:root{--purple:#444159;--green:#008859;--green-dark:#006c47;--teal:#0aa699;--orange:#df600b;--ink:#242431;--muted:#636573;--line:#dddfe8;--bg:#f5f6fa;--font:16px;--danger:#a52b32;--radius:10px}
*{box-sizing:border-box}html{font-size:var(--font);scroll-behavior:smooth;scroll-padding-top:118px;-webkit-text-size-adjust:100%}body{margin:0;font-family:Arial,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.65;background:var(--bg);color:var(--ink)}button,input,textarea,select{font:inherit}button,a,input,textarea,select,summary{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}a{color:#126b63;text-underline-offset:3px}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #bb690c;outline-offset:3px}button:disabled{opacity:.45;cursor:default}[hidden]{display:none!important}h1,h2,h3{line-height:1.23;letter-spacing:-.025em;color:#353247}h1{font-size:2rem;margin:0 0 16px}h2{font-size:1.35rem;margin:0 0 16px}h3{font-size:1.05rem;margin:18px 0 10px}p{margin:0 0 16px}ul,ol{padding-left:1.4rem}li{padding-left:3px;margin-bottom:8px}small,.muted{color:var(--muted)}.muted{font-size:.86rem}.skip{position:fixed;left:12px;top:-70px;padding:12px;background:#fff;z-index:100}.skip:focus{top:8px}
.topbar{height:64px;position:sticky;top:0;z-index:40;background:var(--purple);color:white;display:flex;align-items:center;justify-content:space-between;padding:0 28px;gap:14px}.brand{color:white;text-decoration:none;font-weight:700;display:flex;align-items:center;gap:10px;font-size:1.35rem;letter-spacing:.01em}.brand-mark{background:#ffffff17;border:1px solid #ffffff45;border-radius:7px;width:31px;height:34px;text-align:center;line-height:32px}.brand-sub{font-size:.75rem;color:#efedf6;font-weight:400;letter-spacing:0;padding-left:9px;border-left:1px solid #ffffff35}.top-tools{display:flex;align-items:center;gap:4px}.top-tools button{color:white;background:transparent;border:0;min-width:36px;min-height:40px;border-radius:5px;padding:6px 8px;font-size:.85rem}.top-tools button:hover{background:#ffffff20}#calc-open{border-left:1px solid #ffffff40;margin-left:8px;padding-left:15px}.topnav{position:sticky;top:64px;z-index:35;display:flex;align-items:stretch;gap:6px;background:white;border-bottom:1px solid var(--line);padding:0 26px;min-height:49px;overflow-x:auto}.topnav a{display:flex;align-items:center;white-space:nowrap;padding:12px 15px;text-decoration:none;color:#666271;font-size:.85rem;border-bottom:3px solid transparent}.topnav a[aria-current="page"]{color:var(--green-dark);border-color:var(--green);font-weight:700}#menu-toggle{display:none;background:white;border:0;padding:8px;color:var(--purple)}
.layout{max-width:1500px;margin:auto;display:grid;grid-template-columns:286px minmax(0,1fr)}#sidebar{position:sticky;top:113px;height:calc(100dvh - 113px);overflow:auto;padding:26px 18px 30px 24px;border-right:1px solid var(--line);background:#fafbfe;scrollbar-width:thin}.side-head{font-size:.76rem;text-transform:uppercase;letter-spacing:.12em;color:#747386;margin-bottom:10px}.progress-label{font-size:.8rem;color:var(--muted);display:flex;justify-content:space-between}.track{height:5px;border-radius:10px;background:#e0e5eb;overflow:hidden;margin:8px 0}.track span{display:block;height:100%;background:var(--teal);transition:width .2s}.phase-title{margin:22px 0 8px;font-size:.71rem;letter-spacing:.09em;text-transform:uppercase;color:#797785;font-weight:700}.lesson-link{display:flex;align-items:center;gap:10px;text-decoration:none;color:#4e4b5d;font-size:.82rem;line-height:1.3;padding:10px 8px;margin:2px 0;border-radius:7px;border:1px solid transparent;min-height:43px}.lesson-link:hover{background:#eff1f7}.lesson-link[aria-current="page"]{background:#e7f4ef;border-color:#c6e4d6;color:#006541;font-weight:700}.lesson-no{flex:0 0 25px;width:25px;height:25px;border:1px solid #d6d7e0;border-radius:6px;display:grid;place-items:center;font-size:.72rem;background:white}.lesson-link.mastered .lesson-no{background:var(--green);border-color:var(--green);color:white}.read-dot{margin-left:auto;font-size:.8rem;color:var(--green-dark)}
