/* ============================================================
   ian-brain — documentation site
   One hand-written stylesheet. No frameworks, no build step.
   ============================================================ */

/* ---------- 1. Tokens ---------- */

:root {
  /* Dark is the primary character of this site: a star chart. */
  --bg:            #070a10;
  --bg-deep:       #04060b;
  --panel:         #0c1119;
  --panel-2:       #10161f;
  --ink:           #dbe3ee;
  --ink-strong:    #f2f6fb;
  --ink-dim:       #8d9aad;
  --ink-faint:     #7b8899;
  --rule:          #1c2531;
  --rule-soft:     #151d27;

  --teal:          #63c9bd;
  --teal-deep:     #2e8d85;
  --amber:         #d8a45e;
  --amber-deep:    #a97a3c;
  --sky:           #7fa9d6;
  --sky-deep:      #4d7aa8;
  --rose:          #d1787f;
  --rose-deep:     #a1545b;

  --link:          #7fd4c8;
  --link-visited:  #a9c8e6;

  /* diagram tokens (consumed by inline SVG via var()) */
  --dg-field:      #080c13;
  --dg-box:        #0e141d;
  --dg-box-2:      #131b26;
  --dg-stroke:     #2a3644;
  --dg-hair:       #223040;
  --dg-text:       #d5dde8;
  --dg-dim:        #8b98a9;
  --dg-teal:       #63c9bd;
  --dg-amber:      #d8a45e;
  --dg-sky:        #7fa9d6;
  --dg-rose:       #d1787f;
  --dg-glow:       #63c9bd;

  --texture-opacity: 0.10;
  --texture-blend: screen;

  --measure: 68ch;
  --gutter: clamp(1.1rem, 4vw, 3.25rem);

  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    /* Light mode: the same chart printed on paper. */
    --bg:          #f6f4ef;
    --bg-deep:     #efece4;
    --panel:       #fffefb;
    --panel-2:     #f2efe8;
    --ink:         #1e2733;
    --ink-strong:  #0c1219;
    --ink-dim:     #56626f;
    --ink-faint:   #66707c;
    --rule:        #d8d3c7;
    --rule-soft:   #e5e0d5;

    --teal:        #1c7a70;
    --teal-deep:   #12564f;
    --amber:       #8a5d16;
    --amber-deep:  #6b4711;
    --sky:         #2b5f8e;
    --sky-deep:    #1d4468;
    --rose:        #9c3d45;
    --rose-deep:   #762d34;

    --link:        #14655d;
    --link-visited:#4a3a86;

    --dg-field:    #fffefb;
    --dg-box:      #f4f1ea;
    --dg-box-2:    #e9e5db;
    --dg-stroke:   #b9b2a2;
    --dg-hair:     #cdc6b6;
    --dg-text:     #1e2733;
    --dg-dim:      #5b6673;
    --dg-teal:     #1c7a70;
    --dg-amber:    #8a5d16;
    --dg-sky:      #2b5f8e;
    --dg-rose:     #9c3d45;
    --dg-glow:     #1c7a70;

    --texture-opacity: 0.07;
    --texture-blend: multiply;
  }
}

/* ---------- 2. Reset-ish ---------- */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: clamp(0.975rem, 0.94rem + 0.18vw, 1.06rem);
  line-height: 1.68;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* The constellation texture. Fixed, faint, never loud. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image: url("constellation.png");
  background-size: cover;
  background-position: center;
  opacity: var(--texture-opacity);
  mix-blend-mode: var(--texture-blend);
  pointer-events: none;
  z-index: 0;
}

/* A second, purely CSS starfield wash so the page never looks flat. */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 90% 55% at 18% -8%, rgba(99, 201, 189, 0.10), transparent 62%),
    radial-gradient(ellipse 70% 50% at 96% 8%, rgba(127, 169, 214, 0.09), transparent 60%),
    radial-gradient(ellipse 80% 60% at 50% 108%, rgba(216, 164, 94, 0.06), transparent 62%);
  pointer-events: none;
  z-index: 0;
}

@media (prefers-color-scheme: light) {
  body::after {
    background:
      radial-gradient(ellipse 90% 55% at 18% -8%, rgba(28, 122, 112, 0.07), transparent 62%),
      radial-gradient(ellipse 70% 50% at 96% 8%, rgba(43, 95, 142, 0.06), transparent 60%);
  }
}

