/* tensor-factory — Bauhaus-industrial design system.
   A Berlin gallery wall: concrete grays, one disciplined red, geometric primitives as
   functional ornament. Big Shoulders Display (monumental, condensed) over Jost (geometric,
   Futura-lineage) with Space Mono for technical annotation. Light wall is the default;
   [data-theme="dark"] is the night gallery. The .doc-* and landing rules both live here so
   every page — index, demo, and docs — is of one piece. */

:root {
  /* light: concrete gallery wall (default) */
  --paper:   #e9e7e1;
  --paper-2: #dedbd3;
  --ink:     #15140f;
  --ink-2:   #45423b;
  --muted:   #847f74;
  --line:    #15140f;   /* structural rules are black */
  --hair:    #c7c3b9;   /* hairline grid */
  --red:     #e1261c;   /* THE accent — used sparingly */
  --on-red:  #f6f1e9;
  --code-bg: #15140f;
  --code-fg: #e9e7e1;

  --display: "Big Shoulders Display", "Arial Narrow", sans-serif;
  --sans:    "Jost", "Futura", ui-sans-serif, system-ui, sans-serif;
  --mono:    "Space Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --col: 64rem;
  --gut: clamp(1.4rem, 5vw, 4rem);
}

:root[data-theme="dark"] {
  --paper:   #141310;
  --paper-2: #1c1b17;
  --ink:     #eae7df;
  --ink-2:   #aba79c;
  --muted:   #7a766c;
  --line:    #eae7df;
  --hair:    #2c2a24;
  --red:     #f23a2e;
  --on-red:  #141310;
  --code-bg: #0e0d0a;
  --code-fg: #eae7df;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  overflow-x: hidden;
  background: var(--paper);
  color: var(--ink);
  transition: background-color .35s ease, color .35s ease;
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* the modular grid, barely there — a draughtsman's plate */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    linear-gradient(to right, var(--hair) 1px, transparent 1px),
    linear-gradient(to bottom, var(--hair) 1px, transparent 1px);
  background-size: 4.5rem 4.5rem;
  opacity: .35;
  -webkit-mask-image: radial-gradient(ellipse 120% 80% at 50% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 120% 80% at 50% 0%, #000 30%, transparent 75%);
}

a { color: inherit; text-decoration: none; }
.col { max-width: var(--col); margin-inline: auto; padding-inline: var(--gut); }

/* ===== top bar ===== */
.top {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; flex-wrap: wrap;
  padding-block: 1.5rem;
  border-bottom: 2px solid var(--line);
}
.brand {
  font-family: var(--mono);
  font-size: 0.84rem; font-weight: 700;
  letter-spacing: 0.04em; text-transform: uppercase;
  display: inline-flex; align-items: center;
}
/* the interpunct becomes a red square — a primary form between the words */
.brand .dot {
  display: inline-block; width: 0.6rem; height: 0.6rem; background: var(--red);
  margin: 0 0.45rem; vertical-align: 0.04em;
  overflow: hidden; text-indent: 100%; white-space: nowrap;
}

.nav { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--muted);
  display: flex; gap: 1.25rem; flex-wrap: wrap; align-items: baseline; }
.nav a { position: relative; padding-bottom: 2px; }
.nav a::after {
  content: ""; position: absolute; left: 0; bottom: -2px; height: 2px; width: 100%;
  background: var(--red); transform: scaleX(0); transform-origin: left;
  transition: transform .3s cubic-bezier(.2,.7,.2,1);
}
.nav a.here { color: var(--ink); }
.nav a.here::after, .nav a:hover::after { transform: scaleX(1); }
.nav a:hover { color: var(--ink); }
/* group divider — Guides | Reference | GitHub */
.nav-sep { align-self: center; width: 2px; height: 0.9rem; background: var(--line);
  opacity: 0.45; }
@media (max-width: 520px) { .nav-sep { display: none; } }

.top-right { display: flex; align-items: center; gap: 1.1rem; }
.theme-toggle {
  appearance: none; -webkit-appearance: none;
  display: inline-flex; align-items: center; justify-content: center;
  width: 2.1rem; height: 2.1rem; padding: 0;
  background: transparent; border: 2px solid var(--line); border-radius: 0;
  color: var(--ink); cursor: pointer;
  transition: background .25s, color .25s, transform .25s;
}
.theme-toggle:hover { background: var(--red); border-color: var(--red); color: var(--on-red); }
.theme-toggle:active { transform: translateY(1px); }
.theme-toggle svg { width: 1rem; height: 1rem; display: block; }
.theme-toggle .i-sun, .theme-toggle .i-moon { display: none; }
:root:not([data-theme="dark"]) .theme-toggle .i-moon { display: block; }  /* light → offer dark */
:root[data-theme="dark"] .theme-toggle .i-sun { display: block; }         /* dark → offer light */

