/* Product learning surfaces inherit each World's functional colors. */
.learning-nav{display:flex;align-items:center;gap:4px;margin-left:10px;flex-wrap:wrap}.learning-nav button{font:600 13px var(--font-ui,system-ui);padding:7px 11px;border:1px solid transparent;background:transparent;color:inherit;border-radius:var(--ui-control-radius,7px);cursor:pointer;transition:background-color .16s,color .16s}.learning-nav button:is(:hover,:focus-visible){background:var(--ui-control-hover,var(--accent-soft,#e6eff9))}
.learn-dialog,.glossary-dialog{--learn-ink:var(--text,#17334a);--learn-muted:var(--muted,#536779);color:var(--learn-ink);background:var(--panel,#fff);padding:0;border:1px solid var(--border,#cbd8e1);border-radius:15px;width:min(1120px,calc(100vw - 40px));max-width:none;max-height:calc(100dvh - 40px);box-shadow:var(--shadow-lift,0 8px 26px #081e3521)}.learn-dialog::backdrop,.glossary-dialog::backdrop{background:#10233475;backdrop-filter:blur(3px)}
.learn-dialog-top,.glossary-dialog-top{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:16px 24px;border-bottom:1px solid var(--border,#d6e0e7);position:sticky;top:0;background:var(--panel,#fff);z-index:3}.learn-dialog-top h2,.glossary-dialog-top h2{margin:0;font-size:20px}.learn-dialog-top button,.glossary-dialog-top button,.learn-back{border:1px solid var(--border,#b9c9d6);border-radius:7px;background:var(--panel,#fff);color:inherit;min-height:40px;padding:7px 13px;cursor:pointer;font:inherit}.learn-body,.glossary-dialog .help-panel{padding:24px 32px;max-height:calc(100dvh - 125px);overflow:auto}.glossary-dialog .help-panel{display:block!important}.learn-body :focus-visible,.glossary-dialog :focus-visible{outline:3px solid var(--accent,#287bd0);outline-offset:3px}
.learn-kicker{font:600 11px/1.5 var(--font-ui,system-ui);letter-spacing:.08em;text-transform:uppercase;color:var(--accent,#2260a2)}.learn-home h1,.learn-article h1{font:600 clamp(28px,3.4vw,42px)/1.14 var(--font-display,Georgia,serif);letter-spacing:-.025em;margin:10px 0 16px}.learn-lede{font-size:17px;line-height:1.6;max-width:48ch;color:var(--muted,#516577)}.learn-controls{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin:24px 0}.learn-views{display:flex;border-bottom:1px solid var(--border,#cbd8e1);gap:18px}.learn-views button{font:600 15px var(--font-ui,system-ui);background:transparent;color:inherit;border:0;border-bottom:3px solid transparent;padding:13px 2px;cursor:pointer}.learn-views button[aria-pressed=true]{border-color:var(--accent,#287bd0);color:var(--accent,#2260a2)}.learn-controls input{flex:1;min-width:160px}.learn-controls input,.learn-controls select{background:var(--panel,#fff);color:inherit;border:1px solid var(--border,#b9c9d6);padding:12px;border-radius:7px;font:inherit}.learn-grid{display:grid;grid-template-columns:minmax(0,1fr);border-top:1px solid var(--border,#cbd8e1)}.learn-card{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;column-gap:20px;padding:15px 8px 16px;text-decoration:none!important;color:inherit!important;border-bottom:1px solid var(--border,#cbd8e1);transition:background-color .15s}.learn-card:hover{background:var(--accent-soft,#eef4f9)}.learn-card>*{grid-column:1}.learn-card h3{font:600 20px/1.25 var(--font-display,Georgia,serif);margin:2px 0 0;text-wrap:balance}.learn-card p{max-width:62ch;font-size:14.5px;line-height:1.55;color:var(--muted,#536779);margin:4px 0 0;display:-webkit-box;-webkit-box-orient:vertical;-webkit-line-clamp:2;overflow:hidden}.learn-card>.learn-card-link{grid-column:2;grid-row:1/span 3;font-size:18px;color:var(--accent,#2260a2);transition:transform .15s}.learn-card:hover .learn-card-link{transform:translateX(3px)}h2+.learn-grid .learn-kicker{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}.learn-result-count{font-size:13px;color:var(--muted,#536779)}
