/* LEVIATHAN Documentation -- design system.
   Scoped to /docs: nothing here is loaded by the Azarel landing page or blog.
   Pale ocean-blue paper, a faint survey-chart grid, editorial serif headings,
   Inter for reading, IBM Plex Mono only for units, identifiers and labels. */

:root {
  --paper: #eaf1f6;
  --paper-hi: #f3f7fa;
  --paper-lo: #dfe9f0;
  --ink: #0f2233;
  --ink-2: #33475a;
  --ink-3: #516578;
  --rule: rgba(15, 34, 51, 0.13);
  --rule-2: rgba(15, 34, 51, 0.24);
  --accent: #0a6996;
  --accent-ink: #08557a;
  --signal: #0daaf2;
  --brass: #845413;
  --brass-bg: rgba(160, 110, 30, 0.08);
  --ok: #1d6b4f;
  --grid: rgba(10, 105, 150, 0.055);
  --grid-major: rgba(10, 105, 150, 0.085);
  --shadow: 0 1px 0 rgba(255, 255, 255, 0.7) inset, 0 10px 30px -18px rgba(15, 34, 51, 0.35);
  --serif: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --hdr: 60px;
  --side: 268px;
  --toc: 228px;
  --measure: 46rem;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--hdr) + 18px); }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }

body.docs {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  /* paper grain, then a survey-chart grid (minor 24 px, major 120 px) */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .06 0 0 0 0 .14 0 0 0 0 .2 0 0 0 .55 0'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23n)' opacity='.22'/%3E%3C/svg%3E"),
    linear-gradient(var(--grid-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-major) 1px, transparent 1px),
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 220px 220px, 120px 120px, 120px 120px, 24px 24px, 24px 24px;
  background-attachment: fixed;
  font: 400 16.5px/1.68 var(--sans);
  font-feature-settings: "cv11", "ss01";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.docs a { color: var(--accent); text-decoration: underline; text-decoration-color: rgba(10, 105, 150, 0.35); text-underline-offset: 3px; text-decoration-thickness: 1px; }
.docs a:hover { color: var(--accent-ink); text-decoration-color: currentColor; }
.docs :focus-visible { outline: 2px solid var(--signal); outline-offset: 2px; border-radius: 3px; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.skip { position: absolute; left: 12px; top: -60px; z-index: 100; background: var(--ink); color: #fff !important; padding: 8px 14px; border-radius: 6px; text-decoration: none; }
.skip:focus { top: 10px; }

