body:has(.ci-shell,.lc-classroom,.lc-basic-page){padding-bottom:0}
/* Keep the active task and its controls in one viewport; long material scrolls within the task. */
body:has(.ci-shell,.lc-classroom,.lc-basic-page) .view-container{padding:12px 26px 16px;max-width:none}
body:has(.ci-shell,.lc-classroom,.lc-basic-page) .mobile-nav{display:none}
body:has(.ci-shell,.lc-classroom,.lc-basic-page) .main-shell{padding-bottom:0;min-width:0}
.cc-study-page,.lc-page{height:calc(100dvh - 105px);min-height:400px;max-width:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px;animation:none}
.cc-study-page .course-detail-back,.lc-page .course-detail-back{width:100%;max-width:none;margin:0;min-height:24px;flex-shrink:0}
.cc-study-page .ci-shell,.lc-page .lc-classroom{width:100%;max-width:none;min-height:0;flex:1;margin:0;display:flex;flex-direction:column;overflow:hidden;border-radius:20px}
.ci-header{padding:12px 24px;gap:12px;flex-shrink:0}
.ci-progress-wrap{padding:12px 24px 0;flex-shrink:0}
.ci-progress-info{margin-top:9px}
.ci-main{padding:16px 28px 20px;min-height:0;flex:1;overflow:auto;overscroll-behavior:contain;scrollbar-width:thin;scroll-padding-block:12px}
.ci-main h2{font-size:26px;margin-bottom:10px;line-height:1.4}
.ci-main .ci-eyebrow{margin-bottom:7px}
.ci-description{font-size:14px;line-height:1.75;margin-bottom:14px}
.ci-scene-mark{margin:12px 0;padding:9px 14px}
.ci-scene-mark p{margin:0}
.ci-question h3{margin:14px 0 10px;line-height:1.7;font-size:15px}
.ci-options,.lc-options,.lc-basic-page .example-options{display:flex;flex-wrap:wrap;align-items:stretch;gap:8px}
/* Intrinsic widths keep short answers together; longer text wraps at the task edge. */
.ci-options>.ci-option,.lc-options>.lc-option,.lc-basic-page .example-options>.example-option{flex:0 1 auto;width:auto;min-width:min(132px,100%);max-width:100%;text-align:left}
.lc-basic-page .example-option>span:last-child{min-width:0;overflow-wrap:anywhere}
.ci-option{min-height:46px;padding:9px 12px}
.ci-option>b{line-height:1.65}
.ci-check,.ci-hint-trigger{margin-top:12px}
.ci-footer{flex-shrink:0;padding:12px 24px;gap:12px;border-top:1px solid var(--cc-border);background:var(--ci-paper)}
.ci-footer>div>span{display:none}
.ci-footer .ci-back{min-height:40px}
.ci-primary{min-height:44px;padding:11px 18px}
.ci-tutor-wrap{height:0;padding:0}
.ci-reference{padding:10px 14px;border:1px solid var(--cc-border);border-radius:10px;margin-top:22px}
.ci-reference[open]{margin-bottom:8px}
.ci-feedback{padding:12px 15px;margin-top:12px}
.ci-feedback p{line-height:1.7}
.ci-bridge-steps{margin:12px 0}
.ci-worked-step{padding:14px 18px;font-size:14px;line-height:1.8}
.ci-experiment,.ci-secant-lab{padding:14px}
.ci-observation{margin-top:12px;padding:14px;min-height:0}
.ci-observation>strong{font-size:20px;margin:8px 0;line-height:1.6}
.ci-observation p{line-height:1.7}
.ci-range-label{margin-top:10px}
.ci-discovery{margin-top:12px;padding:10px 14px}
.ci-discovery p{line-height:1.7}
.ci-observation .clab{margin:8px 0;padding:10px 12px}
.ci-observation .clab-plot{max-width:440px;margin-top:3px}
.ci-observation .clab-plot svg{max-height:180px}
.ci-observation .clab-readout{margin-top:3px;padding-top:5px;font-size:13px}
.ci-observation .clab-note{font-size:12px;line-height:1.5}
