/* Book shell. Article and experimental figure styles remain in style.css. */
/* Sourced chapter epigraphs: native text, neutral surface, no accent rail. */
.book-main .chapter-quote{max-width:760px;margin:28px 0 36px;padding:24px 28px;background:var(--surface);border-radius:6px;break-inside:avoid}
.chapter-quote blockquote{margin:0;padding:0;border:0}
.chapter-quote blockquote>p{margin:0 0 14px;overflow-wrap:anywhere}
.chapter-quote blockquote>p:first-child{font-size:20px;line-height:1.7;color:var(--text)}
.chapter-quote blockquote>p:nth-child(2){font-size:16px;line-height:1.7;color:var(--muted)}
.chapter-quote blockquote>p:last-child{font-size:13px;line-height:1.8;color:var(--muted);margin-bottom:0}
.chapter-quote blockquote>p:last-child em{font-style:normal}
@media(max-width:800px){.book-main .chapter-quote{padding:20px;margin:24px 0 28px}.chapter-quote blockquote>p:first-child{font-size:18px}}
/* Glossary: native text and controls, reusing the book's Material 2 tokens. */
.book-main a.glossary-link{text-decoration-style:dotted;text-underline-offset:.22em}
.book-main a.glossary-link:hover{text-decoration-style:solid}
.glossary-search{margin:28px 0 36px}
.glossary-search label{display:block;font-size:15px;font-weight:500;margin-bottom:8px}
#glossary-query{display:block;width:100%;min-height:52px;padding:12px 16px;font:inherit;font-size:16px;border:1px solid var(--border);border-radius:5px;color:var(--text);background:var(--bg)}
#glossary-query:focus-visible{outline:3px solid var(--primary);outline-offset:2px}
#glossary-status{font-size:13px;color:var(--muted);margin:12px 0}
.book-main .glossary-term{padding:22px 0;border-top:1px solid var(--grid);scroll-margin-top:24px}
.book-main .glossary-term h3{font-size:21px;line-height:1.65;margin:0 0 12px;overflow-wrap:anywhere}
.book-main .glossary-term p{margin:12px 0}
.book-main .glossary-term p:last-child{font-size:13px;margin-bottom:0}
.book-main .glossary-term:target{background:var(--surface);outline:2px solid var(--primary);outline-offset:10px}
.glossary-group[hidden],.glossary-term[hidden],.glossary-search[hidden]{display:none}
@media(max-width:800px){.book-main .glossary-term{scroll-margin-top:92px}.book-main .glossary-term h3{font-size:19px}}
@media print{.glossary-search{display:none}.glossary-group[hidden],.glossary-term[hidden]{display:block}.book-main .glossary-term:target{outline:none}.book-main .glossary-term{break-inside:avoid}}
.book{font-size:17px;line-height:1.85}.book-layout{max-width:1336px;margin:0 auto;display:grid;grid-template-columns:252px minmax(0,848px);gap:80px;padding:0 40px}.book-sidebar{height:100vh;position:sticky;top:0;overflow-y:auto;padding:32px 0 24px;scrollbar-width:thin}.cover-link{display:block;margin-bottom:20px}/* Center each intact logo by its painted bounds; approved PNG padding differs.
   Both painted widths occupy 62% of the cover. Bounds are in brand-cover-provenance.json.
