/* Computational Grammar Theory — design system (see DESIGN_SYSTEM.md)
   Ink on warm paper, emerald for structure, brass for emphasis. */

/* ---------- fonts (self-hosted, latin + latin-ext) ---------- */
@font-face{font-family:"Source Serif 4";src:url(../fonts/source-serif-4-latin-400-normal.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(../fonts/source-serif-4-latin-400-italic.woff2) format("woff2");font-weight:400;font-style:italic;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(../fonts/source-serif-4-latin-600-normal.woff2) format("woff2");font-weight:600;font-style:normal;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(../fonts/source-serif-4-latin-600-italic.woff2) format("woff2");font-weight:600;font-style:italic;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(../fonts/source-serif-4-latin-700-normal.woff2) format("woff2");font-weight:700;font-style:normal;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(../fonts/source-serif-4-latin-ext-400-normal.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap;unicode-range:U+0100-024F,U+1E00-1EFF}
@font-face{font-family:"IBM Plex Sans";src:url(../fonts/ibm-plex-sans-latin-400-normal.woff2) format("woff2");font-weight:400;font-display:swap}
@font-face{font-family:"IBM Plex Sans";src:url(../fonts/ibm-plex-sans-latin-600-normal.woff2) format("woff2");font-weight:600;font-display:swap}
@font-face{font-family:"JetBrains Mono";src:url(../fonts/jetbrains-mono-latin-400-normal.woff2) format("woff2");font-weight:400;font-display:swap}

/* ---------- tokens ---------- */
:root{
  --paper:#f7f3ea; --paper-2:#efe8da; --paper-3:#e6dcc8; --card:#fbf8f2;
  --ink:#1c1e21; --ink-2:#3c4045; --ink-3:#6a6e73; --rule:#d6ccb8; --rule-2:#bfb39a;
  --emerald:#0d6b52; --emerald-2:#0a5641; --emerald-tint:#e4efe9;
  --brass:#8a6d2f; --brass-2:#a8873f; --brass-tint:#f3ead6;
  --claret:#8c2f39; --claret-tint:#f6e5e4; --slate:#3d5a80; --slate-tint:#e6ecf3;
  --focus:#0d6b52;
  --serif:"Source Serif 4", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans:"IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono:"JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
  --measure:40rem; --gutter:1rem; --radius:6px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){ :root:not([data-theme="light"]){
  --paper:#141516; --paper-2:#1b1d1f; --paper-3:#24272a; --card:#191b1d;
  --ink:#ece6d9; --ink-2:#cfc8b9; --ink-3:#9a9488; --rule:#33363a; --rule-2:#4a4e53;
  --emerald:#5cc4a0; --emerald-2:#7dd6b6; --emerald-tint:#16292280;
  --brass:#d2b06a; --brass-2:#e2c27f; --brass-tint:#2a241680;
  --claret:#e08a92; --claret-tint:#33191c80; --slate:#9fb7d9; --slate-tint:#1b2533; --focus:#5cc4a0;
  color-scheme:dark;
}}
:root[data-theme="dark"]{
  --paper:#141516; --paper-2:#1b1d1f; --paper-3:#24272a; --card:#191b1d;
  --ink:#ece6d9; --ink-2:#cfc8b9; --ink-3:#9a9488; --rule:#33363a; --rule-2:#4a4e53;
  --emerald:#5cc4a0; --emerald-2:#7dd6b6; --emerald-tint:#16292280;
  --brass:#d2b06a; --brass-2:#e2c27f; --brass-tint:#2a241680;
  --claret:#e08a92; --claret-tint:#33191c80; --slate:#9fb7d9; --slate-tint:#1b2533; --focus:#5cc4a0;
  color-scheme:dark;
}