.ci-secant-lab [data-ci-graph]>svg{max-height:215px;margin-top:8px}
.ci-lab-head strong{font-size:23px;margin-top:3px}
.ci-receipt-star{width:44px;height:44px;font-size:30px;margin:0 auto 12px}
.ci-takeaways{margin:14px 0}.ci-takeaways li{padding:10px 0}
.ci-receipt-evidence{padding:12px;gap:12px}.ci-receipt-evidence strong{margin:3px 0}
.ci-receipt-note{margin:12px 0}
.ci-keypad{margin-top:10px;gap:5px}.ci-keypad button{min-height:40px}

/* The same viewport frame is shared by all subject classrooms. */
.lc-head{padding:12px 24px;gap:12px;flex-shrink:0}
.lc-head h2{font-size:18px;margin-top:3px}
.lc-head span{font-size:11px}
.lc-classroom .knowledge-stage-shell{min-height:0;flex:1;display:flex;flex-direction:column;overflow:hidden;border-radius:0}
.lc-classroom .knowledge-stage-nav{padding:12px 24px 0;flex-shrink:0}
.lc-classroom .knowledge-stage-panel{padding:16px 28px 20px;min-height:0;flex:1;overflow:auto;overscroll-behavior:contain;scrollbar-width:thin;scroll-padding-block:12px}
.lc-status{margin-bottom:18px}
.lc-kicker{margin-bottom:9px}
.lc-task{max-width:760px}
.lc-task h3{font-size:25px;line-height:1.5;margin-bottom:16px}
.lc-task-copy{font-size:17px;line-height:1.8}
.lc-context{margin-top:18px;padding:15px 18px}.lc-context p{line-height:1.75}
.lc-mini-progress{margin-top:18px}.lc-source-note{margin-top:16px}
.lc-classroom .knowledge-stage-actions{flex-shrink:0;min-height:68px;padding:12px 24px;gap:10px;background:var(--surface,#fff)}
.lc-option{padding:11px 14px;min-height:48px}.lc-options{gap:8px}
.lc-feedback{padding:12px 16px;margin-top:14px}.lc-feedback p{font-size:14px;line-height:1.7}
.lc-help{margin-top:12px}.lc-recap{margin:16px 0}.lc-recap>div{padding:10px 0}
.lc-receipt-mark{width:44px;height:44px;margin-bottom:12px;font-size:25px}
.lc-next-name{margin:0;padding:5px 12px;flex-shrink:0}

/* The assistant is anchored to the bottom right, independent of lesson scrolling. */
.ct-coach,.lc-classroom>.ct-coach{position:fixed;right:26px;bottom:20px;z-index:35;margin:0;width:326px;max-width:calc(100vw - 28px);display:flex;flex-direction:column-reverse;gap:12px;pointer-events:none}
.ct-coach>.ct-launch,.ct-coach>.ct-panel{pointer-events:auto}
.ct-launch{align-self:flex-end;min-height:60px;padding:8px 14px;gap:10px;box-shadow:0 4px 0 #e6ebdf,0 10px 24px #21361d12}
.ct-launch>span:last-child{margin-left:5px}
.ct-avatar{width:36px;height:36px;font-size:26px;border-radius:13px}
.ct-panel{margin:0;max-width:none;width:100%;height:min(610px,calc(100dvh - 185px));display:flex;flex-direction:column;box-shadow:0 15px 40px #21361d18}
.ct-panel>header{padding:12px 16px;flex-shrink:0}
.ct-panel>header strong{font-size:14px}
.ct-context{padding:10px 16px;max-height:112px;overflow:auto;flex-shrink:0}
.ct-context p{font-size:12px;line-height:1.7}
.ct-messages{min-height:80px;max-height:none;flex:1;padding:14px 16px;gap:10px}
.ct-message{padding:10px 12px;max-width:100%}.ct-message>p{font-size:13px;line-height:1.75}
.ct-suggestions{padding:0 12px 12px;gap:6px;flex-shrink:0}
.ct-suggestions button{font-size:11px;padding:7px 9px;min-height:32px}
.ct-form{padding:10px 14px 14px;flex-shrink:0}
.ct-form input{font-size:13px;padding:10px;min-height:42px}
.ct-input-label{margin-bottom:5px}

/* Basic lessons keep their figures and supporting resources available in a bounded workspace. */