   Select image order so cached markup from before row classes still receives sizing. */
.brand-cover{position:relative;width:100%;aspect-ratio:3/2;background:#000;box-sizing:border-box}.brand-cover img{position:absolute;display:block;width:100%;height:auto;max-width:100%;left:50%;object-fit:contain}.brand-cover>img:first-of-type{width:81.814433%;top:32%;transform:translate(-41.992188%,-50.438596%)}.brand-cover>img:nth-of-type(2){width:98.278638%;top:68%;transform:translate(-49.902344%,-50.219298%)}.book-cover{display:block}.book-name{display:block;font-size:17px;line-height:1.5;font-weight:500;color:var(--text);text-decoration:none;margin-bottom:24px;max-width:200px}.search-trigger{width:100%;display:flex;justify-content:flex-start;gap:9px;background:var(--surface);border:1px solid var(--grid);padding:10px 12px;border-radius:6px;margin-bottom:24px;font-size:14px}.search-trigger svg{width:20px;height:20px;flex-shrink:0}.search-trigger kbd{font-family:Roboto,sans-serif;font-size:11px;color:var(--muted);margin-left:auto;white-space:nowrap;border:1px solid var(--border);padding:1px 5px;border-radius:3px;background:var(--bg)}.book-nav{display:flex;flex-direction:column;gap:4px}.book-link{font-size:14px;line-height:1.6;padding:12px 14px;text-decoration:none;color:var(--muted);min-height:48px;border-radius:5px}.book-link.current{color:var(--primary);font-weight:500;background:var(--surface)}.book-link:hover{background:var(--surface);color:var(--primary)}.book-sidebar-footer{margin:28px 14px 0;padding-top:20px;border-top:1px solid var(--grid);display:flex;flex-direction:column;gap:12px;font-size:12px}.book-sidebar-footer a{color:var(--muted);text-decoration:none}.book-sidebar-footer a:hover{color:var(--primary)}.book-sidebar-footer button{min-height:48px;align-self:flex-start;background:transparent;border:0;padding:4px 0;font-size:12px;color:var(--muted)}.book-main{min-width:0;padding:30px 0 64px}.page-topline{display:flex;justify-content:space-between;align-items:center;gap:16px;font-size:12px;color:var(--muted);margin-bottom:54px}.page-topline button{padding:8px 0;min-height:48px;border:0;background:transparent;color:var(--muted);font-size:12px}.book-main h1{font-size:clamp(36px,4vw,48px);line-height:1.4;letter-spacing:-.025em;margin:0 0 28px;font-weight:500}.welcome-main{max-width:780px}.welcome-main h1{font-size:48px;line-height:1.15;margin-bottom:24px}.welcome-lead{font-size:clamp(23px,2.3vw,30px);line-height:1.55;font-weight:400;letter-spacing:-.02em;margin:0 0 32px}.welcome-main>p{max-width:720px;margin:22px 0}.welcome-main h2{font-size:24px;margin:48px 0 18px}.welcome-main ul{padding-left:22px;margin:20px 0}.welcome-main li{padding-left:6px;margin:14px 0;font-size:16px}.reading-entry{margin:24px 0 36px;padding:24px 28px;background:var(--surface);border-radius:6px}.reading-entry h3{font-size:22px;margin:8px 0 12px}.reading-entry h3 a{text-decoration:none;color:var(--text);display:block}.reading-entry h3 a:hover{color:var(--primary)}.reading-entry h3 span{float:right;font-size:20px;color:var(--muted)}.reading-entry p:not(.eyebrow){font-size:13px;line-height:1.8;color:var(--muted);margin:0 0 18px}.reading-entry .text-link{font-size:14px;text-decoration:none;display:inline-flex;min-height:48px;align-items:center}.welcome-download{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin:32px 0;font-size:14px}.book-footer{border-top:1px solid var(--grid);padding-top:24px;margin-top:56px;font-size:12px;color:var(--muted);display:flex;justify-content:space-between;gap:12px}.book-mobile-header,.mobile-cover{display:none}.page-contents{border:0;margin:20px 14px 0}.page-contents summary{font-size:12px;color:var(--muted);min-height:48px;padding:12px 0}.page-contents nav{display:flex;flex-direction:column;gap:0}.page-contents a{font-size:12px;color:var(--muted);text-decoration:none;line-height:1.6;padding:8px 0;min-height:36px}.page-contents a:hover{color:var(--primary)}.lesson-page .book-main>h1{max-width:730px}.lesson-page .book-main .lead{font-size:21px;color:var(--muted);margin-bottom:36px}.book-main .lab{max-width:100%}.book-main>section{scroll-margin-top:20px}.book-main h2{scroll-margin-top:30px}.book-main .sources h2{font-size:24px}.book-main .equation{max-width:100%}
