/* Worked news example. Geometry belongs here; type roles remain edition.css tokens. */
.proposal-lesson{padding:28px;margin:0 0 28px;scroll-margin-top:100px;min-width:0}
.proposal-lesson .lesson-heading{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;margin-bottom:26px}
.proposal-lesson .lesson-heading>div{max-width:65ch;min-width:0}
.proposal-lesson .lesson-title{font-size:var(--text-feature);font-weight:700;line-height:1.3;letter-spacing:-.015em;margin:7px 0 12px}
.proposal-lesson .lesson-heading p,.proposal-lesson .lesson-article>p,.proposal-lesson .lesson-task,.proposal-lesson .lesson-evidence-output>p,.proposal-lesson .lesson-conclusion p{font-size:var(--text-body);line-height:1.75;letter-spacing:normal;margin:0 0 15px}
.proposal-lesson .lesson-heading p{color:var(--muted);margin:0}
.proposal-lesson .lesson-eyebrow,.proposal-lesson .lesson-claim-box>span{font-size:var(--text-eyebrow);line-height:1.5;font-weight:650;letter-spacing:.08em;color:var(--muted)}
.proposal-lesson .lesson-demo-label{flex:0 0 auto;padding:10px 13px;border:1px solid var(--line);border-radius:10px;font-size:var(--text-meta);font-weight:650;line-height:1.6;background:var(--surface-soft);color:var(--primary)}
.proposal-lesson .lesson-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:26px;align-items:start}
.proposal-lesson .lesson-reading,.proposal-lesson .lesson-workspace{min-width:0}
.proposal-lesson .lesson-article{padding:24px;border:1px solid var(--line);border-radius:16px;background:var(--surface)}
.proposal-lesson .lesson-publication,.proposal-lesson .lesson-evidence-heading,.proposal-lesson .lesson-workspace-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.proposal-lesson .lesson-publication{padding-bottom:15px;margin-bottom:18px;border-bottom:1px solid var(--line);font-size:var(--text-meta);color:var(--muted)}
.proposal-lesson .lesson-publication>span:first-child{display:flex;gap:7px;align-items:center;font-weight:700;color:var(--primary)}
.proposal-lesson .lesson-publication .icon{width:17px;height:17px}
.proposal-lesson .lesson-article h3{font-size:var(--text-claim);font-weight:700;line-height:1.4;letter-spacing:-.015em;margin:0 0 14px;overflow-wrap:break-word}
.proposal-lesson .lesson-article .lesson-byline{font-size:var(--text-meta);line-height:1.65;color:var(--muted);margin-bottom:22px}
.proposal-lesson .lesson-claim-box{display:grid;gap:9px;margin-top:23px;padding:17px;background:var(--surface-soft);border-left:3px solid var(--sage);border-radius:0 10px 10px 0}
.proposal-lesson .lesson-claim-box>strong{font-size:var(--text-subheading);font-weight:700;line-height:1.6}
.proposal-lesson .lesson-evidence{margin-top:22px}
.proposal-lesson .lesson-evidence-heading h3,.proposal-lesson .lesson-workspace-heading h3{font-size:var(--text-heading);line-height:1.35;margin:0;font-weight:700;letter-spacing:-.015em}
.proposal-lesson .lesson-evidence-heading>span,.proposal-lesson .lesson-workspace-heading>span{font-size:var(--text-meta);color:var(--muted);line-height:1.6}
.proposal-lesson .lesson-evidence>p{font-size:var(--text-support);line-height:1.7;color:var(--muted);margin:11px 0 14px}
.proposal-lesson .lesson-evidence-buttons{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px}
.proposal-lesson .lesson-evidence-buttons button{display:flex;flex-direction:column;align-items:flex-start;gap:9px;text-align:left;min-height:94px;min-width:0;padding:13px 11px;background:var(--surface);border:1px solid var(--line);border-bottom-width:3px;border-radius:11px;color:var(--ink);font-size:var(--text-meta);font-weight:650;line-height:1.55;white-space:normal}