.basic-course-page.lc-basic-page{max-width:none;height:calc(100dvh - 105px);min-height:400px;display:flex;flex-direction:column;gap:10px;animation:none;overflow:auto;scrollbar-width:thin}
.lc-basic-page .basic-lesson-head{gap:10px;flex-shrink:0}.lc-basic-page .basic-lesson-title h1{font-size:21px;margin:3px 0}
.lc-basic-page .basic-breadcrumb{font-size:11px}.lc-basic-page .basic-lesson-meta{font-size:12px}
.lc-basic-page .basic-lesson-goal{font-size:12px;padding:8px 12px;flex-shrink:0}
.lc-basic-page .basic-stepper{gap:6px;flex-shrink:0;margin:0}
.lc-basic-page .basic-stepper-item>button,.lc-basic-page .basic-stepper-locked{padding:8px 10px}
.lc-basic-page .basic-stepper-copy small{display:none}.lc-basic-page .basic-stepper-copy strong{font-size:12px}
.lc-basic-page .basic-stage{padding:18px;min-height:0;flex:1;overflow:auto;scrollbar-width:thin;overscroll-behavior:contain}
.lc-basic-page .basic-stage.is-column{display:flex;flex-direction:column;min-height:200px}
.lc-basic-page .basic-stage.is-column>.basic-explain-list{flex:1;min-height:0;overflow:auto}
.lc-basic-page .basic-explain-card{padding:20px}
.lc-basic-page .basic-explain-card>p:last-child{font-size:16px;line-height:1.8}
.lc-basic-page .basic-stage-actions{padding-top:12px;flex-shrink:0}
.lc-basic-page .basic-example-stem{font-size:18px;line-height:1.7}
.lc-basic-page .example-option{min-height:46px}
.lc-basic-resources{margin:0;padding:0;flex-shrink:0;max-height:40%;overflow:auto}
.lc-basic-resources>summary{font-size:12px;padding:8px}
.lc-basic-page .lesson-note-button{align-self:flex-start;padding:6px 12px;font-size:12px}

@media(min-width:701px){
  /* Only the action bar needs room for the floating launcher. The lesson stays full width. */
  .ci-footer,.lc-classroom .knowledge-stage-actions{padding-right:260px}
}
@media(max-width:1249px){
  .ct-coach,.lc-classroom>.ct-coach{right:20px;bottom:18px;width:320px}
  .ct-launch small{display:none}.ct-launch{min-height:48px;border-radius:16px;padding:7px 10px}
  .ct-avatar{width:30px;height:30px;font-size:23px}.ct-launch strong{font-size:12px}
  .ci-footer,.lc-classroom .knowledge-stage-actions{padding-right:195px}
  .lc-classroom .knowledge-save-state{display:none}
  .lc-basic-page .lesson-note-button{margin-right:170px}
}
@media(max-width:700px){
  body:has(.ci-shell,.lc-classroom,.lc-basic-page) .view-container{padding:8px 12px 12px}
  .cc-study-page,.lc-page,.basic-course-page.lc-basic-page{height:calc(100dvh - 87px);min-height:360px;gap:6px}
  .cc-study-page .course-detail-back,.lc-page .course-detail-back{min-height:22px;font-size:10px;gap:8px}
  .cc-study-page .ci-shell,.lc-page .lc-classroom{border-radius:15px}
  .ci-header,.lc-head{padding:9px 14px;gap:8px}
  .ci-header strong{font-size:12px}.ci-header small{font-size:9px}.ci-brand-star{width:28px;height:28px;font-size:22px}
  .ci-header>button{font-size:10px}.lc-head h2{font-size:15px}.lc-head span{font-size:10px}.lc-directory{font-size:11px;padding:7px}
  .ci-progress-wrap,.lc-classroom .knowledge-stage-nav{padding:10px 14px 0}
  .ci-progress span{font-size:9px}.ci-progress-info{font-size:9px;margin-top:7px}
  .ci-main,.lc-classroom .knowledge-stage-panel{padding:12px 16px 18px}
  .ci-main h2,.lc-task h3{font-size:21px;margin-bottom:10px}
