/* Static explanatory lessons only. Native lab controls and engines are excluded. */
html:has(body.lesson-surface){color-scheme:light;scroll-padding-top:32px}
.lesson-surface{--lesson-ink:#252824;--lesson-muted:#666963;--lesson-line:#dfdfd6;--lesson-paper:#f6f5f0;--lesson-accent:#fc8b4b;margin:0;background:var(--lesson-paper);color:var(--lesson-ink);color-scheme:light;font:16px/1.8 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans Tamil",sans-serif;-webkit-font-smoothing:antialiased}
.lesson-surface *{box-sizing:border-box}
.lesson-surface a{color:#8b3c18;text-underline-offset:5px;text-decoration-thickness:1px}
.lesson-surface a:hover{color:#54240f}
.lesson-surface :focus-visible{outline:3px solid #b0491b;outline-offset:5px}
.lesson-surface neetiit-nav[data-lesson-shell]{display:block;background:#171a18;border-bottom:1px solid #ffffff16}
.lesson-header{display:flex;align-items:center;gap:44px;max-width:1320px;min-height:100px;padding:18px 40px;margin:auto}
.lesson-header .lesson-brand{display:flex;align-items:center;gap:13px;color:#f6f4ed;text-decoration:none;line-height:1.25;font-size:15px;font-weight:750;letter-spacing:.09em;flex:none}
.lesson-brand small{display:block;font-size:8px;letter-spacing:.12em;color:#a7aaa2;font-weight:500;margin-top:5px}
.lesson-brand-mark{position:relative;width:44px;height:44px;overflow:hidden;flex:none;background:#fff;border-radius:12px}
.lesson-brand-mark img{position:absolute;width:86px;height:86px;max-width:none;left:-21px;top:-13px}
.lesson-header>nav{display:flex;align-items:center;gap:30px;margin-left:auto;line-height:1.5;font-size:12px}
.lesson-header>nav a{display:flex;align-items:center;min-height:44px;color:#ced0c7;text-decoration:none}
.lesson-header>nav a:hover{color:#ffaf7e}
.lesson-header .lesson-search{display:flex;gap:9px;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:0 15px;border:1px solid #ffffff29;border-radius:50px;color:#e4e5dd;font-size:12px;text-decoration:none;line-height:1}
.lesson-search svg{width:17px;height:17px;stroke:currentColor;stroke-width:1.5}
.lesson-header :focus-visible,.lesson-hero :focus-visible{outline-color:#ffb586}
.lesson-surface .phy-page{width:100%;max-width:none;margin:0;padding:0;overflow-wrap:anywhere}
.lesson-hero{position:relative;background:#171a18;color:#f8f5ec;isolation:isolate;overflow:hidden}
.lesson-hero::before{content:"";position:absolute;z-index:-1;inset:0;background:radial-gradient(ellipse at 88% 45%,#c9652c12,transparent 48%),linear-gradient(90deg,#ffffff03 1px,transparent 1px);background-size:auto,180px 100%;pointer-events:none}
.lesson-hero-inner{display:grid;grid-template-columns:minmax(0,1fr) 304px;align-items:center;gap:90px;max-width:1320px;margin:auto;padding:38px 40px 82px}
.lesson-hero-copy{min-width:0;animation:lesson-arrive .55s ease both}
.lesson-hero .lesson-hero-copy>nav{display:flex;gap:8px 18px;font-size:11px;margin:0 0 45px;line-height:1.5}
.lesson-hero .lesson-hero-copy>nav a{color:#aeb3a8;min-height:32px;display:inline-flex;align-items:center;text-decoration:none}
.lesson-hero .lesson-hero-copy>nav a:hover{color:#ffc39a}
.lesson-hero .lesson-hero-copy>nav a+a::before{content:"/";margin-right:18px;color:#60675d;pointer-events:none}
.lesson-surface .lesson-hero .phy-kicker{color:#ffaa76;font-size:10px;letter-spacing:.17em;line-height:1.5;margin:0 0 20px;font-weight:650;text-transform:uppercase}
.lesson-surface .lesson-hero h1{max-width:790px;color:#f8f5ec;font-size:clamp(2.7rem,5.1vw,4.5rem);font-weight:550;line-height:1.07;letter-spacing:-.055em;margin:0 0 20px;text-wrap:balance}
.lesson-surface .lesson-hero h1+p{font-size:13px;margin:0 0 25px;line-height:1.6}