.proposal-lesson .lesson-evidence-buttons .icon{width:20px;height:20px;color:var(--primary)}
.proposal-lesson .lesson-evidence-buttons button[aria-expanded=true]{background:var(--purple-soft);border-color:var(--sage)}
.proposal-lesson .lesson-evidence-output{padding:20px;border:1px solid var(--line);background:var(--surface-soft);border-radius:13px;margin-top:13px;min-height:130px}
.proposal-lesson .lesson-evidence-output h4{font-size:var(--text-subheading);line-height:1.5;font-weight:700;margin:7px 0 12px}
.proposal-lesson .lesson-evidence-output .lesson-evidence-context{font-size:var(--text-support);line-height:1.75;color:var(--muted)}
.proposal-lesson .lesson-evidence-license{display:block;border-top:1px solid var(--line);padding-top:12px;font-size:var(--text-meta);line-height:1.65;color:var(--muted)}
.proposal-lesson .lesson-workspace{padding:23px;border:1px solid var(--line);border-top:4px solid var(--lavender);border-radius:16px;background:var(--surface)}
.proposal-lesson .lesson-tabs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px;margin:21px 0}
.proposal-lesson .lesson-tab{display:flex;flex-direction:column;align-items:center;gap:5px;min-width:0;padding:10px 4px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--muted);font-size:var(--text-meta);line-height:1.5}
.proposal-lesson .lesson-tab>strong{font-size:var(--text-subheading);font-weight:750;line-height:1.3}
.proposal-lesson .lesson-tab>span{font-size:var(--text-eyebrow);line-height:1.5;overflow-wrap:anywhere}
.proposal-lesson .lesson-tab[aria-selected=true]{background:var(--purple-soft);border-color:var(--sage);color:var(--primary)}
.proposal-lesson .lesson-stage{min-height:340px}
.proposal-lesson .lesson-stage-heading{display:flex;gap:12px;align-items:center;margin-bottom:16px}
.proposal-lesson .lesson-step-letter{flex:0 0 44px;width:44px;height:44px;display:grid;place-items:center;background:var(--lavender);color:var(--ink);border-radius:50%;font-size:var(--text-claim);font-weight:750;line-height:1}
.proposal-lesson .lesson-stage-heading h3{font-size:var(--text-heading);line-height:1.35;margin:4px 0 0;font-weight:700;letter-spacing:-.015em}
.proposal-lesson .lesson-task{color:var(--muted)}
.proposal-lesson fieldset{min-width:0;border:0;margin:23px 0 0;padding:0}
.proposal-lesson legend{font-size:var(--text-subheading);font-weight:650;line-height:1.6;margin-bottom:12px;padding:0}
.proposal-lesson .lesson-options{display:grid;gap:8px}
.proposal-lesson .lesson-option{font-size:var(--text-body);font-weight:550;line-height:1.6;min-width:0;min-height:48px;text-align:left;padding:12px 13px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);white-space:normal;overflow-wrap:break-word}
.proposal-lesson .lesson-option[aria-pressed=true]{background:var(--purple-soft);border-color:var(--primary);box-shadow:inset 0 0 0 1px var(--primary)}
.proposal-lesson .lesson-step-feedback{background:var(--surface-soft);border-left:3px solid var(--sage);padding:16px;margin-top:17px;border-radius:0 10px 10px 0}
.proposal-lesson .lesson-step-feedback>strong{font-size:var(--text-support);font-weight:700;line-height:1.6}
.proposal-lesson .lesson-step-feedback p{font-size:var(--text-support);line-height:1.75;margin:7px 0 0;color:var(--muted)}
.proposal-lesson .lesson-nav{display:flex;justify-content:space-between;gap:12px;margin-top:23px;padding-top:20px;border-top:1px solid var(--line)}
.proposal-lesson .lesson-nav button,.proposal-lesson #lesson-reveal{font-size:var(--text-label);min-height:46px;white-space:normal}
.proposal-lesson .lesson-action-help{font-size:var(--text-support);line-height:1.7;color:var(--muted);margin:18px 0}
