:root{--bg:#05070b;--panel:#0b111c;--ink:#edf4fb;--muted:#b1c1d1;--line:#263244;--accent:#93c5fd;--secondary:#60a5fa;--warn:#ffd18a}
*{box-sizing:border-box}html{scroll-behavior:auto;scrollbar-gutter:stable}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.72 system-ui,-apple-system,"Segoe UI",sans-serif}
a{color:var(--accent);text-underline-offset:3px}a:hover{color:white}button,input,select{font:inherit}button,select{color:var(--ink);background:var(--panel);border:1px solid var(--line);border-radius:9px;padding:9px 13px}
button{cursor:pointer}button:hover{border-color:var(--accent)}:focus-visible{outline:3px solid var(--warn);outline-offset:4px}
.skip{position:absolute;left:10px;top:-80px;background:var(--panel);padding:8px;z-index:30}.skip:focus{top:10px}
.sitebar{padding:16px max(20px,calc((100% - 1120px)/2));display:flex;flex-wrap:wrap;align-items:center;gap:15px;border-bottom:1px solid var(--line)}
.brand{font-weight:850;text-decoration:none;color:var(--ink)}.sitebar select{max-width:100%;min-width:0;font-size:14px}.sitebar span{font-size:12px;color:var(--muted)}
main{max-width:1020px;margin:auto;padding:45px 24px 75px}h1{font-size:clamp(30px,4.3vw,54px);line-height:1.12;letter-spacing:-.035em;margin:12px 0 20px}h2{font-size:27px;line-height:1.25;margin:40px 0 14px}h3{font-size:20px;line-height:1.4}
p{max-width:82ch;margin:0 0 18px}ul,ol{padding-left:23px}li{margin-bottom:8px}
.eyebrow{font-size:12px;letter-spacing:.11em;text-transform:uppercase;color:var(--accent);font-weight:800}
.question{font-size:22px;color:#d4e5f6;line-height:1.45;max-width:75ch}.meta,.small{font-size:13px;color:var(--muted)}
.box{margin:22px 0;padding:20px;border:1px solid var(--line);border-radius:15px;background:var(--panel)}.warning{border-left:4px solid var(--warn)}.objectives{font-size:15px}
.cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin:27px 0}.card{display:block;color:var(--ink);text-decoration:none;padding:22px;border:1px solid var(--line);border-radius:15px;background:var(--panel)}.card:hover{border-color:var(--accent)}.card h2,.card h3{margin:8px 0 9px}.card p{font-size:15px;color:var(--muted);margin:0}.card .small{color:var(--accent)}
.lesson-list{display:grid;gap:11px}.lesson-item{display:block;padding:16px 18px;border:1px solid var(--line);border-radius:12px;text-decoration:none;color:var(--ink)}.lesson-item strong{display:block;font-size:19px}.lesson-item span{font-size:13px;color:var(--muted)}
.lesson-item[hidden]{display:none}
.search{display:block;width:100%;padding:12px;background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:9px;margin:9px 0 20px}
.table-wrap{max-width:100%;overflow:auto;margin:15px 0}table{width:100%;border-collapse:collapse;font-size:14px;text-align:left}th,td{padding:11px 12px;border-bottom:1px solid var(--line);vertical-align:top}th{color:var(--accent);font-weight:700}caption{text-align:left;color:var(--muted);font-size:13px;padding:8px 0}
.ticket{border:1px solid #496b69;background:linear-gradient(120deg,#183350,var(--panel));border-radius:16px;padding:20px;margin:24px 0}.ticket h3{margin:5px 0}.ticket .buy,.ticket .sell{border:1px solid currentColor;border-radius:4px;padding:2px 5px;font-size:12px;font-weight:800}.ticket .buy{color:var(--accent)}.ticket .sell{color:var(--warn)}
.metrics{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:14px 0}.metric{background:rgba(0,0,0,.15);padding:12px;border:1px solid var(--line);border-radius:10px}.metric span{display:block;color:var(--muted);font-size:12px}.metric b{display:block;font-size:19px;overflow-wrap:anywhere}
.experiment label{font-size:14px}.experiment input[type=range]{width:100%;accent-color:var(--accent)}.experiment output{display:block;font-size:19px;color:var(--accent);font-weight:700;padding:12px 0}
figure{margin:25px 0;padding:16px;border:1px solid var(--line);border-radius:16px;background:var(--panel)}figcaption{font-size:14px;color:var(--muted);margin:10px 0}figure svg{width:100%;height:auto;display:block;min-height:220px}
.axislabel,.ticklabel{fill:#c0d0df;font:13px system-ui,sans-serif}.axislabel{font-size:14px}.grid{stroke:#304153;stroke-width:1}.zero{stroke:#a1b3c6;stroke-width:1.2}.series{fill:none;stroke:var(--accent);stroke-width:2.8}.series-1{stroke:var(--secondary);stroke-dasharray:6 4}.series-2{stroke:var(--warn);stroke-width:1.4;opacity:.8}.series-3{stroke:#85baff;stroke-width:1.4;opacity:.8}.series-4{stroke:#f5a2c1;stroke-width:1.4;opacity:.8}.series-5{stroke:#b9d587;stroke-width:1.4;opacity:.8}
.bar{fill:var(--accent);opacity:.85}.up{stroke:var(--accent);fill:transparent;stroke-width:2}.down{stroke:var(--warn);fill:var(--warn);stroke-width:2}.wick{stroke:#c2d0df;stroke-width:2}