.learn-article-heading{padding:10px 0 22px;border-bottom:1px solid var(--border,#d6e0e7)}.learn-article-layout{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:38px;padding-top:24px}.learn-section{position:relative;margin:0 0 28px}.learn-section h2,.learn-next h2,.learn-mistakes h2,.learn-answer h2{font-size:19px;line-height:1.3;margin:0 0 10px}.learn-prose p,.learn-prose li{max-width:48ch;font-size:16px;line-height:1.75;text-wrap:pretty}.learn-prose p{margin:8px 0}.learn-equation{overflow:auto;border-left:3px solid var(--accent,#287bd0);background:var(--accent-soft,#eef4fa);border-radius:0 7px 7px 0;font:500 19px/1.65 var(--font-math,Georgia,serif);margin:16px 0;color:var(--text,#17334a);white-space:normal}.learn-step-number{display:inline-grid;place-items:center;background:var(--accent-soft,#e9f1f8);color:var(--accent,#2260a2);border-radius:50%;height:28px;width:28px;font:600 13px var(--font-ui,system-ui);margin-bottom:10px}.learn-practice{align-self:start;position:sticky;top:0;padding:21px;border:1px solid var(--border,#cbd8e1);border-radius:10px;background:var(--panel,#fff)}.learn-practice h2{font:600 22px/1.2 var(--font-display,Georgia,serif);margin:10px 0}.learn-practice p{font-size:13px;line-height:1.65}.learn-action{display:flex;justify-content:space-between;align-items:center;gap:10px;background:var(--accent,#2861a4);color:var(--accent-contrast,#fff)!important;text-decoration:none!important;border:1px solid transparent;border-radius:7px;padding:12px;font:600 13px/1.4 var(--font-ui,system-ui);margin:10px 0;cursor:pointer}.learn-secondary{background:transparent;color:var(--text,#17334a)!important;border-color:var(--border,#b9c9d6)}.learn-small-link{display:block;font-size:13px;margin:14px 0}.learn-note{color:var(--muted,#536779)}.learn-next,.learn-answer{padding:20px;background:var(--accent-soft,#eef4fa);border-radius:9px;margin:24px 0}.learn-key-terms{margin:24px 0}.learn-key-terms h2{font-size:19px;line-height:1.3;margin:0 0 10px}.learn-key-terms dl{margin:0}.learn-key-terms dt{font-weight:600;margin-top:12px}.learn-key-terms dd{max-width:48ch;margin:2px 0 0;font-size:15px;line-height:1.7;color:var(--text,#17334a)}.learn-sources{font-size:13px;line-height:1.6;border-top:1px solid var(--border,#ccd9e2);padding:18px 0}.learn-sources summary{cursor:pointer}.learn-terms{display:flex;flex-wrap:wrap;gap:7px;margin:10px 0}.learn-terms button{background:transparent;color:inherit;border:1px solid var(--border,#ccd9e2);border-radius:20px;padding:6px 10px;font:inherit;cursor:pointer}.learn-cross-results{margin-top:24px;border-top:1px solid var(--border,#cbd8e1);padding-top:18px}.learn-cross-results button{display:block;width:100%;text-align:left;margin:8px 0;border:1px solid var(--border,#ccd9e2);border-radius:7px;padding:12px;background:var(--panel,#fff);color:inherit;cursor:pointer}.learn-return{position:fixed;bottom:18px;right:18px;z-index:15000;border:1px solid var(--border,#aebfca);border-radius:30px;padding:12px 18px;background:var(--panel,#fff);color:var(--text,#17334a);box-shadow:0 4px 18px #10233430;cursor:pointer;font:600 13px var(--font-ui,system-ui)}.learn-return[hidden]{display:none}