.lesson-surface .lesson-hero h1+p a{display:inline-flex;align-items:center;gap:7px;color:#e4bc9c;text-decoration:none;padding-bottom:3px;border-bottom:1px solid #a77c566b}
.lesson-surface .lesson-hero h1+p a::before{content:"↗";font-size:15px}
.lesson-surface .lesson-hero p:not(.phy-kicker){color:#b9c0b5}
.lesson-surface .lesson-hero-copy>p:not(.phy-kicker):not(h1+p){max-width:65ch;font-size:16px;line-height:1.9;margin:0 0 25px}
.lesson-surface .lesson-hero .phy-button{display:inline-flex;align-items:center;justify-content:center;min-height:54px;border-radius:100px;background:#f8955c;color:#201b17;font-size:13px;line-height:1.6;font-weight:750;padding:15px 25px;margin:8px 0 25px;text-decoration:none;box-shadow:0 9px 30px #f8955c0c;transition:background .18s,transform .18s}
.lesson-surface .lesson-hero .phy-button:hover{background:#ffb182;color:#201b17;transform:translateY(-2px)}
.lesson-hero-meta{display:flex;flex-wrap:wrap;gap:12px 18px;color:#b8bdb1;font-size:10px;line-height:1.6}
.lesson-hero-meta>span{display:inline-flex;gap:7px;align-items:center}
.lesson-hero-meta>span::before{content:"";height:3px;width:3px;background:#e7ae85;border-radius:50%;flex:none}
.lesson-surface .lesson-hero-meta [lang=ta]{font-size:10px;line-height:1.6}
.lesson-route{position:relative;margin-top:50px;padding:27px 25px 18px;border:1px solid #b7bdad25;border-radius:20px;background:linear-gradient(140deg,#ffffff08,#ffffff02);box-shadow:0 24px 80px #00000016;animation:lesson-arrive .65s .08s ease both}
.lesson-route-top{display:flex;align-items:center;gap:7px;color:#bfc4b6;line-height:1.5;font-size:8px;letter-spacing:.1em}
.lesson-route-top>span:last-child{margin-left:auto;color:#e8b18d;font-size:16px}
.lesson-route-dot{width:4px;height:4px;border-radius:50%;background:#f8955c;box-shadow:0 0 15px #f8955c44}
.lesson-surface .lesson-route .lesson-route-title{font-size:29px;line-height:1.2;font-weight:450;letter-spacing:-.04em;color:#f5f1e6;margin:28px 0 30px}
.lesson-route-title em{font-style:normal;color:#f5a570}
.lesson-route ol{padding:0;margin:0;list-style:none;display:grid;gap:20px}
.lesson-route li{display:grid;grid-template-columns:20px 1fr;gap:11px;margin:0!important;line-height:1.5}
.lesson-route li>span{font-size:9px;color:#dba279;line-height:2}
.lesson-route strong{display:block;font-size:11px;color:#dedfd5;font-weight:600}
.lesson-surface .lesson-route li p{font-size:10px;line-height:1.7;margin:4px 0 0;color:#9fa695}
.lesson-route-bottom{display:flex;justify-content:space-between;margin-top:28px;padding-top:16px;border-top:1px solid #ffffff16;font-size:7px;letter-spacing:.12em;color:#9ca38f}
.lesson-reading{display:grid;grid-template-columns:minmax(0,820px) minmax(180px,240px);align-items:start;gap:88px;max-width:1256px;margin:0 auto;padding:70px 40px 80px}
.lesson-reader{min-width:0}
.lesson-section{position:relative;border-top:1px solid var(--lesson-line);padding:26px 0 32px;scroll-margin-top:30px}
.lesson-section:first-child{border-top:0;padding-top:0}
.lesson-section-index{display:block;font-size:10px;color:#a15b36;letter-spacing:.1em;margin:0 0 12px;font-weight:650}
.lesson-surface .lesson-reader h2{font-size:clamp(1.5rem,2.5vw,2rem);font-weight:600;line-height:1.3;letter-spacing:-.035em;margin:0 0 22px;color:#282d25;max-width:25ch;text-wrap:balance}
.lesson-surface .lesson-reader h3{font-size:16px;font-weight:650;line-height:1.5;letter-spacing:-.015em;margin:0 0 12px;color:#31382c}
.lesson-surface .lesson-reader p{max-width:75ch;color:#555e50;font-size:15px;line-height:1.95;margin:12px 0 0}
.lesson-surface .lesson-reader [lang=ta]{font-size:16px;line-height:2.2;letter-spacing:0}
.lesson-surface .lesson-reader .phy-note{border-left:3px solid #d17845;background:#efede4;border-radius:0 14px 14px 0;padding:22px 25px;margin:0}