/* ------------------------------------------------------------------ header */
.dh {
  position: sticky; top: 0; z-index: 40; height: var(--hdr);
  background: rgba(234, 241, 246, 0.94);
  border-bottom: 1px solid var(--rule-2);
}
@supports (backdrop-filter: blur(8px)) { .dh { background: rgba(234, 241, 246, 0.82); backdrop-filter: blur(8px) saturate(1.2); } }
/* a measuring-tape rule under the header */
.dh::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 5px; pointer-events: none;
  background-image:
    linear-gradient(90deg, var(--rule-2) 1px, transparent 1px),
    linear-gradient(90deg, var(--rule) 1px, transparent 1px);
  background-size: 60px 5px, 12px 3px; background-repeat: repeat-x; background-position: 0 100%, 0 100%;
}
.dh-in { height: 100%; display: flex; align-items: center; gap: 22px; padding: 0 22px; max-width: 1560px; margin: 0 auto; }
.docs .dh-brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); flex: none; }
.dh-brand img { border-radius: 6px; }
.dh-word { font: 600 15px/1 var(--sans); letter-spacing: 0.22em; }
.dh-sep { width: 1px; height: 18px; background: var(--rule-2); }
.dh-doc { font: 400 17px/1 var(--serif); color: var(--ink-2); }
.dh-search { position: relative; flex: 1; max-width: 460px; margin-left: auto; }
.dh-search input {
  width: 100%; height: 36px; padding: 0 38px 0 36px; border-radius: 8px;
  border: 1px solid var(--rule-2); background: var(--paper-hi); color: var(--ink);
  font: 400 14.5px/1 var(--sans);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='none' stroke='%23516578' stroke-width='1.6'%3E%3Ccircle cx='7' cy='7' r='5'/%3E%3Cpath d='m11 11 3.5 3.5'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: 12px 50%;
}
.dh-search input::placeholder { color: var(--ink-3); }
.dh-search input::-webkit-search-cancel-button { display: none; }
.dh-search kbd { position: absolute; right: 9px; top: 50%; transform: translateY(-50%); font: 500 11px/1 var(--mono); color: var(--ink-3); border: 1px solid var(--rule-2); border-radius: 4px; padding: 3px 6px; background: var(--paper); }
.dh-results {
  position: absolute; top: calc(100% + 6px); left: 0; right: 0; margin: 0; padding: 6px; list-style: none;
  background: var(--paper-hi); border: 1px solid var(--rule-2); border-radius: 10px; box-shadow: 0 18px 44px -14px rgba(15, 34, 51, 0.38);
  max-height: min(70vh, 520px); overflow: auto; z-index: 60;
}
.dh-results li { padding: 9px 11px; border-radius: 7px; cursor: pointer; }
.dh-results li[aria-selected="true"], .dh-results li:hover { background: rgba(10, 105, 150, 0.09); }
.dh-results .r-t { display: block; font: 500 14px/1.35 var(--sans); color: var(--ink); }
.dh-results .r-g { display: block; font: 400 11px/1.4 var(--mono); letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 2px; }
.dh-results .r-x { display: block; font: 400 13px/1.45 var(--sans); color: var(--ink-2); margin-top: 2px; }
.dh-results mark { background: rgba(13, 170, 242, 0.2); color: inherit; border-radius: 2px; padding: 0 1px; }
.dh-results .r-none { cursor: default; color: var(--ink-3); font-size: 14px; }
.dh-links { display: flex; align-items: center; gap: 18px; flex: none; }
.docs .dh-links a { font: 500 13.5px/1 var(--sans); color: var(--ink-2); text-decoration: none; display: inline-flex; align-items: center; gap: 7px; }
.docs .dh-links a:hover { color: var(--ink); }
.dh-az { padding: 7px 11px; border: 1px solid var(--rule-2); border-radius: 999px; }
.dh-menu { display: none; width: 38px; height: 38px; border: 1px solid var(--rule-2); background: var(--paper-hi); border-radius: 8px; cursor: pointer; padding: 0; flex: none; }
.dh-menu span { display: block; width: 16px; height: 1.5px; background: var(--ink); margin: 3.5px auto; }

/* ------------------------------------------------------------------ layout */
.dl { display: grid; grid-template-columns: var(--side) minmax(0, 1fr) var(--toc); max-width: 1560px; margin: 0 auto; min-height: calc(100vh - var(--hdr)); }
.home .dl { grid-template-columns: var(--side) minmax(0, 1fr); }

.ds { position: sticky; top: var(--hdr); height: calc(100vh - var(--hdr)); overflow-y: auto; border-right: 1px solid var(--rule); background: rgba(223, 233, 240, 0.55); scrollbar-width: thin; }
.ds-in { padding: 22px 16px 40px 22px; }
.docs .ds-home { display: block; font: 500 14px/1.3 var(--sans); color: var(--ink); text-decoration: none; padding: 7px 10px; border-radius: 6px; margin-bottom: 14px; }
.ds-g { margin: 0 0 18px; }
.ds-gt { margin: 0 0 6px; padding: 0 10px; font: 500 11px/1.5 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-3); display: flex; gap: 9px; }
.ds-n { color: var(--accent); }
.ds ul { list-style: none; margin: 0; padding: 0 0 0 10px; border-left: 1px solid var(--rule); margin-left: 14px; }
.docs .ds li a { display: block; padding: 5px 10px; margin-left: -1px; border-left: 2px solid transparent; font: 400 14px/1.4 var(--sans); color: var(--ink-2); text-decoration: none; border-radius: 0 6px 6px 0; }
.docs .ds li a:hover { color: var(--ink); background: rgba(10, 105, 150, 0.05); }
.docs .ds li a.on, .docs .ds-home.on { color: var(--ink); font-weight: 600; border-left-color: var(--accent); background: rgba(10, 105, 150, 0.08); }
.docs .ds-home.on { border-left: 0; }