/* The pill hides while the on-screen keypad is open: it covered keys (student review #31). */
:root[data-math-keyboard="open"] .learn-return{display:none}
.welcome-strip{margin:0 20px 14px;padding:20px 26px;border:1px solid var(--border,#cbd8e1);background:var(--panel,#fff);border-radius:12px;display:flex;align-items:center;justify-content:space-between;gap:24px}.welcome-strip[hidden]{display:none}.welcome-strip h2{font:600 25px/1.2 var(--font-display,Georgia,serif);margin:0 0 8px}.welcome-strip p{font-size:14px;line-height:1.6;max-width:570px;margin:0;color:var(--muted,#52687a)}.welcome-actions{display:flex;flex-wrap:wrap;gap:8px;}.welcome-actions button{padding:11px 14px;border:1px solid var(--border,#b9c9d6);border-radius:7px;background:var(--panel,#fff);color:inherit;font:600 13px var(--font-ui,system-ui);cursor:pointer}.welcome-actions .welcome-primary{background:var(--accent,#2861a4);color:var(--accent-contrast,#fff);border-color:transparent}.welcome-dismiss{align-self:start;background:transparent;border:0;font:22px var(--font-ui,system-ui);color:inherit;cursor:pointer;min-width:32px;min-height:32px}.biology-learn-link{margin:4px 0 14px;display:inline-block;color:var(--accent-text,var(--accent,#2260a2));font-size:13px}.biology-workflow-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}.biology-workflow-actions button{padding:10px 12px;border:1px solid var(--border,#bdcbd6);border-radius:7px;color:inherit;background:var(--panel,#fff);cursor:pointer}.biology-number-cells{display:flex;flex-wrap:wrap;gap:8px}.biology-number-cells input{width:92px}.biology-record-card .biology-number-cells label{font-size:12px}
.learn-public{--text:#18384a;--muted:#506575;--panel:#fff;--border:#cfdae2;--accent:#245c98;--accent-soft:#eef4f9;--font-ui:'DM Sans',system-ui,sans-serif;--font-display:Newsreader,Georgia,serif;margin:0;background:#f0f5f8;color:var(--text);font:16px/1.65 var(--font-ui)}.learn-public-header{display:flex;align-items:center;justify-content:space-between;gap:20px;max-width:1080px;margin:auto;padding:20px 24px}.learn-public-brand{display:flex;align-items:center;gap:10px;font:600 25px var(--font-display);text-decoration:none;color:inherit}.learn-public-header nav{display:flex;gap:4px;font-size:14px}.learn-public a{color:var(--accent)}.learn-public-header nav a{padding:6px 10px;border-radius:7px;color:var(--text);font-weight:500;text-decoration:none}.learn-public-header nav a:hover{background:var(--accent-soft)}.learn-public-header nav a[aria-current=page]{color:var(--accent);font-weight:600;box-shadow:inset 0 -2px var(--accent);border-radius:7px 7px 0 0}.learn-public :focus-visible{outline:2px solid var(--accent);outline-offset:2px}.learn-public-main{max-width:1040px;margin:0 auto 40px;padding:32px;background:white;border:1px solid var(--border);border-radius:14px}.learn-public-footer{max-width:1040px;margin:24px auto;padding:0 24px;font-size:13px;color:var(--muted)}.learn-breadcrumb{font-size:13px;margin-bottom:20px}.learn-public .learn-home>p{max-width:700px}.learn-public *{box-sizing:border-box}
@media(max-width:1000px){.toolbar{flex-wrap:wrap}.learning-nav{order:3;width:100%;justify-content:center;margin:0;padding-top:4px}.welcome-strip{flex-wrap:wrap}.welcome-actions{min-width:0}.learn-article-layout{grid-template-columns:minmax(0,1fr) 230px;gap:24px}}
