/* Rest Math • v2026.09.08 — shared screen and print design system. */
:root{--bg:#f8faf9;--paper:#fff;--ink:#182e34;--muted:#627579;--line:#dae4e2;--accent:#087c73;--accent-strong:#065a54;--soft:#e9f3ef;--warm:#faf4e7;--warm-ink:#886324;--header:76px;--reading-size:18px;--radius:16px;color-scheme:light;--shadow:0 12px 38px #143c3610}
:root[data-theme=dark]{--bg:#101d21;--paper:#182a2f;--ink:#edf5f2;--muted:#abc0c0;--line:#30454a;--accent:#76cebf;--accent-strong:#a4e9d9;--soft:#193c38;--warm:#383224;--warm-ink:#e4c791;color-scheme:dark;--shadow:0 12px 38px #0002}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.7 -apple-system,BlinkMacSystemFont,'Segoe UI','Noto Sans CJK KR','Malgun Gothic',sans-serif;-webkit-text-size-adjust:100%;text-size-adjust:100%}button,input,textarea,select{font:inherit}button,a,input,textarea,select{touch-action:manipulation}a{color:inherit;text-decoration:none}button{cursor:pointer}button:disabled{opacity:.5;cursor:not-allowed}button,a,input,textarea,select,summary{outline-offset:5px}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--accent)}button{border:0}button,input,textarea,select{color:var(--ink)}button{background:transparent}img,svg{max-width:100%}h1,h2,h3,h4,p{margin-top:0}h1,h2,h3,h4{line-height:1.35;word-break:keep-all;overflow-wrap:anywhere}p{word-break:keep-all;overflow-wrap:anywhere}h1{font-size:clamp(34px,4.3vw,58px);letter-spacing:-.045em}h2{font-size:30px;letter-spacing:-.035em}h3{font-size:21px;letter-spacing:-.025em}[hidden]{display:none!important}.skip-link{position:fixed;left:16px;top:-80px;z-index:1000;padding:10px 18px;background:var(--ink);color:var(--paper)}.skip-link:focus{top:12px}.wrap{width:min(1200px,calc(100% - 64px));margin-inline:auto}.site-header{height:var(--header);position:sticky;top:0;z-index:50;background:var(--paper);border-bottom:1px solid var(--line)}.header-inner{height:100%;display:flex;align-items:center;gap:30px}.brand{display:inline-flex;align-items:center;gap:11px;white-space:nowrap}.brand-mark{width:35px;height:35px;display:grid;place-items:center;border:1.5px solid var(--accent);border-radius:9px;color:var(--accent);font:italic 29px/1 Georgia,'Times New Roman',serif}.brand-name{font-size:25px;font-weight:750;letter-spacing:-1.2px}.brand-name em{color:var(--accent);font-style:normal}.brand-sub{display:block;font-size:9px;letter-spacing:.2em;color:var(--muted);line-height:1;margin-top:1px}.main-nav{display:flex;gap:28px;align-items:center;margin-left:auto;font-size:14px;font-weight:600}.main-nav a{padding-block:23px;position:relative}.main-nav a:hover,.main-nav a.active{color:var(--accent)}.main-nav a.active:after{content:'';height:2px;position:absolute;bottom:14px;left:0;right:0;background:var(--accent)}.header-actions{display:flex;gap:6px;align-items:center}.icon-button{height:40px;min-width:40px;display:inline-flex;align-items:center;justify-content:center;border-radius:10px;color:var(--ink)}.icon-button:hover{background:var(--soft)}.icon-button svg{width:19px;height:19px;stroke:currentColor;fill:none;stroke-width:1.65;stroke-linecap:round;stroke-linejoin:round}.menu-button{display:none}.reading-progress{height:2px;background:var(--accent);position:fixed;top:calc(var(--header) - 1px);left:0;width:0;z-index:60;transition:width .1s linear}.eyebrow{font-size:11px;font-weight:750;letter-spacing:.18em;text-transform:uppercase;color:var(--accent);margin-bottom:18px}.hero{padding:72px 0 58px;display:grid;grid-template-columns:1.15fr 1fr;gap:64px;align-items:center}.hero h1{margin-bottom:24px}.hero h1 em{font-style:normal;color:var(--accent)}.hero-description{color:var(--muted);font-size:17px;line-height:1.95;max-width:590px;margin-bottom:29px}.actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.button{border-radius:9px;padding:11px 18px;font-weight:650;font-size:14px;line-height:1.5;display:inline-flex;align-items:center;gap:10px;justify-content:center;min-height:44px;border:1px solid var(--line);background:var(--paper)}.button:hover{border-color:var(--accent);color:var(--accent)}.button.primary{background:var(--accent);border-color:var(--accent);color:#fff}.button.primary:hover{background:var(--accent-strong)}:root[data-theme=dark] .button.primary{color:#102420}.button.small{font-size:12px;min-height:36px;padding:7px 11px}.text-link{color:var(--accent);font-size:14px;font-weight:600}.text-link:hover{text-decoration:underline}.hero-panel{min-height:352px;border:1px solid var(--line);border-radius:22px;background:var(--soft);position:relative;overflow:hidden;padding:24px 26px 20px;background-image:linear-gradient(var(--line) 1px,transparent 1px),linear-gradient(90deg,var(--line) 1px,transparent 1px);background-size:28px 28px}.hero-panel::before{content:'';position:absolute;inset:0;background:radial-gradient(ellipse at 45% 45%,transparent,var(--soft) 90%);pointer-events:none}.panel-cap,.panel-bottom{position:relative;display:flex;justify-content:space-between;align-items:center;font-size:10px;letter-spacing:.16em;font-weight:650;color:var(--accent-strong)}.panel-cap span:last-child{font-size:9px;color:var(--muted)}.hero-coordinates{display:block;width:100%;height:236px;position:relative}.hero-coordinates .axis{stroke:var(--muted);stroke-width:1.2}.hero-coordinates .accent-axis{stroke:var(--accent);stroke-width:2}.hero-coordinates .orb{stroke:var(--accent);opacity:.2;fill:none}.hero-coordinates text{fill:var(--ink);font:italic 16px Georgia,serif}.hero-coordinates .solid{fill:var(--accent)}.panel-bottom{border-top:1px solid var(--line);padding-top:16px;letter-spacing:.03em}.panel-bottom .math-unit{font-size:20px;color:var(--ink)}.context-strip{display:grid;grid-template-columns:1fr 1fr 1.7fr;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:23px 0;margin-bottom:66px}.context-item{padding-inline:26px;border-right:1px solid var(--line);display:flex;gap:14px;align-items:center}.context-item:first-child{padding-left:0}.context-item:last-child{border:0}.context-item