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.library-crumbs li+li:before{content:"‹"}.library-crumbs a{color:inherit;text-underline-offset:3px}.library-hero{gap:var(--library-gap);border-block-end:1px solid var(--elev-line);align-items:center;margin-block-end:24px;padding-block-end:24px;display:grid}.library-hero__text{gap:4px;display:grid}.library-hero__lead{color:var(--elev-ink-soft)}.library-hero__video{aspect-ratio:16/9;border-radius:var(--library-radius);background:var(--elev-ink);justify-self:start;width:min(100%,420px);display:block;position:relative;overflow:hidden;box-shadow:0 8px 24px #2527441f}.library-hero__video img{object-fit:cover;width:100%;height:100%;transition:transform .4s cubic-bezier(.16,1,.3,1);display:block}.library-hero__video:hover img{transform:scale(1.03)}.library-hero__play{width:56px;height:56px;color:var(--elev-brand-dark);background:#fffffff0;border-radius:50%;place-items:center;margin:auto;display:grid;position:absolute;inset:0}@media (min-width:760px){.library-hero--with-video{grid-template-columns:minmax(0,1fr) minmax(0,300px)}.library-hero--with-video .library-hero__video{justify-self:end}}.library-cta{border:1.5px solid var(--elev-brand);min-height:44px;color:var(--elev-brand-dark);white-space:nowrap;border-radius:999px;justify-content:center;align-items:center;gap:8px;margin-block:8px;padding:8px 20px;font-weight:600;text-decoration:none;transition:background-color .2s,transform .15s;display:inline-flex}.library-cta:hover{background:var(--elev-brand-soft)}.library-cta:active{transform:translateY(1px)}.library-cta--primary{background:var(--elev-brand);color:var(--elev-on-color)}.library-cta--primary:hover{background:var(--elev-brand-dark)}.library-cta:focus-visible,.library-hero__video:focus-visible{outline:3px solid var(--elev-gold);outline-offset:2px}.library-note{border-radius:var(--library-radius-sm);background:var(--elev-canvas);color:var(--elev-ink-soft);padding:8px 12px;font-size:.875rem}.library-toc{border-radius:var(--library-radius);background:var(--elev-canvas);margin-block:8px 24px;padding:12px 16px}.library-toc__title{margin:0 0 4px;font-size:.9375rem;font-weight:600}.library-toc ol{gap:2px;margin:0;padding-inline-start:20px;font-size:.9375rem;display:grid}.library-toc a{color:var(--elev-brand-dark);text-underline-offset:3px}.library-math{margin-block:8px;overflow-x:auto}.library-figure{margin-block:16px;overflow-x:auto}.library-block--tip,.library-block--bigRule,.library-block--pitfall{border-radius:var(--library-radius);background:var(--elev-brand-soft);padding:12px 16px}.library-block--example{border-radius:var(--library-radius);border:1px solid var(--elev-line);background:var(--elev-surface);padding:12px 16px}.library-activity{border-radius:var(--library-radius);background:var(--elev-surface);border:1px solid var(--elev-line);border-inline-start:4px solid var(--elev-brand);margin-block:16px;padding:14px 16px}.library-activity__title{color:var(--elev-brand-dark);align-items:center;gap:8px;margin:0 0 4px;font-size:.875rem;font-weight:600;display:flex}.library-exercises{margin-block-start:24px}.library-exercise{border-radius:var(--library-radius);border:1px solid var(--elev-line);background:var(--elev-surface);margin-block:16px;padding:16px;scroll-margin-top:96px}.library-exercise__number{color:var(--elev-ink-soft);font-variant-numeric:tabular-nums;margin:0;font-size:.8125rem;font-weight:600}.library-exercise__question{font-weight:600}.library-options{padding-inline-start:24px}.library-options--choice{gap:8px;margin-block:12px;padding:0;list-style:none;display:grid}.library-option{border:1px solid var(--elev-line);border-radius:var(--library-radius-sm);background:var(--elev-canvas);align-items:center;gap:12px;min-height:44px;padding:6px 12px;display:flex}.library-option__letter{background:var(--elev-surface);border:1px solid var(--elev-line);border-radius:50%;flex:none;place-items:center;width:28px;height:28px;font-size:.875rem;font-weight:600;display:grid}.library-match{grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:8px;display:grid}.library-spell{letter-spacing:.15em;font-size:1.5rem;font-weight:600}.library-translate{font-weight:600}.library-table{overflow-x:auto}.library-table