[data-edu]{--inst-hl-yellow:#fbe7a1;--inst-hl-green:#cfe8d6;--inst-hl-blue:#d3e3f6;--inst-hl-pink:#f6d6de;--inst-note:#fff6d1;--inst-note-edge:#ead9a0;--inst-good:#1a7a3c;--inst-good-bg:#e8f3ec;--inst-bad:#a8361a;--inst-bad-bg:#fbebe5;--inst-reader-measure:68ch}.inst-page{min-height:60vh}.inst-bar{border-bottom:var(--edu-border-w) solid var(--edu-border);background:var(--edu-card)}.inst-bar__inner{max-width:var(--edu-container);margin-inline:auto;padding-inline:var(--edu-gutter);min-height:3.5rem;display:flex;align-items:center;justify-content:space-between;gap:var(--edu-s4)}.inst-bar__brand{font-weight:600;color:var(--edu-text-head);text-decoration:none;letter-spacing:-.01em}.inst-bar__brand span{color:var(--edu-muted);font-weight:400}.inst-bar__link{font-size:var(--edu-meta-size);color:var(--edu-muted);text-decoration:none}.inst-bar__link:hover{color:var(--edu-accent-ink)}.inst-wrap{max-width:var(--edu-container);margin-inline:auto;padding-inline:var(--edu-gutter)}.inst-narrow{max-width:var(--edu-container-narrow)}.inst-section{padding-block:var(--edu-section-y-sm)}.inst-section--white{background:var(--edu-card)}.inst-hero{padding-block:var(--edu-hero-top) var(--edu-section-y-sm)}.inst-h1{font-size:var(--edu-h1-size);line-height:var(--edu-h1-lh);letter-spacing:var(--edu-h1-ls);font-weight:var(--edu-h1-weight);color:var(--edu-text-head);margin:0;max-width:16ch;text-wrap:balance}.inst-h1--sm{font-size:var(--edu-h2-size);line-height:var(--edu-h2-lh);letter-spacing:var(--edu-h2-ls);max-width:24ch}.inst-lede{margin:var(--edu-s5) 0 0;font-size:var(--edu-lede-size);line-height:1.5;color:var(--edu-muted);max-width:52ch}.inst-h2{font-size:var(--edu-h2-size-sm);line-height:var(--edu-h2-lh);letter-spacing:var(--edu-h2-ls);margin:0 0 var(--edu-s6)}.inst-h2,.inst-h3{font-weight:550;color:var(--edu-text-head)}.inst-h3{font-size:var(--edu-card-title-size);line-height:var(--edu-card-title-lh);margin:0}.inst-meta{font-size:var(--edu-meta-size);color:var(--edu-subtle);margin:0}.inst-muted{color:var(--edu-muted)}.inst-crumb{font-size:var(--edu-meta-size);margin:0 0 var(--edu-s4)}.inst-crumb a{color:var(--edu-accent-ink);text-decoration:none}.inst-crumb a:hover{text-decoration:underline;text-underline-offset:.1875rem}.inst-actions{display:flex;flex-wrap:wrap;gap:var(--edu-s3);margin-top:var(--edu-s7);align-items:center}.inst-btn{appearance:none;display:inline-flex;align-items:center;justify-content:center;gap:var(--edu-s2);height:var(--edu-btn-h);padding-inline:var(--edu-btn-px);border-radius:var(--edu-btn-radius);font:inherit;font-size:var(--edu-body-sm-size);font-weight:500;line-height:1;cursor:pointer;text-decoration:none;white-space:nowrap;border:var(--edu-border-w) solid var(--edu-border-strong);background:transparent;color:var(--edu-accent-ink);transition:background-color var(--edu-dur) var(--edu-ease),border-color var(--edu-dur) var(--edu-ease)}.inst-btn:hover{background:var(--edu-band-soft)}.inst-btn:disabled{opacity:.5;cursor:not-allowed}.inst-btn--primary{background:var(--edu-accent);border-color:var(--edu-accent);color:#fff}.inst-btn--primary:hover{background:var(--edu-accent-hover);border-color:var(--edu-accent-hover)}.inst-btn--sm{height:var(--edu-btn-h-sm);padding-inline:var(--edu-btn-px-sm)}.inst-btn--quiet{border-color:transparent;padding-inline:var(--edu-s2);height:auto;min-height:2rem}.inst-btn--quiet:hover{background:transparent;text-decoration:underline;text-underline-offset:.1875rem}.inst-btn--danger{color:var(--inst-bad)}.inst-grid{display:grid;gap:var(--edu-s5);grid-template-columns:repeat(auto-fill,minmax(min(100%,20rem),1fr))}.inst-card{display:flex;flex-direction:column;gap:var(--edu-s3);background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-lg);padding:var(--edu-card-pad);color:inherit;text-decoration:none;transition:border-color