.proposal-lesson #lesson-reveal{width:100%;justify-content:center}
.proposal-lesson .lesson-error{font-size:var(--text-support);line-height:1.65;color:var(--ink);border-left:3px solid var(--primary);padding-left:12px;margin:13px 0 0}
.proposal-lesson .lesson-conclusion{margin-top:23px;padding:20px;border:1px solid var(--sage);background:var(--surface-soft);border-radius:13px}
.proposal-lesson .lesson-conclusion h3{font-size:var(--text-heading);line-height:1.4;margin:8px 0 18px;font-weight:700}
.proposal-lesson .lesson-conclusion ul{padding-left:19px;margin:0}
.proposal-lesson .lesson-conclusion li{padding:0 0 12px}
.proposal-lesson .lesson-conclusion li>strong{font-size:var(--text-subheading);line-height:1.6}
.proposal-lesson .lesson-conclusion li>p{margin:6px 0 0}
.proposal-lesson .lesson-takeaway{border-top:1px solid var(--line);padding-top:17px;margin-top:6px}
.proposal-lesson .lesson-takeaway>strong{font-size:var(--text-subheading);line-height:1.6}
.proposal-lesson .lesson-takeaway>p{margin:7px 0 0}
.proposal-lesson .lesson-footer{display:flex;gap:20px;align-items:flex-start;justify-content:space-between;padding-top:20px;margin-top:25px;border-top:1px solid var(--line)}
.proposal-lesson .lesson-footer p{font-size:var(--text-meta);line-height:1.75;color:var(--muted);max-width:85ch;margin:0}
.proposal-lesson .lesson-footer button{font-size:var(--text-label);white-space:normal;flex:0 0 auto;min-height:44px;text-align:left}
.proposal-lesson button:hover:not(:disabled){border-color:var(--sage);background:var(--surface-soft)}
.proposal-lesson button:focus-visible{outline:3px solid var(--focus);outline-offset:4px}
.proposal-lesson button:active:not(:disabled){box-shadow:inset 0 2px 3px #252D4010}
.proposal-lesson button:disabled{opacity:.5;cursor:not-allowed}
.proposal-lesson [hidden]{display:none!important}
@media(max-width:1100px){.proposal-lesson .lesson-grid{grid-template-columns:1fr}.proposal-lesson .lesson-stage{min-height:0}.proposal-lesson .lesson-heading{flex-wrap:wrap}.proposal-lesson .lesson-demo-label br{display:none}}
@media(max-width:560px){.proposal-lesson{padding:21px 16px}.proposal-lesson .lesson-heading{gap:15px}.proposal-lesson .lesson-article,.proposal-lesson .lesson-workspace{padding:19px 16px}.proposal-lesson .lesson-tabs{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.proposal-lesson .lesson-tab{flex-direction:column;justify-content:center;gap:6px;padding:11px 8px}.proposal-lesson .lesson-tab>span{font-size:var(--text-meta)}.proposal-lesson .lesson-evidence-buttons{grid-template-columns:1fr}.proposal-lesson .lesson-evidence-buttons button{min-height:48px;flex-direction:row;align-items:center;gap:10px;font-size:var(--text-label)}.proposal-lesson .lesson-footer{flex-direction:column;gap:10px}.proposal-lesson .lesson-nav{gap:8px}.proposal-lesson .lesson-nav button{padding:10px;gap:5px}.proposal-lesson .lesson-conclusion{padding:17px}}
@media(prefers-reduced-motion:reduce){.proposal-lesson *{animation:none!important;transition:none!important}}
@media(forced-colors:active){.proposal-lesson .lesson-tab[aria-selected=true],.proposal-lesson .lesson-option[aria-pressed=true]{border:2px solid Highlight}}

.proposal-lesson .lesson-counterexamples{border-top:1px solid var(--line);padding-top:18px;margin-top:18px}.proposal-lesson .lesson-counterexamples h4{font-size:var(--text-subheading);line-height:1.5;margin:0 0 10px}.proposal-lesson .lesson-counterexamples li{font-size:var(--text-support);line-height:1.75}.proposal-lesson .lesson-counterexamples li strong{font-size:inherit}