strong{font-size:29px;letter-spacing:-1px;line-height:1.1}.context-item span{font-size:12px;color:var(--muted);line-height:1.65}.context-item:last-child strong{font-size:16px;letter-spacing:-.3px;display:block;margin-bottom:4px}.section-top{display:flex;justify-content:space-between;align-items:end;gap:24px;margin-bottom:25px}.section-top h2{margin:0 0 8px}.section-top p{color:var(--muted);font-size:14px;margin:0}.section-number{font:12px/1.5 ui-monospace,Consolas,monospace;color:var(--accent);margin-bottom:8px;display:block}.library-section{padding-bottom:72px;scroll-margin-top:100px}.search-row{display:flex;gap:14px;margin-bottom:18px}.search-field{display:flex;align-items:center;gap:12px;background:var(--paper);border:1px solid var(--line);border-radius:11px;padding:0 16px;flex:1;min-width:0}.search-field:focus-within{border-color:var(--accent);box-shadow:0 0 0 3px var(--soft)}.search-field svg{height:20px;width:20px;stroke:var(--muted);fill:none;stroke-width:1.5;flex:none}.search-field input{height:51px;flex:1;min-width:0;border:0;outline:none;background:transparent;font-size:15px}.search-field kbd{border:1px solid var(--line);border-radius:4px;padding:0 5px;font-size:11px;color:var(--muted)}.filter-row{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:26px}.filter-chip{border:1px solid var(--line);border-radius:7px;font-size:12px;padding:7px 11px;background:var(--paper);display:flex;align-items:center;gap:7px;min-height:37px}.filter-chip span{font:11px ui-monospace,monospace;opacity:.65}.filter-chip[aria-pressed=true]{background:var(--ink);border-color:var(--ink);color:var(--paper)}.results-meta{font-size:12px;color:var(--muted);display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}.results-meta button{font-size:12px;color:var(--accent)}.article-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.note-card{background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:22px 23px;position:relative;min-height:248px;display:flex;flex-direction:column;transition:transform .2s,border-color .2s,box-shadow .2s}.note-card:hover{transform:translateY(-3px);border-color:var(--accent);box-shadow:var(--shadow)}.note-card .category{font-size:10px;color:var(--accent);letter-spacing:.05em;font-weight:700;display:flex;gap:7px;align-items:center;margin-bottom:22px;padding-right:30px}.category:before{content:'';height:5px;width:5px;background:currentColor;border-radius:50%}.note-card h3{font-size:20px;line-height:1.45;margin-bottom:4px;letter-spacing:-.035em}.note-card .english{font-size:11px;color:var(--muted);margin-bottom:14px;line-height:1.4}.note-card p{font-size:13px;line-height:1.8;color:var(--muted);margin-bottom:24px}.note-card footer{margin-top:auto;padding-top:12px;border-top:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;font-size:11px}.note-card footer a{font-weight:650;color:var(--accent)}.note-card footer .note-no{font:10px ui-monospace,Consolas,monospace;color:var(--muted)}.print-select{position:absolute;right:18px;top:18px;display:grid;place-items:center;width:28px;height:28px;cursor:pointer}.print-select input{accent-color:var(--accent);width:15px;height:15px;cursor:pointer}.more-row{text-align:center;margin-top:26px}.empty-state{padding:54px 22px;border:1px dashed var(--line);text-align:center;border-radius:12px;color:var(--muted)}.paths-section{padding:58px 0 64px;background:var(--soft);border-block:1px solid var(--line)}.paths-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:36px}.path-card{padding-right:24px;border-right:1px solid var(--line)}.path-card:last-child{border:0;padding-right:0}.path-symbol{font:italic 31px Georgia,serif;color:var(--accent);margin-bottom:12px}.path-card h3{font-size:20px;margin-bottom:10px}.path-card>p{color:var(--muted);font-size:13px;margin-bottom:20px}.path-step{display:flex;align-items:center;gap:12px;padding:9px 0;font-size:13px}.path-step span{font:10px ui-monospace,monospace;border:1px solid var(--line);border-radius:50%;width:24px;height:24px;display:grid;place-items:center;flex:none;color:var(--accent)}.path-step:hover{color:var(--accent)}.tools-teaser{padding:62px 0;display:grid;grid-template-columns:1fr 1fr;gap:42px;align-items:center}.tools-teaser h2{font-size:31px}.tools-teaser p{font-size:15px;color:var(--muted)}.tool-links{display:grid;gap:10px}.tool-entry{border:1px solid var(--line);border-radius:10px;padding:16px 19px;background:var(--paper);display:flex;align-items:center;justify-content:space-between}.tool-entry strong{font-size:14px}.tool-entry small{display:block;color:var(--muted);font-size:11px;margin-top:3px}.tool-entry:hover{border-color:var(--accent)}.about-teaser{border-top:1px solid var(--line);padding:40px 0 48px;display:grid;grid-template-columns:180px 1fr auto;gap:30px;align-items:center}.about-teaser .mini-brand{font:italic 23px Georgia,serif;color:var(--accent)}.about-teaser p{font-size:14px;color:var(--muted);margin:0}.site-footer{padding:30px 0;background:var(--paper);border-top:1px solid var(--line);font-size:11px;color:var(--muted)}.footer-inner{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}.footer-links{display:flex;gap:22px;flex-wrap:wrap}.footer-links a:hover{color:var(--accent)}.print-tray{position:fixed;bottom:20px;left:50%;transform:translateX(-50%);z-index:45;box-shadow:0 8px 30px #0002;background:var(--ink);color:var(--paper);display:flex;gap:22px;align-items:center;padding:13px 17px 13px 22px;border-radius:13px;width:max-content;max-width:calc(100% - 28px)}.print-tray p{font-size:13px;margin:0}.print-tray .button{min-height:34px;padding:7px 12px;font-size:12px}.print-tray button:not(.button){color:var(--paper);font-size:12px}.toast{position:fixed;bottom:26px;left:50%;transform:translateX(-50%);padding:11px 20px;border-radius:10px;background:var(--ink);color:var(--paper);box-shadow:var(--shadow);z-index:300;font-size:13px;max-width:calc(100% - 