/* ===== shared display type ===== */
.kicker {
  font-family: var(--mono); font-size: 0.74rem; font-weight: 700;
  letter-spacing: 0.22em; text-transform: uppercase; color: var(--ink);
  margin: 0 0 1.6rem; display: inline-flex; align-items: center; gap: 0.7rem;
}
.kicker::before { content: ""; width: 0.7rem; height: 0.7rem; background: var(--red);
  display: inline-block; border-radius: 50%; }   /* a red disc — primary form */

/* ===== hero (landing) ===== */
.hero { padding-block: clamp(3.5rem, 11vh, 7rem) clamp(2.5rem, 7vh, 4.5rem); position: relative; }
h1 {
  font-family: var(--display); font-weight: 800;
  font-size: clamp(3.2rem, 13vw, 9rem); line-height: 0.86;
  letter-spacing: -0.01em; text-transform: uppercase;
  margin: 0; max-width: 14ch;
}
h1 em { font-style: normal; color: var(--red); }
.lede {
  margin: 2rem 0 0; max-width: 44ch;
  font-size: clamp(1.05rem, 2vw, 1.3rem); line-height: 1.5; color: var(--ink-2);
}
.actions { margin-top: 2.6rem; display: flex; gap: 1.4rem; align-items: center; flex-wrap: wrap; }
.link-arrow {
  font-family: var(--mono); font-size: 0.78rem; font-weight: 700;
  letter-spacing: 0.04em; text-transform: uppercase;
  display: inline-flex; align-items: center; gap: 0.6rem;
  padding: 0.7rem 1.1rem; border: 2px solid var(--line);
  transition: background .25s, color .25s, border-color .25s;
}
.link-arrow .a { transition: transform .25s cubic-bezier(.2,.7,.2,1); }
.link-arrow:hover { background: var(--ink); color: var(--paper); }
.link-arrow:hover .a { transform: translateX(4px); }
.link-arrow.primary { background: var(--red); border-color: var(--red); color: var(--on-red); }
.link-arrow.primary:hover { background: var(--ink); border-color: var(--ink); color: var(--paper); }

/* the constructed composition — primary forms, one red */
.plate {
  position: absolute; top: 14%; right: calc(-1 * var(--gut) / 2); width: min(32vw, 17rem);
  aspect-ratio: 1; pointer-events: none; z-index: -1;
}
.plate .circle { position: absolute; inset: 0; border: 2px solid var(--line); border-radius: 50%; }
.plate .quarter {
  position: absolute; right: 0; top: 0; width: 56%; aspect-ratio: 1;
  background: var(--red); border-radius: 0 0 0 100%;
}
.plate .square { position: absolute; left: 4%; bottom: 2%; width: 30%; aspect-ratio: 1;
  border: 2px solid var(--line); background: var(--paper); }
.plate .bar { position: absolute; left: 50%; top: -8%; width: 2px; height: 116%;
  background: var(--line); transform: translateX(-50%); }
@media (max-width: 760px) { .plate { display: none; } }

/* ===== section frame ===== */
section { border-top: 2px solid var(--line); }
.sec-pad { padding-block: clamp(3rem, 8vh, 5.5rem); }
.eyebrow {
  font-family: var(--mono); font-size: 0.72rem; font-weight: 700;
  letter-spacing: 0.18em; text-transform: uppercase; color: var(--muted);
  margin: 0 0 2.2rem; display: flex; align-items: center; gap: 0.8rem;
}
.eyebrow::before { content: ""; width: 0.7rem; height: 0.7rem; background: var(--red); display: inline-block; }

/* ===== spec row (stats) — gauge plates ===== */
.spec { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2px; background: var(--line);
  border: 2px solid var(--line); }
.spec > div { background: var(--paper); padding: 1.7rem 1.5rem; position: relative; }
.spec .n {
  font-family: var(--display); font-weight: 700;
  font-size: clamp(2.2rem, 5vw, 3.2rem); line-height: 0.9; letter-spacing: -0.01em;
}
.spec .n sup { font-size: 0.42em; vertical-align: top; color: var(--red); font-family: var(--mono); }
.spec .n span { color: var(--red); }
.spec .u { font-family: var(--mono); font-size: 0.7rem; text-transform: uppercase;
  letter-spacing: 0.04em; color: var(--muted); margin-top: 0.9rem; line-height: 1.45; }
.spec-note { font-family: var(--mono); font-size: 0.72rem; color: var(--muted); margin: 1rem 0 0;
  text-transform: uppercase; letter-spacing: 0.04em; }
.spec-note a { color: var(--ink); border-bottom: 2px solid var(--red); padding-bottom: 1px;
  transition: background .2s, color .2s; }
.spec-note a:hover { background: var(--red); color: var(--on-red); }