  .ci-description{font-size:13px;line-height:1.7;margin-bottom:10px}
  .ci-scene-mark{padding:7px 10px;display:block;margin:10px 0}.ci-scene-mark p{display:none}
  .ci-question h3{font-size:14px;margin:12px 0 8px}.ci-option{padding:8px 10px;min-height:44px}.ci-option>b{font-size:12px}
  .ci-footer,.lc-classroom .knowledge-stage-actions{position:relative;padding:9px 13px 60px;min-height:114px;gap:8px;flex-wrap:nowrap}
  .ci-footer .ci-primary{font-size:12px!important;padding:10px 13px;min-height:42px}
  .ci-footer .ci-back{font-size:11px!important}
  .ci-numeric-form input{width:140px}.ci-numeric-form label{font-size:11px}
  .ci-worked-step{padding:12px;font-size:13px}
  .ci-bridge-steps{gap:5px;margin:9px 0}.ci-bridge-steps>span{font-size:10px;padding:7px}
  .ci-experiment,.ci-secant-lab{padding:10px}.ci-experiment-tabs{gap:5px}.ci-experiment-tabs button{padding:7px 5px;gap:4px;font-size:10px}
  .ci-observation{padding:10px}.ci-observation>strong{font-size:18px}.ci-observation .clab{padding:8px}
  .ci-observation .clab-plot svg{max-height:145px}.ci-secant-lab [data-ci-graph]>svg{max-height:170px}
  .ci-lab-head strong{font-size:19px}.ci-lab-head>div>span{font-size:10px}
  .ci-reference{font-size:10px;padding:8px 10px}
  .lc-status{font-size:9px;margin-bottom:14px}.lc-task-copy{font-size:15px;line-height:1.85}.lc-context{padding:12px;margin-top:14px}
  .lc-context p{font-size:13px}.lc-task h3{line-height:1.5}.lc-option{padding:10px;gap:9px}.lc-option strong{font-size:13px}
  .lc-classroom .knowledge-stage-actions>.button{font-size:12px;padding:10px 12px;min-height:42px}
  .ct-coach,.lc-classroom>.ct-coach{right:20px;bottom:max(22px,env(safe-area-inset-bottom));width:min(340px,calc(100vw - 40px));gap:8px}
  .ct-launch{min-height:42px;gap:7px;padding:5px 10px;border-radius:14px}.ct-launch>span:last-child{font-size:18px}
  .ct-avatar{width:27px;height:27px;font-size:22px;border-radius:10px}
  .ct-panel{height:min(530px,calc(100dvh - 145px));border-radius:17px}
  .ct-context{max-height:90px}.ct-suggestions button{min-height:36px}.ct-form input{font-size:16px}
  .lc-basic-page .basic-lesson-head{display:flex;flex-wrap:wrap;gap:5px 10px}.lc-basic-page .basic-lesson-title{flex:1}.lc-basic-page .basic-lesson-title h1{font-size:16px}
  .lc-basic-page .basic-lesson-goal{line-height:1.6;font-size:11px}
  .lc-basic-page .basic-stepper{display:grid;grid-template-columns:repeat(3,minmax(0,1fr))}
  .lc-basic-page .basic-stepper-item>button,.lc-basic-page .basic-stepper-locked{padding:7px 6px;gap:4px}.lc-basic-page .basic-stepper-copy strong{font-size:10px}
  .lc-basic-page .basic-stage{padding:12px}.lc-basic-page .basic-explain-card{padding:13px}.lc-basic-page .basic-explain-card>p:last-child{font-size:14px}
  .lc-basic-page .lesson-note-button{min-height:42px;margin-bottom:4px}
}
@media(max-height:720px) and (min-width:701px){
  .ci-header,.lc-head{padding-block:8px}.ci-progress-wrap,.lc-classroom .knowledge-stage-nav{padding-top:9px}
  .ci-main h2,.lc-task h3{font-size:23px}.ci-main .ci-eyebrow{display:none}
  .ci-description{margin-bottom:9px}.ci-scene-mark{display:none}
  .ci-main,.lc-classroom .knowledge-stage-panel{padding-top:12px}
}
/* Viewport height changes should not animate into a temporarily scrollable page. */
body:has(.ci-shell,.lc-classroom,.lc-basic-page) .app-shell{transition-property:grid-template-columns}