/* ---------- base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font:400 1.0625rem/1.66 var(--serif);font-feature-settings:"onum" 1,"kern" 1;text-rendering:optimizeLegibility;overflow-x:hidden}
a{color:var(--emerald);text-decoration-thickness:1px;text-underline-offset:.18em}
a:hover{color:var(--emerald-2);text-decoration-thickness:2px}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px;border-radius:2px}
h1,h2,h3,h4{font-family:var(--serif);font-weight:600;line-height:1.22;letter-spacing:-.005em;color:var(--ink);text-wrap:balance}
h1{font-size:clamp(1.9rem,1.2rem + 2.6vw,2.75rem);margin:.2em 0 .5em}
h2{font-size:1.5rem;margin:2.4em 0 .6em;padding-top:.4em;border-top:1px solid var(--rule)}
h3{font-size:1.18rem;margin:1.8em 0 .5em}
h4{font-size:1rem;margin:1.4em 0 .4em}
p{margin:.85em 0}
code,kbd,pre{font-family:var(--mono);font-size:.86em}
:not(pre)>code{background:var(--paper-2);padding:.08em .32em;border-radius:3px}
hr{border:0;border-top:1px solid var(--rule);margin:2.5em 0}
img,svg{max-width:100%}
.vh{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:-999px;top:0;background:var(--ink);color:var(--paper);padding:.5em 1em;z-index:100}
.skip:focus{left:1rem;top:.5rem}
.lede{font-size:1.15rem;color:var(--ink-2);max-width:46rem}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:40;display:flex;align-items:center;gap:1.25rem;padding:.55rem 1.25rem;background:color-mix(in srgb,var(--paper) 92%,transparent);backdrop-filter:saturate(1.2) blur(6px);border-bottom:1px solid var(--rule);font-family:var(--sans);font-size:.9rem}
.brand{display:flex;align-items:center;gap:.6rem;color:var(--ink);text-decoration:none;flex:0 0 auto}
.brand-mark{font-family:var(--serif);font-weight:600;color:var(--emerald);font-size:1.15rem;letter-spacing:-.02em;border:1px solid var(--rule-2);padding:.05rem .35rem;border-radius:4px}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-title{font-family:var(--serif);font-weight:600;font-size:1rem}
.brand-sub{color:var(--ink-3);font-size:.74rem;letter-spacing:.02em}
.site-nav{display:flex;gap:.15rem;flex-wrap:wrap;flex:1 1 auto}
.site-nav a{color:var(--ink-2);text-decoration:none;padding:.3rem .55rem;border-radius:4px}
.site-nav a:hover{background:var(--paper-2);color:var(--ink)}
.site-nav a[aria-current="page"]{color:var(--emerald);box-shadow:inset 0 -2px 0 var(--emerald)}
.tools{display:flex;align-items:center;gap:.5rem;flex:0 0 auto}
.search{position:relative}
.search input{font:inherit;width:15rem;max-width:40vw;padding:.38rem .6rem;border:1px solid var(--rule-2);border-radius:5px;background:var(--card);color:var(--ink)}
.search-pop{position:absolute;right:0;top:calc(100% + 6px);width:min(30rem,90vw);max-height:70vh;overflow:auto;background:var(--card);border:1px solid var(--rule-2);border-radius:var(--radius);box-shadow:0 12px 32px #0002;padding:.35rem}
.search-pop a{display:block;padding:.45rem .6rem;border-radius:4px;color:var(--ink);text-decoration:none}
.search-pop a:hover,.search-pop a[aria-selected="true"]{background:var(--emerald-tint)}
.search-pop .k{font-size:.72rem;text-transform:uppercase;letter-spacing:.06em;color:var(--brass);margin-right:.4rem}
.search-pop .c{display:block;font-size:.78rem;color:var(--ink-3)}
.theme-toggle{display:inline-flex;align-items:center;justify-content:center;background:none;border:1px solid var(--rule-2);color:var(--ink-2);border-radius:5px;width:2.1rem;height:2.1rem;cursor:pointer;padding:0}
.theme-toggle svg{width:1.05rem;height:1.05rem}

