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.qa__label{color:var(--color-accent-primary-strong)}.qa__say-body{font-size:1.0625rem;color:var(--color-text-primary)}.qa__sigs{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--space-5);padding-top:var(--space-4);border-top:1px dashed var(--color-separator)}.qa__sigs:has(> :only-child){grid-template-columns:minmax(0,1fr)}.qa__sig{font-size:var(--text-md);color:var(--color-text-secondary)}.qa__sig-ic{width:14px;height:14px;flex:none;background:currentColor;-webkit-mask:var(--qa-ic) center/contain no-repeat;mask:var(--qa-ic) center/contain no-repeat}.qa__sig--good{--qa-ic:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath d='M3.5 8.5l3 3 6-7' fill='none' stroke='%23000' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E")}.qa__sig--bad{--qa-ic:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath d='M4.5 4.5l7 7M11.5 4.5l-7 7' fill='none' stroke='%23000' 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var(--color-border)}.whatif__step{margin:0 0 var(--space-4) !important;padding:0 !important}.whatif__step:last-child{margin-bottom:0 !important}.whatif__q{margin:0 0 6px !important;font-family:var(--font-heading);font-weight:var(--weight-semibold);line-height:1.45;color:var(--color-text-primary)}.whatif__tag{margin-right:2px;color:var(--color-accent-primary);font-weight:var(--weight-bold)}.whatif__a{font-size:var(--text-md);color:var(--color-text-secondary)}.qa-group{margin:var(--space-8) 0 0;scroll-margin-top:calc(var(--header-height) + 80px)}.qa-group:first-child{margin-top:var(--space-5)}.qa-group__head{margin:0 0 var(--space-5)}.qa-group__band{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:6px var(--space-3);padding:14px var(--space-5);border-radius:var(--radius-md);background:var(--color-band);background-image:linear-gradient(100deg,rgba(255,255,255,.08),transparent 60%);color:#fff}.course .qa-group__band h2{margin:0 !important;color:#fff !important;font-size:1.25rem;line-height:1.3;letter-spacing:-.01em}.qa-group__n{flex:none;padding:3px 10px;border-radius:var(--radius-pill);background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.28);color:#fff;font-family:var(--font-heading);font-size:var(--text-2xs);font-weight:var(--weight-bold);letter-spacing:.04em;text-transform:uppercase}.qa-group__head > p{margin:var(--space-3) 0 0 !important;padding:0 2px;font-size:var(--text-md);color:var(--color-text-secondary)}.mbank__card{display:flex;gap:var(--space-4);align-items:flex-start;padding:var(--space-5);border:1px solid var(--color-accent-primary-border);border-radius:var(--radius-lg);background:linear-gradient(135deg,var(--color-accent-primary-soft),var(--color-surface-raised) 70%)}.mbank__card--soon{background:var(--color-surface);border-style:dashed;border-color:var(--color-border)}.mbank__icon .ci{width:40px;height:40px;padding:9px;border-radius:var(--radius-md);background:var(--color-surface-raised);border:1px solid var(--color-accent-primary-border);color:var(--color-accent-primary)}.mbank__main{flex:1;min-width:0}.mbank__kicker{margin:0 0 2px !important;font-family:var(--font-heading);font-size:var(--text-2xs);font-weight:var(--weight-bold);text-transform:uppercase;letter-spacing:var(--tracking-caps);color:var(--color-accent-primary)}.mbank__title{font-family:var(--font-heading);font-size:1.1875rem;font-weight:var(--weight-bold);color:var(--color-text-primary);text-decoration:none}a.mbank__title:hover{color:var(--color-accent-primary)}.mbank__sum{margin:6px 0 8px !important;font-size:var(--text-md);color:var(--color-text-secondary)}.mbank__meta{display:flex;flex-wrap:wrap;gap:4px 16px;margin:0 !important;font-family:var(--font-heading);font-size:var(--text-xs);color:var(--color-text-muted)}.module-head{margin:0 