.dm { min-width: 0; padding: 40px 56px 80px; outline: none; }
.doc { max-width: var(--measure); margin: 0 auto; }
.home .doc { max-width: 64rem; }

.dt { position: sticky; top: var(--hdr); height: calc(100vh - var(--hdr)); overflow-y: auto; scrollbar-width: thin; }
.dt-in { padding: 42px 22px 40px 6px; }
.dt-t { margin: 0 0 10px; font: 500 11px/1.4 var(--mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); }
.dt ol { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--rule); }
.dt li a { display: block; padding: 4px 0 4px 12px; margin-left: -1px; border-left: 1px solid transparent; font: 400 13px/1.4 var(--sans); color: var(--ink-3); text-decoration: none; }
.dt li.l3 a { padding-left: 24px; font-size: 12.5px; }
.dt li a:hover { color: var(--ink); }
.dt li a.on { color: var(--accent-ink); border-left-color: var(--accent); }

/* ------------------------------------------------------------------ typography */
.eyebrow { display: flex; gap: 14px; margin: 0 0 14px; font: 500 11.5px/1 var(--mono); letter-spacing: 0.14em; color: var(--ink-3); }
.eyebrow span:first-child { color: var(--accent); }
.doc h1 { font: 500 clamp(2.1rem, 3.6vw, 2.85rem)/1.12 var(--serif); letter-spacing: -0.012em; margin: 0 0 18px; font-variation-settings: "opsz" 48; }
.doc .lede { font: 400 1.18rem/1.6 var(--sans); color: var(--ink-2); margin: 0 0 30px; max-width: 42rem; }
.doc { counter-reset: h2; }
.doc h2 {
  counter-increment: h2;
  font: 500 1.62rem/1.25 var(--serif); letter-spacing: -0.006em; margin: 56px 0 14px; padding-top: 18px;
  border-top: 1px solid var(--rule); position: relative; font-variation-settings: "opsz" 32;
}
.doc h2::before { content: "§ " counter(h2, decimal-leading-zero); display: block; font: 500 11px/1 var(--mono); letter-spacing: 0.12em; color: var(--accent); margin-bottom: 10px; }
.doc h3 { font: 600 1.08rem/1.35 var(--sans); margin: 34px 0 8px; letter-spacing: -0.003em; }
.doc h4 { font: 600 0.82rem/1.4 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); margin: 24px 0 6px; }
.doc p, .doc li { color: var(--ink); }
.doc p { margin: 0 0 16px; }
.doc ul, .doc ol { padding-left: 1.3em; margin: 0 0 18px; }
.doc li { margin: 0 0 6px; }
.doc li::marker { color: var(--ink-3); }
.doc strong { font-weight: 600; }
.doc .u, .doc code {
  font: 400 0.86em/1 var(--mono); color: var(--ink-2); background: rgba(15, 34, 51, 0.055);
  border-radius: 4px; padding: 0.12em 0.36em; white-space: nowrap;
}
.doc .muted { color: var(--ink-3); }
.doc hr { border: 0; border-top: 1px solid var(--rule); margin: 40px 0; }

/* equations: typeset as text, no script dependency */
.eq {
  font: italic 400 1.14rem/1.6 var(--serif); text-align: center; margin: 22px 0 24px; padding: 16px 18px;
  background: var(--paper-hi); border: 1px solid var(--rule); border-radius: 6px; overflow-x: auto; white-space: nowrap;
  position: relative;
}
.eq .r { font-style: normal; }
.eq b { font-style: normal; font-weight: 600; }
.eq-n { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); font: 400 11px/1 var(--mono); color: var(--ink-3); font-style: normal; }
.where { font-size: 0.95rem; color: var(--ink-2); }
.where dt { font: italic 400 1.02rem/1.4 var(--serif); color: var(--ink); float: left; clear: left; width: 7.6rem; }
.where dd { margin: 0 0 6px 8rem; }
.gloss { margin: 0 0 20px; }
.gloss dt { font: 600 0.98rem/1.4 var(--sans); margin-top: 14px; }
.gloss dd { margin: 2px 0 0; color: var(--ink-2); }
.where::after { content: ""; display: block; clear: both; }