/* ---------- layout ---------- */
.main{max-width:calc(var(--measure) + 2*var(--gutter));margin:0 auto;padding:2rem var(--gutter) 4rem;min-width:0;width:100%}
.main>*{max-width:100%}
body.home .main,body.lab-page .main,body.ledger .main{max-width:68rem}
body.has-toc{display:grid;grid-template-columns:minmax(0,1fr);grid-template-areas:"h" "m" "f"}
body.has-toc .site-header{grid-area:h}
body.has-toc .main{grid-area:m}
body.has-toc .site-footer{grid-area:f}
.chapter-toc{display:none}
@media (min-width:1180px){
  body.has-toc{grid-template-columns:17rem minmax(0,1fr);grid-template-areas:"h h" "t m" "f f"}
  .chapter-toc{display:block;grid-area:t;position:sticky;top:3.6rem;align-self:start;max-height:calc(100vh - 4rem);overflow:auto;padding:2.2rem 1rem 2rem 1.5rem;font-family:var(--sans);font-size:.82rem;border-right:1px solid var(--rule)}
  body.has-toc .main{margin:0 auto 0 max(2rem,calc((100vw - 17rem - var(--measure))/2 - 6rem))}
}
.chapter-toc ol{list-style:none;margin:0;padding:0}
.chapter-toc li{margin:.15rem 0}
.chapter-toc a{color:var(--ink-2);text-decoration:none;display:block;padding:.15rem .3rem;border-radius:3px}
.chapter-toc a:hover,.chapter-toc a.active{color:var(--emerald);background:var(--emerald-tint)}
.chapter-toc .toc-l3{padding-left:1rem;font-size:.78rem}
.toc-title{font-weight:600;text-transform:uppercase;letter-spacing:.08em;color:var(--brass);font-size:.72rem}
.toc-src{margin-top:1.2rem;font-size:.74rem}
.secno{font-family:var(--sans);font-weight:400;color:var(--brass);font-size:.82em;margin-right:.35em;font-variant-numeric:tabular-nums}

/* ---------- chapter opener ---------- */
.chapter-opener{margin:1rem 0 2.5rem;padding-bottom:1.5rem;border-bottom:3px double var(--rule-2)}
.chapter-kicker{font-family:var(--sans);font-size:.78rem;text-transform:uppercase;letter-spacing:.12em;color:var(--ink-3);margin:0}
.chapter-number{font-family:var(--serif);font-variant:small-caps;letter-spacing:.08em;color:var(--brass);font-size:1.25rem;margin:.6rem 0 0}
.chapter-opener h1{margin-top:.1em}
.epigraph{font-style:italic;color:var(--ink-2);border-left:2px solid var(--brass-2);padding-left:1rem;max-width:34rem}
.chapter-status{font-family:var(--sans);font-size:.85rem;color:var(--ink-3)}

/* ---------- math ---------- */
.katex{font-size:1.06em}
.equation{position:relative;overflow-x:auto;overflow-y:hidden;margin:1.2em 0;padding:.2em 0}
.equation .katex-display{margin:0}
.katex-display>.katex{max-width:100%}
.math-error{color:var(--claret);font-weight:600}

/* ---------- environments ---------- */
.env{margin:1.6em 0;padding:.9rem 1.1rem 1rem;border-radius:var(--radius);background:var(--card);border:1px solid var(--rule)}
.env-head{font-family:var(--sans);font-size:.86rem;display:flex;flex-wrap:wrap;align-items:baseline;gap:.4rem .6rem;margin-bottom:.35rem}
.env-name{font-weight:600;letter-spacing:.02em;text-transform:uppercase;font-size:.78rem}
.env-title{font-family:var(--serif);font-size:1rem;color:var(--ink-2)}
.env-ledger{margin-left:auto}
.env-body>:first-child{margin-top:0}.env-body>:last-child{margin-bottom:0}
.env-definition{border-left:4px solid var(--emerald)}
.env-definition .env-name{color:var(--emerald)}
.env-theorem,.env-proposition,.env-lemma,.env-corollary{border-left:4px solid var(--ink)}
.env-theorem .env-body,.env-proposition .env-body,.env-lemma .env-body,.env-corollary .env-body{font-style:italic}
.env-theorem .env-body .katex,.env-proposition .env-body .katex{font-style:normal}
.env-conjecture{border-left:4px dashed var(--slate)}
.env-conjecture .env-name{color:var(--slate)}
.env-observation{border-left:4px solid var(--slate);background:var(--slate-tint)}
.env-algorithm{border-left:4px solid var(--brass)}
.env-example{background:transparent;border-style:dashed}
.env-example .env-name{color:var(--ink-3)}
.env-remark,.env-history{background:transparent;border:0;border-left:2px solid var(--rule-2);border-radius:0;padding:.2rem 0 .2rem 1rem}
.env-remark .env-name,.env-history .env-name{color:var(--ink-3)}
.env-proof{background:transparent;border:0;padding:0 0 0 0;margin-top:-.6em}
.env-proof .env-head{font-family:var(--serif);font-size:1rem}
.qed{float:right;color:var(--ink-3);margin-top:-1.6em}
.env-exercise{border-left:4px solid var(--brass);background:var(--brass-tint)}
.env-exercise .env-name{color:var(--brass)}
.env-solution{border:1px solid var(--rule);background:var(--card);padding:.4rem 1rem}
.env-solution summary{cursor:pointer;font-family:var(--sans);font-size:.85rem;color:var(--ink-2);padding:.3rem 0}
.env-objectives{background:var(--emerald-tint);border:0}
.env-objectives .env-name,.env-summary .env-name{color:var(--emerald)}
.env-summary{border-top:3px double var(--rule-2);border-radius:0;background:transparent;border-left:0;border-right:0;border-bottom:1px solid var(--rule)}
.env-boundary{border:1px solid var(--claret);background:var(--claret-tint)}
.env-boundary .env-name{color:var(--claret)}
.env-demo{background:var(--paper-2);border:1px solid var(--rule-2);max-width:none}