@media(max-width:650px){.learning-nav{justify-content:flex-start;border-top:1px solid var(--border,#d6e0e7);gap:6px}.learning-nav button{padding:8px 12px;min-height:42px}.learn-dialog,.glossary-dialog{width:100%;max-height:100dvh;height:100dvh;border-radius:0;border:0;margin:0}.learn-dialog-top,.glossary-dialog-top{padding:12px 16px}.learn-body,.glossary-dialog .help-panel{padding:20px 18px;max-height:calc(100dvh - 67px)}.learn-grid{grid-template-columns:1fr}.learn-article-layout{display:flex;flex-direction:column;gap:20px}.learn-practice{position:static;order:0;width:100%;box-sizing:border-box}.learn-practice>.learn-kicker,.learn-practice>p:not(.learn-note){display:none}.learn-practice h2{font-size:20px}.learn-article h1{font-size:31px}.learn-action{min-height:42px;box-sizing:border-box}.welcome-strip{margin:8px 12px 16px;padding:19px;position:relative;gap:14px}.welcome-strip h2{font-size:24px;padding-right:16px}.welcome-dismiss{position:absolute;right:6px;top:6px}.welcome-actions{width:100%}.welcome-actions button{min-height:44px}.learn-return{bottom:74px;right:12px}.learn-public-header{flex-wrap:wrap}.learn-public-main{padding:22px 18px;border-radius:0;border-left:0;border-right:0}.learn-public .learn-practice{order:0}.learn-dialog button,.glossary-dialog button{touch-action:manipulation}}
@media(prefers-reduced-motion:reduce){.learn-card,.learn-card-link{transition:none}.learn-card:hover .learn-card-link{transform:none}}
@media print{.learning-nav,.welcome-strip,.learn-return{display:none!important}.learn-public-header nav,.learn-practice{display:none}.learn-public-main{border:0;margin:0;padding:0}.learn-article-layout{display:block}}

/* App header layout (owner redesign, 2026-10-04). Desktop is one row: brand and document on the
   left, the study resources beside them, document actions and settings on the right. Narrow and
   touch layouts keep the resources as their own row so file controls are never squeezed. */
body > .toolbar{max-width:100%;box-sizing:border-box}
body > .toolbar .toolbar-actions{margin-left:auto}
body > .toolbar #help-button{display:none}
@media (max-width:1000px),(hover:none){
  body > .toolbar{flex-wrap:wrap!important;row-gap:8px!important}
  body > .toolbar .learning-nav{flex:0 0 100%;order:5;margin:0;justify-content:flex-start;border-top:1px solid var(--frame-line,var(--border,#d4dfe7));padding-top:4px;box-sizing:border-box}
  body > .toolbar .document-meta{min-width:150px;flex:1 1 240px;overflow:hidden;display:grid;grid-template-columns:minmax(100px,1fr) minmax(100px,1fr);gap:0 8px;max-width:550px}
  body > .toolbar .document-meta .save-state{display:block;grid-column:1 / -1;padding-left:8px;font-size:11px}
}
@media (min-width:1001px) and (hover:hover){
  body > .toolbar{flex-wrap:nowrap;column-gap:16px!important;padding:5px 14px 5px 20px!important;min-height:58px!important}
  body > .toolbar .learning-nav{order:1;flex:0 0 auto;margin:0;padding-left:12px;border-left:1px solid var(--frame-line,var(--border,#d4dfe7));gap:2px}
  body > .toolbar .toolbar-actions{order:2}
  body > .toolbar .document-meta{display:grid!important;grid-template-columns:auto minmax(0,1fr);grid-template-areas:"title title" "state tags";align-items:center;gap:0 2px!important;flex:0 1 330px;min-width:190px;max-width:none!important;overflow:hidden}
  body > .toolbar #document-title{grid-area:title;font-size:15px;font-weight:600;padding:1px 6px}
  body > .toolbar .document-meta .save-state{grid-area:state;padding:0 6px 0 7px!important;font-size:11px!important}
  body > .toolbar #workspace-tags{grid-area:tags;font-size:11.5px;padding:1px 6px}