30px);text-align:center;pointer-events:none}.modal{border:1px solid var(--line);background:var(--paper);color:var(--ink);border-radius:16px;padding:0;max-width:720px;width:calc(100% - 32px);max-height:85vh;box-shadow:0 25px 80px #0004}.modal::backdrop{background:#102d3366;backdrop-filter:blur(3px)}.modal-head{display:flex;align-items:center;justify-content:space-between;padding:20px 24px;border-bottom:1px solid var(--line)}.modal-head h2{font-size:18px;margin:0}.modal-body{padding:24px}.modal textarea{width:100%;min-height:160px;background:var(--bg);border:1px solid var(--line);border-radius:9px;padding:15px;font:13px/1.8 ui-monospace,Consolas,monospace;resize:vertical;white-space:pre-wrap;overflow-wrap:anywhere}.modal label{font-size:12px;display:block;color:var(--muted);margin:16px 0 6px}.modal .formula-preview{overflow-x:auto;padding:18px;background:var(--soft);border-radius:9px}.modal .formula-preview math{font-size:23px}.modal .source-note{font-size:12px;color:var(--muted);margin-top:16px}.settings-line{display:flex;align-items:center;gap:10px;justify-content:space-between;margin-bottom:20px}.settings-line p{margin:0;font-size:14px}.settings-controls{display:flex;gap:6px}.mobile-nav-links{display:grid;gap:4px}.mobile-nav-links a{padding:12px 0;border-bottom:1px solid var(--line);font-size:16px}.search-results{list-style:none;padding:0;margin:15px 0 0;max-height:50vh;overflow:auto}.search-results li{border-bottom:1px solid var(--line)}.search-results a{display:block;padding:15px 5px}.search-results strong{display:block;font-size:15px}.search-results small{font-size:11px;color:var(--muted)}.search-results a:hover{color:var(--accent)}
/* Reader */
.reader-wrap{width:min(1190px,calc(100% - 64px));margin:0 auto}.breadcrumb{font-size:11px;color:var(--muted);padding:25px 0;display:flex;gap:9px;flex-wrap:wrap}.breadcrumb a:hover{color:var(--accent)}.reader-layout{display:grid;grid-template-columns:216px minmax(0,1fr);gap:54px;padding-bottom:80px}.reader-toc{position:sticky;top:108px;align-self:start;max-height:calc(100vh - 145px);overflow:auto;overscroll-behavior:contain;padding-right:15px}.toc-label{font-size:10px;letter-spacing:.15em;color:var(--muted);font-weight:700;margin:4px 0 18px}.toc-list{list-style:none;margin:0 0 25px;padding:0;border-left:1px solid var(--line)}.toc-list a{display:block;padding:7px 0 7px 16px;line-height:1.7;font-size:11px;color:var(--muted);word-break:break-word;overflow-wrap:anywhere}.toc-list a.active{color:var(--accent);border-left:2px solid var(--accent);margin-left:-1px}.toc-list a:hover{color:var(--accent)}.toc-bottom{padding-top:18px;border-top:1px solid var(--line);font-size:11px;display:grid;gap:12px;color:var(--muted)}.reader-article{min-width:0;max-width:870px}.article-head{padding:12px 0 26px;border-bottom:1px solid var(--line);margin-bottom:30px}.article-head .eyebrow{margin-bottom:18px;font-size:10px}.article-head h1{font-size:clamp(29px,3.6vw,43px);margin:0 0 8px;line-height:1.36}.article-head .article-english{font-size:15px;color:var(--muted);margin-bottom:23px}.article-description{font-size:16px;line-height:1.85;margin-bottom:22px}.article-meta{display:flex;align-items:center;gap:14px;flex-wrap:wrap;font-size:11px;color:var(--muted)}.article-meta .meta-divider{width:1px;height:12px;background:var(--line)}.reader-toolbar{display:flex;align-items:center;gap:7px;flex-wrap:wrap;margin-top:20px}.reader-toolbar .button{font-size:11px;min-height:34px;padding:7px 10px}.mobile-toc-button{display:none}.reader-note{border-left:3px solid var(--accent);padding:12px 16px;background:var(--soft);font-size:12px;line-height:1.85;margin-bottom:30px;border-radius:0 8px 8px 0}.reader-note strong{display:block;margin-bottom:3px}.reader-note p{margin:0;color:var(--muted)}.article-content{font-size:var(--reading-size);line-height:1.9}.article-content .section-heading{margin:42px 0 20px;font-size:24px;line-height:1.5;letter-spacing:-.02em;border-top:1px solid var(--line);padding-top:24px;scroll-margin-top:105px}.article-content h3.section-heading{font-size:19px;padding-top:0;border-top:0;margin-top:30px;margin-bottom:15px}.article-content .minor-heading{font-size:14px;line-height:1.7;font-weight:650;color:var(--muted);margin:24px 0 10px}.article-content .section-intro{color:var(--muted);font-size:16px;line-height:1.8;margin:14px 0 22px}.article-content .source-paragraph{margin:10px 0 16px;font-size:1em;font-weight:400;line-height:1.9;word-break:normal}.formula-line{position:relative;margin:10px 0 15px;padding:8px 8px 8px 16px;border-left:2px solid var(--line);min-width:0;max-width:100%;overflow-x:auto;overflow-y:hidden;scrollbar-width:thin}.formula-line:hover{border-left-color:var(--accent)}.math-unit{vertical-align:middle;max-width:100%;font-weight:400}.math-unit math{font-family:'Cambria Math','STIX Two Math','STIX Math','DejaVu Math TeX Gyre',math;font-size:1.1em}.math-unit math[display=block]{text-align:left;margin:4px 0;display:block math;max-width:none}.source-paragraph .math-unit math,.section-heading .math-unit math,.minor-heading .math-unit math{font-size:1em}.formula-line .math-unit{display:inline-block;vertical-align:middle}.formula-line>.math-unit:only-child{display:block;width:max-content;min-width:1px;max-width:none;padding-right:32px}.math-copy{position:absolute;right:0;top:0;background:var(--paper);color:var(--muted);padding:3px 7px;border-radius:5px;font-size:9px;opacity:0;border:1px solid var(--line);z-index:2}.formula-line:hover .math-copy,.formula-line:focus-within .math-copy{opacity:1}.math-unit[data-tex]{cursor:zoom-in}.math-unit[data-tex]:hover{color:var(--accent-strong)}.original-media{display:inline-flex;flex-direction:column;align-items:flex-start;max-width:100%;gap:6px;padding:6px 0;vertical-align:middle}.original-media img{height:auto;width:auto;max-width:100%;object-fit:contain;display:block;background:#fff}.media-unavailable{border:1px