll-padding-top:150px}.lecture-hero{padding:44px 22px 0}.lecture-hero h1{font-size:clamp(3.2rem,11vw,5rem)}.eyebrow{font-size:12px;line-height:1.6}.hero-bottom p{font-size:22px}.translation-strip{flex-wrap:wrap;justify-content:start;gap:10px 20px;font-size:16px}.translation-strip b{display:none}.reading-layout{display:block;padding:32px 22px}.lecture-nav{position:static;display:grid;grid-template-columns:1fr 1fr;gap:6px 14px;padding-bottom:30px;border-bottom:1px solid var(--rule);margin-bottom:40px}.lecture-nav .eyebrow{grid-column:1/-1}.lecture-nav a{font-size:14px}.intro-note{margin-bottom:50px;padding-left:18px}.intro-note h2{font-size:29px}.intro-note p{font-size:18px}.chapter>header{gap:18px}.chapter h2{font-size:30px}.chapter-number{font-size:36px}.concept h3{font-size:25px}.concept .concept-lead{font-size:20px}.lecture-page{font-size:17px}.demo{padding:20px 16px}.demo figcaption b{font-size:21px}.bar-row{grid-template-columns:64px 1fr;gap:10px;font-size:14px}.scale{margin-left:74px;font-size:12px}.bar{padding-left:8px;font-size:13px;min-width:60px}.area-stage{gap:18px;justify-content:space-between}.area-stage>div{min-width:0;flex:1}.square{width:64px;height:64px}.compared{width:90.51px;height:90.51px}.compared.wrong{width:128px;height:128px}.area-stage p{font-size:13px}.baseline-column>div{width:65px}.course-materials .grid-2{grid-template-columns:1fr}.course-materials .resource-row{flex-direction:column}.closing-note p{font-size:30px}.slide{padding:30px 24px;min-height:calc(100dvh - 135px)}.slide h1{font-size:2.3rem}.slide-lead{font-size:1.5rem}.slide-content{display:block}.slide-content ul{font-size:1.3rem}.slide-content svg{width:100%;margin-top:20px}.translation .slide-content ul{grid-template-columns:1fr 1fr;font-size:1.1rem}.slide-content .demo{margin-top:25px}.cover h1,.closing h1,.statement h1{font-size:3rem}.deck-controls{gap:10px;padding:10px;font-size:13px}.deck-controls a{padding:8px}.deck-bars{justify-content:center;margin-top:25px}.big-equation{font-size:4rem}.notes{font-size:16px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}
@media print{body.lecture-page,.deck{background:white;color:black}.site-nav,.lecture-nav,.deck-controls,.download,.resource-row,.demo button,.skip{display:none!important}.lecture-hero,.reading-layout{display:block;padding:20px;max-width:none}.lecture-hero h1{font-size:50px}.chapter,.concept{break-inside:avoid}.concept p,.intro-note p,.muted,.chapter>header p,.slide-lead,.key-points,.slide-content,.notes{color:#222!important}.slide[hidden]{display:block}.slide{height:7.5in;min-height:0;break-after:page;padding:40px}.slide h1{font-size:40px}.slide-content ul{font-size:24px}.slide .eyebrow{color:#333}.notes{display:none!important}.demo{break-inside:avoid;border:1px solid #aaa}.concealed{visibility:visible}.lecture-hero h1 span,.concept-lead,.closing-note p{color:#125466!important}}