.legend{display:flex;flex-wrap:wrap;gap:7px 15px;margin:5px 0;font-size:12px;color:var(--muted)}.legend span{padding:3px 6px;border:1px solid var(--line);border-radius:5px}
details{border:1px solid var(--line);border-radius:10px;padding:13px 15px;margin:13px 0}summary{cursor:pointer;font-weight:700;color:var(--accent)}details p{margin-top:13px}details[open] summary{margin-bottom:10px}
.check{border:1px solid var(--line);padding:18px;border-radius:12px;margin:15px 0}.check h3{margin:0 0 10px}.critical{font-size:11px;color:var(--warn);font-weight:800;text-transform:uppercase;letter-spacing:.06em}
.calc-button{display:inline-block;color:var(--accent);margin:6px 8px 6px 0}.formula{padding:16px;background:#091520;border-radius:10px;overflow:auto;white-space:pre-wrap;font:15px/1.75 ui-monospace,Consolas,monospace;color:#e7faf7}
dialog{color:var(--ink);background:var(--panel);border:1px solid #4c6877;border-radius:18px;width:min(840px,calc(100vw - 24px));max-height:86dvh;max-height:86vh;padding:0}dialog::backdrop{background:rgba(0,0,0,.76)}.dialog-head{padding:17px 22px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:12px;position:sticky;top:0;background:var(--panel);z-index:2}.dialog-head h2{margin:0;font-size:23px}.dialog-body{padding:23px}.dialog-body p{font-size:16px}.dialog-close{white-space:nowrap}
.prevnext{display:flex;justify-content:space-between;gap:15px;border-top:1px solid var(--line);padding-top:25px;margin-top:36px}.prevnext a{max-width:48%;font-size:14px}.sources{font-size:14px}.source-note{font-size:12px;color:var(--muted)}
@media(max-width:650px){body{font-size:16px}main{padding:30px 17px 55px}.cards,.metrics{grid-template-columns:1fr}.sitebar{padding:12px 17px}.sitebar select{width:100%}.question{font-size:20px}.ticket,figure,.box{padding:14px}th,td{padding:9px 8px}.dialog-head,.dialog-body{padding:15px}figure svg{min-height:180px}.axislabel{font-size:15px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}
@media print{body{background:white;color:black}.sitebar,.calc-button,.experiment{display:none}main{max-width:none}.box,.ticket,figure{background:white;color:black;border-color:#aaa}.small,.meta,figcaption{color:#333}a{color:#111}}
/* Site navigation inside education documents only; lesson/tool styles stay isolated. */
.sitebar .quantool-course-directory{position:relative;flex:0 0 auto;padding:0;margin:0;border:0;border-radius:0;background:transparent;color:#e5efff;font:600 13px/1.4 "Segoe UI",Arial,sans-serif}
.sitebar .quantool-course-directory>summary{display:flex;align-items:center;gap:9px;min-height:36px;padding:8px 12px;box-sizing:border-box;border:1px solid #5c81ac;border-radius:6px;background:#183350;color:#e3efff;cursor:pointer;list-style:none;letter-spacing:.4px;font-size:11px}
.sitebar .quantool-course-directory>summary::-webkit-details-marker{display:none}
.sitebar .quantool-course-directory>summary:hover,.sitebar .quantool-course-directory[open]>summary{background:#284d75;border-color:#8abbf2}
.sitebar .quantool-course-directory>nav{position:fixed;top:auto;left:auto;z-index:50;display:flex;flex-direction:column;gap:7px;width:min(328px,calc(100vw - 34px));max-height:calc(100dvh - 100px);padding:12px;box-sizing:border-box;border:1px solid #456286;border-radius:10px;background:#111d2e;box-shadow:0 15px 45px #0009;color:#e5efff}
.sitebar .quantool-course-directory:not([open])>nav{display:none}
.sitebar .quantool-course-directory label{font-size:11px;color:#9db5d2}
.sitebar .quantool-course-directory input{display:block;width:100%;min-height:37px;margin:0;padding:7px 10px;box-sizing:border-box;border:1px solid #3b526f;border-radius:5px;background:#192b41;color:#f0f6ff;font:13px/1.4 "Segoe UI",Arial,sans-serif}
.sitebar .quantool-course-directory-links{display:flex;flex-direction:column;gap:3px;overflow:auto;min-height:0;max-height:52vh;overscroll-behavior:contain;scrollbar-width:thin}
.sitebar .quantool-course-directory a{display:block;flex:0 0 auto;min-height:40px;padding:10px;box-sizing:border-box;border:1px solid transparent;border-radius:5px;color:#d6e5f8;text-decoration:none;font:500 13px/1.4 "Segoe UI",Arial,sans-serif;overflow-wrap:anywhere}
.sitebar .quantool-course-directory a:hover,.sitebar .quantool-course-directory a[aria-current=page]{background:#203e5f;color:#fff}
.sitebar .quantool-course-directory [hidden]{display:none!important}
.sitebar .quantool-course-directory p{margin:4px 0;color:#9db5d2;font-size:12px}
.sitebar .quantool-course-directory :focus-visible{outline:2px solid #94c6ff;outline-offset:2px}
@media print{.sitebar .quantool-course-directory{display:none!important}}