:root{font-family:"Segoe UI",Arial,sans-serif;color:#27282c;background:#fff;font-synthesis:none;--accent:#b52437;--soft:#fbebee;--line:#dfdfe3;--muted:#62636d;--rail:#f8f7f5;--focus:#2457d6}
*{box-sizing:border-box}body{margin:0}button,input,textarea,select{font:inherit}button,a,input,textarea,summary{touch-action:manipulation}button{cursor:pointer;color:inherit}button{border:1px solid var(--line);border-radius:8px;background:white;padding:11px 15px;line-height:1.3}button:disabled{opacity:.45;cursor:default}a{color:var(--accent);text-underline-offset:4px}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--focus);outline-offset:3px}button:hover:not(:disabled){border-color:#a6a6af;background:#f7f7f9}.primary{color:white;background:var(--accent);border-color:var(--accent);font-weight:600}.primary:hover:not(:disabled){background:#942033;border-color:#942033}.skip{position:fixed;left:20px;top:-100px;padding:12px;background:white;z-index:100}.skip:focus{top:12px}.shell{display:grid;grid-template-columns:280px minmax(0,1fr) 290px;min-height:100vh}.rail{position:sticky;top:0;height:100vh;overflow-y:auto;background:var(--rail);border-right:1px solid var(--line);padding:30px 24px;display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:12px;color:#27282c;text-decoration:none;font-size:16px;line-height:1.25;font-weight:700}.brand svg{color:var(--accent);flex-shrink:0}.module-label{font-size:13px;color:var(--muted);margin-top:34px}.rail h2{font-size:29px;letter-spacing:-.8px;margin:5px 0 10px}.rail-intro{font-size:14px;line-height:1.5;color:var(--muted);margin:0 0 25px}.progress-label{font-size:12px;display:flex;justify-content:space-between;color:var(--muted)}progress{appearance:none;width:100%;height:5px;border:0;border-radius:8px;overflow:hidden;margin:10px 0 23px;flex-shrink:0}progress::-webkit-progress-bar{background:#e4e0e0}progress::-webkit-progress-value{background:var(--accent)}progress::-moz-progress-bar{background:var(--accent)}#navigation{display:grid;gap:4px}#navigation a{display:flex;gap:11px;align-items:center;padding:11px 10px;color:#545560;text-decoration:none;font-size:14px;line-height:1.35;border-radius:7px}#navigation a[aria-current="page"]{background:var(--soft);color:#942033;font-weight:650}#navigation a:hover{background:#eeece9}.step-number{width:23px;height:23px;display:flex;align-items:center;justify-content:center;border:1px solid #c7c4c7;border-radius:50%;font-size:11px;flex-shrink:0}.done .step-number{background:var(--accent);border-color:var(--accent);color:white}.rail-bottom{margin-top:auto;padding-top:26px}.rail-bottom button{width:100%;text-align:left;font-weight:600}.rail-bottom p{font-size:12px;color:var(--muted);line-height:1.7;margin-bottom:0}main{padding:30px clamp(24px,4vw,64px) 32px;min-width:0;max-width:1000px;width:100%;margin:auto;align-self:start}.reading-top{display:flex;align-items:center;justify-content:space-between;gap:14px;color:var(--muted);font-size:12px;margin-bottom:42px}.reading-top button{font-size:12px;padding:8px 10px}article{font-size:16px;line-height:1.75;overflow-wrap:anywhere}article h1{font-size:clamp(30px,3.2vw,43px);line-height:1.17;letter-spacing:-1.2px;margin:0 0 22px;font-weight:700;color:#23242a}article .lead{font-size:19px;line-height:1.6;color:#52535c;margin-bottom:28px}article h2{font-size:23px;letter-spacing:-.4px;line-height:1.3;margin:34px 0 12px}article h3{font-size:17px;line-height:1.4;margin:24px 0 8px}article p{margin:13px 0}article li{margin:8px 0}article ul,article ol{padding-left:23px}.callout{border-left:3px solid var(--accent);background:#faf4f5;padding:17px 21px;margin:24px 0;border-radius:0 8px 8px 0}.callout p:first-child{margin-top:0}.callout p:last-child{margin-bottom:0}.example{background:#f6f6f8;border:1px solid #e3e3e8;border-radius:10px;padding:22px;margin:24px 0}.example h3{margin-top:0}.example blockquote{margin:0;font-size:18px;line-height:1.6}blockquote{margin:20px 0;padding-left:20px;border-left:3px solid #cacbd2;color:#4f505a}code{background:#f0eff2;border-radius:4px;padding:2px 5px;font-family:Consolas,monospace;font-size:.9em}table{border-collapse:collapse;width:100%;font-size:14px;margin:22px 0}th,td{text-align:left;vertical-align:top;padding:13px 10px;border-bottom:1px solid var(--line)}th{color:#555660;background:#f7f7f9;font-weight:600}.table-wrap{overflow-x:auto}details{border:1px solid var(--line);border-radius:8px;margin:18px 0;padding:15px 19px}summary{cursor:pointer;font-weight:600}details[open] summary{margin-bottom:12px}.prompt{white-space:pre-wrap;font-family:inherit;background:#f6f6f8;border:1px solid var(--line);border-radius:8px;padding:20px;font-size:14px;line-height:1.7;margin:15px 0}.exercise{border:1px solid var(--line);border-radius:10px;padding:22px;margin:25px 0}.exercise h3{margin:0 