main{min-width:0;padding:34px clamp(22px,4vw,65px) 70px;max-width:1120px;width:100%}main:focus{outline:none}.eyebrow{font-size:.73rem;text-transform:uppercase;letter-spacing:.12em;color:var(--green-dark);font-weight:700;margin-bottom:12px;display:flex;gap:12px;align-items:center}.eyebrow .pill{letter-spacing:0;text-transform:none;background:#e5f0eb;padding:2px 8px;border-radius:5px}.lead{font-size:1.05rem;color:#646273;max-width:780px;line-height:1.6}.lesson-top{border-bottom:1px solid var(--line);padding-bottom:22px;margin-bottom:24px}.lesson-meta{font-size:.78rem;color:var(--muted);display:flex;flex-wrap:wrap;gap:14px}.jump{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px}.jump a{border:1px solid #dbdde7;padding:5px 12px;border-radius:6px;text-decoration:none;background:white;font-size:.8rem}.goals{background:#eceff5;border-radius:var(--radius);padding:16px 20px;margin:0 0 22px}.goals h2{font-size:.83rem;letter-spacing:0;margin-bottom:9px}.goals ul{margin:0;display:flex;flex-wrap:wrap;gap:8px 24px;padding-left:17px;font-size:.8rem;color:#575469}.goals li{margin:0}.section{border:1px solid var(--line);background:white;border-radius:var(--radius);margin:12px 0;overflow:hidden}.section summary{padding:20px 23px;font-weight:700;font-size:1.04rem;color:#353247;cursor:pointer;list-style:none;display:flex;align-items:center;gap:13px}.section summary::-webkit-details-marker{display:none}.section summary::after{content:'+';margin-left:auto;font-weight:400;font-size:1.3rem;color:#868491}.section[open] summary::after{content:'−'}.section-number{font-size:.74rem;display:grid;place-items:center;flex:0 0 25px;height:25px;color:#807a90;background:#f1f0f5;border-radius:50%}.section-body{padding:0 24px 10px}.section-body p:last-child{margin-bottom:12px}.formula{font-family:Georgia,"Times New Roman",serif;font-size:1.1rem;color:#2e3554;background:#f0f3fa;border-left:3px solid #6c799e;padding:16px 18px;margin:18px 0;line-height:1.9;overflow-wrap:anywhere}.table-scroll{max-width:100%;overflow:auto;margin:15px 0}table{border-collapse:collapse;width:100%;font-size:.84rem;line-height:1.55;margin:15px 0}th,td{padding:11px 12px;border:1px solid #dedfe7;text-align:left;vertical-align:top}th{background:#f0f1f6;color:#4e4962;font-weight:700}tr:nth-child(even) td{background:#fbfcfe}.note{font-size:.9rem;border-left:3px solid var(--orange);padding:12px 16px;background:#fff7ed}
.example{margin:30px 0;background:#fff;border:1px solid var(--line);border-top:3px solid var(--teal);border-radius:var(--radius);padding:24px}.block-label{font-size:.71rem;font-weight:700;text-transform:uppercase;letter-spacing:.1em;color:var(--green-dark);margin-bottom:9px}.example h2{font-size:1.18rem}.steps{list-style:none;padding:0;margin:0;counter-reset:steps}.steps li{counter-increment:steps;position:relative;padding:12px 10px 12px 43px;margin:0;border-top:1px solid #ececf2}.steps li:before{content:counter(steps);position:absolute;left:2px;top:15px;background:#e7f5ef;color:#08744d;border-radius:50%;width:25px;height:25px;display:grid;place-items:center;font-size:.75rem;font-weight:700}.step-placeholder{border:1px dashed #d8dce6;color:var(--muted);font-size:.88rem;padding:15px;margin:12px 0}.actions{display:flex;gap:9px;align-items:center;flex-wrap:wrap;margin-top:16px}.btn{border:1px solid #d3d7e0;background:white;color:var(--purple);border-radius:6px;min-height:41px;padding:8px 15px;text-decoration:none;font-size:.83rem;font-weight:700;display:inline-flex;align-items:center;justify-content:center;gap:6px}.btn:hover{border-color:var(--green);background:#f5faf7}.btn.primary{background:var(--green);color:white;border-color:var(--green)}.btn.primary:hover{background:var(--green-dark)}.btn.danger{color:var(--danger)}.btn.small{min-height:34px;padding:5px 10px;font-size:.77rem}.pitfalls{border-left:3px solid var(--orange);padding:14px 20px;background:#fff6ea;margin:24px 0;border-radius:0 8px 8px 0}.pitfalls h2{font-size:.88rem;color:#8b4909;margin-bottom:8px}.pitfalls ul{font-size:.88rem;margin:0}.pitfalls li:last-child{margin-bottom:0}