/* ---------- status badges ---------- */
.status{font-family:var(--sans);font-size:.7rem;font-weight:600;letter-spacing:.04em;text-transform:uppercase;border-radius:999px;padding:.12rem .55rem;border:1px solid currentColor;white-space:nowrap;display:inline-block;line-height:1.5}
.status-proved-here{color:var(--emerald)}
.status-standard{color:var(--ink-2)}
.status-adapted{color:var(--ink-3)}
.status-empirical{color:var(--slate)}
.status-conjecture{color:var(--slate);border-style:dashed}
.status-rejected{color:var(--claret)}
.status-definition{color:var(--emerald);border-style:dotted}
.status-proposed{color:var(--brass)}
.status-mixed,.status-draft{color:var(--ink-3)}
.ledger-id{font-family:var(--mono);font-size:.74rem;color:var(--brass);text-decoration:none;border-bottom:1px dotted var(--brass)}
.citation{white-space:normal}
.cite{white-space:nowrap}
.cite{text-decoration:none;overflow-wrap:anywhere}
.cite:hover{text-decoration:underline}
.gloss{color:inherit;text-decoration:underline dotted var(--emerald);text-underline-offset:.2em}
.xref{text-decoration:none;border-bottom:1px solid var(--emerald-tint)}

/* ---------- code ---------- */
figure.code{margin:1.3em 0;border:1px solid var(--rule);border-radius:var(--radius);background:var(--card);overflow:hidden}
figure.code figcaption{font-family:var(--sans);font-size:.72rem;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-3);padding:.35rem .8rem;border-bottom:1px solid var(--rule);background:var(--paper-2)}
figure.code pre{margin:0;padding:.8rem 1rem;overflow-x:auto;line-height:1.5}
figure.code-output{background:var(--paper-2)}
.tok-k{color:var(--emerald);font-weight:600}.tok-s{color:var(--brass)}.tok-c{color:var(--ink-3);font-style:italic}.tok-n{color:var(--slate)}
pre.install{background:var(--card);border:1px solid var(--rule);padding:.8rem 1rem;border-radius:var(--radius);overflow-x:auto}

/* ---------- tables ---------- */
.table-wrap{overflow-x:auto;margin:1.2em 0;position:relative}
table{border-collapse:collapse;width:100%;font-size:.92rem;font-variant-numeric:tabular-nums}
thead th{font-family:var(--sans);font-size:.78rem;text-transform:uppercase;letter-spacing:.04em;color:var(--ink-2);text-align:left;border-bottom:1.5px solid var(--ink);padding:.45rem .55rem}
tbody td{border-bottom:1px solid var(--rule);padding:.42rem .55rem;vertical-align:top}
tbody tr:last-child td{border-bottom:1.5px solid var(--ink)}
tbody tr:target{background:var(--brass-tint)}