0 var(--space-7)}.mtopic{margin:0 0 var(--space-7);scroll-margin-top:calc(var(--header-height) + var(--space-5))}.course .mtopic h2{margin:0 0 var(--space-2);font-size:var(--text-h3)}.mtopic__sum{margin:0 0 var(--space-4);color:var(--color-text-secondary);font-size:1rem}.lrows{list-style:none;margin:0;padding:0;border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden;background:var(--color-surface-raised)}.lrow{display:flex;align-items:center;gap:var(--space-3);margin:0;padding:12px var(--space-4);border-top:1px solid var(--color-separator)}.lrow:first-child{border-top:0}.lrow__icon{flex:none;display:grid;place-items:center;width:32px;height:32px;border-radius:var(--radius-md);background:var(--color-surface);color:var(--color-text-muted)}.lrow--free .lrow__icon{background:var(--color-success-soft);color:var(--color-success-text)}.lrow--premium .lrow__icon{background:var(--color-accent-primary-soft);color:var(--color-accent-primary)}.lrow--questions 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var(--space-4);max-width:18ch}.chub-hero .dek{max-width:62ch}.chub-hero__cta{display:flex;flex-wrap:wrap;gap:var(--space-3);margin:0 0 var(--space-6)}.chub-hero__cta .btn{border-radius:var(--radius-pill);padding:12px 22px;min-height:46px;font-size:var(--text-md)}.chub-stats{display:grid;grid-template-columns:repeat(4,minmax(0,140px));gap:var(--space-4);margin:0}.chub-stats div{padding-left:var(--space-3);border-left:2px solid var(--color-accent-primary-border)}.chub-stats dt{font-family:var(--font-heading);font-size:var(--text-xs);color:var(--color-text-muted);text-transform:uppercase;letter-spacing:var(--tracking-caps);font-weight:var(--weight-bold)}.chub-stats dd{margin:2px 0 0;font-family:var(--font-heading);font-size:1.75rem;font-weight:var(--weight-bold);color:var(--color-text-primary)}.chub{padding-bottom:var(--space-8)}.chub > section{margin-top:var(--space-8)}.chub h2{font-size:var(--text-h2);margin:0 0 var(--space-3);letter-spacing:var(--tracking-tight)}.chub__lead{margin:0 0 var(--space-5);color:var(--color-text-secondary);max-width:70ch}.hsteps{list-style:none;margin:var(--space-5) 0 0;padding:0;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:var(--space-3);counter-reset:s}.hsteps li{position:relative;display:flex;flex-direction:column;gap:4px;margin:0;padding:var(--space-4);border:1px solid var(--color-border);border-radius:var(--radius-lg);background:var(--color-surface-raised);font-size:var(--text-md);color:var(--color-text-secondary)}.hsteps li strong{font-family:var(--font-heading);font-size:1.0625rem;color:var(--color-text-primary)}.hsteps__no{display:grid;place-items:center;width:28px;height:28px;margin-bottom:6px;border-radius:50%;background:var(--color-accent-primary);color:#fff;font-family:var(--font-mono);font-size:var(--text-sm)}.hsteps li:last-child 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var(--transition-fast)}.mcard__link:hover{border-color:var(--color-accent-primary);box-shadow:var(--shadow-md);color:var(--color-text-primary)}.mcard__no{flex:none;font-family:var(--font-mono);font-size:1.5rem;line-height:1;font-weight:var(--weight-medium);color:var(--color-accent-primary);padding-top:2px}.mcard__body{flex:1;min-width:0;display:flex;flex-direction:column;gap:6px}.mcard__title{font-family:var(--font-heading);font-size:1.1875rem;font-weight:var(--weight-bold);line-height:1.3}.mcard__sum{font-size:var(--text-md);line-height:1.55;color:var(--color-text-secondary)}.mcard__topics{font-size:var(--text-sm);color:var(--color-text-muted)}.mcard__foot{margin-top:auto;padding-top:var(--space-3);display:flex;flex-wrap:wrap;align-items:center;gap:var(--space-2) var(--space-3);font-family:var(--font-heading);font-size:var(--text-xs);color:var(--color-text-muted)}.mcard__bar{flex:1 