var(--edu-dur) var(--edu-ease),box-shadow var(--edu-dur) var(--edu-ease)}a.inst-card:hover{border-color:var(--edu-border-accent);box-shadow:var(--edu-shadow-raised)}.inst-card p{margin:0}.inst-card__go{margin-top:auto;padding-top:var(--edu-s3);color:var(--edu-accent-ink);font-size:var(--edu-body-sm-size);font-weight:500}.inst-rows{list-style:none;margin:0;padding:0;border-top:var(--edu-border-w) solid var(--edu-border)}.inst-row{display:flex;align-items:center;justify-content:space-between;gap:var(--edu-s5);padding-block:var(--edu-s5);border-bottom:var(--edu-border-w) solid var(--edu-border);color:inherit;text-decoration:none}.inst-row:hover .inst-h3{color:var(--edu-accent-ink)}.inst-row__main{min-width:0}.inst-row__main p{margin:var(--edu-s1) 0 0}.inst-row__go{flex-shrink:0;color:var(--edu-accent-ink);font-size:var(--edu-body-sm-size);font-weight:500}.inst-empty{border:var(--edu-border-w) dashed var(--edu-border-strong);border-radius:var(--edu-radius-lg);padding:var(--edu-s8) var(--edu-card-pad);text-align:center;color:var(--edu-muted)}.inst-empty p{margin:0 auto;max-width:46ch}.inst-stars{display:inline-flex;gap:2px;color:var(--edu-accent-2);vertical-align:middle}.inst-star{position:relative;display:inline-block;width:1rem;height:1rem}.inst-star svg{width:1rem;height:1rem;display:block}.inst-star__fill{position:absolute;inset:0 auto 0 0;overflow:hidden}.inst-star-input .inst-star,.inst-star-input .inst-star svg,.inst-stars--lg .inst-star,.inst-stars--lg .inst-star svg{width:1.75rem;height:1.75rem}.inst-star-input{display:inline-flex;gap:var(--edu-s1);border:0;padding:0;margin:0}.inst-star-input label{cursor:pointer;color:var(--edu-border-strong);display:inline-flex;padding:.25rem;border-radius:var(--edu-radius-sm)}.inst-star-input label.is-on{color:var(--edu-accent-2)}.inst-star-input input{position:absolute;opacity:0;width:1px;height:1px}.inst-star-input input:focus-visible+.inst-star{outline:2px solid var(--edu-accent);outline-offset:2px;border-radius:.25rem}.inst-reader{display:grid;gap:var(--edu-s9);grid-template-columns:minmax(0,1fr);align-items:start}@media (min-width:1024px){.inst-reader{grid-template-columns:minmax(0,1fr) 20rem}}.inst-reader__aside{position:relative}@media (min-width:1024px){.inst-reader__aside{position:sticky;top:calc(var(--edu-s6));max-height:calc(100vh - 3rem);overflow:auto}}.inst-prose{max-width:var(--inst-reader-measure);font-size:1.125rem;line-height:1.7;color:var(--edu-text)}.inst-prose>*+*{margin-top:var(--edu-s5)}.inst-block{position:relative}.inst-prose h2{font-size:var(--edu-h3-size);line-height:var(--edu-h3-lh);letter-spacing:var(--edu-h3-ls);margin-top:var(--edu-s9)}.inst-prose h2,.inst-prose h3{font-weight:550;color:var(--edu-text-head)}.inst-prose h3{font-size:var(--edu-card-title-size);margin-top:var(--edu-s7)}.inst-prose :is(h2,h3,p,ul,ol,blockquote,pre){margin-bottom:0}.inst-prose ol,.inst-prose ul{padding-left:1.4em}.inst-prose li+li{margin-top:var(--edu-s2)}.inst-prose