/* ---------- contents / home ---------- */
.part{margin:2.5rem 0}
.part h2{border-top:0;margin:0 0 .4rem;font-size:1.35rem}
.part-no{display:block;font-family:var(--sans);font-size:.75rem;text-transform:uppercase;letter-spacing:.12em;color:var(--brass);font-weight:600}
.part-blurb{color:var(--ink-2);margin:.2rem 0 .8rem;max-width:44rem}
.chapter-list{list-style:none;margin:0;padding:0;border-top:1px solid var(--rule)}
.chapter-list li{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:.1rem 1rem;padding:.7rem 0;border-bottom:1px solid var(--rule);align-items:baseline}
.chapter-list a{text-decoration:none;color:var(--ink);display:flex;gap:.8rem;align-items:baseline}
.chapter-list a:hover .cl-title{color:var(--emerald)}
.cl-no{font-family:var(--sans);color:var(--brass);font-weight:600;min-width:2.2rem;font-variant-numeric:tabular-nums}
.cl-title{font-size:1.1rem;font-weight:600}
.cl-desc{grid-column:1/2;margin:0 0 0 3rem;color:var(--ink-3);font-size:.94rem}
.hero{padding:3.5rem 0 2.5rem;border-bottom:3px double var(--rule-2);max-width:56rem}
.hero-kicker{font-family:var(--sans);text-transform:uppercase;letter-spacing:.16em;font-size:.78rem;color:var(--brass);margin:0}
.hero-title{font-size:clamp(2.1rem,1.3rem + 3vw,3.6rem);line-height:1.08;letter-spacing:-.015em;margin:.6rem 0 1rem}
.hero-lede{font-size:1.2rem;color:var(--ink-2);max-width:44rem}
.hero-author{display:flex;flex-direction:column;margin:1.6rem 0 1.2rem;border-left:3px solid var(--emerald);padding-left:.9rem}
.author-name{font-variant:small-caps;letter-spacing:.1em;font-weight:600;font-size:1.25rem}
.author-role{font-family:var(--sans);color:var(--ink-3);font-size:.9rem}
.btn{display:inline-block;font-family:var(--sans);font-size:.92rem;padding:.6rem 1rem;border:1px solid var(--rule-2);border-radius:5px;color:var(--ink);text-decoration:none;margin:.25rem .4rem .25rem 0;background:var(--card)}
.btn:hover{border-color:var(--emerald);color:var(--emerald)}
.btn-primary{background:var(--emerald);border-color:var(--emerald);color:var(--paper)}
.btn-primary:hover{background:var(--emerald-2);color:var(--paper)}
.home-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(16rem,1fr));gap:1.2rem;margin:2.5rem 0}
.home-card{background:var(--card);border:1px solid var(--rule);border-radius:var(--radius);padding:1.1rem 1.25rem}
.home-card h2{border:0;margin:0 0 .4rem;padding:0;font-size:1.15rem}
.three{padding-left:1.2rem}
.home-start h2{border:0}

/* ---------- index / glossary / bibliography / ledger ---------- */
.filter{display:flex;flex-wrap:wrap;gap:.3rem;margin:1rem 0;font-family:var(--sans)}
.filter button{font:inherit;font-size:.82rem;border:1px solid var(--rule-2);background:var(--card);color:var(--ink-2);padding:.3rem .65rem;border-radius:999px;cursor:pointer}
.filter button[aria-pressed="true"]{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.glossary dt{font-weight:600;margin-top:1.1rem}
.glossary dd{margin:.2rem 0 0 0;color:var(--ink-2)}
.aliases{font-weight:400;color:var(--ink-3);font-size:.9rem}
.bibliography{padding-left:0;list-style:none}
.bibliography li{margin:.9rem 0;padding-left:0}
.bib-label{font-family:var(--sans);font-weight:600;font-size:.85rem;color:var(--brass);display:block}
.bib-note{display:block;font-size:.88rem;color:var(--ink-3);font-style:italic}
.verif{font-family:var(--sans);font-size:.68rem;text-transform:uppercase;letter-spacing:.04em;padding:.05rem .4rem;border-radius:3px;margin-left:.3rem;white-space:nowrap}
.verif-metadata-verified{background:var(--emerald-tint);color:var(--emerald)}
.verif-secondary-only{background:var(--brass-tint);color:var(--brass)}
.verif-unverified{background:var(--claret-tint);color:var(--claret)}
.ledger-crumb{font-family:var(--sans);font-size:.85rem;color:var(--ink-3)}
.ledger-doc h1{font-size:2rem}
.ledger-doc table{font-size:.86rem}
.ledger-doc code{overflow-wrap:anywhere}
.ledger-doc [id^="CGT-"]:target,.ledger-doc :target{background:var(--brass-tint);outline:4px solid var(--brass-tint)}
.ledger-list li{margin:.4rem 0}
.chapter-refs{font-size:.92rem}
.chapter-refs ol{padding-left:1.2rem}
.pager{display:flex;justify-content:space-between;gap:1rem;margin-top:3rem;padding-top:1rem;border-top:1px solid var(--rule);font-family:var(--sans);font-size:.88rem}
.pager a{text-decoration:none;max-width:48%}
.pager .next{text-align:right;margin-left:auto}

