/* Code is exempt from prose checks.
```css
*/
/* Lesson-only geometry. Shared controls and teaching states live in site.css. */
.lesson-page .eg{font-style:normal}
.lesson-heading{margin-bottom:24px}
.lesson-heading h1{text-wrap:balance}
.lesson-heading-copy{min-width:0;max-width:720px}
.lesson-badges{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 16px}
.lesson-heading .rule-box{margin:0 0 16px}
.lesson-heading .jump-links{margin:0}
.lesson-header-art{aspect-ratio:480/322;object-fit:contain}
.lesson-introduction{margin:0 0 24px}
.lesson-introduction .meta{margin-top:16px}
.lesson-page .lesson-layout{align-items:start}
.lesson-contents{min-width:0}
.lesson-contents details{margin:0}
.lesson-contents ol{list-style:none;padding:0;margin:0}
.lesson-contents li{margin:0}
.lesson-contents a{padding:8px 0;font:14px/21px var(--font-ui)}
.lesson-body>h2:first-child{margin-top:0}
.lesson-body .lesson-examples{margin:16px 0}
.lesson-body .example-row p:last-child{margin-bottom:0}
.lesson-body .example-row .no,.lesson-body .example-row .ok{color:inherit}
.lesson-body .written-quiz>li{padding:12px 8px;border-bottom:1px solid var(--color-border);margin:0}
.lesson-body .written-quiz{padding-left:24px;margin:16px 0 24px}
.lesson-practice{margin:24px 0}
.lesson-practice>h3{margin-top:0}
.lesson-practice .task-shell{margin-top:24px}
.lesson-practice h4{margin:16px 0}
.lesson-practice legend{font-family:var(--font-reading)}
.lesson-practice .field input,.lesson-practice .field select{width:100%}
.lesson-practice .field{margin:16px 0}
.lesson-practice .field.is-correct input,.lesson-practice .field.is-correct select{background:var(--color-success-bg)}
.lesson-practice .field.is-wrong input,.lesson-practice .field.is-wrong select{background:var(--color-error-bg)}
.lesson-practice .progress{display:block;margin:12px 0 16px}
.lesson-practice .result-slot h3{margin-top:0}
.lesson-practice .result-slot .link-row{margin:16px 0}
.lesson-practice .quiz-review li{margin:16px 0}
.lesson-practice .quiz-review p{margin:8px 0}
.lesson-practice .result-copy{width:100%;margin-top:12px}
.lesson-answers{margin-top:24px}
.lesson-references{margin-top:16px}
.lesson-sr{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
.lesson-page .typing-status{min-height:48px;font:16px/24px var(--font-ui);position:fixed;left:0;right:0;top:0;margin:0;display:flex;align-items:center}
@media(min-width:768px){.lesson-page[data-lesson="prepositions-in-on-at"] table th:first-child,.lesson-page[data-lesson="prepositions-in-on-at"] table td:first-child{width:112px}}
@media(min-width:1024px){
 .lesson-heading{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:48px;align-items:end}
 .lesson-heading .lesson-header-art{margin:0 0 0 auto;align-self:center}
 .lesson-page .lesson-layout{grid-template-columns:minmax(0,680px)}
}
@media(min-width:1280px){
 .lesson-heading{grid-template-columns:720px 320px;gap:80px}
 .lesson-introduction{margin-left:280px}
 .lesson-page .lesson-layout{grid-template-columns:232px minmax(0,680px);gap:48px}
 .lesson-contents{position:sticky;top:calc(var(--header-height) + 24px);max-height:calc(100dvh - var(--header-height) - 48px);overflow:auto}
 .lesson-contents summary{cursor:default}
}
@media print{.lesson-practice,.lesson-contents{display:none}.lesson-introduction{margin-left:0}.lesson-page .lesson-layout{display:block}}

/*
```
*/
.eg-play{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;margin:-10px 0 -10px 2px;padding:0;vertical-align:middle;border:0;border-radius:50%;background:transparent;color:var(--color-accent);cursor:pointer}
.eg-play:hover,.eg-play.is-playing{background:var(--color-accent-subtle)}
.eg-play:focus-visible{outline:3px solid var(--color-focus);outline-offset:1px}
.voice-choice{display:flex;flex-wrap:wrap;align-items:center;gap:8px 12px;margin:16px 0 0;font:var(--type-caption)/1.5 var(--font-ui);color:var(--color-secondary)}
.voice-option{min-height:44px;padding:0 14px;border:1px solid var(--color-control-border);border-radius:999px;background:var(--color-surface);color:var(--color-text);font:inherit;cursor:pointer}
.voice-option[aria-pressed=true]{background:var(--color-accent);border-color:var(--color-accent);color:var(--color-on-accent)}