.shell { position: relative; z-index: 1; }

img, svg { max-width: 100%; }
svg { height: auto; }

/* ---------- 3. Typography ---------- */

h1, h2, h3, h4 {
  color: var(--ink-strong);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.012em;
  margin: 0 0 0.5em;
  text-wrap: balance;
}

h1 { font-size: clamp(1.7rem, 1.15rem + 2.4vw, 2.85rem); letter-spacing: -0.022em; }
h2 { font-size: clamp(1.28rem, 1.05rem + 1.05vw, 1.72rem); margin-top: 2.6em; }
h3 { font-size: clamp(1.04rem, 0.97rem + 0.36vw, 1.19rem); margin-top: 2em; }
h4 { font-size: 0.94rem; margin-top: 1.7em; color: var(--ink); }

h2 + h3, h3 + h4 { margin-top: 1.1em; }

p { margin: 0 0 1.15em; }

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}
a:visited { color: var(--link-visited); }
a:hover { color: var(--ink-strong); }

:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 3px;
  border-radius: 2px;
}

code, kbd, samp, pre { font-family: var(--mono); }

code {
  font-size: 0.875em;
  background: var(--panel-2);
  border: 1px solid var(--rule-soft);
  border-radius: 3px;
  padding: 0.08em 0.34em;
  overflow-wrap: break-word;
}

h1 code, h2 code, h3 code { font-size: 0.9em; background: none; border: none; padding: 0; }

strong { color: var(--ink-strong); font-weight: 600; }

.lede {
  font-size: clamp(1.03rem, 0.98rem + 0.4vw, 1.22rem);
  color: var(--ink-dim);
  line-height: 1.62;
  max-width: 62ch;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.19em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 0.9rem;
}

.eyebrow--amber { color: var(--amber); }
.eyebrow--sky { color: var(--sky); }

ul, ol { margin: 0 0 1.2em; padding-left: 1.3em; }
li { margin-bottom: 0.42em; }
li::marker { color: var(--ink-faint); }

hr {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 3rem 0;
}

/* ---------- 4. Page frame ---------- */

.page {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 var(--gutter) 5rem;
}

.prose { max-width: var(--measure); }
.prose--wide { max-width: 92ch; }

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--panel);
  color: var(--ink-strong);
  padding: 0.7rem 1.1rem;
  border: 1px solid var(--teal);
  border-radius: 4px;
  z-index: 50;
}
.skip:focus { left: 1rem; top: 1rem; }

/* ---------- 5. Constellation minimap (site navigation) ---------- */

.minimap {
  border-bottom: 1px solid var(--rule-soft);
  padding: 1.4rem 0 1.1rem;
  margin-bottom: 2.6rem;
}

.minimap-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.9rem 1.4rem;
}

.mm-home {
  font-family: var(--mono);
  font-size: 0.79rem;
  letter-spacing: 0.06em;
  color: var(--ink);
  text-decoration: none;
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 0.28rem 0.85rem;
  white-space: nowrap;
  background: color-mix(in srgb, var(--panel) 70%, transparent);
  flex: none;
}
.mm-home:hover { color: var(--ink-strong); border-color: var(--teal); }
.mm-home .lozenge { color: var(--teal); margin-right: 0.35rem; }

.mm-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
}
.mm-list li { display: flex; align-items: center; margin: 0.15rem 0; }
.mm-list li + li::before {
  content: "";
  display: block;
  width: clamp(10px, 2vw, 20px);
  height: 1px;
  background: var(--rule);
  margin: 0 0.5rem;
  flex: none;
}

.mm-item {
  display: inline-flex;
  align-items: center;
  gap: 0.42rem;
  text-decoration: none;
  font-family: var(--mono);
  font-size: 0.745rem;
  letter-spacing: 0.03em;
  color: var(--ink-dim);
  white-space: nowrap;
  padding: 0.2rem 0.15rem;
}
.mm-item:hover { color: var(--ink-strong); }
.mm-item:hover .mm-dot { background: var(--teal); box-shadow: 0 0 0 3px color-mix(in srgb, var(--teal) 22%, transparent); }