/* ------------------------------------------------------------------ callouts + tags */
.call { margin: 22px 0; padding: 14px 18px 14px 16px; border: 1px solid var(--rule); border-left: 3px solid var(--accent); background: rgba(243, 247, 250, 0.78); border-radius: 0 6px 6px 0; font-size: 0.955rem; }
.call > :last-child { margin-bottom: 0; }
.call .call-t { display: block; font: 500 10.5px/1 var(--mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }
.call.limit { border-left-color: var(--brass); background: rgba(250, 246, 238, 0.7); }
.call.limit .call-t { color: var(--brass); }
.tag { display: inline-block; font: 500 10.5px/1 var(--mono); letter-spacing: 0.05em; text-transform: uppercase; padding: 4px 8px; border-radius: 999px; border: 1px solid rgba(15, 34, 51, 0.16); color: var(--ink-2); background: transparent; vertical-align: 0.1em; white-space: nowrap; }
.tag.canon { color: var(--accent-ink); border-color: rgba(10, 105, 150, 0.32); }
.tag.ref { color: var(--ok); border-color: rgba(29, 107, 79, 0.32); }
.tag.legacy, .tag.partial { color: var(--brass); border-color: rgba(132, 84, 19, 0.3); }
.tag.iface { color: var(--ink-3); }

/* ------------------------------------------------------------------ figures
   One system: .fig (standard: the text column), .fig.wide (bleeds past the column on large screens),
   .fig.compact (narrow content), .fig.native (UI fragments shown at their own pixel size). */
.fig { margin: 36px 0 40px; }
.fig .frame { display: block; border: 1px solid rgba(15, 34, 51, 0.13); border-radius: 10px; overflow: hidden; background: #0e1620; }
.fig img { display: block; width: 100%; height: auto; }
.fig figcaption { margin-top: 12px; font: 400 0.875rem/1.55 var(--sans); color: var(--ink-3); max-width: 42rem; }
.fig-n { font: 500 10.5px/1 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); margin-right: 8px; white-space: nowrap; }
@media (min-width: 1400px) { .fig.wide { margin-left: -6rem; margin-right: -6rem; } .fig.wide figcaption { margin-left: 6rem; } }
.home .fig.wide { margin-left: 0; margin-right: 0; }
.home .fig.wide figcaption { margin-left: 0; }
.fig.compact { max-width: 30rem; }
.fig.native .frame { display: inline-block; max-width: 100%; }
.fig.native img { width: auto; max-width: 100%; }
.fig.diagram .frame { background: var(--paper-hi); padding: 28px 30px; border-color: rgba(15, 34, 51, 0.1); }
.fig svg { display: block; width: 100%; height: auto; }

/* diagram typography and marks (inline SVG, class-styled) */
.dg text { font-family: var(--sans); }
.dg .dg-t { font-size: 16px; font-weight: 600; fill: var(--ink); }
.dg .dg-s { font-size: 13px; font-weight: 400; fill: var(--ink-3); }
.dg .dg-step { font-size: 14px; font-weight: 500; fill: var(--ink-2); }
.dg .dg-l { font-size: 12.5px; fill: var(--ink-3); }
.dg .dg-caps { font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.1em; text-transform: uppercase; fill: var(--accent-ink); }
.dg .dg-edge { stroke: #7d8e9c; stroke-width: 1.4; fill: none; }
.dg .dg-dash { stroke-dasharray: 4 5; }
.dg .dg-arrowhead { stroke: #7d8e9c; stroke-width: 1.4; }
.dg .dg-mark { fill: var(--paper-hi); stroke: var(--ink-2); stroke-width: 2; }
.dg .dg-mark-hi { fill: var(--accent); stroke: var(--accent); stroke-width: 2; }
.dg .dg-band { fill: rgba(10, 105, 150, 0.04); }
.dg .dg-cell { fill: #f7fafc; stroke: rgba(15, 34, 51, 0.16); stroke-width: 1; }
.dg .dg-cell-hi { fill: rgba(10, 105, 150, 0.07); stroke: rgba(10, 105, 150, 0.42); stroke-width: 1.2; }
.dg .dg-group { fill: rgba(15, 34, 51, 0.025); stroke: rgba(15, 34, 51, 0.16); stroke-width: 1; }
.dg .dg-dashed { stroke-dasharray: 5 4; }