dashed var(--line);border-radius:7px;padding:15px 18px;font:12px/1.8 -apple-system,BlinkMacSystemFont,'Segoe UI','Noto Sans CJK KR',sans-serif;color:var(--muted);background:var(--paper);max-width:100%;word-break:break-all}.media-unavailable small{display:block;font:10px/1.7 ui-monospace,monospace;margin-top:5px}.source-figure{margin:26px 0;max-width:100%}.source-figure .original-media{display:flex;align-items:center}.source-figure .media-unavailable{width:100%;text-align:center;padding:30px}.source-code,.source-inline{font:12px/1.9 ui-monospace,Consolas,monospace;white-space:pre-wrap;overflow-wrap:anywhere;background:var(--soft);border-radius:4px;padding:2px 5px}.derivation{border:0;margin:0}.derivation>summary{cursor:pointer;list-style:none;position:relative}.derivation>summary::-webkit-details-marker{display:none}.derivation>summary:after{content:'−';position:absolute;right:1px;top:28px;color:var(--accent);font-size:22px}.derivation:not([open])>summary:after{content:'+'}.derivation>summary h2{padding-right:30px;margin-bottom:18px}.derivation .source-section{padding-bottom:5px}.table-scroll{overflow:auto;max-width:100%;margin:20px 0;scrollbar-width:thin}.data-table{border-collapse:collapse;max-width:100%;font-size:14px;line-height:1.75;background:var(--paper)}.data-table td,.data-table th{border:1px solid var(--line);padding:9px 11px;vertical-align:middle;text-align:left}.data-table tr:first-child{background:var(--soft)}.data-table .math-unit math{font-size:17px}.video-box{background:var(--soft);border:1px solid var(--line);padding:19px;border-radius:10px;display:flex;align-items:center;gap:18px;flex-wrap:wrap;margin:16px 0 28px;font-size:12px}.video-play{font-weight:700;color:var(--accent);padding:6px 0}.video-link{color:var(--muted);font-size:11px}.video-box iframe{display:block;width:100%;aspect-ratio:16/9;border:0;height:auto}.source-provenance{border:1px solid var(--line);border-radius:10px;padding:15px 18px;font-size:11px;color:var(--muted);margin-top:48px;line-height:1.9}.source-provenance summary{cursor:pointer;font-weight:600}.source-provenance p{margin:12px 0 0}.source-provenance .original-heading{font-size:12px;line-height:1.8;color:var(--muted)}.source-provenance .Title,.source-provenance .Section{margin:0;font-size:12px}.related-notes{margin-top:40px;border-top:1px solid var(--line);padding-top:24px}.related-notes h2{font-size:18px;margin-bottom:14px}.related-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.related-link{background:var(--paper);border:1px solid var(--line);border-radius:9px;padding:16px;font-size:13px;line-height:1.7}.related-link small{display:block;font-size:10px;color:var(--muted);margin-bottom:5px}.related-link:hover{border-color:var(--accent);color:var(--accent)}
/* About and interactive lab */
.page-heading{padding:54px 0 37px;max-width:800px}.page-heading h1{font-size:44px;margin:0 0 20px}.page-heading p{font-size:16px;color:var(--muted);line-height:1.9}.lab-tabs{display:flex;gap:9px;flex-wrap:wrap;margin:4px 0 25px}.lab-panel{display:grid;grid-template-columns:minmax(0,.92fr) minmax(0,1.08fr);border:1px solid var(--line);border-radius:16px;background:var(--paper);overflow:hidden;margin-bottom:35px}.lab-inputs{padding:28px;border-right:1px solid var(--line)}.lab-results{padding:28px;background:var(--soft);min-width:0}.lab-panel h2{font-size:24px;margin-bottom:11px}.lab-panel p{font-size:13px;color:var(--muted);line-height:1.85}.input-label{display:block;font-size:12px;font-weight:600;margin:20px 0 8px}.field-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.field-grid label{font-size:11px;color:var(--muted)}.field-grid input,.number-input{width:100%;border:1px solid var(--line);border-radius:7px;background:var(--bg);padding:9px 10px;min-height:43px}.angle-row{display:flex;gap:15px;align-items:center}.angle-row input[type=range]{flex:1;accent-color:var(--accent);min-width:0}.angle-row .number-input{width:90px}.lab-results .formula-line{padding:10px 0;border:0;overflow:auto}.lab-results .formula-line math{font-size:18px}.result-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;margin:22px 0}.result-cell{padding:12px 8px;background:var(--paper);border:1px solid var(--line);border-radius:7px;text-align:center}.result-cell small{display:block;font:11px/1.5 ui-monospace,monospace;color:var(--muted)}.result-cell output{font:16px/1.8 ui-monospace,monospace;font-weight:600}.lab-visual{display:block;width:100%;height:240px;background:var(--paper);border:1px solid var(--line);border-radius:9px}.lab-visual text{font-size:12px;fill:var(--muted)}.result-line{display:flex;justify-content:space-between;gap:15px;padding:12px 0;border-bottom:1px solid var(--line);font-size:13px}.result-line output{font:12px/1.8 ui-monospace,Consolas,monospace;text-align:right;overflow-wrap:anywhere}.lab-error{padding:9px 12px;background:var(--warm);color:var(--warm-ink);font-size:12px;border-radius:7px;margin-top:12px}.lab-textarea{width:100%;height:205px;resize:vertical;border:1px solid var(--line);border-radius:8px;padding:12px;background:var(--bg);font:13px/1.8 ui-monospace,Consolas,monospace}.lab-convention{margin-top:16px;padding-top:16px;border-top:1px solid var(--line);font-size:11px!important}.external-tools{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:22px 0 65px}.manifesto{padding:40px;background:var(--soft);border-radius:16px;margin-bottom:35px;max-width:930px}.manifesto blockquote{margin:0 0 25px;font-size:28px;font-weight:600;letter-spacing:-.04em;line-height:1.6;word-break:keep-all}.manifesto p{font-size:15px;color:var(--muted)}.about-columns{display:grid;grid-template-columns:1fr 1fr;gap:50px;padding:20px 0 55px}.about-columns h2{font-size:23px}.about-columns p{font-size:14px;color:var(--muted);line-height:1.95}.about-columns dl{display:grid;grid-template-columns:90px 1fr;gap:12px;font-size:13px}.about-columns