:root{color-scheme:light;--ink:#10283d;--muted:#4a5f70;--paper:#f7fafc;--line:#d7e1e8;--teal:#00796f;--blue:#155bb3;font-family:Arial,Helvetica,sans-serif;color:var(--ink);background:var(--paper)}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;font-size:17px;line-height:1.65}a{color:var(--blue);text-underline-offset:4px}a:hover{color:var(--teal)}a:focus-visible,summary:focus-visible{outline:3px solid #d47d23;outline-offset:5px}.wrap{max-width:1180px;padding:0 32px;margin:auto}.top{border-bottom:1px solid var(--line);background:#fff}.top .wrap{min-height:78px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{font-size:19px;font-weight:700;text-decoration:none;color:var(--ink)}.brand span{font-size:14px;font-weight:400;color:var(--muted);padding-left:16px;margin-left:16px;border-left:1px solid var(--line)}.langs{display:flex;gap:5px}.langs a{padding:8px 12px;min-height:44px;font-size:14px;text-decoration:none;color:var(--muted)}.langs a[aria-current=page]{color:var(--teal);border-bottom:2px solid var(--teal)}.skip{position:absolute;left:20px;top:-90px;background:white;padding:10px}.skip:focus{top:12px;z-index:2}.hero{padding:42px 0 32px;display:grid;grid-template-columns:1fr 200px;gap:50px}.eyebrow,.code,.meta{font-size:14px;color:var(--teal);letter-spacing:.02em}.eyebrow{margin:0 0 13px}h1,h2,h3,p{margin-top:0}h1{font:500 clamp(38px,5vw,58px)/1.12 Cambria,Georgia,serif;letter-spacing:-.025em;margin:0 0 22px}h2{font:500 clamp(27px,3vw,35px)/1.2 Cambria,Georgia,serif;margin-bottom:20px}h3{font-size:21px;line-height:1.35;margin-bottom:12px;font-weight:600}.lead{font-size:21px;line-height:1.55;margin-bottom:20px;max-width:790px}.model{font-size:16px;max-width:790px;color:var(--muted);border-left:3px solid var(--teal);padding-left:18px}.level{border-left:1px solid var(--line);padding-left:26px;display:flex;flex-direction:column;justify-content:space-between}.level strong{font:500 110px/.95 Cambria,Georgia,serif;color:var(--teal)}.level p{font-size:14px;color:var(--muted);margin:12px 0 0}.nav{display:flex;flex-wrap:wrap;gap:9px;padding:0 0 34px}.nav a{padding:9px 15px;min-height:44px;border:1px solid var(--line);background:white;text-decoration:none;color:var(--ink);font-size:15px}.section{border-top:1px solid var(--ink);padding:30px 0 44px}.intro{max-width:860px;color:var(--muted)}.three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px}.three article{border-top:3px solid var(--teal);padding-top:19px}.three p{font-size:16px;color:var(--muted);margin-bottom:14px}.three .proof{color:var(--ink);font-size:15px}.principle{background:#eaf3f4;padding:25px 28px;margin-top:28px;border-left:3px solid var(--teal)}.principle p{margin:0}.knowledge{display:grid;grid-template-columns:1fr 1fr;gap:0 30px}.unit{border-top:1px solid var(--line);min-width:0}.unit summary{display:flex;gap:18px;align-items:baseline;cursor:pointer;padding:18px 2px;list-style:none;font-size:18px;font-weight:600}.unit summary::-webkit-details-marker{display:none}.unit summary:after{content:'+';margin-left:auto;color:var(--teal);font-size:22px}.unit[open] summary:after{content:'−'}.unit .code{font:400 14px ui-monospace,monospace;flex:none}.unit-body{padding:0 0 20px 48px;font-size:16px}.unit-body p{margin-bottom:12px}.unit-body strong{color:var(--ink)}.unit-body .prereq{font-size:14px;color:var(--muted)}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:22px;list-style:none;padding:0;margin:25px 0 0;counter-reset:step}.steps li{counter-increment:step;border-top:1px solid var(--line);padding-top:14px;font-size:16px}.steps li:before{content:'0' counter(step);display:block;font-size:14px;color:var(--teal);margin-bottom:10px}.steps b{display:block;font-size:18px;margin-bottom:7px}.steps p{color:var(--muted);margin:0}.two{display:grid;grid-template-columns:1fr 1fr;gap:38px}.two p{font-size:16px}.stages{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}.stages span{background:#eaf3f4;padding:7px 12px;font-size:15px}.table-wrap{overflow-x:auto}table{border-collapse:collapse;width:100%;font-size:16px}th,td{padding:13px 14px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}th{background:#eaf3f4;font-weight:600}td:first-child{font-weight:600}.note{font-size:14px;color:var(--muted);margin-top:16px}.docs{display:grid;grid-template-columns:1fr 1fr;gap:18px}.doc{border:1px solid var(--line);background:#fff;padding:24px}.doc p{font-size:15px;color:var(--muted);margin-bottom:17px}.actions{display:flex;gap:14px;flex-wrap:wrap}.actions a{border:1px solid var(--line);padding:9px 16px;min-height:44px;text-decoration:none;font-size:15px}.actions a.primary{background:var(--ink);color:white;border-color:var(--ink)}.footer{border-top:1px solid var(--line);padding:25px 0 35px;font-size:14px;color:var(--muted)}.footer>div{display:flex;gap:22px;justify-content:space-between;flex-wrap:wrap}.footer details{max-width:900px;margin-top:20px}.footer summary{cursor:pointer;padding:8px 0}.footer details p{margin:12px 0}li{margin-bottom:8px}@media(max-width:800px){.hero{grid-template-columns:1fr 115px;gap:25px}.level{padding-left:20px}.level strong{font-size:85px}.three{grid-template-columns:1fr}.steps{grid-template-columns:1fr 1fr}.knowledge,.two{grid-template-columns:1fr}.unit-body{padding-left:0}}@media(max-width:520px){.wrap{padding:0 20px}.top .wrap{flex-wrap:wrap;gap:4px;padding-top:12px;padding-bottom:8px}.brand span{font-size:13px;padding-left:10px;margin-left:10px}.hero{grid-template-columns:1fr;padding-top:28px;gap:10px}.level{border-left:0;border-top:1px solid var(--line);padding:12px 0 0;flex-direction:row;align-items:center;gap:20px}.level strong{font-size:48px}.level p{margin:0}.lead{font-size:19px}h1{font-size:39px}.nav{padding-bottom:28px}.nav a{font-size:14px;padding:9px 12px}.section{padding:26px 0 34px}.docs,.steps{grid-template-columns:1fr}.principle{padding:20px}.doc{padding:20px}.unit summary{font-size:17px;gap:12px}.footer>div{display:block}.footer p{margin-bottom:10px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}@media print{.top,.nav,.skip,.langs,.level{display:none}.hero{display:block}.wrap{padding:0}.section{break-inside:auto}.three,.two,.knowledge{display:block}.unit{break-inside:avoid}body{background:white;color:black}a{color:inherit}}