body:has(.ci-shell,.lc-classroom,.lc-basic-page) .sidebar{transition-property:transform,padding,width}

/* Size the classroom from the space actually available. The desktop topbar is
   hidden; the mobile topbar stays in the flex layout and contributes its height. */
body:has(.ci-shell,.ri-shell,.ew-shell,.ev-shell,.eg-shell,.lc-classroom,.lc-basic-page){--study-edge:16px;--study-inline:26px;padding-bottom:0}
body:has(.ci-shell,.ri-shell,.ew-shell,.ev-shell,.eg-shell,.lc-classroom,.lc-basic-page) .main-shell{height:100dvh;min-height:0;overflow:hidden;padding-bottom:0}
body:has(.ci-shell,.ri-shell,.ew-shell,.ev-shell,.eg-shell,.lc-classroom,.lc-basic-page) .topbar{flex-shrink:0}
body:has(.ci-shell,.ri-shell,.ew-shell,.ev-shell,.eg-shell,.lc-classroom,.lc-basic-page) .view-container{display:flex;flex-direction:column;flex:1;min-height:0;max-width:none;padding:12px var(--study-inline) var(--study-edge)}
.view-container>:is(.cc-study-page,.rc-study-page,.ew-shell,.ev-shell,.eg-shell,.lc-page,.lc-basic-page){height:auto;min-height:0;flex:1;gap:8px}
body:has(.ci-shell,.ri-shell,.ew-shell,.ev-shell,.eg-shell,.lc-classroom,.lc-basic-page) .ct-coach{right:var(--study-inline);bottom:var(--study-edge)}
.ci-header,.ri-header,.lc-head{padding:10px 22px}
.ci-brand-star,.ri-brand-star{width:34px;height:34px;font-size:25px;border-radius:12px}
.ci-progress-wrap,.ri-progress-wrap{padding:8px 22px 0}
.ci-progress-info,.ri-progress-info{margin-top:6px}
.ci-main,.ri-main,.lc-classroom .knowledge-stage-panel{padding:12px 24px 14px}
.ci-main h2,.ri-main h2{font-size:24px;line-height:1.35;margin-bottom:8px}
.ci-main>.ci-eyebrow,.ri-main>.ri-eyebrow{margin-bottom:5px}
.ci-description,.ri-description{line-height:1.65;margin-bottom:10px}
.ci-reference,.ri-reference{margin-top:12px;padding:7px 12px}
.ci-main:has(.ci-experiment,.ci-secant-lab)>.ci-reference{margin-top:8px;padding-block:5px}
.ci-footer,.ri-footer,.lc-classroom .knowledge-stage-actions{min-height:76px;padding-block:12px}
.ci-discovery{display:flex;align-items:center;gap:12px;margin-top:10px;padding:8px 12px}
.ci-discovery>span{flex-shrink:0}
.ci-discovery p{margin:0;font-size:12px;line-height:1.6}

/* Give the visual, controls and explanation their own columns instead of
   stacking three cards. Text can still grow and the lesson keeps its scroll fallback. */
@media(min-width:901px){
  .ci-experiment{display:grid;grid-template-columns:minmax(155px,.55fr) minmax(0,3fr);grid-template-rows:1fr auto;gap:10px 16px;padding:12px}
  .ci-experiment-tabs{grid-column:1;grid-row:1;flex-direction:column;align-self:start;gap:7px}
  .ci-experiment-tabs button{flex:0 0 auto;min-height:42px;padding:8px 10px;text-align:left}
  .ci-experiment>.ci-range-label{grid-column:1;grid-row:2;align-self:end;margin:0;font-size:10px}
  .ci-experiment>.ci-range-label input{margin-top:4px}
  .ci-experiment>.ci-observation{grid-column:2;grid-row:1/3;margin:0;padding:12px;align-content:center}
  .ci-observation:has(.clab){display:grid;grid-template-columns:minmax(0,1.9fr) minmax(150px,1fr);grid-template-rows:auto auto 1fr;column-gap:16px;align-content:start}
  .ci-observation:has(.clab)>span{grid-column:2;grid-row:1;margin-top:16px}
  .ci-observation:has(.clab)>strong{grid-column:2;grid-row:2;font-size:20px;margin:10px 0}