0 10px}.exercise label{display:flex;align-items:flex-start;gap:10px;margin:12px 0;cursor:pointer;font-size:15px}.exercise input{margin-top:7px;accent-color:var(--accent)}.feedback{font-size:14px;color:#43454e;margin-top:15px!important}.feedback:empty{display:none}.lesson-actions{display:flex;align-items:center;gap:16px;margin-top:40px;padding-top:25px;border-top:1px solid var(--line)}#completion-note{font-size:12px;color:var(--muted)}.pager{display:flex;justify-content:space-between;gap:15px;margin-top:26px}.pager button{font-size:14px}footer{font-size:12px;color:var(--muted);line-height:1.6;margin-top:35px}.support{border-left:1px solid var(--line);background:#fcfcfd;padding:34px 24px;min-width:0}.support-inner{position:sticky;top:30px}.support-label{font-size:12px;color:var(--accent);font-weight:650}.support h2{font-size:20px;line-height:1.35;letter-spacing:-.3px;margin:9px 0 13px}.support p{font-size:14px;line-height:1.65;color:var(--muted)}.support label{display:block;font-size:13px;font-weight:600;margin:20px 0 7px}.support textarea{min-height:95px;font-size:14px}.support .save-note{font-size:12px;margin-top:14px}.support-help{border-top:1px solid var(--line);padding-top:20px;margin-top:27px}.support-help h3{font-size:14px;margin:0 0 6px}.support-help p{font-size:13px}.text-link{font-size:13px;line-height:1.7}input[type="text"],textarea{display:block;width:100%;padding:12px;border:1px solid #c5c6ce;border-radius:7px;background:white;color:#27282c;line-height:1.5;resize:vertical}.field{margin:24px 0}.field label{font-size:15px;font-weight:650;display:block;margin-bottom:7px}.field .hint{font-size:13px;color:var(--muted);margin:7px 0 9px}.field textarea{min-height:115px}.field input{min-height:46px}.notebook-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 22px}.notebook-grid .wide{grid-column:1/-1}.notebook-actions{display:flex;flex-wrap:wrap;gap:10px;margin:25px 0}.preview{padding:22px;background:#f6f6f8;border:1px solid var(--line);border-radius:8px;white-space:pre-wrap;font-size:13px;line-height:1.65;font-family:Consolas,monospace;max-height:430px;overflow:auto}.checklist{padding:0;list-style:none}.checklist label{display:flex;gap:12px;align-items:flex-start;cursor:pointer;font-size:15px;padding:12px 0;border-bottom:1px solid var(--line)}.checklist input{margin-top:7px;accent-color:var(--accent);width:17px;height:17px;flex-shrink:0}.status{position:fixed;bottom:22px;left:50%;transform:translateX(-50%);background:#27282c;color:white;font-size:14px;max-width:calc(100vw - 32px);padding:13px 20px;border-radius:8px;z-index:80;box-shadow:0 6px 25px #0002}.status:empty{display:none}.danger-zone{margin-top:30px;border-top:1px solid var(--line);padding-top:18px}.danger-zone p{font-size:13px;color:var(--muted)}.danger-zone button{color:#942033}.mobile-header{display:none}.noscript{position:fixed;inset:0;background:white;padding:40px;z-index:100}
@media(min-width:1600px){.shell{grid-template-columns:310px minmax(0,1fr) 330px}.rail{padding:35px}.support{padding:40px 30px}}
@media(max-width:1150px){.shell{grid-template-columns:250px minmax(0,1fr)}.rail{padding:25px 18px}.support{grid-column:2;border-left:0;border-top:1px solid var(--line);padding:25px 32px}.support-inner{position:static;max-width:750px;margin:auto}.rail{grid-row:1/3}.support textarea{min-height:80px}}
@media(max-width:760px){.mobile-header{display:flex;position:sticky;top:0;z-index:30;align-items:center;justify-content:space-between;gap:10px;background:#fff;border-bottom:1px solid var(--line);padding:12px 16px;font-size:12px}.mobile-header button{font-size:13px;padding:9px}.shell{display:block}.rail{display:none;position:static;height:auto;max-height:none;border-bottom:1px solid var(--line);border-right:0;padding:24px}.rail.is-open{display:flex}.rail-bottom{margin-top:15px}main{padding:25px 22px}.reading-top{margin-bottom:30px}article{font-size:16px}article h1{font-size:32px}article .lead{font-size:18px}.support{padding:27px 22px}.support-inner{position:static}.notebook-grid{display:block}.lesson-actions{align-items:flex-start;flex-direction:column}.pager button{max-width:50%;padding:11px;font-size:13px}.example,.exercise{padding:18px}table{min-width:400px}.reading-top{flex-wrap:wrap}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}
@media print{.rail,.support,.mobile-header,.reading-top button,.lesson-actions,.pager,.notebook-actions,.danger-zone,.skip,.status,.exercise button{display:none!important}.shell{display:block}main{padding:0;max-width:none}body{color:black;font-size:11pt}article h1{font-size:24pt}article h2{font-size:16pt}details> *{display:block}details{break-inside:avoid}.callout,.example,.exercise{break-inside:avoid}.preview{max-height:none;overflow:visible}.reading-top{margin-bottom:20px}a{color:inherit}}