dt{color:var(--muted)}.about-columns dd{margin:0}.legacy-about{border-top:1px solid var(--line);padding:22px 0 45px;font-size:12px;color:var(--muted)}.legacy-about summary{cursor:pointer}.legacy-about blockquote{border-left:2px solid var(--line);padding:10px 18px;margin:20px 0;font:italic 16px/1.8 Georgia,serif}.print-controls{display:flex;gap:15px;align-items:center;flex-wrap:wrap;border:1px solid var(--line);padding:20px;border-radius:12px;background:var(--paper);margin:24px 0}.print-controls p{margin:0;font-size:13px;color:var(--muted)}.print-document{max-width:820px;margin:40px auto;padding:25px;background:var(--paper);border:1px solid var(--line);border-radius:10px}.print-doc-head{border-bottom:1px solid var(--line);padding-bottom:20px;margin-bottom:25px}.print-doc-head h1{font-size:31px;margin:12px 0}.print-doc-head p{font-size:13px;color:var(--muted);margin:0}.print-source-line{display:none}.print-only{display:none}.back-top{position:fixed;right:22px;bottom:25px;height:38px;width:38px;border:1px solid var(--line);border-radius:10px;background:var(--paper);z-index:30;color:var(--accent);font-size:16px;box-shadow:var(--shadow)}
@media(min-width:1450px){.wrap{width:min(1260px,calc(100% - 96px))}.hero{padding-top:82px}.reader-wrap{width:1190px}.reader-layout{grid-template-columns:230px minmax(0,1fr);gap:65px}}
@media(max-width:1024px){.wrap,.reader-wrap{width:calc(100% - 44px)}.header-inner{gap:20px}.main-nav{gap:18px;font-size:12px}.hero{gap:32px;padding-top:48px}.hero h1{font-size:42px}.hero-panel{padding:22px 20px;min-height:325px}.hero-coordinates{height:210px}.article-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.context-item{padding-inline:18px}.reader-layout{grid-template-columns:175px minmax(0,1fr);gap:32px}.lab-inputs,.lab-results{padding:22px}.result-cell output{font-size:13px}.paths-grid{gap:25px}.path-card{padding-right:18px}}
@media(max-width:760px){:root{--header:66px;--reading-size:17px}.wrap,.reader-wrap{width:calc(100% - 36px)}.header-inner{gap:12px}.brand-name{font-size:22px}.brand-mark{height:32px;width:32px;font-size:25px}.brand-sub{font-size:8px}.main-nav{display:none}.header-actions{margin-left:auto;gap:0}.menu-button{display:inline-flex}.hero{grid-template-columns:1fr;gap:30px;padding:38px 0 32px}.hero h1{font-size:40px;letter-spacing:-.05em;margin-bottom:21px}.hero-description{font-size:14px;line-height:1.9;margin-bottom:24px}.hero .eyebrow{font-size:10px;margin-bottom:15px}.hero-panel{min-height:0;padding:17px 21px}.hero-coordinates{height:181px}.panel-bottom{padding-top:10px}.context-strip{grid-template-columns:1fr 1fr;padding:18px 0;margin-bottom:39px;gap:0}.context-item{padding:0 10px;gap:10px}.context-item strong{font-size:25px}.context-item span{font-size:11px}.context-item:nth-child(2){border:0}.context-item:last-child{grid-column:1/-1;border-top:1px solid var(--line);margin-top:17px;padding:15px 0 0}.context-item:last-child strong{font-size:14px}.section-top{gap:15px;align-items:start}.section-top h2{font-size:25px}.section-top p{font-size:12px}.section-top .text-link{font-size:12px;white-space:nowrap}.search-row{gap:8px}.search-field{padding-inline:12px;gap:9px}.search-field input{font-size:13px;height:48px}.search-field kbd{display:none}.filter-row{gap:6px;margin-bottom:20px}.filter-chip{font-size:10px;padding:6px 9px;min-height:34px;gap:5px}.filter-chip span{font-size:9px}.article-grid{gap:11px}.note-card{padding:18px 16px;min-height:241px;border-radius:11px}.note-card .category{font-size:9px;letter-spacing:0;margin-bottom:18px;max-width:calc(100% - 14px);padding-right:0}.note-card h3{font-size:17px;line-height:1.5}.note-card .english{font-size:9px;line-height:1.5}.note-card p{font-size:11px;line-height:1.85;margin-bottom:17px}.note-card footer{font-size:10px}.print-select{right:9px;top:12px;width:25px}.note-card footer .note-no{font-size:9px}.library-section{padding-bottom:43px}.paths-section{padding:39px 0}.paths-grid{grid-template-columns:1fr;gap:24px}.path-card{padding:0 0 25px;border:0;border-bottom:1px solid var(--line)}.path-card:last-child{padding:0}.path-symbol{font-size:27px;float:left;margin-right:15px}.path-card h3{font-size:20px;padding-top:4px}.path-card>p{clear:both;margin-bottom:12px}.path-step{font-size:12px;padding-block:7px}.tools-teaser{grid-template-columns:1fr;gap:25px;padding:40px 0}.tools-teaser h2{font-size:26px}.tools-teaser p{font-size:13px}.about-teaser{grid-template-columns:1fr;gap:14px;padding:29px 0 37px}.about-teaser p{font-size:12px}.footer-inner{gap:14px}.site-footer{font-size:10px;padding:24px 0}.footer-links{gap:15px}.print-tray{padding:10px 12px;gap:12px;bottom:13px}.print-tray p{font-size:11px}.back-top{right:12px;bottom:75px;width:33px;height:33px}.reader-layout{display:block;padding-bottom:45px}.reader-toc{display:none}.breadcrumb{font-size:10px;padding-block:18px}.article-head{padding-top:5px;margin-bottom:22px;padding-bottom:23px}.article-head h1{font-size:32px;margin-bottom:7px}.article-head .article-english{font-size:12px;margin-bottom:19px}.article-description{font-size:14px;margin-bottom:20px}.article-meta{font-size:10px;gap:9px}.reader-toolbar{gap:6px;margin-top:18px}.reader-toolbar .button{font-size:10px;padding:7px 9px}.mobile-toc-button{display:inline-flex}.reader-note{font-size:11px;line-height:1.85;padding:11px 13px;margin-bottom:22px}.article-content .section-heading{font-size:22px;line-height:1.55;margin-top:33px;padding-top:20px}.article-content h3.section-heading{font-size:17px;margin-top:23px}.article-content .minor-heading{font-size:13px;margin-top:22px}.article-content .section-intro{font-size:14px}.formula-line{padding:8px 0 8px 11px;margin:9px 0 12px}.formula-line>.math-unit:only-child{padding-right:20px}.math-copy{opacity:1;font-size:8px;padding:1px 4px}.math-unit math{font-size:1.06em}.data-table td,.data-table th{padding:7px 8px}.data-table{font-size:11px}.data-table .math-unit math{font-size:15px}.related-grid{gap:8px}.related-link{font-size:12px;padding:13px}.related-link small{font-size:9px}.source-provenance{font-size:10px;padding:12px 15px}.modal-head{padding:16px 19px}.modal-body{padding:19px}.modal textarea{font-size:11px}.page-heading{padding:34px 0 23px}.page-heading h1{font-size:34px;margin-bottom:15px}.page-heading p{font-size:13px}.lab-panel{grid-template-columns:1fr}.lab-inputs{border-right:0;border-bottom:1px solid var(--line);padding:22px 19px}.lab-results{padding:22px 19px}.lab-panel h2{font-size:22px}.lab-panel p{font-size:12px}.result-grid{margin:17px 0}.result-cell output{font-size:14px}.lab-results .formula-line math{font-size:16px}.external-tools{grid-template-columns:1fr;gap:10px;margin-bottom:42px}.lab-tabs{gap:6px}.lab-tabs .filter-chip{font-size:11px}.manifesto{padding:25px 21px}.manifesto blockquote{font-size:23px;margin-bottom:20px}.manifesto p{font-size:13px}.about-columns{grid-template-columns:1fr;gap:23px;padding-bottom:30px}.about-columns p{font-size:13px}.about-columns h2{font-size:21px}.print-document{padding:17px 13px}.print-document .article-content{font-size:16px}}
@media(max-width:380px){.wrap,.reader-wrap{width:calc(100% - 28px)}.hero h1{font-size:35px}.brand-name{font-size:20px}.article-grid{grid-template-columns:1fr}.note-card{min-height:215px;padding:20px}.note-card h3{font-size:20px}.note-card p{font-size:12px}.note-card .category{font-size:10px}.note-card .english{font-size:11px}.header-actions .icon-button{min-width:34px}.result-cell output{font-size:12px}.article-head h1{font-size:29px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}
/* A4 output. Interactive controls never become part of the handout. */
@page{size:A4 portrait;margin:17mm 17mm 18mm}
@media print{
 :root,:root[data-theme=dark]{--bg:#fff;--paper:#fff;--ink:#111;--muted:#444;--line:#cbd3d2;--accent:#155d58;--soft:#f1f5f4;color-scheme:light;--reading-size:11pt}
 html{scroll-behavior:auto}body{margin:0;background:#fff!important;color:#111;font-size:10.5pt;line-height:1.55}
 .site-header,.site-footer,.reader-toc,.reader-toolbar,.reader-note,.breadcrumb,.related-notes,.source-provenance,.print-controls,.print-tray,.back-top,.toast,.modal,.skip-link,.reading-progress,.math-copy,.no-print,.mobile-toc-button,.print-select{display:none!important}
 .wrap,.reader-wrap{width:auto!important;max-width:none!important;margin:0}.reader-layout{display:block;padding:0}.reader-article{max-width:none;width:100%}
 .article-head{padding:0 0 7mm;margin:0 0 7mm;border-bottom:1pt solid #555}.article-head h1{font-size:22pt;line-height:1.35;letter-spacing:-.025em;margin:0 0 2mm}.article-head .eyebrow{font-size:8pt;margin-bottom:4mm}.article-head .article-english{font-size:10pt;margin-bottom:4mm}.article-description{font-size:10.5pt;margin-bottom:4mm}.article-meta{font-size:8pt;gap:4mm}
 .article-content{font-size:11pt;line-height:1.6}.article-content .source-paragraph{line-height:1.6;margin:2.4mm 0;orphans:3;widows:3}.article-content .section-intro{font-size:10pt;line-height:1.65;margin:3mm 0}.article-content .section-heading{font-size:15pt;margin:8mm 0 3.5mm;padding-top:4mm;line-height:1.45;break-after:avoid-page;page-break-after:avoid}.article-content h3.section-heading{font-size:12pt;margin:5mm 0 2.5mm;padding-top:0}.article-content .minor-heading{font-size:10pt;margin:4.5mm 0 2mm;color:#444;break-after:avoid-page;page-break-after:avoid}
 h1,h2,h3,h4,summary{break-after:avoid-page;page-break-after:avoid}p{orphans:3;widows:3}.derivation{display:block!important}.derivation>summary{display:block;list-style:none}.derivation>summary:after{display:none}.derivation>div{display:block!important;content-visibility:visible!important}.derivation>summary h2{padding-right:0}
 .formula-line{overflow:visible!important;border-left:1pt solid #cbd3d2;padding:2mm 0 2mm 3mm;margin:2mm 0 3mm;break-inside:avoid-page;page-break-inside:avoid;max-width:100%;min-width:0}.formula-line .math-unit,.formula-line>.math-unit:only-child{padding:0;max-width:none}.math-unit{color:#111!important;cursor:default}.math-unit math{font-size:12pt}.math-unit math[display=block]{margin:0}.math-unit.print-scaled{transform-origin:left center}
 .original-media img{max-width:100%;max-height:190mm;object-fit:contain}.source-figure{margin:4mm 0;break-inside:avoid-page}.source-figure img{max-height:170mm}.media-unavailable{font-size:8pt;background:#fff;padding:3mm 4mm}.media-unavailable small{font-size:7pt}.table-scroll{overflow:visible!important;margin:4mm 0}.data-table{font-size:9pt;max-width:100%;width:auto}.data-table td,.data-table th{padding:2mm 2.5mm;border:1pt solid #bbb}.data-table .math-unit math{font-size:10pt}.data-table tr{break-inside:avoid-page}.data-table thead{display:table-header-group}.source-code{font-size:8pt;background:#f5f5f5;white-space:pre-wrap}
 .video-box{display:block;padding:3mm 4mm;margin:3mm 0 5mm;background:#fff;font-size:8pt;border:1pt solid #bbb;break-inside:avoid-page}.video-play,.video-box iframe{display:none!important}.video-link{font-size:8pt}.video-link:before{content:'참고 영상: ';color:#444}.video-link:after{content:' (' attr(href) ')';font-size:7pt;overflow-wrap:anywhere}