/* showcase gallery: equal aspect, two columns, caption under each */
.gallery { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px 22px; margin: 32px 0 40px; }
.gallery figure { margin: 0; }
.gallery .frame { display: block; border: 1px solid rgba(15, 34, 51, 0.13); border-radius: 10px; overflow: hidden; background: #0e1620; }
.gallery img { display: block; width: 100%; height: auto; aspect-ratio: 5 / 3; object-fit: cover; }
.gallery figcaption { margin-top: 10px; font: 400 0.86rem/1.5 var(--sans); color: var(--ink-3); }
.gallery figcaption b { display: block; font: 600 0.95rem/1.35 var(--sans); color: var(--ink); margin-bottom: 2px; }
.gallery a { text-decoration: none; color: inherit; }
.gallery.three { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px 16px; }

/* channel comparison: one capture, several aligned outputs; images dominate, plain labels beneath */
.channels { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 26px 22px; }
.channels figure { margin: 0; }
.channels .frame { display: block; border: 1px solid rgba(15, 34, 51, 0.13); border-radius: 8px; overflow: hidden; background: #0e1620; }
.channels img { display: block; width: 100%; height: auto; aspect-ratio: 992 / 656; }
.channels figcaption.ch, .fig.wide .channels figcaption.ch { margin: 8px 0 0; max-width: none; font: 600 0.9rem/1.35 var(--sans); color: var(--ink); }
.channels-fig > figcaption { margin-top: 22px; margin-left: 0; }
.channel-strip { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; margin: 22px 0 10px; }
.channel-strip figure { margin: 0; }
.channel-strip .frame { display: block; border: 1px solid rgba(15, 34, 51, 0.13); border-radius: 6px; overflow: hidden; }
.channel-strip img { display: block; width: 100%; height: auto; }
.channel-strip figcaption { margin-top: 6px; font: 500 0.78rem/1.3 var(--sans); color: var(--ink-2); }
@media (max-width: 1100px) { .channels { grid-template-columns: minmax(0, 1fr); gap: 24px; } }
@media (max-width: 720px) { .channel-strip { grid-template-columns: repeat(2, minmax(0, 1fr)); } }

/* comparison pairs: the same subject in two views, aligned at half the wide figure width */
.compare { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 22px; margin: 36px 0 40px; align-items: start; }
.compare .fig { margin: 0; }
.compare .frame { display: inline-block; max-width: 100%; vertical-align: top; }
.compare .fig img { width: auto; max-width: 100%; }
@media (min-width: 1400px) { .compare, .gallery.wide { margin-left: -6rem; margin-right: -6rem; } }
@media (max-width: 1100px) { .compare { grid-template-columns: minmax(0, 1fr); gap: 28px; } }

/* legacy grids, kept for small UI fragments and channel strips */
.grid2, .grid3, .grid5 { display: grid; gap: 18px 16px; }
.grid2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid5 { grid-template-columns: repeat(auto-fill, minmax(180px, 248px)); }
.cell { margin: 0; }
.cell span { display: block; margin-top: 8px; font: 500 11.5px/1.35 var(--mono); letter-spacing: 0.03em; color: var(--ink-2); }
.cell span em { font-style: normal; color: var(--ink-3); font-weight: 400; }
.cell figcaption { margin-top: 8px; }
.px img { image-rendering: pixelated; }
.ui-cards { display: flex; flex-wrap: wrap; gap: 18px; align-items: flex-start; margin: 32px 0 36px; }
.ui-cards .cell { flex: 0 1 auto; }
.ui-cards .frame { border-radius: 10px; }
.ui-cards img { width: auto; max-width: 100%; }