table{border-collapse:collapse;font-variant-numeric:tabular-nums}.library-table th,.library-table td{border:1px solid var(--elev-line);text-align:center;padding:6px 12px}.library-proof{padding-inline-start:24px}.library-answer{margin-block:8px}.library-answer summary{cursor:pointer;min-height:44px;color:var(--elev-brand-dark);background:var(--elev-brand-soft);border-radius:999px;align-items:center;gap:8px;padding:4px 14px;font-weight:600;list-style:none;display:inline-flex}.library-answer summary::-webkit-details-marker{display:none}.library-answer summary:focus-visible{outline:3px solid var(--elev-gold);outline-offset:2px}.library-answer[open]{border-radius:var(--library-radius);background:var(--elev-canvas);padding:8px 12px 12px}.library-answer[open] summary{margin-block-end:4px}.library-inline,.library-end{border-radius:var(--library-radius);background:var(--elev-brand-soft);margin-block:24px;padding:20px}.library-inline__title{margin:0;font-weight:700}.library-end{justify-items:start;gap:4px;margin-block-start:40px;display:grid}.library-end h2{margin-block-start:0}.library-end .library-cta{margin-inline-end:8px}.library-vocab{border-radius:var(--library-radius);border:1px solid var(--elev-line);background:var(--elev-surface);margin-block:32px;padding:16px}.library-vocab h2{margin-block-start:0}.library-vocab dl{gap:8px;margin:0;display:grid}.library-vocab dl>div{flex-wrap:wrap;align-items:baseline;gap:4px 12px;display:flex}.library-vocab dt{font-weight:700}.library-vocab dd{margin:0}.library-vocab__translit{color:var(--elev-ink-soft);font-style:italic}.library-pager{flex-wrap:wrap;justify-content:space-between;gap:8px;margin-block:32px;font-size:.9375rem;display:flex}.library-pager a{min-height:44px;color:var(--elev-brand-dark);text-underline-offset:3px;align-items:center;display:inline-flex}.library-sticky{inset-inline:0;z-index:40;padding:6px max(16px, env(safe-area-inset-right,0px)) calc(6px + env(safe-area-inset-bottom,0px)) max(16px, env(safe-area-inset-left,0px));border-block-start:1px solid var(--elev-line);background:#fffffff5;justify-content:center;align-items:center;gap:12px;display:flex;position:fixed;bottom:0;box-shadow:0 -4px 16px #25274414}.library-sticky__text{margin:0;font-size:.9375rem}.library-sticky .library-cta{background:var(--elev-brand);color:var(--elev-on-color);margin:0}.library-sticky__close{width:44px;height:44px;color:var(--elev-ink-soft);cursor:pointer;background:0 0;border:0;border-radius:50%;place-items:center;display:grid}.library-sticky__close:hover{background:var(--elev-canvas)}.library-sticky__close:focus-visible{outline:3px solid var(--elev-gold);outline-offset:2px}@media (prefers-reduced-motion:no-preference){.library-sticky:not([hidden]){animation:.25s cubic-bezier(.16,1,.3,1) library-sticky-in}}@keyframes library-sticky-in{0%{transform:translateY(100%)}to{transform:translateY(0)}}.library-sticky:not([hidden])~.wa-float{--wa-lift:60px}@media (max-width:520px){.library-sticky__text{display:none}}.library-list{gap:8px;margin:16px 0;padding:0;list-style:none;display:grid}.library-list a{border-radius:var(--library-radius);border:1px solid var(--elev-line);height:100%;color:inherit;background:var(--elev-surface);padding:14px 16px;text-decoration:none;transition:border-color .2s,box-shadow .2s;display:block}.library-list a:hover{border-color:var(--elev-brand);box-shadow:0 4px 16px #25274414}.library-list a:focus-visible{outline:3px solid var(--elev-gold);outline-offset:2px}.library-list small{color:var(--elev-ink-soft);margin-block-start:2px;font-size:.875rem;display:block}@media (min-width:640px){.library-list--grid{grid-template-columns:repeat(2,minmax(0,1fr))}}.library-list--steps{counter-reset:library-step}.library-list--steps li{counter-increment:library-step}.library-list--steps a{align-items:center;gap:12px;display:flex}.library-list--steps a:before{content:counter(library-step);background:var(--elev-brand-soft);width:32px;height:32px;color:var(--elev-brand-dark);font-variant-numeric:tabular-nums;border-radius:50%;flex:none;place-items:center;font-weight:600;display:grid}@media (prefers-reduced-motion:reduce){.library-hero__video img,.library-cta,.library-list a{transition:none}.library-hero__video:hover img{transform:none}}