@import url('https://fonts.googleapis.com/css2?family=Titillium+Web:wght@400;600&display=swap');
:root{color-scheme:dark;--bg:#070e1c;--surface:#10213b;--line:#314262;--text:#f1f4fa;--muted:#adbbd0;--gold:#d6b16f;--blue:#28539b;--header:#0b1930;--code:#0b1930;--consent:#152b49}
:root[data-theme="light"]{color-scheme:light;--bg:#f6f8fc;--surface:#fff;--line:#b5c5df;--text:#10274c;--muted:#4e6385;--gold:#805a1e;--blue:#1955ce;--header:#eaf0fa;--code:#edf3fe;--consent:#fff}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:400 1.05rem/1.65 'Titillium Web',sans-serif}button{font:inherit}
a{color:var(--gold)}a:hover{text-decoration:underline}.shell{width:min(1050px,calc(100% - 36px));margin-inline:auto}.skip{position:absolute;left:-9999px}.skip:focus{left:12px;top:12px;background:var(--gold);color:#071326;padding:6px}
.header{border-bottom:1px solid var(--line);background:var(--header)}.header-row{display:flex;justify-content:space-between;align-items:center;gap:20px;min-height:72px}.brand{display:inline-flex;align-items:center;gap:9px;font-size:1.35rem;font-weight:600;color:var(--text);text-decoration:none;white-space:nowrap}.brand img{width:28px;height:28px}.header nav{display:flex;gap:16px;align-items:center}.header nav a{text-decoration:none}.header button{background:var(--surface);color:var(--text);border:1px solid var(--line);padding:5px 9px;cursor:pointer}
.breadcrumbs{display:flex;gap:10px;flex-wrap:wrap;color:var(--muted);font-size:.86rem;padding:28px 0 18px}.eyebrow{text-transform:uppercase;letter-spacing:.12em;color:var(--gold);font-size:.82rem;font-weight:600}.unit-identity{display:flex;gap:8px;flex-wrap:wrap;margin-top:13px}.unit-identity span{padding:5px 11px;border:1px solid var(--line);background:var(--surface);color:var(--muted);font-size:.88rem}.unit-identity strong{color:var(--text);font-weight:600;letter-spacing:.04em}h1,h2,h3,h4{line-height:1.22;font-weight:600}h1{font-size:clamp(2.25rem,4.5vw,4rem);margin:12px 0 17px}.intro{max-width:760px;color:var(--muted)}
.lesson-nav{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:12px;padding:17px 0;margin:26px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.lesson-nav a{text-decoration:none;font-weight:600;display:flex;flex-direction:column}.lesson-nav a:nth-child(2){text-align:center}.lesson-nav a:last-child{text-align:right}.lesson-nav a small{font-size:.73rem;color:var(--muted);font-weight:400;letter-spacing:.06em}
.prose{overflow-wrap:break-word;line-height:1.75}.prose>p,.prose>ul,.prose>ol,.prose>blockquote{max-width:78ch}.prose h2{font-size:1.65rem;margin-top:2.3rem}.prose h3{font-size:1.35rem;margin-top:2rem}.prose h4{font-size:1.15rem;margin-top:1.6rem}.prose blockquote{border-left:3px solid var(--gold);margin-left:0;padding-left:18px;color:var(--muted)}.prose pre{overflow:auto;background:var(--code);border:1px solid var(--line);padding:18px;font-size:.85rem}.prose code{font-family:ui-monospace,Consolas,monospace;font-size:.86em}.table-hint{display:none;color:var(--muted);font-size:.8rem;margin-bottom:0}.table-scroll{max-width:100%;overflow-x:auto;margin:1.4rem 0;border:1px solid var(--line)}.table-scroll:focus-visible,.diagram-viewport:focus-visible{outline:2px solid var(--gold);outline-offset:2px}.prose table{width:max-content;min-width:100%;border-collapse:collapse}.prose td,.prose th{border:1px solid var(--line);padding:9px 12px;min-width:9rem;max-width:21rem;vertical-align:top;overflow-wrap:normal;word-break:normal}.prose th{background:var(--surface);text-align:left}.prose img{max-width:100%;height:auto}.prose a{overflow-wrap:anywhere}.prose .rubric{margin:.65rem 0 1rem;padding:.4rem .75rem;border-left:2px solid var(--line);background:var(--surface);font-size:.94rem}.prose .rubric summary{cursor:pointer;color:var(--gold);font-weight:600}.prose .rubric div{padding-top:.4rem}.diagram{margin:1.3rem 0 2rem;border:1px solid var(--line);background:var(--code);padding:12px 12px 8px}.diagram-viewport{max-width:100%;overflow-x:auto;overflow-y:hidden}.diagram-viewport img{display:block;width:auto;max-width:none;height:auto;margin-inline:auto}.diagram figcaption{color:var(--muted);font-size:.83rem;padding:5px 3px}.diagram details{margin:.3rem 3px}.diagram summary{cursor:pointer;color:var(--gold);font-size:.88rem}.diagram pre{max-height:300px;font-size:.76rem}.answers{margin:34px 0;background:var(--surface);border:1px solid var(--line);padding:20px}.answers summary{cursor:pointer;font-size:1.3rem;font-weight:600;color:var(--gold)}.footer{margin-top:65px;border-top:1px solid var(--line);padding:24px 0;color:var(--muted);font-size:.86rem}.footer .shell{display:flex;gap:15px;flex-wrap:wrap;align-items:center}
#analytics-consent{position:fixed;z-index:100;bottom:16px;left:16px;max-width:460px;padding:17px;background:var(--consent);border:1px solid var(--gold);box-shadow:0 15px 35px #0009;color:var(--text)}#analytics-consent p{margin:0 0 12px}#analytics-consent div{display:flex;gap:9px;align-items:center;flex-wrap:wrap}#analytics-consent button{border:1px solid var(--gold);background:transparent;color:var(--text);padding:5px 10px;cursor:pointer}#analytics-consent button+button{background:var(--blue)}#analytics-settings{background:transparent;border:0;color:var(--muted);text-decoration:underline;cursor:pointer}
@media(max-width:620px){.header-row{align-items:flex-start;flex-direction:column;padding:12px 0}.header nav{gap:11px}.brand{font-size:1.2rem}.lesson-nav{display:grid;grid-template-columns:1fr 1fr}.lesson-nav a:last-child{text-align:right}.lesson-nav a:nth-child(2){grid-column:1 / -1;grid-row:2;text-align:center}.prose td,.prose th{min-width:10rem}.table-hint{display:block}h1{font-size:clamp(2rem,8vw,2.8rem)}}