/* ===== pipeline steps ===== */
.steps { margin: 0; }
.step { display: grid; grid-template-columns: 4.5rem 1fr; gap: 1.6rem; padding-block: 1.8rem;
  border-top: 1px solid var(--hair); align-items: baseline; }
.step:first-child { border-top: none; }
.step .num { font-family: var(--display); font-weight: 700; font-size: 2.4rem; line-height: 1;
  color: var(--red); }
.step h3 { font-family: var(--display); font-weight: 700; text-transform: uppercase;
  font-size: 1.7rem; letter-spacing: 0; margin: 0 0 0.35rem; }
.step p { margin: 0; color: var(--ink-2); max-width: 54ch; }

/* ===== landing intro paragraph (scoped to <p> so it can't cap the doc container) ===== */
p.prose { max-width: 56ch; color: var(--ink-2); margin: 0 0 1.8rem; }
pre {
  margin: 0 0 1.3rem; background: var(--code-bg); color: var(--code-fg);
  border: 2px solid var(--line); border-radius: 0;
  padding: 1.4rem 1.5rem; overflow-x: auto;
  font-family: var(--mono); font-size: 0.82rem; line-height: 1.85; letter-spacing: 0;
}
pre code { background: none; color: inherit; padding: 0; font-size: inherit; }
pre .c { color: #8f8a7e; }
pre .k { color: var(--red); }
pre .s { color: #c8a23c; }
:root[data-theme="dark"] pre .s { color: #d8b86a; }

/* ===== packages ===== */
.pkg { display: grid; grid-template-columns: 15rem 1fr; gap: 1.6rem; padding-block: 1.4rem;
  border-top: 1px solid var(--hair); align-items: baseline; }
.pkg:first-of-type { border-top: none; }
.pkg .name { font-family: var(--mono); font-size: 0.9rem; font-weight: 700; }
.pkg .name .star { color: var(--red); }
.pkg .desc { color: var(--ink-2); margin: 0; max-width: 52ch; }

/* ===== landing: documentation routes ===== */
.docs-group { font-family: var(--mono); font-size: 0.74rem; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase; color: var(--red);
  margin: 0 0 0.6rem; }
.docs-group + .pkg { border-top: none; }
.docs-group:not(:first-of-type) { margin-top: 2.6rem; }
.pkg .name a { border-bottom: 2px solid var(--red); padding-bottom: 1px;
  transition: background .2s, color .2s; }
.pkg .name a:hover { background: var(--red); color: var(--on-red); }

/* ===== example callout ===== */
.example { border: 2px solid var(--line); padding: 2rem 2.2rem; background: var(--paper-2); position: relative; }
.example::before { content: ""; position: absolute; left: 0; top: 0; width: 0.6rem; height: 100%; background: var(--red); }
.example .tag { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--red); font-weight: 700; }
.example h3 { font-family: var(--display); font-weight: 700; text-transform: uppercase;
  font-size: 1.9rem; margin: 0.6rem 0 0.6rem; }
.example p { margin: 0 0 1.2rem; color: var(--ink-2); max-width: 58ch; }

/* ===== documentation header ===== */
.doc-head { padding-block: clamp(3rem, 9vh, 5rem) clamp(1.6rem, 4vh, 2.4rem); }
.doc-head h1 { font-size: clamp(2.6rem, 8vw, 5rem); line-height: 0.9; max-width: none; }
.doc-head h1 em { color: var(--red); }
.doc-head .lede { margin-top: 1.6rem; max-width: 58ch; }

/* ===== doc body: prose + sticky index ===== */
.doc-layout { display: grid; grid-template-columns: 1fr 14rem; gap: clamp(1.6rem, 5vw, 3.5rem);
  align-items: start; padding-block: clamp(1.5rem, 4vh, 2.5rem) clamp(3rem, 8vh, 5rem);
  border-top: 2px solid var(--line); }
.toc { position: sticky; top: 1.5rem; font-family: var(--mono); font-size: 0.72rem;
  text-transform: uppercase; letter-spacing: 0.04em; line-height: 1.5;
  border-left: 2px solid var(--line); padding-left: 1.1rem; }
.toc .toc-label { color: var(--red); font-weight: 700; letter-spacing: 0.14em; display: block; margin-bottom: 0.9rem; }
.toc a { display: block; color: var(--muted); padding: 0.24rem 0; transition: color .2s; }
.toc a:hover { color: var(--ink); }
.toc a.sub { padding-left: 0.9rem; }