a{color:var(--edu-accent-ink);text-underline-offset:.1875rem}.inst-prose code{font-size:.9em;background:var(--edu-band);padding:.1em .35em;border-radius:.375rem}.inst-prose pre{background:var(--edu-band);padding:var(--edu-s4);border-radius:var(--edu-radius-sm);overflow-x:auto;font-size:.9rem;line-height:1.55}.inst-prose pre code{background:none;padding:0}.inst-prose blockquote{margin-inline:0;padding-left:var(--edu-s5);border-left:.1875rem solid var(--edu-accent-2);color:var(--edu-text-head)}.inst-prose hr{border:0;border-top:var(--edu-border-w) solid var(--edu-border);margin-block:var(--edu-s8)}::highlight(inst-yellow){background-color:var(--inst-hl-yellow,#fbe7a1);color:inherit}::highlight(inst-green){background-color:var(--inst-hl-green,#cfe8d6);color:inherit}::highlight(inst-blue){background-color:var(--inst-hl-blue,#d3e3f6);color:inherit}::highlight(inst-pink){background-color:var(--inst-hl-pink,#f6d6de);color:inherit}::highlight(inst-flash){background-color:rgba(26,122,60,.22)}.inst-pin{position:absolute;top:.2em;left:-2.5rem;width:1.75rem;height:1.75rem;border-radius:50%;border:var(--edu-border-w) solid var(--edu-border);background:var(--edu-card);color:var(--edu-muted);display:inline-flex;align-items:center;justify-content:center;cursor:pointer;opacity:0;transition:opacity var(--edu-dur) var(--edu-ease)}.inst-block:hover .inst-pin,.inst-pin:focus-visible{opacity:1}@media (max-width:1100px){.inst-pin{left:auto;right:-.375rem;top:-1.875rem}}@media (hover:none){.inst-pin{display:none}}.inst-note{margin-top:var(--edu-s3);background:var(--inst-note);border:var(--edu-border-w) solid var(--inst-note-edge);border-radius:var(--edu-radius-sm);padding:var(--edu-s3) var(--edu-s4);font-size:var(--edu-body-sm-size);line-height:1.5;color:var(--edu-text)}.inst-note p{margin:0;white-space:pre-wrap}.inst-note__bar{display:flex;gap:var(--edu-s2);justify-content:flex-end;margin-top:var(--edu-s2)}.inst-note textarea{background:#fffdf3}.inst-tool{position:fixed;z-index:60;display:flex;align-items:center;gap:var(--edu-s1);padding:.375rem;background:var(--edu-text-head);border-radius:var(--edu-radius-pill);box-shadow:0 .375rem 1.5rem rgba(23,22,15,.25);transform:translateX(-50%)}.inst-tool button{appearance:none;border:0;background:transparent;color:#fff;font:inherit;font-size:var(--edu-meta-sm-size);min-width:2rem;height:2rem;border-radius:var(--edu-radius-pill);display:inline-flex;align-items:center;justify-content:center;padding-inline:.625rem;cursor:pointer}.inst-tool button:hover{background:hsla(0,0%,100%,.12)}.inst-swatch{width:1.125rem;height:1.125rem;border-radius:50%;border:2px solid hsla(0,0%,100%,.85);display:block}.inst-panel{background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-lg);padding:var(--edu-s5)}.inst-tabs{display:flex;gap:var(--edu-s1);margin-bottom:var(--edu-s4);border-bottom:var(--edu-border-w) solid var(--edu-border)}.inst-tab{appearance:none;background:none;border:0;border-bottom:2px solid transparent;margin-bottom:-1px;padding:var(--edu-s2) var(--edu-s3);font:inherit;font-size:var(--edu-body-sm-size);color:var(--edu-muted);cursor:pointer}.inst-tab[aria-selected=true]{color:var(--edu-text-head);border-bottom-color:var(--edu-accent);font-weight:550}.inst-panel ul{list-style:none;margin:0;padding:0;display:grid;gap:var(--edu-s3)}.inst-panel li{font-size:var(--edu-body-sm-size);line-height:1.45}.inst-panel__item{display:flex;gap:var(--edu-s3);align-items:flex-start}.inst-panel__item