#search-dialog{width:min(660px,calc(100vw - 32px));max-height:min(80vh,800px);padding:24px;border:1px solid var(--border);border-radius:10px;background:var(--bg);color:var(--text);box-shadow:0 12px 60px #0003;overflow:auto}#search-dialog::backdrop{background:#0005}.search-dialog-heading{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:16px}.search-dialog-heading h2{font-size:19px;margin:0}.search-dialog-heading button{font-size:13px;background:transparent}#search-input{display:block;width:100%;font:inherit;font-size:16px;padding:14px 16px;border:1px solid var(--border);border-radius:5px;background:var(--surface);color:var(--text);min-height:52px}#search-input:focus-visible{outline:3px solid var(--primary);outline-offset:2px}#search-status{font-size:13px;color:var(--muted);margin:18px 0}#search-results a{display:block;text-decoration:none;color:var(--text);padding:14px 12px;border-top:1px solid var(--grid)}#search-results a:hover{background:var(--surface)}#search-results small{font-size:11px;color:var(--muted);display:block}#search-results strong{display:block;font-size:16px;margin:3px 0 6px}#search-results span{display:block;font-size:12px;line-height:1.7;color:var(--muted)}
@media(max-width:1100px){.book-layout{grid-template-columns:220px minmax(0,1fr);gap:44px;padding:0 28px}.book-sidebar{padding-top:24px}.book-main{padding-top:20px}.page-topline{margin-bottom:40px}.book-main .lab{padding:24px}}
@media(max-width:800px){.book-layout{display:block;padding:0 24px;overflow-x:clip}.book-mobile-header{display:flex;justify-content:space-between;gap:16px;align-items:center;position:sticky;top:0;z-index:12;background:var(--bg);padding:8px 20px;border-bottom:1px solid var(--grid)}.book-mobile-header>a{font-size:13px;line-height:1.45;font-weight:500;color:var(--text);text-decoration:none;max-width:190px}.book-mobile-header button{font-size:12px;padding:10px 12px;min-height:48px;background:transparent}.book-sidebar{display:none;position:relative;height:auto;padding:20px 0;overflow:visible;border-bottom:1px solid var(--grid)}.menu-open .book-sidebar{display:block}.menu-open .book-sidebar .cover-link,.menu-open .book-name{display:none}.book-sidebar-footer{margin-top:16px}.page-contents{display:none}.book-main{padding:24px 0 48px;overflow-x:clip}.page-topline{display:none}.mobile-cover{display:block;max-width:390px;margin:0 auto 32px}.welcome-main h1{font-size:40px;margin-bottom:20px}.welcome-lead{font-size:25px;line-height:1.6;margin-bottom:28px}.book{font-size:16px;line-height:1.9}.welcome-main h2{font-size:23px;margin-top:40px}.welcome-main li{font-size:15px}.reading-entry{padding:22px}.reading-entry h3{font-size:20px;line-height:1.7}.reading-entry h3 span{display:none}.book-footer{font-size:11px;margin-top:40px;flex-wrap:wrap}.book-main h1{font-size:33px;line-height:1.55}.book-main h2{scroll-margin-top:88px}.book-main .lab{padding:18px 12px}.book-main>section{scroll-margin-top:72px}.book-main .lead{font-size:19px}.book-main .equation{font-size:15px}#search-dialog{padding:20px}.search-dialog-heading h2{font-size:17px}}
@media print{.book-layout{display:block;padding:0}.book-sidebar,.book-mobile-header,.page-topline,.mobile-cover,#search-dialog{display:none!important}.book-main{max-width:none;padding:0}.book-footer{margin-top:30px}.book-main h1{font-size:30pt}}

/* Welcome editorial refresh. Route: no-image-generator.