.lab{padding:24px;background:#eef7f6;border:1px solid #cce1de;border-radius:var(--radius);margin:24px 0}.lab h2{font-size:1.2rem}.lab p{font-size:.88rem}.lab-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px 18px}.field{display:flex;flex-direction:column;gap:5px;font-size:.8rem;color:#405754;min-width:0}.field input,.field select,select,input[type="search"]{min-height:42px;border:1px solid #bfcfce;border-radius:5px;padding:8px 10px;background:#fff;width:100%;min-width:0;color:var(--ink)}.field input[type="range"]{padding:0;accent-color:var(--green);height:35px}.lab-result{margin-top:18px;border-top:1px solid #c9e1dc;padding-top:17px}.results{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.metric{background:#fff;border:1px solid #d6e4df;padding:12px;border-radius:7px;min-width:0}.metric b{display:block;font-size:1.17rem;color:#146b55;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.metric span{font-size:.74rem;color:#687a72}.lab svg{width:100%;height:auto;display:block;margin:14px 0;background:white;border-radius:6px}.lab svg text{font-family:Arial,sans-serif;font-size:12px;fill:#666879}.lab-equation{font-variant-numeric:tabular-nums;font-size:.9rem!important;margin:15px 0 0}.lab-error{padding:12px;background:#fff0f0;color:#95232a;font-size:.88rem;border-radius:6px}.number-list{font-size:1rem!important}
.quiz{margin:30px 0}.quiz>h2{margin-bottom:8px}.question{background:white;border:1px solid var(--line);border-radius:var(--radius);padding:23px;margin:14px 0}.question legend{font-weight:700;padding:0;line-height:1.5;font-size:.97rem}.question fieldset{border:0;padding:0;margin:0;min-width:0}.answers{display:grid;gap:8px;margin-top:15px}.answer{display:flex;align-items:flex-start;gap:10px;border:1px solid #dddfe8;border-radius:6px;padding:12px;font-size:.88rem;cursor:pointer;min-height:44px}.answer:hover{background:#f7f9fc}.answer:has(input:checked){border-color:var(--green);background:#edf7f1}.answer input{accent-color:var(--green);margin-top:5px;flex-shrink:0}.feedback{padding:13px 15px;margin-top:15px;border-radius:6px;background:#e9f6ef;color:#19583e;font-size:.88rem}.feedback.wrong{background:#fff0e5;color:#8b4315}.feedback strong{display:block;margin-bottom:3px}.question-result{font-size:.77rem;color:var(--muted);margin-top:12px}.sources{margin-top:25px;font-size:.78rem;color:var(--muted);border-top:1px solid var(--line);padding-top:16px}.sources ul{padding-left:17px}.sources li{margin-bottom:6px}.lesson-bottom{margin-top:26px;border-top:1px solid var(--line);padding-top:22px;display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px}.reading-state{font-size:.8rem;color:var(--green-dark);margin:10px 0}.card{background:white;border:1px solid var(--line);border-radius:var(--radius);padding:23px;margin:15px 0}.card h2{font-size:1.2rem}.card-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.card-grid .card{margin:0}.searchbar{margin:20px 0;max-width:550px}.glossary-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.glossary-term{padding:18px 20px;background:white;border:1px solid var(--line);border-radius:8px}.glossary-term h2{font-size:1rem;margin-bottom:8px}.glossary-term p{font-size:.86rem;margin-bottom:9px}.glossary-term a{font-size:.78rem}.empty{padding:25px;color:var(--muted);background:white;border:1px dashed var(--line)}.stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin:22px 0}.stats .metric b{font-size:1.8rem}.stats .metric{padding:20px}.status-row{display:flex;align-items:center;gap:15px;padding:14px 0;border-bottom:1px solid var(--line);font-size:.86rem}.status-row a{flex:1}.status-row span{white-space:nowrap;color:var(--muted);font-size:.77rem}.notes{display:block;width:100%;min-height:170px;padding:13px;border:1px solid #ccd1df;border-radius:6px;resize:vertical;line-height:1.6;background:#fff;color:var(--ink);font-size:1rem}.rubric{background:#f2f7f4;border:1px solid #d7e4dc;padding:14px 18px;border-radius:7px;margin:16px 0}.rubric summary{cursor:pointer;font-weight:700;font-size:.9rem}.rubric ul{font-size:.88rem}.case-header{display:flex;gap:12px;justify-content:space-between;align-items:center}.case-meta{font-size:.75rem;color:var(--muted)}.chip{font-size:.73rem;background:#edf1f6;border-radius:4px;color:#666077;padding:3px 8px}.source-card a{display:inline-flex}.source-card p{font-size:.85rem}.footer-note{font-size:.77rem;color:var(--muted);margin:24px 0}.lesson-status{font-size:.78rem;color:var(--green-dark)}