/* ---------- SDK / API ---------- */
.api-module{margin-top:2.5rem}
.api-member{border-top:1px solid var(--rule);padding:.6rem 0}
.api-member h3{font-size:.95rem;margin:.4rem 0;font-family:var(--mono);font-weight:400;overflow-wrap:anywhere}
.api-kind{font-family:var(--sans);font-size:.7rem;text-transform:uppercase;color:var(--brass);margin-left:.4rem}
.api-docstring{white-space:pre-wrap;font-family:var(--serif);font-size:.95rem;background:none;margin:.2rem 0;color:var(--ink-2)}
.api-moves code{font-size:.78rem}

/* ---------- laboratory widgets ---------- */
.demo{font-family:var(--sans);font-size:.92rem}
.demo-fallback{font-family:var(--serif);color:var(--ink-2)}
.demo.ready .demo-fallback{display:none}
.lab-panel{display:grid;gap:.9rem}
.lab-row{display:flex;flex-wrap:wrap;gap:.5rem;align-items:center}
.lab-row label{font-size:.82rem;color:var(--ink-2)}
.lab-row input,.lab-row select,.lab-row textarea{font:inherit;font-family:var(--mono);font-size:.85rem;padding:.35rem .5rem;border:1px solid var(--rule-2);border-radius:4px;background:var(--card);color:var(--ink)}
.lab-row textarea{width:100%;min-height:4.5rem}
.lab-row button{font:inherit;font-size:.85rem;padding:.38rem .8rem;border-radius:4px;border:1px solid var(--emerald);background:var(--emerald);color:var(--paper);cursor:pointer}
.lab-row button.secondary{background:var(--card);color:var(--emerald)}
.lab-out{font-family:var(--mono);font-size:.82rem;background:var(--card);border:1px solid var(--rule);border-radius:4px;padding:.6rem .8rem;white-space:pre-wrap;overflow-x:auto;max-height:22rem;overflow-y:auto}
.lab-cmp{display:grid;grid-template-columns:repeat(auto-fit,minmax(14rem,1fr));gap:.8rem}
.lab-card{background:var(--card);border:1px solid var(--rule);border-radius:var(--radius);padding:.7rem .9rem}
.lab-card h4{margin:0 0 .4rem;font-family:var(--sans);font-size:.85rem;text-transform:uppercase;letter-spacing:.04em;color:var(--ink-2)}
.big-number{font-family:var(--serif);font-size:2rem;font-weight:600;color:var(--emerald);font-variant-numeric:tabular-nums;line-height:1.1}
.cells{display:flex;flex-wrap:wrap;gap:1.15rem 3px;margin:1.2rem 0 .4rem}
.cell{min-width:2.1rem;height:2.1rem;display:flex;flex-direction:column;align-items:center;justify-content:center;border:1px solid var(--rule-2);border-radius:3px;font-family:var(--mono);font-size:.78rem;background:var(--card);position:relative}
.cell small{position:absolute;top:-1.1rem;font-size:.6rem;color:var(--ink-3)}
.cell.hit{background:var(--emerald);color:var(--paper);border-color:var(--emerald)}
.cell.walk{background:var(--brass-tint);border-color:var(--brass)}
.bar-row{display:grid;grid-template-columns:9rem 1fr 4.5rem;gap:.5rem;align-items:center;margin:.25rem 0;font-size:.82rem}
.bar{height:.9rem;background:var(--emerald);border-radius:2px;min-width:1px}
.bar.b2{background:var(--brass)}.bar.b3{background:var(--slate)}.bar.b4{background:var(--claret)}
svg.lab-svg{width:100%;height:auto;background:var(--card);border:1px solid var(--rule);border-radius:var(--radius)}
svg.lab-svg text{font-family:var(--sans);font-size:11px;fill:var(--ink)}
svg.lab-svg .edge{stroke:var(--rule-2);stroke-width:1.4;fill:none}
svg.lab-svg marker path{fill:var(--ink-3)}
svg.lab-svg .edge.on{stroke:var(--emerald);stroke-width:2.4}
svg.lab-svg .node{fill:var(--paper-2);stroke:var(--ink-3);stroke-width:1.2}
svg.lab-svg .node.on{fill:var(--emerald);stroke:var(--emerald)}
svg.lab-svg .node.cur{fill:var(--brass);stroke:var(--brass)}
svg.lab-svg .lbl{font-size:10px;fill:var(--ink-3)}
.lab-note{font-family:var(--serif);font-size:.92rem;color:var(--ink-3)}
.lab-section{margin:2.5rem 0}
.lab-section>h2{margin-top:0}