.lesson-surface .lesson-reader .phy-note p{margin:0;color:#58614f}
.lesson-surface .lesson-reader .phy-notes{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.lesson-surface .lesson-reader .phy-card{padding:25px 23px;border:1px solid #dedfd4;border-radius:15px;background:#fffefa;margin:0;box-shadow:0 3px 5px #262c2002}
.lesson-surface .lesson-reader .phy-notes .phy-card:first-child{background:#eaece2;border-color:#d9ddcd}
.lesson-surface .lesson-reader .phy-notes .phy-card:first-child h3{color:#4c5b3f}
.lesson-surface .lesson-reader .phy-notes .phy-card:first-child p{font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-size:14px;line-height:1.95;color:#34432b;white-space:normal}
.lesson-surface .lesson-reader .phy-card p{font-size:13px;line-height:1.9}
.lesson-surface .lesson-reader .phy-card h2{font-size:24px;max-width:none;margin:0 0 18px}
.lesson-surface .lesson-reader .lesson-section>section{margin:0}
.lesson-surface .lesson-reader ul{padding-left:22px;font-size:15px;color:#555e50}
.lesson-surface .lesson-reader li{padding-left:3px;margin:10px 0}
.lesson-surface .lesson-reader details{padding:14px 0 0;margin-top:18px;border-top:1px solid #dfe0d4}
.lesson-surface .lesson-reader summary{display:list-item;color:#90502c;cursor:pointer;min-height:44px;font-size:13px;font-weight:650;padding-block:9px;line-height:1.8}
.lesson-surface .lesson-reader .phy-muted{background:#eceee5;border-radius:12px;font-size:12px;color:#646e59!important;padding:20px 24px;margin:5px 0 35px;line-height:1.9;border:1px solid #dee1d4}
.lesson-surface .lesson-reader .phy-pager{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;padding:0;border:0;margin:0 0 40px;font-size:12px}
.lesson-surface .lesson-reader .phy-pager a{display:flex;align-items:center;min-height:86px;border:1px solid #d8dbcd;border-radius:13px;padding:18px;background:#f0f1e9;line-height:1.7;color:#59634c;text-decoration:none;transition:border-color .18s,background .18s}
.lesson-surface .lesson-reader .phy-pager a:last-child{justify-content:flex-end;text-align:right}
.lesson-surface .lesson-reader .phy-pager a:hover{border-color:#a87855;background:#efebe1}
.lesson-surface .lesson-reader footer{border-top:1px solid #d9dccd;margin:0;padding-top:22px}
.lesson-surface .lesson-reader footer p{font-size:10px;line-height:1.9;color:#707765;margin-top:10px}
.lesson-surface .lesson-reader footer p a{color:#7c5941}
.lesson-outline{position:sticky;top:30px;padding-top:6px}
.lesson-outline nav{display:block!important}
.lesson-outline .lesson-outline-label{font-size:9px;color:#888c80;font-weight:650;letter-spacing:.14em;line-height:1.5;margin:0 0 18px}
.lesson-outline ol{display:grid;gap:0;list-style:none;padding:0;margin:0;border-left:1px solid #d9dccd}
.lesson-outline li{margin:0!important;padding:0!important;line-height:1.6}
.lesson-outline li a{display:grid;grid-template-columns:17px minmax(0,1fr);gap:10px;align-items:start;min-height:44px;padding:10px 0 10px 17px;color:#707765;font-size:10px;text-decoration:none;border-left:2px solid transparent;margin-left:-1px;transition:color .18s,border-color .18s}
.lesson-outline li a>span{font-size:8px;line-height:2;color:#a17653}
.lesson-outline li a:hover{border-left-color:#c97746;color:#63432a}
.lesson-outline-note{margin-top:40px;padding:23px;border-radius:13px;background:#edece4;border:1px solid #e2e1d7}
.lesson-outline-note>span{font-size:24px;color:#a76137;line-height:1}
.lesson-surface .lesson-outline-note p{font-size:17px;font-weight:500;color:#5d6554;line-height:1.35;letter-spacing:-.025em;margin:17px 0}
.lesson-outline-note a{display:inline-flex;align-items:center;min-height:44px;color:#8f603f;font-size:10px}
.lesson-surface .phy-skip{position:fixed;top:-120px;left:16px;font-size:14px}