   QuantCorner / Quantseras Design System; existing approved logos unchanged. */
.welcome-main .welcome-hero{padding-bottom:32px;border-bottom:1px solid var(--grid)}
.welcome-main .welcome-kicker{font-size:13px;color:var(--muted);margin:0 0 16px}
.welcome-main .welcome-lead{font-size:clamp(28px,3vw,40px);font-weight:500;line-height:1.5;letter-spacing:0;margin:0 0 20px;text-wrap:balance}
.welcome-main .welcome-summary{font-size:18px;line-height:1.85;max-width:640px;margin:0 0 24px;color:var(--muted)}
.welcome-actions{display:flex;align-items:center;flex-wrap:wrap;gap:12px 24px}
.welcome-actions .button{gap:16px;padding-inline:24px}
.welcome-main .welcome-text-link{display:inline-flex;align-items:center;gap:8px;min-height:48px;font-size:14px;line-height:1.7;text-decoration:none;overflow-wrap:anywhere}
.welcome-main .welcome-text-link:hover{text-decoration:underline;text-underline-offset:5px}
.welcome-main .welcome-format{font-size:13px;color:var(--muted);margin:24px 0 0}
.welcome-preparation{background:var(--surface);border-radius:6px;padding:24px 28px;margin:28px 0 40px}
.welcome-main .welcome-preparation h2,.welcome-main .welcome-resources h3{font-size:19px;font-weight:500;margin:0 0 12px}
.welcome-main .welcome-preparation p,.welcome-main .welcome-resources p{font-size:15px;line-height:1.85;margin:0 0 8px}
.welcome-main .welcome-lessons{margin:28px 0 40px}
.welcome-lesson{display:grid;grid-template-columns:48px minmax(0,1fr);gap:24px;border-top:1px solid var(--grid);padding:24px 0}
.welcome-lesson:last-child{border-bottom:1px solid var(--grid)}
.welcome-lesson-number{font-size:26px;font-weight:400;font-variant-numeric:tabular-nums;line-height:1.5;color:var(--muted)}
.welcome-main .welcome-lesson-label{font-size:12px;color:var(--muted);margin:0 0 6px}
.welcome-main .welcome-lesson h3{font-size:22px;line-height:1.55;margin:0 0 8px;font-weight:500;overflow-wrap:anywhere}
.welcome-lesson h3 a{color:var(--text);text-decoration:none}
.welcome-lesson h3 a:hover{color:var(--primary);text-decoration:underline}
.welcome-main .welcome-lesson p{font-size:15px;line-height:1.8;margin:0 0 8px}
.welcome-main .welcome-lesson .welcome-lesson-label{font-size:12px}
.welcome-main .welcome-lesson .welcome-topics{font-size:13px;color:var(--muted);margin-bottom:4px}
.welcome-resources{padding:28px;background:var(--surface);border-radius:6px;margin-top:32px}
.welcome-resources .welcome-download{margin:12px 0 0;gap:8px 24px}
.welcome-resources .welcome-download a{display:inline-flex;align-items:center;min-height:48px;font-size:14px}
@media(max-width:800px){
 .welcome-main .welcome-lead{font-size:clamp(25px,5vw,36px)}
 .welcome-main .welcome-summary{font-size:16px}
 .welcome-main .welcome-format{max-width:320px;line-height:1.9}
 .welcome-preparation,.welcome-resources{padding:20px}
 .welcome-lesson{grid-template-columns:32px minmax(0,1fr);gap:12px;padding:24px 0}
 .welcome-lesson-number{font-size:22px}
 .welcome-main .welcome-lesson h3{font-size:20px}
 .welcome-main .welcome-lesson .welcome-text-link{font-size:13px}
}
@media print{
 .welcome-main .welcome-hero{padding-bottom:20px}
 .welcome-preparation,.welcome-lesson,.welcome-resources{break-inside:avoid}
}

/* Licensed editorial photograph; the image file is an unmodified Commons thumbnail. */
.welcome-photo{margin:32px 0 40px}
.welcome-photo img{display:block;width:100%;height:auto;border-radius:6px}
.welcome-photo figcaption{margin-top:10px;font-size:12px;line-height:1.8;color:var(--muted)}
.welcome-photo figcaption a{color:inherit;text-underline-offset:3px}
@media(max-width:800px){.welcome-photo{margin:24px 0 32px}}

/* Shared author tie-in, rendered from author_profile in _config.yml. */
.author-card{display:flex;align-items:flex-start;gap:24px;margin:56px 0 0;padding:28px;border:1px solid var(--grid);border-radius:12px;background:var(--surface,var(--paper))}