}
.welcome-strip{box-sizing:border-box;flex-wrap:wrap;position:relative;padding-right:42px}
.welcome-strip>div:first-child{flex:1 1 380px;min-width:0}.welcome-actions{flex:1 1 400px;min-width:0}.welcome-dismiss{position:absolute;right:8px;top:8px}
.brand-mark .chemistry-mark{shape-rendering:geometricPrecision}.brand{gap:10px}.brand-heading{display:contents;margin:0;font:inherit}.brand-mark{flex-shrink:0}
@media(max-width:650px){body > .toolbar .learning-nav{justify-content:space-evenly}.welcome-strip>div:first-child,.welcome-actions{flex-basis:100%}.welcome-strip{padding-right:24px}}
/* Welcome: one clear first step, two alternatives, and Learn as a quieter link. */
.welcome-actions .welcome-link{border-color:transparent;background:transparent;padding-inline:4px;color:var(--accent-text,var(--accent,#2260a2));font-weight:600;text-decoration:underline;text-underline-offset:3px}
@media(max-width:650px){.welcome-strip{margin:0 12px 10px;padding:16px 40px 16px 16px;gap:12px}.welcome-strip h2{font-size:21px;margin-bottom:6px}.welcome-strip p{font-size:13.5px}.welcome-actions{display:grid;grid-template-columns:1fr 1fr;gap:8px}.welcome-actions .welcome-primary,.welcome-actions .welcome-link{grid-column:1/-1}.welcome-actions button{min-height:44px}}

.workspace-learning-footer{border-top:1px solid var(--border,#d0dce6);color:var(--muted,#526779)}.workspace-learning-footer h2{font-size:17px;color:var(--text,#17334a)}.workspace-learning-footer p{max-width:720px;line-height:1.6}.workspace-learning-footer a{color:var(--accent-text,var(--accent,#245c98))}@media print{}

/* Size the workspace from the actual header/welcome height. */
body:not(.learn-public){display:flex;flex-direction:column}
body > .toolbar{height:auto!important;flex-shrink:0;padding-top:8px;padding-bottom:6px;column-gap:18px}
body > .app-shell{flex:1 1 auto;min-height:0;height:auto!important}
body > .welcome-strip{flex-shrink:0}
body > .toolbar .document-meta input{width:100%;min-width:0;box-sizing:border-box}
body:not(.learn-public){--text:var(--ink);--border:var(--line);--accent:var(--accent-ui);--accent-contrast:var(--on-accent-ui);--accent-soft:var(--c96);--font-ui:var(--world-font-navigation,'DM Sans',system-ui,sans-serif);--font-display:Newsreader,Georgia,serif}
.learn-body,.glossary-dialog .help-panel{--font-ui:'DM Sans',system-ui,sans-serif}
.workspace-learning-footer{flex-shrink:0;padding:7px 24px;font-size:12px;display:flex;gap:14px;align-items:center}.workspace-learning-footer h2,.workspace-learning-footer p{display:none}
@media(max-width:650px){body > .toolbar .document-meta{display:none!important}.workspace-learning-footer{display:none}}

/* The welcome banner already links to Learn; the footer link (kept in the page for crawlers) waits for it to close. */
body:has(#welcome-strip:not([hidden])) .workspace-learning-footer{display:none}
@media print{.workspace-learning-footer{display:none!important}}

.learn-controls input::placeholder{color:var(--muted,#536779);opacity:1}

/* Equations are typeset once; semantic MathML accompanies the visual layout. */
.learn-equation{position:relative;line-height:1.6;max-width:100%;box-sizing:border-box;padding:20px 18px;overflow-x:auto;font-size:19px}
.learn-math-accessible{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