/* ------------------------------------------------------------------ tables
   Editorial: a top rule, quiet header, horizontal separators only, generous cells. */
.tw { margin: 30px 0 36px; overflow-x: auto; -webkit-overflow-scrolling: touch; border-top: 1.5px solid rgba(15, 34, 51, 0.55); }
.tw:focus-visible { outline-offset: 2px; }
table { width: 100%; border-collapse: collapse; font-size: 0.905rem; line-height: 1.5; }
caption { caption-side: bottom; text-align: left; padding: 12px 0 0; font: 400 0.84rem/1.5 var(--sans); color: var(--ink-3); }
th, td { padding: 12px 18px 12px 0; text-align: left; vertical-align: top; border-bottom: 1px solid rgba(15, 34, 51, 0.09); }
th:last-child, td:last-child { padding-right: 0; }
thead th { font: 600 10.5px/1.3 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-3); padding-top: 13px; padding-bottom: 11px; border-bottom: 1px solid rgba(15, 34, 51, 0.22); white-space: nowrap; }
tbody tr:last-child > * { border-bottom: 1px solid rgba(15, 34, 51, 0.22); }
tbody th { font-weight: 600; color: var(--ink); }
table.cols-2 tbody th, table.cols-2 thead th:first-child { width: 30%; }
table.cols-3 tbody th, table.cols-4 tbody th, table.cols-5 tbody th { width: 22%; min-width: 8.5rem; }
td.n, th.n { font-family: var(--mono); font-size: 0.84rem; white-space: nowrap; text-align: right; }
td.c { font-family: var(--mono); font-size: 0.83rem; color: var(--ink-2); }
td.na { color: var(--ink-3); }
table.compact th, table.compact td { padding-top: 9px; padding-bottom: 9px; }

/* ------------------------------------------------------------------ cards (home + index lists) */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(15.5rem, 1fr)); gap: 12px; margin: 22px 0 30px; }
.docs a.card { display: block; text-decoration: none; color: var(--ink); background: rgba(243, 247, 250, 0.86); border: 1px solid var(--rule-2); border-radius: 10px; padding: 16px 18px 18px; transition: border-color .15s ease, background-color .15s ease; position: relative; }
.docs a.card:hover { border-color: var(--accent); background: var(--paper-hi); }
.card .k { display: block; font: 500 10.5px/1 var(--mono); letter-spacing: 0.12em; color: var(--accent); margin-bottom: 10px; text-transform: uppercase; }
.card .t { display: block; font: 500 1.16rem/1.25 var(--serif); margin-bottom: 6px; }
.card .d { display: block; font: 400 0.88rem/1.5 var(--sans); color: var(--ink-2); }

.home-hero { margin: 4px 0 36px; }
.home-hero h1 { font-size: clamp(2.4rem, 4.4vw, 3.4rem); margin-bottom: 14px; }
.home-meta { display: flex; flex-wrap: wrap; gap: 8px 20px; margin: 0 0 26px; font: 400 12px/1.4 var(--mono); letter-spacing: 0.04em; color: var(--ink-3); }
.home-meta b { color: var(--ink); font-weight: 500; }

/* key facts strip */
.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr)); border: 1px solid var(--rule-2); border-radius: 8px; overflow: hidden; margin: 24px 0 30px; background: rgba(243, 247, 250, 0.8); }
.facts div { padding: 14px 16px; border-right: 1px solid var(--rule); }
.facts div:last-child { border-right: 0; }
.facts b { display: block; font: 500 1.6rem/1.1 var(--serif); }
.facts span { display: block; margin-top: 4px; font: 400 11.5px/1.35 var(--mono); color: var(--ink-3); letter-spacing: 0.03em; }