.lesson-surface .phy-skip:focus{top:15px;z-index:10000;border-radius:8px;background:#fff6ea;color:#4a2e1c;padding:10px 18px}
/* The practice keeps all its controls and theme; only its outer reading width changes. */
.lesson-surface .lesson-reader .learning-cycle{margin:50px 0 0;max-width:100%;width:100%}
.lesson-surface .lesson-reader .learning-cycle h2{max-width:none;font-size:clamp(1.5rem,3vw,2rem);color:#10283f;line-height:1.4}
.lesson-surface .lesson-reader .learning-cycle p{max-width:none;color:inherit;font-size:1rem;line-height:1.8}
.lesson-surface .lesson-reader .learning-cycle .lc-eyebrow,.lesson-surface .lesson-reader .learning-cycle .lc-small{font-size:.875rem}
.lesson-surface .lesson-reader .learning-cycle .lc-steps ol{display:flex;flex-wrap:wrap}
.lesson-surface .lesson-reader .learning-cycle [lang=ta]{font-size:inherit;line-height:1.95}
.lesson-surface .lesson-reader .learning-cycle h3{font-size:1.35rem;color:#10283f;letter-spacing:normal}
.lesson-surface .lesson-reader .learning-cycle summary{font-size:1rem;color:#124f84}
.lesson-surface .lesson-reader .learning-cycle li{padding-left:0}
.lesson-surface .lesson-reader .learning-cycle{border-color:#d8d8cc;border-radius:18px;background:#fffefa}
.lesson-surface .lesson-reader .learning-cycle button{border-color:#b98b67;background:#f6eee5;color:#793d1e;border-radius:9px}
.lesson-surface .lesson-reader .learning-cycle button:hover{background:#eee0d0}
.lesson-surface .lesson-reader .learning-cycle .lc-language button[aria-pressed=true],.lesson-surface .lesson-reader .learning-cycle .lc-launch{background:#974420;color:#fff;border-color:#974420}
.lesson-surface .lesson-reader .learning-cycle .lc-steps a{background:#f1ece2;color:#80502e}
.lesson-surface .lesson-reader .learning-cycle .lc-stage{border-color:#deddd2}
.lesson-surface .lesson-reader .learning-cycle .lc-question{border-color:#d8d8cc;background:#f8f7f1}
.lesson-surface .lesson-reader .learning-cycle .lc-options label{border-color:#dcddd1;background:#fffefa}
.lesson-surface .lesson-reader .learning-cycle input[type=radio]{accent-color:#974420}
.lesson-surface .lesson-reader .learning-cycle .lc-options label:has(input:checked){border-color:#ac7048;background:#f4e8dc}
.lesson-surface .lesson-reader .learning-cycle summary{color:#8b491f}
@keyframes lesson-arrive{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}
@media(min-width:1500px){.lesson-hero-inner{gap:110px;padding-bottom:90px}.lesson-hero-copy>nav{margin-bottom:55px!important}}
@media(max-width:1100px){.lesson-header{gap:26px;padding-inline:30px}.lesson-header>nav{gap:22px}.lesson-hero-inner{gap:40px;padding:30px 30px 65px;grid-template-columns:minmax(0,1fr) 270px}.lesson-route{padding:25px 22px}.lesson-reading{gap:45px;padding:55px 30px 65px;grid-template-columns:minmax(0,1fr) 200px}.lesson-surface .lesson-reader .phy-notes{grid-template-columns:1fr}.lesson-surface .lesson-hero-copy>p:not(.phy-kicker):not(h1+p){font-size:15px}}
@media(max-width:800px){.lesson-header{gap:15px;min-height:84px;padding:15px 24px}.lesson-header>nav{gap:20px}.lesson-header>nav a{font-size:11px}.lesson-brand-mark{height:39px;width:39px}.lesson-header .lesson-brand{font-size:12px;gap:10px}.lesson-brand small{font-size:7px}.lesson-search span{display:none}.lesson-header .lesson-search{padding:0;width:44px}.lesson-route{display:none}.lesson-hero-inner{display:block;padding:26px 24px 54px}.lesson-hero .lesson-hero-copy>nav{margin-bottom:30px}.lesson-surface .lesson-hero h1{font-size:clamp(2.7rem,7vw,4rem);max-width:760px}.lesson-surface .lesson-hero-copy>p:not(.phy-kicker):not(h1+p){font-size:16px;max-width:65ch}.lesson-reading{display:flex;flex-direction:column;padding:40px 24px 