.mm-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ink-faint);
  flex: none;
  transition: background 0.15s ease, box-shadow 0.15s ease;
}

.mm-item[aria-current="page"] { color: var(--teal); }
.mm-item[aria-current="page"] .mm-dot {
  background: var(--teal);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--teal) 25%, transparent);
}

/* ---------- 6. Node graph (landing page) ---------- */

.graph-stage {
  position: relative;
  padding: clamp(1.5rem, 4vw, 3.5rem) 0 1rem;
}

.graph-stage svg { display: block; width: 100%; }

.gnode { cursor: pointer; }
.gnode .gnode-hit { fill: transparent; }
.gnode .gnode-disc { transition: fill 0.18s ease, r 0.18s ease; }
.gnode .gnode-ring { transition: opacity 0.18s ease, r 0.18s ease; opacity: 0.35; }
.gnode .gnode-title { font-weight: 600; }
.gnode:hover .gnode-disc, .gnode:focus .gnode-disc { fill: var(--dg-glow); }
.gnode:hover .gnode-ring, .gnode:focus .gnode-ring { opacity: 1; }
.gnode:hover .gnode-title, .gnode:focus .gnode-title { fill: var(--ink-strong); }
.gnode:focus { outline: none; }
.gnode:focus-visible .gnode-ring { opacity: 1; stroke-width: 2; }

.graph-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.5rem;
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  margin: 0.6rem 0 0;
  padding: 0;
  list-style: none;
}
.graph-legend li { display: flex; align-items: center; gap: 0.45rem; margin: 0; }
.graph-legend .swatch {
  width: 9px; height: 9px; border-radius: 50%; flex: none;
}

/* A text fallback / accessible index of the same graph. */
.graph-index {
  margin: 2.4rem 0 0;
  border-top: 1px solid var(--rule-soft);
  padding-top: 1.6rem;
}
.graph-index dl {
  margin: 0;
  display: grid;
  gap: 0.25rem 1.6rem;
  grid-template-columns: 1fr;
}
@media (min-width: 720px) {
  .graph-index dl { grid-template-columns: minmax(11rem, 15rem) 1fr; }
}
.graph-index dt {
  font-family: var(--mono);
  font-size: 0.83rem;
  color: var(--ink);
  padding-top: 0.15rem;
}
.graph-index dd {
  margin: 0 0 0.9rem;
  color: var(--ink-dim);
  font-size: 0.92rem;
}
@media (min-width: 720px) {
  .graph-index dd { margin-bottom: 0.6rem; }
}

/* ---------- 7. Figures / diagrams ---------- */

figure.diagram {
  margin: 2.4rem 0 2.8rem;
  padding: 0;
  border: 1px solid var(--rule-soft);
  border-radius: 6px;
  background:
    linear-gradient(to bottom, color-mix(in srgb, var(--panel) 82%, transparent), color-mix(in srgb, var(--bg-deep) 70%, transparent));
  overflow: hidden;
}

figure.diagram > svg {
  display: block;
  width: 100%;
  padding: clamp(0.5rem, 2vw, 1.25rem);
}

figure.diagram > figcaption {
  border-top: 1px solid var(--rule-soft);
  padding: 0.85rem clamp(0.9rem, 2.4vw, 1.4rem);
  font-size: 0.855rem;
  line-height: 1.55;
  color: var(--ink-dim);
  background: color-mix(in srgb, var(--bg-deep) 45%, transparent);
}
figure.diagram > figcaption b {
  color: var(--ink);
  font-weight: 600;
  font-family: var(--mono);
  font-size: 0.92em;
  letter-spacing: 0.02em;
}