 .print-only,.print-source-line{display:block}.print-source-line{font-size:7.5pt;color:#555;margin-top:4mm;overflow-wrap:anywhere}.print-document{padding:0;margin:0;border:0;border-radius:0;max-width:none;break-before:page}.print-document:first-of-type{break-before:auto}.print-doc-head{padding-bottom:5mm;margin-bottom:6mm}.print-doc-head h1{font-size:21pt}.print-doc-head p{font-size:9pt}.print-index-title{display:none}.lab-tabs,.lab-inputs .actions,.lab-inputs input[type=range],.external-tools{display:none}.lab-panel{display:block;border:0;overflow:visible;break-before:page}.lab-inputs,.lab-results{padding:0;border:0;background:#fff}.lab-panel input,.lab-panel textarea{border:1pt solid #bbb}.lab-results .lab-visual{height:68mm;break-inside:avoid-page}.result-grid{break-inside:avoid-page}.page-heading{padding:0 0 5mm}.page-heading h1{font-size:23pt}.manifesto{background:#fff;border:1pt solid #bbb}.about-columns{display:block}.hero{padding-top:0}.hero h1{font-size:27pt}.hero-panel{break-inside:avoid-page}.hero-coordinates{height:45mm}.context-strip{margin-bottom:7mm}.article-grid{grid-template-columns:repeat(2,1fr)}.note-card{break-inside:avoid-page;box-shadow:none;transform:none;min-height:0}.note-card p{font-size:9pt}.paths-grid{display:block}.path-card{border:0;break-inside:avoid-page}.paths-section{padding:5mm 0}.library-section,.tools-teaser{padding:5mm 0}.search-row,.filter-row,.more-row,.results-meta{display:none}
}
/* Dynamic states and MathML-specific measurements. */
.lab-tabs [aria-selected=true]{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.plot-grid{stroke:var(--line);stroke-width:1}.plot-fit{stroke:var(--accent);stroke-width:2.6}.plot-point{fill:var(--paper);stroke:var(--ink);stroke-width:1.7}.plot-label{fill:var(--muted);font:11px -apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif}
.formula-line>.math-unit:first-child{width:max-content;max-width:none;display:inline-block}.math-unit math[display=block]{text-align:left}.math-unit{overflow-wrap:normal;word-break:normal}.formula-line>.math-unit{vertical-align:middle}
.global-results a{display:block}.search-results a{display:flex;flex-direction:column;padding:12px 8px;border-bottom:1px solid var(--line)}.search-results small{font-size:12px;color:var(--muted)}.search-results strong{font-size:15px}.lab-convention strong{font-size:12px}
@media(max-width:760px){.desktop-break{display:none}.lab-tabs{overflow-x:auto}.lab-tabs .button{white-space:nowrap}.formula-line{padding-right:12px}.formula-line .math-copy{position:static;display:block;opacity:1;margin-top:8px}.result-line{gap:12px}.result-line output{text-align:right;overflow-wrap:anywhere}.source-provenance{overflow-wrap:anywhere}.source-note{overflow-wrap:anywhere}}
@media print{.formula-line>.math-unit:first-child{width:max-content;max-width:none}.lab-panel{break-before:auto}.plot-fit{stroke:#145e58}.plot-point{stroke:#111;fill:#fff}.plot-label{fill:#333}.math-copy{display:none!important}.source-provenance{display:none!important}}

.mini-brand{white-space:normal;line-height:1.2}.mini-brand span{display:block;font:12px/1.6 -apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;letter-spacing:.1em;margin-top:10px;color:var(--muted)}

.related-link{display:flex;flex-direction:column;gap:7px}.related-link small{font-size:10px;color:var(--muted)}.related-link strong{font-size:14px}.related-link>span{font-size:11px;color:var(--accent)}
@media print{.lead-in{break-after:avoid-page;page-break-after:avoid}.article-content .formula-line{padding-top:1.6mm;padding-bottom:1.6mm;margin-top:1.5mm;margin-bottom:2.5mm}.article-content .minor-heading{margin-top:4mm;margin-bottom:1.5mm}}

/* v2: only equations and content, with no conversion-record UI. */
.inline-code{font-family:ui-monospace,Consolas,monospace;font-size:.9em;overflow-wrap:anywhere;}

/* v3: all original heading notation is part of the reading/print content. */
.topic-notation{border:1px solid var(--line);border-radius:10px;background:var(--soft);margin:0 0 28px;padding:13px 16px;min-width:0;max-width:100%;scroll-margin-top:105px}
.topic-notation-label{font-size:11px;font-weight:650;letter-spacing:.04em;color:var(--muted);margin:0 0 5px;line-height:1.6}
.topic-notation .topic-notation-content{border:0;margin:0;padding:6px 28px 6px 0;overflow-x:auto}
.topic-notation .topic-heading-text{margin:0;font-size:.88em;line-height:1.8;white-space:normal;overflow-wrap:normal}
.topic-notation .math-unit math{font-size:1em}
math .rm-math-wrap>mtr>mtd{text-align:left!important}
.complete-document{padding-bottom:42px;scroll-margin-top:100px}.complete-document+.complete-document{border-top:2px solid var(--line);padding-top:36px}
.complete-doc-head{margin:0 0 24px}.complete-doc-head h2{font-size:30px;margin:0 0 8px}.complete-doc-head p[lang]{color:var(--muted);font-size:14px}.complete-doc-head .text-link{font-size:12px}
.complete-toc a span{display:inline-block;font-size:9px;margin-right:7px;opacity:.7}
.complete-reader .page-heading{padding-top:35px}.complete-reader .reader-article{overflow-wrap:anywhere}
@media(max-width:760px){.topic-notation{padding:11px 12px;margin-bottom:22px}.topic-notation .topic-notation-content{padding-right:0}.topic-notation .topic-heading-text{font-size:.84em;line-height:1.9}.complete-doc-head h2{font-size:25px}.complete-document{padding-bottom:26px}}
@media print{.topic-notation{padding:2.8mm 3.3mm;margin:0 0 5mm;border:.6pt solid #cbd3d2;background:#fff!important;break-inside:avoid-page}.topic-notation-label{font-size:8pt;margin-bottom:1mm;color:#555}.topic-notation .topic-notation-content{padding:0;margin:0;border:0;overflow:visible!important}.topic-notation .topic-heading-text{font-size:10pt;line-height:1.6}.topic-notation .math-unit math{font-size:10pt}.complete-document{padding:0;margin:0}.complete-document+.complete-document{break-before:page;border:0;padding-top:0}.complete-doc-head{break-after:avoid-page;margin-bottom:5mm}.complete-doc-head h2{font-size:20pt}.complete-doc-head p[lang]{font-size:10pt}.complete-reader>.page-heading{display:none!important}}

/* v4 — Korean explanatory reading layer; original equations stay independent. */
.article-content .learning-guide,
.article-content .learning-explanation,
.article-content .learning-summary{font-size:var(--reading-size);line-height:1.9;min-width:0;overflow-wrap:anywhere;color:var(--ink)}
.article-content .learning-guide{padding:26px 30px 23px;background:var(--paper);border:1px solid var(--line);border-top:3px solid var(--accent);border-radius:12px;margin:0 0 34px}
.article-content .learning-label{font-size:11px;font-weight:750;color:var(--accent);letter-spacing:.1em;margin:0 0 9px}