button.inst-jump{appearance:none;background:none;border:0;padding:0;text-align:left;font:inherit;color:var(--edu-text);cursor:pointer;flex:1;min-width:0}.inst-panel__item button.inst-jump:hover{color:var(--edu-accent-ink)}.inst-dot{flex-shrink:0;width:.625rem;height:.625rem;border-radius:50%;margin-top:.45em}.inst-panel__hint{font-size:var(--edu-meta-sm-size);color:var(--edu-subtle);margin:var(--edu-s4) 0 0}.inst-pdf{display:flex;flex-wrap:wrap;align-items:center;gap:var(--edu-s4);justify-content:space-between;padding:var(--edu-s4) var(--edu-s5);border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-md);background:var(--edu-card);margin-bottom:var(--edu-s8);max-width:var(--inst-reader-measure)}.inst-pdf p{margin:0}.inst-pager{display:flex;justify-content:space-between;gap:var(--edu-s4);flex-wrap:wrap;margin-top:var(--edu-s10);padding-top:var(--edu-s6);border-top:var(--edu-border-w) solid var(--edu-border);max-width:var(--inst-reader-measure)}.inst-pager a{color:var(--edu-accent-ink);text-decoration:none;font-weight:500}.inst-pager a:hover{text-decoration:underline;text-underline-offset:.1875rem}.inst-form{display:grid;gap:var(--edu-s4)}.inst-field{display:grid;gap:var(--edu-s2)}.inst-label{font-size:var(--edu-meta-size);font-weight:550;color:var(--edu-text-head)}.inst-input,.inst-select,.inst-textarea{width:100%;font:inherit;font-size:var(--edu-body-sm-size);color:var(--edu-text);background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border-strong);border-radius:var(--edu-radius-sm);padding:.625rem .875rem;min-height:2.75rem}.inst-textarea{resize:vertical;line-height:1.55}.inst-textarea--code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.875rem}.inst-input:focus,.inst-select:focus,.inst-textarea:focus{outline:2px solid var(--edu-focus-ring);border-color:var(--edu-accent)}.inst-check{display:flex;gap:var(--edu-s3);align-items:flex-start;font-size:var(--edu-meta-size);color:var(--edu-muted);line-height:1.5}.inst-check input{margin-top:.25em;width:1.125rem;height:1.125rem;accent-color:var(--edu-accent);flex-shrink:0}.inst-check a{color:var(--edu-accent-ink)}.inst-error{color:var(--inst-bad)}.inst-error,.inst-ok{font-size:var(--edu-meta-size);margin:0}.inst-ok{color:var(--inst-good)}.inst-hp{position:absolute;left:-624.9375rem;width:1px;height:1px;overflow:hidden}.inst-comments{display:grid;gap:var(--edu-s4);list-style:none;margin:var(--edu-s7) 0 0;padding:0}.inst-comment{border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-md);padding:var(--edu-s4) var(--edu-s5);background:var(--edu-card)}.inst-comment--pending{border-style:dashed;border-color:var(--edu-border-accent)}.inst-comment__head{display:flex;flex-wrap:wrap;gap:var(--edu-s3);align-items:baseline;margin-bottom:var(--edu-s2)}.inst-comment__name{font-weight:550;color:var(--edu-text-head);font-size:var(--edu-body-sm-size)}.inst-comment p{margin:0;white-space:pre-wrap;font-size:var(--edu-body-sm-size);color:var(--edu-muted);line-height:1.6}.inst-badge{font-size:var(--edu-meta-sm-size);color:var(--edu-accent-ink);border:var(--edu-border-w) solid var(--edu-border-accent);border-radius:var(--edu-radius-pill);padding:1px .625rem}.inst-quiz{max-width:47.5rem}.inst-quiz__top{position:sticky;top:0;z-index:5;display:flex;align-items:center;justify-content:space-between;gap:var(--edu-s4);padding-block:var(--edu-s3);background:var(--edu-bg);border-bottom:var(--edu-border-w) solid