1 80px;height:4px;border-radius:2px;background:var(--color-surface-sunken);overflow:hidden;min-width:60px}.mcard__bar span{display:block;height:100%;background:var(--color-accent-primary);border-radius:2px}.hguides ul{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--space-3)}.hguides li{margin:0;display:flex;flex-direction:column;gap:2px;padding:var(--space-4);border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface)}.hguides a{display:flex;gap:8px;align-items:flex-start;font-family:var(--font-heading);font-weight:var(--weight-bold);color:var(--color-text-primary);text-decoration:none;line-height:1.35}.hguides a .ci{margin-top:2px;color:var(--color-success)}.hguides a:hover{color:var(--color-accent-primary)}.hguides__mod{padding-left:24px;font-family:var(--font-heading);font-size:var(--text-xs);color:var(--color-text-muted)}.chub-faq{max-width:820px}.chub-faq details > p{margin:0;padding:0 var(--space-5) var(--space-4);color:var(--color-text-secondary);font-size:var(--text-md)}@media (max-width:1279px){.course-layout{grid-template-columns:244px minmax(0,1fr);gap:var(--space-6)}}.course .toc-mobile{margin:0 0 var(--space-6);border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);font-family:var(--font-heading);font-size:var(--text-md)}.course .toc-mobile > summary{list-style:none;cursor:pointer;display:flex;align-items:center;justify-content:space-between;padding:12px var(--space-4);font-weight:var(--weight-bold);min-height:48px}.course .toc-mobile > summary::-webkit-details-marker{display:none}.course .toc-mobile ol{list-style:none;margin:0;padding:0 var(--space-4) var(--space-2);border-top:1px solid var(--color-border)}.course .toc-mobile a{display:block;padding:10px 0;color:var(--color-text-secondary);text-decoration:none;border-bottom:1px solid var(--color-separator)}.course .toc-mobile li:last-child a{border-bottom:0}@media (max-width:999px){.course-layout{grid-template-columns:minmax(0,1fr);gap:0;padding-top:var(--space-4)}.course .toc-mobile{display:block}.focus-btn{display:none}.course-bar{margin-bottom:var(--space-5)}.course-drawer{position:static;margin:0 0 var(--space-5);border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface-raised)}.course-drawer__btn{display:flex;align-items:center;justify-content:space-between;list-style:none;cursor:pointer;padding:12px var(--space-4);min-height:48px;font-family:var(--font-heading);font-weight:var(--weight-bold);font-size:var(--text-md)}.course-drawer__btn::-webkit-details-marker{display:none}.course-drawer__btn::after{content:"";width:8px;height:8px;border-right:2px solid currentColor;border-bottom:2px solid currentColor;transform:rotate(45deg);margin-top:-4px;transition:transform var(--transition-fast)}.course-drawer[open] > .course-drawer__btn::after{transform:rotate(225deg);margin-top:4px}.course-nav{max-height:65vh;padding:var(--space-3) var(--space-4);border-top:1px solid var(--color-border)}.hsteps{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (max-width:760px){.mcards,.hguides ul{grid-template-columns:minmax(0,1fr)}.chub-stats{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (max-width:640px){.hsteps{grid-template-columns:minmax(0,1fr)}.qf{position:static;background:none;backdrop-filter:none}.course .qa__q{font-size:1.125rem !important}.qa__sigs{grid-template-columns:minmax(0,1fr);gap:var(--space-4)}.qf__tools{margin-left:0}.mbank__card{flex-direction:column;padding:var(--space-4)}.say{padding:var(--space-4) var(--space-4) var(--space-4) 56px}.say::before{left:16px;top:18px}.mcard__link{padding:var(--space-4)}.lrow{padding:10px var(--space-3)}.lrow .pill{display:none}.lrow--premium .pill,.lrow--free .pill{display:inline-flex}}@media