dialog{border:1px solid var(--line);border-radius:12px;width:420px;max-width:calc(100vw - 24px);padding:0;box-shadow:0 20px 80px #20203040;color:var(--ink);max-height:90dvh;overflow:auto}dialog::backdrop{background:#24243b77}.dialog-head{display:flex;align-items:center;justify-content:space-between;background:var(--purple);color:white;padding:13px 19px;margin:0}.dialog-head h2{color:white;font-size:1.05rem;margin:0}.icon-button{font-size:1.5rem;color:inherit;border:0;background:transparent;width:35px;height:35px}.calc-body{padding:18px}.calc-body label{font-size:.8rem}.calc-body input{display:block;width:100%;padding:10px;border:1px solid #ccd1df;border-radius:5px;font-size:1rem}.calc-body output{display:block;min-height:65px;padding:10px;text-align:right;font-size:1.5rem;overflow-wrap:anywhere;font-variant-numeric:tabular-nums}.calc-keys{display:grid;grid-template-columns:repeat(4,1fr);gap:6px;margin-bottom:14px}.calc-keys button{padding:8px;border:1px solid #d9dce5;border-radius:5px;background:#f6f7fa;min-height:43px}.calc-keys button[data-key="="]{background:var(--green);color:white}#toast{position:fixed;bottom:22px;left:50%;transform:translateX(-50%);z-index:100;background:#34364a;color:white;font-size:.83rem;border-radius:8px;padding:12px 20px;box-shadow:0 3px 25px #0002;max-width:90vw;pointer-events:none;opacity:0;transition:opacity .2s}#toast.show{opacity:1}
@media(min-width:1450px){main{padding-right:90px}.layout{grid-template-columns:300px minmax(0,1fr)}}
@media(max-width:1000px){.layout{grid-template-columns:245px minmax(0,1fr)}#sidebar{padding-left:12px;padding-right:12px}main{padding:28px 24px 60px}.brand-sub{display:none}.topbar{padding:0 18px}.topnav{padding:0 12px}.topnav a{padding:12px}.lab-grid{gap:10px}.results{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:760px){.topbar{height:56px;padding:0 12px}.brand{font-size:1.15rem}.brand-mark{width:27px;height:29px;line-height:27px}.desktop-label{display:none}.top-tools{gap:0}.top-tools button{font-size:.8rem;min-width:32px;padding:5px}#calc-open{padding-left:9px;margin-left:3px}.topnav{top:56px;padding:0 6px;gap:0;min-height:47px}.topnav a{padding:11px 10px;font-size:.78rem}#menu-toggle{display:block;white-space:nowrap;font-size:.85rem}#menu-toggle span{display:none}.layout{display:block}#sidebar{display:none;position:fixed;z-index:33;left:0;top:103px;width:min(320px,90vw);height:calc(100dvh - 103px);box-shadow:8px 10px 30px #20203020;padding:20px}body.menu-open #sidebar{display:block}main{padding:24px 16px 45px;max-width:none}h1{font-size:1.65rem}.lead{font-size:1rem}.lesson-top{padding-bottom:18px;margin-bottom:18px}.section summary{padding:17px 16px;font-size:1rem;gap:9px}.section-body{padding:0 16px 8px}.goals{padding:14px 16px}.goals ul{display:block}.goals li{margin:5px 0}.formula{padding:12px;font-size:1rem;line-height:1.9}.example,.question,.lab,.card{padding:18px 16px}.lab-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.field{font-size:.76rem}.field input,.field select{font-size:1rem}.results,.stats{gap:8px}.metric{padding:10px}.metric b{font-size:1rem}.metric span{font-size:.7rem}.stats .metric{padding:13px 10px}.stats .metric b{font-size:1.4rem}.stats{grid-template-columns:repeat(3,minmax(0,1fr))}.glossary-grid,.card-grid{grid-template-columns:1fr}.status-row{gap:7px;flex-wrap:wrap}.status-row a{flex-basis:60%}.status-row span{white-space:normal}.case-header{align-items:flex-start}.eyebrow{font-size:.67rem}.jump{gap:6px}.jump a{font-size:.76rem;padding:5px 10px}th,td{padding:8px;min-width:100px}table{font-size:.8rem}.lesson-bottom .btn{flex:1}.lesson-bottom{gap:8px}.lesson-meta{font-size:.72rem;gap:10px}html{scroll-padding-top:114px}}
@media(max-width:370px){main{padding:19px 12px 40px}.lab-grid{grid-template-columns:1fr}.top-tools button{min-width:30px}.brand-mark{display:none}.topnav a{padding:11px 8px}.results{grid-template-columns:1fr 1fr}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
@media print{.topbar,.topnav,#sidebar,.jump,.lab,.question,.lesson-bottom,.actions,#toast,dialog{display:none!important}.layout{display:block}body{background:white}main{padding:0;max-width:none}.section,.example{break-inside:avoid}.section{border:0}.section-body{padding-left:0}.sources{font-size:10pt}h1{font-size:22pt}}