.learn-table-wrap{overflow-x:auto;margin:20px 0}.learn-table{width:100%;border-collapse:collapse;font:14px/1.6 var(--font-ui,system-ui);text-align:left}.learn-table caption{text-align:left;font-weight:600;margin-bottom:10px}.learn-table th,.learn-table td{padding:10px 12px;border:1px solid var(--border,#cbd8e1)}.learn-table thead{background:var(--accent-soft,#eef4fa)}
.learn-deeper,.learn-solution{border:1px solid var(--border,#cbd8e1);border-radius:8px;padding:14px 18px;margin:18px 0;line-height:1.7}.learn-deeper summary,.learn-solution summary{font-weight:600;cursor:pointer}.learn-deeper[open] summary,.learn-solution[open] summary{margin-bottom:12px}.learn-practice-problem{margin:28px 0;padding:22px;border:2px solid var(--accent,#2861a4);border-radius:10px}.learn-practice-problem h2{margin-top:0}.learn-solution h3{font-size:17px}
.learn-fragments{margin:20px 0;color:var(--text,#17334a)}.learn-fragments figcaption{font-size:14px;font-weight:600;margin-bottom:14px}.learn-fragments svg{width:100%;height:auto;min-width:280px;font:15px var(--font-ui,system-ui);display:block}.learn-fragments{overflow-x:auto}
@media(max-width:650px){.learn-equation{font-size:17px;padding:18px 12px}.learn-prose p{font-size:16px}.learn-practice-problem{padding:18px 14px}.learn-table th,.learn-table td{padding:8px}.learn-section{margin-bottom:32px}}

.learn-public-brand sup { font-size:.55em;line-height:0;vertical-align:super;margin-left:1px; }

/* Only authored alternate layouts opt into stacked long equations. */
.learn-prose:has(.learn-responsive-equation){container-type:inline-size}
.learn-responsive-equation .learn-equation-wide{display:none}
.learn-responsive-equation .learn-equation-narrow{display:block}
@container (min-width:620px){.learn-responsive-equation .learn-equation-wide{display:block}.learn-responsive-equation .learn-equation-narrow{display:none}}

.learn-home.learn-home-compact h1{font-size:24px;margin:0 0 12px}
/* Find on the public Learn index (learn/find.js); hidden without JavaScript. */
.learn-find{display:grid;gap:6px;max-width:520px;margin:18px 0 6px}.learn-find label{font-weight:600;font-size:14px}.learn-find input{font:inherit;padding:10px 12px;border:1px solid var(--border,#cfdae2);border-radius:8px;background:var(--panel,#fff);color:var(--text,#18384a);min-height:44px}.learn-find input:focus-visible{outline:2px solid var(--accent,#245c98);outline-offset:2px}.learn-find-status{min-height:1.5em;margin:0 0 8px;color:var(--muted,#506575);font-size:14px}.learn-home [hidden]{display:none}

/* Public Learn pages (owner redesign, 2026-10-04): course jump list, balanced headings, one filled
   action per Try panel, and the not-found page. */
.learn-home h1,.learn-article h1,.learn-section h2,.learn-home h2{text-wrap:balance}
.learn-home h2{font-family:var(--font-display,Georgia,serif);font-size:26px;letter-spacing:-.01em}
.learn-courses{display:grid;gap:6px;margin:18px 0 26px;font-size:14px}.learn-courses p{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 14px;margin:0}.learn-courses span{min-width:84px;color:var(--muted,#506575);font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase}.learn-courses a{text-decoration:none;font-weight:500}.learn-courses a:hover{text-decoration:underline;text-underline-offset:3px}
.learn-practice .learn-action~.learn-action:not(.learn-secondary){color:var(--accent,#245c98)!important;background:var(--accent-soft,#eef4f9);border-color:transparent}
.learn-missing{max-width:640px;padding:28px 0 12px}.learn-missing-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}.learn-missing-actions .learn-action{margin:0;gap:0}