.author-card-welcome{margin:32px 0}
.author-portrait{width:112px;height:112px;object-fit:cover;border-radius:50%;flex-shrink:0}
.author-copy{min-width:0;flex:1}
.book-main .author-label{margin:0 0 6px;color:var(--muted);font-size:13px;letter-spacing:.02em}
.book-main .author-card h2{margin:0 0 12px;padding:0;border:0;font-size:22px;line-height:1.4;overflow-wrap:anywhere}
.book-main .author-copy>p:not(.author-label){font-size:15px;line-height:1.85;margin:0 0 12px}
.book-main .author-copy .author-invitation{color:var(--muted);font-size:14px}
.author-links{display:flex;flex-wrap:wrap;gap:4px 24px}
.author-links a{display:inline-flex;align-items:center;gap:6px;min-height:48px;font-size:14px;text-underline-offset:4px}
@media(max-width:800px){.author-card{padding:20px;gap:16px;flex-direction:column}.author-portrait{width:88px;height:88px}.book-main .author-card h2{font-size:20px}}
@media print{.author-card{break-inside:avoid}}

/* Keep referenced equations below the sticky mobile header. */
.equation-anchor{scroll-margin-top:6rem}

/* Wide source tables remain readable and keyboard-scrollable on small screens. */
.table-scroll{max-width:100%;overflow-x:auto;margin:24px 0}
.table-scroll table{min-width:600px;max-width:none;margin:0}
.table-scroll [id="tab:vrp_summary"]{min-width:960px}
.table-scroll:focus-visible{outline:3px solid var(--primary);outline-offset:3px}
@media print{.table-scroll{overflow:visible}.table-scroll table,.table-scroll [id="tab:vrp_summary"]{min-width:0;font-size:10px}}

/* Interactive lessons: native computed SVG, QuantCorner no-image-generator route. */
.viz-lab{position:relative;scroll-margin-top:88px}
.viz-lab .lab-title{padding-right:72px}
.viz-reset{position:absolute;top:24px;right:20px;font-size:12px}
.viz-choice{margin:12px 0 20px}.viz-choice label{display:block;font-size:14px;margin-bottom:8px}.viz-choice select{width:100%;max-width:100%}
.viz-stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:16px}
.viz-stats strong{font-size:clamp(19px,3vw,28px)!important;overflow-wrap:anywhere}
.viz-legend{display:flex;flex-wrap:wrap;gap:8px 20px;font-size:13px;margin:24px 0 4px}
.viz-legend>span{display:inline-flex;align-items:center;gap:8px}
.viz-key{display:inline-block;width:24px;border-top:3px solid var(--primary)}
.viz-key-1{border-color:var(--text);border-top-style:dashed}.viz-key-2{border-color:var(--primary);border-top-style:dotted}
.viz-line-0{stroke:var(--primary)}.viz-line-1{stroke:var(--text);stroke-dasharray:8 5}.viz-line-2{stroke:var(--primary);stroke-dasharray:2 5;stroke-width:3}
.viz-data{font-size:13px;margin-top:12px}.viz-data summary{cursor:pointer;min-height:48px;padding:12px 0}.viz-data table{font-size:12px}
.viz-tree-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--grid);border-radius:6px;margin:24px 0}
.viz-tree-scroll:focus-visible{outline:3px solid var(--primary);outline-offset:3px}
.viz-tree-scroll svg{display:block;width:100%;min-width:760px;height:430px}.viz-tree-scroll text{font-size:11px;fill:var(--text)}
.viz-tree-edge{stroke:var(--border);stroke-width:1.5}.viz-node{fill:var(--surface);stroke:var(--primary)}.viz-node.exercise{fill:var(--bg);stroke:var(--text);stroke-dasharray:3 2}
.viz-lab input[type=range]{width:100%}.interactive-mount{scroll-margin-top:90px}
.viz-directory{padding:24px;background:var(--surface);border-radius:6px;margin:32px 0}.viz-directory ul{margin:12px 0}.viz-directory a{display:inline-flex;min-height:48px;align-items:center}
@media(max-width:600px){.viz-lab .lab-title{padding-right:0}.viz-reset{position:static;margin-bottom:16px}.viz-stats{grid-template-columns:repeat(2,minmax(0,1fr))}.viz-legend{gap:8px}.viz-lab .controls.two{grid-template-columns:1fr}}