60px;gap:35px}.lesson-outline{position:static;order:-1;padding:0;width:100%}.lesson-outline nav{padding:19px 20px;background:#edeee6;border:1px solid #dfe1d4;border-radius:14px}.lesson-outline .lesson-outline-label{margin-bottom:12px;font-size:8px}.lesson-outline ol{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 16px;border-left:0}.lesson-outline li a{padding:7px 0;min-height:40px;border-left:0;gap:6px;font-size:10px}.lesson-outline-note{display:none}.lesson-surface .lesson-reader .phy-notes{grid-template-columns:repeat(2,minmax(0,1fr))}.lesson-reader{width:100%}.lesson-section{padding-bottom:30px}.lesson-surface .lesson-reader h2{font-size:1.75rem;max-width:27ch}}
@media(max-width:560px){.lesson-header{flex-wrap:wrap;gap:4px 14px;padding:13px 20px 8px}.lesson-header .lesson-brand{font-size:12px;margin-right:auto}.lesson-header .lesson-search{order:2;min-height:44px;height:44px}.lesson-header>nav{order:3;width:100%;margin:3px 0 0;gap:26px;font-size:11px}.lesson-header>nav a{min-height:40px}.lesson-hero-inner{padding:22px 20px 43px}.lesson-hero .lesson-hero-copy>nav{gap:4px 12px;font-size:9px;margin-bottom:27px}.lesson-hero .lesson-hero-copy>nav a{min-height:25px}.lesson-hero .lesson-hero-copy>nav a+a::before{margin-right:12px}.lesson-surface .lesson-hero .phy-kicker{font-size:9px;margin-bottom:16px}.lesson-surface .lesson-hero h1{font-size:clamp(2.3rem,10vw,3.4rem);line-height:1.12;letter-spacing:-.05em;margin-bottom:19px}.lesson-surface .lesson-hero h1+p{font-size:12px;margin-bottom:22px}.lesson-surface .lesson-hero-copy>p:not(.phy-kicker):not(h1+p){font-size:14px;line-height:1.95;margin-bottom:24px}.lesson-surface .lesson-hero .phy-button{min-height:54px;width:100%;margin-top:0;margin-bottom:22px;padding-inline:15px;font-size:12px}.lesson-hero-meta{font-size:9px;gap:8px 12px}.lesson-surface .lesson-hero-meta [lang=ta]{font-size:9px}.lesson-reading{padding:30px 20px 50px;gap:30px}.lesson-outline nav{padding:16px}.lesson-outline ol{grid-template-columns:repeat(2,minmax(0,1fr));gap:0 10px}.lesson-outline li a{font-size:12px;grid-template-columns:16px minmax(0,1fr);padding:8px 0;min-height:48px;line-height:1.6}.lesson-outline li a>span{font-size:9px}.lesson-surface .lesson-reader h2{font-size:1.5rem;line-height:1.35;letter-spacing:-.035em;margin-bottom:18px}.lesson-section-index{font-size:9px;margin-bottom:12px}.lesson-surface .lesson-reader p{font-size:14px}.lesson-surface .lesson-reader .phy-note{padding:17px 19px}.lesson-surface .lesson-reader [lang=ta]{font-size:14px;line-height:2.15}.lesson-surface .lesson-reader .phy-notes{grid-template-columns:1fr;gap:12px}.lesson-surface .lesson-reader .phy-card{padding:22px 20px}.lesson-surface .lesson-reader .phy-card p{font-size:13px}.lesson-surface .lesson-reader .phy-card h3{font-size:15px}.lesson-surface .lesson-reader .phy-notes .phy-card:first-child p{font-size:14px}.lesson-surface .lesson-reader .phy-pager{gap:12px;font-size:10px}.lesson-surface .lesson-reader .phy-pager a{padding:15px;min-height:88px}.lesson-surface .lesson-reader .phy-muted{font-size:11px;padding:18px;margin-bottom:28px}.lesson-surface .lesson-reader .learning-cycle{margin:35px 0 0;padding:18px 14px}.lesson-surface .lesson-reader .learning-cycle .lc-steps ol{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}.lesson-surface .lesson-reader .learning-cycle p{font-size:.94rem}.lesson-surface .lesson-reader .learning-cycle .lc-eyebrow,.lesson-surface .lesson-reader .learning-cycle .lc-small{font-size:.8rem}}
@media(prefers-reduced-motion:reduce){html:has(body.lesson-surface){scroll-behavior:auto}.lesson-surface,.lesson-surface *,.lesson-surface *::before,.lesson-surface *::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}