/* ---------- footer ---------- */
.site-footer{border-top:1px solid var(--rule);padding:1.5rem 1.25rem 2.5rem;font-family:var(--sans);font-size:.82rem;color:var(--ink-3);text-align:center}
.site-footer p{margin:.3rem auto;max-width:56rem}
.status-note{color:var(--ink-3)}

/* ---------- responsive ---------- */
@media (max-width:900px){
  .site-header{flex-wrap:wrap;gap:.4rem .8rem;padding:.5rem 1rem}
  .site-nav{order:3;width:100%;overflow-x:auto;flex-wrap:nowrap;padding-bottom:.2rem}
  .site-nav a{white-space:nowrap}
  .tools{margin-left:auto}
  .search input{width:10rem}
}
@media (max-width:560px){
  body{font-size:1rem}
  .brand-sub{display:none}
  .search input{width:7.5rem}
  .env{padding:.75rem .8rem}
  .cl-desc{margin-left:0}
  .bar-row{grid-template-columns:6rem 1fr 3.5rem}
}

/* ---------- print edition ---------- */
/* reader feedback (optional backend) */
.feedback-form{display:grid;gap:.9rem;margin:1.2rem 0 2rem;padding:1.1rem 1.2rem;background:var(--card);border:1px solid var(--rule);border-radius:var(--radius);font-family:var(--sans);font-size:.92rem}
.feedback-form[hidden]{display:none}
.ff-row{display:grid;gap:.3rem}
.ff-row label{font-weight:600;color:var(--ink-2)}
.ff-opt{font-weight:400;color:var(--ink-3)}
.feedback-form input,.feedback-form select,.feedback-form textarea{font:inherit;color:var(--ink);background:var(--paper);border:1px solid var(--rule-2);border-radius:4px;padding:.5rem .6rem;width:100%;box-sizing:border-box}
.feedback-form textarea{resize:vertical;font-family:var(--serif);font-size:1rem;line-height:1.5}
.feedback-form input:focus,.feedback-form select:focus,.feedback-form textarea:focus{outline:2px solid var(--focus);outline-offset:1px}
.ff-hp{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}
.ff-actions{display:flex;flex-wrap:wrap;align-items:center;gap:.8rem}
.ff-actions button{font:600 .92rem var(--sans);background:var(--emerald);color:var(--paper);border:0;border-radius:4px;padding:.55rem 1.1rem;cursor:pointer}
.ff-actions button:disabled{opacity:.6;cursor:progress}
.ff-status{margin:0;color:var(--ink-3)}
.ff-status.ok{color:var(--emerald)}
.ff-status.err{color:var(--claret)}
.feedback-unavailable{padding:.8rem 1rem;border:1px solid var(--claret);background:var(--claret-tint);border-radius:var(--radius)}
.chapter-feedback{font-family:var(--sans);font-size:.85rem;margin:2rem 0 0}
.checks-empty{color:var(--ink-3);font-style:italic}
.outcome{font:600 .75rem var(--sans);text-transform:uppercase;letter-spacing:.04em}
.outcome-confirmed{color:var(--emerald)}
.outcome-differs,.outcome-issue-found{color:var(--claret)}
.outcome-failed{color:var(--ink-3)}

@media print{
  :root{--paper:#fff;--card:#fff;--paper-2:#f6f6f6}
  .site-header,.site-footer,.chapter-toc,.pager,.chapter-feedback,.theme-toggle,.env-demo,.search{display:none!important}
  body{font-size:10.5pt;background:#fff}
  .main{max-width:none;padding:0}
  .print-chapter{break-before:page}
  .env{break-inside:avoid}
  .equation{overflow:visible}
  .equation .katex-display{white-space:normal}
  .table-wrap{overflow:visible}
  pre,figure.code pre,pre.install{white-space:pre-wrap;overflow-wrap:anywhere;overflow:visible;font-size:8pt}
  figure.code{overflow:visible}
  .katex-display{font-size:.95em}
  h2,h3{break-after:avoid}
  a{color:inherit;text-decoration:none}
  .print-title{height:90vh;display:flex;flex-direction:column;justify-content:center}
  .print-title h1{font-size:34pt}
  details.env-solution{display:block}
}
@page{size:A4;margin:22mm 20mm}