var(--edu-border);margin-bottom:var(--edu-s7)}.inst-timer{font-variant-numeric:tabular-nums;font-size:1.25rem;font-weight:550;color:var(--edu-text-head);display:inline-flex;align-items:center;gap:var(--edu-s2)}.inst-timer--low{color:var(--inst-bad)}.inst-modes{display:inline-flex;border:var(--edu-border-w) solid var(--edu-border-strong);border-radius:var(--edu-radius-pill);padding:.1875rem;gap:2px}.inst-modes button{appearance:none;border:0;background:transparent;font:inherit;font-size:var(--edu-meta-size);padding:.5rem .875rem;border-radius:var(--edu-radius-pill);color:var(--edu-muted);cursor:pointer}.inst-modes button[aria-pressed=true]{background:var(--edu-text-head);color:#fff}.inst-q{padding-block:var(--edu-s6)}.inst-q+.inst-q{border-top:var(--edu-border-w) solid var(--edu-border)}.inst-q__prompt{font-size:var(--edu-card-title-size);line-height:1.4;font-weight:550;color:var(--edu-text-head);margin:0 0 var(--edu-s5)}.inst-q__num{color:var(--edu-subtle);font-weight:400;margin-right:var(--edu-s2)}.inst-options{display:grid;gap:var(--edu-s3);border:0;margin:0;padding:0}.inst-option{display:flex;gap:var(--edu-s3);align-items:flex-start;padding:.875rem var(--edu-s4);border:var(--edu-border-w) solid var(--edu-border-strong);border-radius:var(--edu-radius-md);background:var(--edu-card);cursor:pointer;line-height:1.45;transition:border-color var(--edu-dur) var(--edu-ease),background-color var(--edu-dur) var(--edu-ease)}.inst-option:hover{border-color:var(--edu-accent)}.inst-option input{margin-top:.2em;width:1.125rem;height:1.125rem;accent-color:var(--edu-accent);flex-shrink:0}.inst-option.is-chosen{border-color:var(--edu-accent);background:var(--edu-band-soft)}.inst-option.is-right{border-color:var(--inst-good);background:var(--inst-good-bg);cursor:default}.inst-option.is-wrong{border-color:var(--inst-bad);background:var(--inst-bad-bg);cursor:default}.inst-option.is-static{cursor:default}.inst-option.is-static:hover{border-color:var(--edu-border-strong)}.inst-option__why{display:block;margin-top:var(--edu-s2);font-size:var(--edu-meta-size);color:var(--edu-muted)}.inst-option__tag{margin-left:auto;flex-shrink:0;font-size:var(--edu-meta-sm-size);font-weight:550}.inst-option.is-right .inst-option__tag{color:var(--inst-good)}.inst-option.is-wrong .inst-option__tag{color:var(--inst-bad)}.inst-explain{margin-top:var(--edu-s4);padding:var(--edu-s4);border-radius:var(--edu-radius-md);background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border);font-size:var(--edu-body-sm-size);line-height:1.6}.inst-explain p{margin:0}.inst-explain strong{color:var(--edu-text-head)}.inst-dots{display:flex;flex-wrap:wrap;gap:var(--edu-s2);margin-top:var(--edu-s7)}.inst-dots button{appearance:none;width:2.25rem;height:2.25rem;border-radius:50%;border:var(--edu-border-w) solid var(--edu-border-strong);background:var(--edu-card);font:inherit;font-size:var(--edu-meta-sm-size);color:var(--edu-muted);cursor:pointer}.inst-dots button.is-done{background:var(--edu-band);color:var(--edu-text-head)}.inst-dots button[aria-current=true]{border-color:var(--edu-accent);color:var(--edu-accent-ink);border-width:2px}.inst-dots button.is-right{background:var(--inst-good-bg);border-color:var(--inst-good);color:var(--inst-good)}.inst-dots