.problem-page{max-width:860px;padding-block:32px 72px}.problem-page__crumbs{margin-bottom:24px;font-size:var(--fs-14)}.problem-page__crumbs a{color:inherit}.problem-page__meta{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0 0}.problem-page__cta{display:flex;flex-wrap:wrap;gap:12px;margin:28px 0 0}.problem-page__lesson{margin-top:56px;padding-top:28px;border-top:var(--bw-3) solid rgb(var(--c-ink))}.problem-page__lesson>.kicker{margin:0 0 8px}.problem-page .doc{max-width:none}.problem-page__more{margin-top:56px;padding-top:28px;border-top:var(--bw-3) solid rgb(var(--c-ink))}.problem-page__more h2{margin:0 0 16px;font:800 var(--fs-h3) / 1.2 var(--font-display)}.problem-page__more ul{display:grid;gap:10px;margin:0;padding:0;list-style:none}.problem-page__more li{display:flex;flex-wrap:wrap;align-items:center;gap:10px}.problem-page .sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.problem-page :is(th,td).align-center{text-align:center}.problem-page :is(th,td).align-right{text-align:right}.card-topics{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;margin:40px 0 0;padding:0;list-style:none}.card-topics__item{padding:18px 20px;border:var(--bw-2) solid rgb(var(--c-ink));background:rgb(var(--c-surface));box-shadow:var(--sh-sm)}.card-topics__item h2{margin:0;font:800 var(--fs-20) / 1.2 var(--font-display)}.card-topics__item p{margin:8px 0 0;font-size:var(--fs-14)}.card-topics__count,.card-list__count{color:rgb(var(--c-muted));font:600 var(--fs-12) / 1.4 var(--font-mono)}.card-list ol{display:grid;gap:14px;margin:40px 0 0;padding-left:1.6em}.card-list li::marker{color:rgb(var(--c-muted));font-family:var(--font-mono)}.card-list__meta{display:inline-flex;flex-wrap:wrap;gap:6px;margin-left:6px;vertical-align:middle}.doc-hero .card-page__question{font-size:clamp(1.75rem,4vw,2.5rem);line-height:1.2}.card-blank{display:inline-block;width:4em;border-bottom:var(--bw-3) solid currentColor}.card-options{display:grid;gap:10px;padding:0;list-style:none}.card-option{padding:10px 14px;border:var(--bw-2) solid rgb(var(--c-ink) / .25)}.card-option--correct{border-color:rgb(var(--c-ink));background:rgb(var(--c-pass) / .14)}.card-option__mark{display:inline-block;width:1.2em;font-weight:800}.card-pager{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:40px}.card-pager__link{display:block;padding:14px 16px;border:var(--bw-2) solid rgb(var(--c-ink));color:inherit;text-decoration:none}.card-pager__link:hover{box-shadow:var(--sh-sm)}.card-pager__link--next{text-align:right}.card-pager__label{display:block;margin-bottom:4px;color:rgb(var(--c-muted));font:600 var(--fs-12) / 1.4 var(--font-mono);text-transform:uppercase}@media(max-width:640px){.card-pager{grid-template-columns:1fr}.card-pager__link--next{text-align:left}}