.article-content .learning-guide h2{font-size:24px;margin:0 0 16px;scroll-margin-top:105px}
.article-content .learning-guide>p:not(.learning-label){margin-bottom:21px}
.article-content .learning-guide h3{font-size:15px;letter-spacing:-.015em;color:var(--accent-strong);margin:24px 0 9px}
.article-content .learning-symbols{margin:0;font-size:.85em;line-height:1.75}
.learning-symbol-row{display:grid;grid-template-columns:minmax(105px,1fr) minmax(0,3fr);gap:18px;padding:10px 0;border-bottom:1px solid var(--line)}
.learning-symbol-row:last-child{border-bottom:0}
.learning-symbol-row dt{font-weight:700;overflow-wrap:anywhere;word-break:normal}
.learning-symbol-row dd{margin:0;word-break:keep-all;overflow-wrap:anywhere}
.learning-route{padding-top:3px}
.article-content .learning-route p{font-size:.92em;margin-bottom:0}
.article-content .learning-explanation{padding:20px 0 2px;margin:23px 0 8px;border-top:1px solid var(--line)}
.article-content .learning-explanation .learning-step-title{display:flex;align-items:baseline;gap:11px;font-size:20px;line-height:1.65;letter-spacing:-.025em;margin:0 0 11px;scroll-margin-top:105px}
.learning-step-no{font:12px/1.7 ui-monospace,Consolas,monospace;color:var(--accent);flex:none;letter-spacing:.02em}
.article-content .learning-explanation p{font-size:1em;margin:0 0 12px;line-height:1.9;word-break:keep-all;overflow-wrap:anywhere}
.article-content .learning-explanation p:last-child{margin-bottom:2px}
.article-content .learning-summary{border-left:3px solid var(--accent);background:var(--soft);padding:20px 24px;margin:36px 0 18px;border-radius:0 9px 9px 0}
.article-content .learning-summary h2{font-size:20px;margin:0 0 9px;scroll-margin-top:105px}
.article-content .learning-summary p{margin:0;font-size:.96em;line-height:1.85}
.reader-toc .learning-toc-entry a{font-size:12px;line-height:1.65;padding-block:8px}
.original-toc-entry{display:none}
:root[data-explanations=hide] [data-editorial],
:root[data-explanations=hide] .learning-toc-entry{display:none}
:root[data-explanations=hide] .original-toc-entry{display:list-item}
@media(max-width:720px){
 .article-content .learning-guide{padding:19px 18px;margin-bottom:26px;border-radius:9px}
 .article-content .learning-guide h2{font-size:22px}
 .article-content .learning-guide h3{font-size:15px}
 .article-content .learning-guide,.article-content .learning-explanation,.article-content .learning-summary{font-size:var(--reading-size);line-height:1.85}
 .learning-symbol-row{grid-template-columns:minmax(80px,1fr) minmax(0,2.2fr);gap:12px;padding:10px 0}
 .article-content .learning-symbols{font-size:.8em}
 .article-content .learning-explanation{margin-top:25px;padding-top:17px}
 .article-content .learning-explanation .learning-step-title{font-size:18px;gap:9px;line-height:1.55;margin-bottom:12px}
 .article-content .learning-explanation p{line-height:1.9}
 .article-content .learning-summary{padding:18px;margin:29px 0 14px}
 .article-content .learning-summary h2{font-size:19px}
 .reader-toolbar [data-action=toggle-explanations]{border-color:var(--accent);color:var(--accent-strong)}
}
@media(max-width:380px){
 .learning-symbol-row{grid-template-columns:1fr;gap:3px}
 .article-content .learning-guide{padding-inline:16px}
}
@media print{
 /* Print the explanations even when the user has temporarily hidden them on screen. */
 :root[data-explanations=hide] [data-editorial],[data-editorial]{display:block!important}
 .article-content .learning-guide,.article-content .learning-explanation,.article-content .learning-summary{font-size:10.5pt;line-height:1.65;box-shadow:none;break-inside:auto;page-break-inside:auto}
 .article-content .learning-guide{border:.6pt solid #cbd3d2;border-top:1.2pt solid #49665f;border-radius:0;background:white;padding:4mm 4.5mm;margin:0 0 5mm}
 .article-content .learning-label{font-size:7.5pt;color:#3a5c56;margin:0 0 1mm}
 .article-content .learning-guide h2{font-size:14pt;line-height:1.45;margin:0 0 2.4mm}
 .article-content .learning-guide h3{font-size:10.5pt;color:#263d39;margin:3mm 0 1.4mm}
 .article-content .learning-guide>p:not(.learning-label){margin-bottom:3mm}
 .article-content .learning-symbols{font-size:9.2pt;line-height:1.55}
 .learning-symbol-row{grid-template-columns:minmax(25mm,1fr) minmax(0,3fr);gap:4mm;padding:1.5mm 0;break-inside:avoid-page;page-break-inside:avoid}
 .learning-route{padding:0}.article-content .learning-route p{font-size:10pt;line-height:1.6}
 .article-content .learning-explanation{padding:3mm 0 0;margin:4mm 0 2mm;border-top:.5pt solid #d7dfdd}
 .article-content .learning-explanation .learning-step-title{font-size:12pt;line-height:1.5;margin:0 0 2mm;gap:2.6mm;break-after:avoid-page;page-break-after:avoid}
 .learning-step-no{font-size:8pt;color:#435e59}
 .article-content .learning-explanation p{font-size:10.5pt;line-height:1.65;margin:0 0 2.2mm;orphans:3;widows:3}
 .article-content .learning-summary{border-left:1pt solid #526b65;border-radius:0;background:white;padding:3mm 4mm;margin:5mm 0 3mm}
 .article-content .learning-summary h2{font-size:12pt;line-height:1.5;margin:0 0 2mm}
 .article-content .learning-summary p{font-size:10.5pt;line-height:1.65}
}
/* Keep A4 pages compact without reducing equation or prose font sizes. */
@media print{
 .article-content .formula-line{padding-top:1.2mm;padding-bottom:1.2mm;margin-top:1mm;margin-bottom:1.8mm}
 .article-content .section-heading{font-size:13.5pt;line-height:1.4;margin-top:5.5mm;margin-bottom:2.5mm;padding-top:2.5mm}
 .article-content .learning-explanation{margin-top:3.5mm;padding-top:2.5mm}
 .article-content .learning-summary{margin-top:3.5mm;padding-top:2.5mm;padding-bottom:2.5mm}
 .print-source-line{margin-top:2.5mm}
}
@media print{
 /* Keep a short explanation attached to the first formula that follows it. */
 .learning-explanation{break-after:avoid-page;page-break-after:avoid}
}