/* step lists */
ol.steps { counter-reset: st; list-style: none; padding: 0; }
ol.steps > li { counter-increment: st; position: relative; padding-left: 3rem; margin-bottom: 18px; }
ol.steps > li::before { content: counter(st, decimal-leading-zero); position: absolute; left: 0; top: 0.1em; font: 500 12px/1 var(--mono); color: var(--accent); border: 1px solid rgba(10, 105, 150, 0.35); border-radius: 4px; padding: 5px 6px; background: var(--paper-hi); }

/* previous / next */
.pn { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 64px; padding-top: 22px; border-top: 1px solid var(--rule-2); }
.docs .pn a { display: block; padding: 14px 16px; border: 1px solid var(--rule-2); border-radius: 8px; text-decoration: none; color: var(--ink); font: 500 1.02rem/1.3 var(--serif); background: rgba(243, 247, 250, 0.7); }
.docs .pn a:hover { border-color: var(--accent); }
.pn a span { display: block; font: 500 10.5px/1 var(--mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 8px; }
.pn .pn-n { text-align: right; grid-column: 2; }

/* ------------------------------------------------------------------ footer */
.df { border-top: 1px solid var(--rule-2); background: rgba(223, 233, 240, 0.6); }
.df-in { max-width: 1560px; margin: 0 auto; padding: 26px 22px 34px calc(var(--side) + 56px); font-size: 0.86rem; color: var(--ink-2); }
.df-in p { margin: 0 0 8px; max-width: 46rem; }
.df-meta { display: flex; flex-wrap: wrap; gap: 8px 20px; font: 400 12px/1.4 var(--mono); color: var(--ink-3); }

/* ------------------------------------------------------------------ responsive */
@media (max-width: 1240px) {
  .dl { grid-template-columns: var(--side) minmax(0, 1fr); }
  .dt { display: none; }
  .dm { padding: 36px 44px 72px; }
}
@media (max-width: 920px) {
  :root { --hdr: 56px; }
  .dl, .home .dl { grid-template-columns: minmax(0, 1fr); }
  .dh-menu { display: block; }
  .dh-links a:not(.dh-az) { display: none; }
  .dh-in { gap: 12px; padding: 0 14px; }
  .dh-doc, .dh-sep { display: none; }
  .ds {
    position: fixed; top: var(--hdr); left: 0; bottom: 0; height: auto; width: min(84vw, 320px); z-index: 50;
    background: var(--paper); border-right: 1px solid var(--rule-2); box-shadow: 18px 0 40px -24px rgba(15, 34, 51, 0.5);
    transform: translateX(-102%); visibility: hidden;
  }
  .ds.open { transform: none; visibility: visible; }
  .ds-scrim { position: fixed; inset: var(--hdr) 0 0 0; background: rgba(15, 34, 51, 0.28); z-index: 45; }
  .dm { padding: 28px 16px 64px; }
  .df-in { padding: 24px 16px 30px; }
  .grid3, .gallery.three { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (prefers-reduced-motion: no-preference) and (max-width: 920px) { .ds { transition: transform .2s ease, visibility .2s; } }
@media (max-width: 560px) {
  body.docs { font-size: 16px; }
  .dh-search kbd { display: none; }
  .dh-az { padding: 6px 9px; }
  .dh-word { letter-spacing: 0.14em; font-size: 14px; }
  .grid2, .grid3, .gallery, .gallery.three { grid-template-columns: minmax(0, 1fr); }
  .grid5 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .fig.diagram .frame { padding: 18px 14px; overflow-x: auto; }
  .fig.diagram svg.dg { min-width: 620px; }
  .tw table.cols-4, .tw table.cols-5, .tw table.cols-6, .tw table.cols-7, .tw table.cols-8 { min-width: 38rem; }
  .tw table.cols-3 { min-width: 30rem; }
  .pn { grid-template-columns: 1fr; }
  .pn .pn-n { grid-column: 1; }
  .eq { font-size: 1rem; text-align: left; }
  .where dt { float: none; width: auto; }
  .where dd { margin-left: 0; }
  .facts div { border-right: 0; border-bottom: 1px solid var(--rule); }
}
@media print {
  body.docs { background: #fff; }
  .dh, .ds, .dt, .pn, .df, .skip { display: none !important; }
  .dl { display: block; }
}