/* shared SVG text conventions */
.d-label { font-family: var(--mono); font-size: 12px; fill: var(--dg-text); }
.d-label-sm { font-family: var(--mono); font-size: 10.5px; fill: var(--dg-dim); }
.d-label-xs { font-family: var(--mono); font-size: 9.5px; fill: var(--dg-dim); }
.d-head { font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em; fill: var(--dg-dim); text-transform: uppercase; }
.d-title { font-family: var(--mono); font-size: 13px; font-weight: 600; fill: var(--dg-text); }
.d-box { fill: var(--dg-box); stroke: var(--dg-stroke); stroke-width: 1; }
.d-box-2 { fill: var(--dg-box-2); stroke: var(--dg-stroke); stroke-width: 1; }
.d-field { fill: var(--dg-field); stroke: var(--dg-hair); stroke-width: 1; }
.d-hair { stroke: var(--dg-hair); stroke-width: 1; fill: none; }
.d-edge { stroke: var(--dg-stroke); stroke-width: 1.2; fill: none; }
.d-edge-teal { stroke: var(--dg-teal); stroke-width: 1.4; fill: none; }
.d-edge-amber { stroke: var(--dg-amber); stroke-width: 1.4; fill: none; }
.d-edge-sky { stroke: var(--dg-sky); stroke-width: 1.4; fill: none; }
.d-edge-rose { stroke: var(--dg-rose); stroke-width: 1.4; fill: none; }
.d-dash { stroke-dasharray: 4 4; }
.d-teal { fill: var(--dg-teal); }
.d-amber { fill: var(--dg-amber); }
.d-sky { fill: var(--dg-sky); }
.d-rose { fill: var(--dg-rose); }
.d-dim { fill: var(--dg-dim); }

/* ---------- 8. Terminal renderings ---------- */

.term {
  margin: 2rem 0 2.4rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--bg-deep);
  overflow: hidden;
}

@media (prefers-color-scheme: light) {
  .term { background: #14181e; border-color: #2a3038; }
}

.term-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.85rem;
  border-bottom: 1px solid #1e2732;
  background: #0b1017;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: #7d8b9c;
}
.term-dots { display: flex; gap: 5px; margin-right: 0.35rem; }
.term-dots i { width: 9px; height: 9px; border-radius: 50%; background: #232d39; display: block; }

.term-body {
  margin: 0;
  padding: 0.95rem 1rem 1.1rem;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.795rem;
  line-height: 1.62;
  color: #b9c6d4;
  white-space: pre;
  tab-size: 2;
}

.term-body .p  { color: #4f8f88; }          /* prompt */
.term-body .c  { color: #e8eef5; }          /* typed command */
.term-body .f  { color: #d8a45e; }          /* flag / argument */
.term-body .s  { color: #7fbfb4; }          /* string */
.term-body .o  { color: #8d9dad; }          /* stdout */
.term-body .ok { color: #63c9bd; }
.term-body .warn { color: #d8a45e; }
.term-body .err { color: #d1787f; }
.term-body .cm { color: #74838f; font-style: italic; }
.term-body .k  { color: #7fa9d6; }          /* json key */

.term + .term-note,
.diagram + .term-note {
  margin-top: -1.4rem;
}
.term-note {
  font-size: 0.85rem;
  color: var(--ink-faint);
  margin-bottom: 2rem;
}

/* ---------- 9. Callouts, pull quotes ---------- */

.pull {
  margin: 2.4rem 0;
  padding: 0.2rem 0 0.2rem 1.35rem;
  border-left: 2px solid var(--teal);
  font-size: clamp(1.05rem, 1rem + 0.5vw, 1.3rem);
  line-height: 1.45;
  color: var(--ink-strong);
  letter-spacing: -0.008em;
  max-width: 46ch;
}
.pull p { margin: 0 0 0.5em; }
.pull cite {
  display: block;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-style: normal;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
  margin-top: 0.7rem;
}
.pull--amber { border-left-color: var(--amber); }
.pull--sky { border-left-color: var(--sky); }

.callout {
  margin: 2rem 0;
  padding: 1.05rem 1.25rem;
  border: 1px solid var(--rule);
  border-left-width: 3px;
  border-left-color: var(--sky);
  border-radius: 4px;
  background: color-mix(in srgb, var(--panel) 75%, transparent);
  font-size: 0.94rem;
}
.callout > :last-child { margin-bottom: 0; }
.callout-title {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sky);
  margin: 0 0 0.5rem;
}
.callout--warn { border-left-color: var(--amber); }
.callout--warn .callout-title { color: var(--amber); }
.callout--stop { border-left-color: var(--rose); }
.callout--stop .callout-title { color: var(--rose); }
.callout--teal { border-left-color: var(--teal); }
.callout--teal .callout-title { color: var(--teal); }