  .ci-observation:has(.clab)>p{grid-column:2;grid-row:3;font-size:13px;line-height:1.7}
  .ci-observation>.clab{grid-column:1;grid-row:1/4;display:grid;grid-template-columns:minmax(0,1fr) auto;column-gap:12px;align-items:center;margin:0;padding:0;border:0;border-radius:0;background:transparent}
  .ci-observation .clab-heading,.ci-observation .clab-plot{grid-column:1/-1}
  .ci-observation .clab-heading{font-size:12px;gap:4px 12px}
  .ci-observation .clab-heading .cm-math{font-size:14px}
  .ci-observation .clab-plot{width:100%;max-width:440px;margin-top:2px;padding-block:2px}
  .ci-observation .clab-plot svg{max-height:170px}
  .ci-observation .clab-note{font-size:11px;line-height:1.5}
  .ci-observation .clab-readout{font-size:12px;margin:0;padding:0;border:0}
  .ci-secant-lab{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(240px,1fr);gap:8px 24px;padding:14px 18px}
  .ci-secant-lab>[data-ci-graph]{grid-column:1;grid-row:1/5;align-self:center}
  .ci-secant-lab [data-ci-graph]>svg{max-height:245px;margin:0}
  .ci-secant-lab>.ci-legend{grid-column:1;grid-row:5}
  .ci-secant-lab>:is(.ci-lab-head,.ci-range-label,.ci-lab-sides,.ci-lab-equation,small){grid-column:2;margin:0;align-self:center}
  .ci-secant-lab .ci-lab-equation{padding-top:6px}
  .ci-secant-lab .katex-display{margin:.35em 0}
  .ri-entry-canvas{padding:14px 18px}
  .ri-entry-caption{margin-bottom:10px}
  .ri-entry-target{padding-top:10px;margin-top:12px}
  .ri-observation-label{margin-top:12px}
  .ri-entry-writing .ri-entry-pieces button,.ri-entry-material .ri-entry-pieces button,.ri-entry-case .ri-entry-pieces button{padding:8px 12px;font-size:14px;line-height:1.65}
  .ri-main>.ri-operation-task{display:flex;align-items:center;gap:12px;margin-top:10px;padding:10px 14px}
  .ri-main>.ri-operation-task>span{flex-shrink:0}
  .ri-main>.ri-operation-task>small{margin:0;line-height:1.6}
  .ri-visual-frame{min-height:220px}
  .ri-visual-frame svg{max-height:230px}
}
@media(max-width:900px){
  body:has(.ci-shell,.ri-shell,.lc-classroom,.lc-basic-page){--study-edge:max(12px,env(safe-area-inset-bottom));--study-inline:18px}
}
@media(max-width:700px){
  body:has(.ci-shell,.ri-shell,.lc-classroom,.lc-basic-page){--study-inline:12px}
  body:has(.ci-shell,.ri-shell,.lc-classroom,.lc-basic-page) .view-container{padding-top:8px}
  .view-container>:is(.cc-study-page,.rc-study-page,.lc-page,.lc-basic-page){gap:6px}
  .ci-header,.ri-header,.lc-head{padding:9px 12px}
  .ci-brand-star,.ri-brand-star{width:28px;height:28px;font-size:21px}
  .ci-progress-wrap,.ri-progress-wrap{padding:8px 12px 0}
  .ci-main,.ri-main,.lc-classroom .knowledge-stage-panel{padding:10px 14px 12px}
  .ci-main h2,.ri-main h2{font-size:20px}
  .ci-footer,.ri-footer,.lc-classroom .knowledge-stage-actions{min-height:108px;padding:8px 12px 58px}
  .ci-experiment-tabs{flex-direction:row;flex-wrap:wrap}
  .ci-experiment-tabs button{flex:1 1 auto;width:auto;min-width:70px;padding:7px}
  .ci-experiment{padding:10px}
  .ci-observation{padding:10px;margin-top:8px}
  .ci-observation>.clab{padding:6px;border:0}
  .ci-discovery{align-items:flex-start;gap:8px}
  .ci-reference,.ri-reference{margin-top:10px}
  body:has(.ci-shell,.ri-shell,.ew-shell,.ev-shell,.eg-shell,.lc-classroom,.lc-basic-page) .ct-coach{right:20px}
}