.prose { min-width: 0; }
.prose > section { scroll-margin-top: 1.5rem; padding-block: 0.4rem; }
.prose > section + section { margin-top: 2.8rem; padding-top: 2.8rem; border-top: 1px solid var(--hair); }
.prose h2 { font-family: var(--display); font-weight: 700; text-transform: uppercase;
  font-size: clamp(1.7rem, 4vw, 2.4rem); letter-spacing: 0; margin: 0 0 1rem; line-height: 1; }
.prose h3 { font-family: var(--sans); font-weight: 600; font-size: 1.3rem; margin: 2rem 0 0.6rem; }
.prose h4 { font-family: var(--mono); font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.04em; font-size: 0.86rem; margin: 1.6rem 0 0.5rem; color: var(--ink); }
.prose p { color: var(--ink-2); margin: 0 0 1.1rem; max-width: 72ch; }
.prose ul, .prose ol { color: var(--ink-2); margin: 0 0 1.1rem; padding-left: 1.3rem; max-width: 72ch; }
.prose li { margin: 0.4rem 0; }
.prose li::marker { color: var(--red); }
.prose a.inline { color: var(--ink); border-bottom: 2px solid var(--red); transition: background .2s, color .2s; }
.prose a.inline:hover { background: var(--red); color: var(--on-red); }
.prose strong { color: var(--ink); font-weight: 600; }
.prose hr { border: none; border-top: 2px solid var(--line); margin: 2rem 0; }
.prose code { font-family: var(--mono); font-size: 0.8em; background: var(--paper-2);
  color: var(--ink); padding: 0.12em 0.4em; border: 1px solid var(--hair); }
:root[data-theme="dark"] .prose code { color: var(--code-fg); }

.prose table { width: 100%; border-collapse: collapse; margin: 0 0 1.4rem; font-size: 0.88rem; }
.prose th, .prose td { text-align: left; padding: 0.6rem 0.8rem; border-bottom: 1px solid var(--hair); vertical-align: top; }
.prose th { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ink); font-weight: 700; border-bottom: 2px solid var(--line); }
.prose td { color: var(--ink-2); }
.prose td code { white-space: nowrap; }

/* callouts */
.note { border: 2px solid var(--line); padding: 1.2rem 1.4rem; background: var(--paper-2);
  margin: 0 0 1.3rem; position: relative; }
.note::before { content: ""; position: absolute; left: 0; top: 0; width: 0.5rem; height: 100%; background: var(--red); }
.note p:last-child { margin-bottom: 0; }
.note .tag { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--red); font-weight: 700; display: block; margin-bottom: 0.5rem; }
.note.warn::before { background: var(--ink); }
.note.warn .tag { color: var(--ink); }

/* API signature blocks */
.sig { font-family: var(--mono); font-size: 0.84rem; background: var(--paper-2);
  border: 2px solid var(--line); padding: 0.7rem 1rem; margin: 1.4rem 0 0.7rem;
  overflow-x: auto; color: var(--ink); }
.sig .ret { color: var(--red); }

/* prev/next footer nav */
.pager { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap;
  border-top: 2px solid var(--line); padding-block: 2rem;
  font-family: var(--mono); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }
.pager a { color: var(--ink-2); transition: color .2s; }
.pager a:hover { color: var(--red); }
.pager .nxt { text-align: right; margin-left: auto; }
.pager .lbl { display: block; color: var(--muted); font-size: 0.66rem; letter-spacing: 0.12em; margin-bottom: 0.2rem; }

/* footer */
footer { border-top: 2px solid var(--line); }
.foot { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.6rem;
  padding-block: 2.2rem 3.4rem; font-family: var(--mono); font-size: 0.72rem;
  text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); }
.foot a:hover { color: var(--red); }

/* entrance motion — constructivist assembly */
[data-rise] { opacity: 0; transform: translateY(16px); animation: rise .7s cubic-bezier(.2,.7,.2,1) forwards; animation-delay: var(--d, 0s); }
@keyframes rise { to { opacity: 1; transform: none; } }
.plate .quarter { transform-origin: top right; animation: swing 1s cubic-bezier(.2,.7,.2,1) .3s both; }
@keyframes swing { from { transform: scale(0); } to { transform: scale(1); } }

@media (max-width: 820px) { .doc-layout { grid-template-columns: 1fr; } .toc { display: none; } }
@media (max-width: 700px) { .spec { grid-template-columns: 1fr 1fr; } .pkg { grid-template-columns: 1fr; gap: 0.3rem; } }
@media (prefers-reduced-motion: reduce) {
  [data-rise], .plate .quarter { animation: none; opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}