print{.course-drawer,.focus-btn,.qf,.paywall,.pager,.qa__reveal > summary{display:none !important}.course-layout{display:block}}.pills{display:inline-flex;flex-wrap:wrap;gap:4px;flex:none}.lesson-meta .pills{margin-right:2px}.cn-item--free .ci{color:var(--color-success)}.chub-hero{position:relative;overflow:hidden;isolation:isolate}.chub-hero__bg{position:absolute;inset:0;z-index:-1;pointer-events:none}.chub-hero__bg::before{content:"";position:absolute;inset:0;background-image:radial-gradient(rgba(91,60,196,.16) 1.1px,transparent 1.2px);background-size:24px 24px;-webkit-mask-image:radial-gradient(ellipse 60% 90% at 85% 50%,#000 20%,transparent 80%);mask-image:radial-gradient(ellipse 60% 90% at 85% 50%,#000 20%,transparent 80%)}.chub-hero__bg::after{content:"";position:absolute;right:-10%;top:-30%;width:55%;aspect-ratio:1;border-radius:50%;background:radial-gradient(closest-side,rgba(242,102,43,.14),rgba(91,60,196,.1) 55%,transparent);animation:chub-glow 10s ease-in-out infinite alternate}@keyframes chub-glow{from{opacity:.7;transform:scale(1)}to{opacity:1;transform:scale(1.08) translate(-2%,3%)}}.chub-tile{position:absolute;left:var(--x);top:var(--y);display:flex;align-items:center;justify-content:center;width:58px;aspect-ratio:1;margin:-29px 0 0 -29px;border-radius:14px;background:var(--color-glass);border:1.5px dashed rgba(91,60,196,.3);color:rgba(91,60,196,.5);transform:rotate(var(--r));animation:chub-float 8s ease-in-out infinite;animation-delay:calc(var(--d) * -1)}.chub-tile .ui-icon{width:46%;height:46%}@keyframes chub-float{0%,100%{translate:0 0}50%{translate:0 -10px}}@media (max-width:1100px){.chub-tile:nth-child(7),.chub-tile:nth-child(1),.chub-tile:nth-child(6){display:none}}@media (max-width:760px){.chub-hero__bg .chub-tile{display:none}}@media (prefers-reduced-motion:reduce){.chub-tile,.chub-hero__bg::after{animation:none}}@media (max-width:640px){.lrow .pills{display:none}.lrow--premium .pills,.lrow--free .pills{display:inline-flex}.lrow .pill--soon{display:none}.lrow--soon .pills{display:inline-flex}.lrow--soon .pills .pill--premium{display:none}}.course article > .lblock{max-width:none}.lblock{margin:var(--space-6) 0;padding:var(--space-4) var(--space-5);border-radius:var(--radius-lg);font-size:1.0625rem;line-height:1.65}.lblock > :last-child{margin-bottom:0}.lblock p{margin:0 0 var(--space-3)}.lblock__label{margin:0 0 var(--space-2) !important;font-family:var(--font-heading);font-size:1.0625rem;font-weight:var(--weight-bold);color:var(--color-text-primary)}.lblock--define{background:var(--color-surface);border:1px solid var(--color-border);border-top:3px solid var(--color-accent-primary)}.lblock--try{display:grid;grid-template-columns:auto minmax(0,1fr);column-gap:var(--space-4);background:var(--color-accent-secondary-soft);border:1px dashed color-mix(in srgb,var(--color-accent-secondary) 45%,transparent)}.lblock--try::before{content:"";grid-row:span 9;width:36px;height:36px;border-radius:50%;background:var(--color-accent-secondary) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3E%3Cpath d='M7 4.5v11l8-5.5z' fill='%23fff'/%3E%3C/svg%3E") center/16px no-repeat}.lblock--try .lblock__label{color:var(--color-accent-secondary-text)}.course article > .approach{max-width:none}.approach{margin:var(--space-3) 0;border-radius:var(--radius-lg);background:var(--ap-soft);font-size:1.0625rem;line-height:1.65;transition:box-shadow .15s}.approach + .approach{margin-top:var(--space-3)}.approach__sum{display:flex;align-items:center;justify-content:space-between;gap:var(--space-3);padding:14px var(--space-5);cursor:pointer;list-style:none;user-select:none;border-radius:inherit}.approach__sum::-webkit-details-marker{display:none}.approach__sum:hover{box-shadow:inset 0 0 0 