button.is-wrong{background:var(--inst-bad-bg);border-color:var(--inst-bad);color:var(--inst-bad)}.inst-score{display:flex;flex-wrap:wrap;align-items:baseline;gap:var(--edu-s3) var(--edu-s7);padding:var(--edu-s6);background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-lg);margin-bottom:var(--edu-s7)}.inst-score__big{font-size:var(--edu-metric-size);line-height:1;font-weight:550;color:var(--edu-text-head);letter-spacing:-.03em;font-variant-numeric:tabular-nums}.inst-score__big small{font-size:.4em;color:var(--edu-muted);font-weight:400;letter-spacing:0}.inst-history{list-style:none;margin:0;padding:0;display:grid;gap:var(--edu-s2)}.inst-history li{display:flex;justify-content:space-between;gap:var(--edu-s4);font-size:var(--edu-meta-size);color:var(--edu-muted);padding-block:var(--edu-s2);border-bottom:var(--edu-border-w) solid var(--edu-border);font-variant-numeric:tabular-nums}.inst-studio{display:grid;gap:var(--edu-s7);grid-template-columns:minmax(0,1fr);align-items:start}@media (min-width:1024px){.inst-studio{grid-template-columns:18.75rem minmax(0,1fr)}}.inst-tree{background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-lg);padding:var(--edu-s4)}.inst-tree ul{list-style:none;margin:0;padding:0}.inst-tree li ul{padding-left:var(--edu-s4);border-left:var(--edu-border-w) solid var(--edu-border);margin:var(--edu-s1) 0 var(--edu-s3) var(--edu-s2)}.inst-tree button{appearance:none;width:100%;text-align:left;background:none;border:0;border-radius:var(--edu-radius-sm);font:inherit;font-size:var(--edu-meta-size);padding:.375rem .5rem;color:var(--edu-text);cursor:pointer;display:flex;justify-content:space-between;gap:var(--edu-s2)}.inst-tree button:hover{background:var(--edu-band-soft)}.inst-tree button[aria-current=true]{background:var(--edu-band);font-weight:550;color:var(--edu-text-head)}.inst-tree .inst-tree__add{color:var(--edu-accent-ink)}.inst-tree__draft{color:var(--edu-subtle);font-weight:400;font-size:var(--edu-meta-sm-size)}.inst-editor{background:var(--edu-card);border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-lg);padding:var(--edu-card-pad)}.inst-cols{display:grid;gap:var(--edu-s4);grid-template-columns:repeat(auto-fit,minmax(min(100%,12.5rem),1fr))}.inst-qedit{border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-md);padding:var(--edu-s4);display:grid;gap:var(--edu-s3);background:var(--edu-surface)}.inst-qedit__head{display:flex;justify-content:space-between;align-items:center;gap:var(--edu-s3);flex-wrap:wrap}.inst-optedit{display:grid;gap:var(--edu-s2);grid-template-columns:auto minmax(0,1fr) auto;align-items:start}.inst-optedit input[type=radio]{margin-top:.875rem;width:1.125rem;height:1.125rem;accent-color:var(--edu-accent)}.inst-optedit__why{grid-column:2/3}.inst-preview{border:var(--edu-border-w) dashed var(--edu-border-strong);border-radius:var(--edu-radius-md);padding:var(--edu-s5);max-height:32.5rem;overflow:auto;background:var(--edu-bg)}.inst-mod{display:grid;gap:var(--edu-s3);list-style:none;margin:0;padding:0}.inst-mod li{border:var(--edu-border-w) solid var(--edu-border);border-radius:var(--edu-radius-md);padding:var(--edu-s4);background:var(--edu-card);display:grid;gap:var(--edu-s2)}.inst-mod p{margin:0}.inst-toast{position:fixed;bottom:1.5rem;left:50%;transform:translateX(-50%);background:var(--edu-text-head);color:#fff;padding:.625rem 1.125rem;border-radius:var(--edu-radius-pill);font-size:var(--edu-meta-size);z-index:70;max-width:calc(100vw - 2rem)}.inst-sr{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}