1px var(--ap-border)}.approach__sum:focus-visible{outline:2px solid 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var(--space-3);font-size:1.15rem}.deeper__title .ci{width:18px;height:18px;color:var(--color-accent-primary)}.deeper__lead{margin:0 0 var(--space-3);color:var(--color-text-secondary);font-size:.95rem}.deeper__chips{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:8px}.deeper__chips li{margin:0;display:inline-flex;align-items:center;gap:6px;padding:6px 12px;border:1px solid var(--color-border);border-radius:var(--radius-pill);font-family:var(--font-heading);font-size:.88rem;background:var(--color-surface-raised)}.deeper__chips a{text-decoration:none;font-weight:var(--weight-medium,500)}.deeper__chips li span:first-child{color:var(--color-text-muted)}.deeper__chips .pill{padding:3px 6px}.deeper__list{list-style:none;margin:0;padding:0}.deeper__list li{margin:0;border-top:1px solid var(--color-separator)}.deeper__list li:first-child{border-top:0}.deeper__list a{display:flex;justify-content:space-between;gap:var(--space-3);align-items:center;padding:11px 2px;text-decoration:none;color:var(--color-text-primary);font-family:var(--font-heading)}.deeper__list a:hover .deeper__t{color:var(--color-accent-primary)}.deeper__m{flex:none;display:flex;gap:8px;align-items:center;font-size:var(--text-xs);color:var(--color-text-muted)}.hh-group{margin:var(--space-6) 0 var(--space-4);font-size:1rem;font-family:var(--font-heading);text-transform:uppercase;letter-spacing:.08em;color:var(--color-text-secondary);display:flex;align-items:baseline;gap:10px}.hh-group span{font-size:var(--text-xs);letter-spacing:.04em;color:var(--color-text-muted);text-transform:none}.hh-group:first-of-type{margin-top:0}.done-box{display:flex;flex-wrap:wrap;align-items:center;gap:var(--space-3) var(--space-4);margin:var(--space-6) 0;padding:var(--space-4) var(--space-5);border:1px dashed var(--color-border-strong);border-radius:var(--radius-md);background:var(--color-surface)}.done-box.is-done{border-style:solid;border-color:var(--color-success-border);background:var(--color-success-soft)}.done-box__btn svg{flex:none}.done-box__hint,.done-box__nudge{margin:0;flex:1 1 260px;font-size:var(--text-sm);color:var(--color-text-secondary)}.done-box__nudge{flex-basis:100%}.done-box__state{display:flex;align-items:center;gap:8px;margin:0;font-family:var(--font-heading);font-weight:var(--weight-semibold);color:var(--color-success-text)}.done-box__undo{border:0;background:none;padding:4px 6px;font:inherit;font-size:var(--text-sm);color:var(--color-text-secondary);text-decoration:underline;cursor:pointer}.done-box__undo:hover{color:var(--color-text-primary)}.cn-progress{margin:0 0 var(--space-3);font-size:.75rem;color:var(--color-text-muted)}.cn-progress__bar{display:block;height:4px;margin-bottom:6px;border-radius:2px;background:var(--color-separator);overflow:hidden}.cn-progress__bar > span{display:block;height:100%;background:var(--color-success);transition:width .3s}.cn-progress__txt{display:block}.cn-progress__in{display:inline-block;margin-top:2px;font-weight:var(--weight-semibold)}.cn-item.is-done > a::after,.lrow.is-done .lrow__title::after,.hh-row.is-done .hh-row__t > a::after{content:"";flex:none;display:inline-block;width:14px;height:14px;margin-left:auto;border-radius:50%;vertical-align:-2px;background:var(--color-success-soft) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3E%3Cpath d='m5.5 10.5 3 3 6-7' fill='none' stroke='%231F6B47' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center/10px no-repeat;box-shadow:inset 0 0 0 1px var(--color-success-border)}.lrow.is-done .lrow__title::after,.hh-row.is-done .hh-row__t > a::after{margin-left:8px}.cn-item--qa.is-done > a::after{display:none}