/* ---------- 10. Tables ---------- */

.scroll-x {
  overflow-x: auto;
  margin: 1.8rem 0 2.2rem;
  border: 1px solid var(--rule-soft);
  border-radius: 5px;
  background: color-mix(in srgb, var(--panel) 60%, transparent);
}

table {
  border-collapse: collapse;
  width: 100%;
  min-width: 34rem;
  font-size: 0.87rem;
}

caption {
  caption-side: top;
  text-align: left;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding: 0.85rem 1rem 0.55rem;
}

th, td {
  text-align: left;
  padding: 0.6rem 0.95rem;
  border-bottom: 1px solid var(--rule-soft);
  vertical-align: top;
}

thead th {
  font-family: var(--mono);
  font-weight: 600;
  font-size: 0.73rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-dim);
  border-bottom-color: var(--rule);
  white-space: nowrap;
}

tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: color-mix(in srgb, var(--panel-2) 60%, transparent); }

td code { background: none; border: none; padding: 0; color: var(--teal); }
td .muted { color: var(--ink-faint); }

.num { font-family: var(--mono); font-variant-numeric: tabular-nums; white-space: nowrap; }

/* ---------- 11. Annotated code ---------- */

.srcblock {
  margin: 2rem 0 2.4rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  overflow: hidden;
  background: color-mix(in srgb, var(--panel) 82%, transparent);
}

.srcblock-head {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.9rem;
  align-items: baseline;
  padding: 0.55rem 0.95rem;
  border-bottom: 1px solid var(--rule-soft);
  background: color-mix(in srgb, var(--bg-deep) 55%, transparent);
  font-family: var(--mono);
  font-size: 0.745rem;
  letter-spacing: 0.04em;
}
.srcblock-head .path { color: var(--teal); }
.srcblock-head .what { color: var(--ink-faint); }

.srcblock pre {
  margin: 0;
  padding: 0.9rem 0.95rem 1rem;
  overflow-x: auto;
  font-size: 0.785rem;
  line-height: 1.65;
  color: var(--ink);
  white-space: pre;
  tab-size: 2;
}

.srcblock .kw { color: var(--sky); }
.srcblock .str { color: var(--teal); }
.srcblock .num2 { color: var(--amber); }
.srcblock .com { color: var(--ink-faint); font-style: italic; }
.srcblock .fn { color: var(--ink-strong); }

.srcblock-note {
  border-top: 1px solid var(--rule-soft);
  padding: 0.75rem 0.95rem;
  font-size: 0.85rem;
  color: var(--ink-dim);
  background: color-mix(in srgb, var(--bg-deep) 35%, transparent);
}
.srcblock-note > :last-child { margin-bottom: 0; }

/* ---------- 12. Spec lists / tool entries ---------- */

.spec {
  margin: 1.6rem 0 2.2rem;
  border-top: 1px solid var(--rule-soft);
}
.spec > div {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.1rem 1.4rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--rule-soft);
}
@media (min-width: 640px) {
  .spec > div { grid-template-columns: minmax(9rem, 13rem) 1fr; }
}
.spec dt {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--teal);
  overflow-wrap: anywhere;
}
.spec dd { margin: 0; font-size: 0.92rem; color: var(--ink-dim); }
.spec dd code { color: var(--ink); }

.tool {
  margin: 0 0 0.35rem;
  padding: 1rem 0 1.15rem;
  border-bottom: 1px solid var(--rule-soft);
}
.tool:last-child { border-bottom: 0; }
.tool h3 {
  margin: 0 0 0.15rem;
  font-family: var(--mono);
  font-size: 0.97rem;
  font-weight: 600;
  color: var(--ink-strong);
  letter-spacing: 0;
}
.tool .sig {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-faint);
  margin: 0 0 0.55rem;
  overflow-wrap: anywhere;
}
.tool p { margin: 0 0 0.5em; font-size: 0.93rem; }
.tool > :last-child { margin-bottom: 0; }

.tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.12rem 0.45rem;
  border-radius: 3px;
  border: 1px solid currentColor;
  vertical-align: 0.12em;
  margin-left: 0.4rem;
  opacity: 0.85;
}
.tag--read { color: var(--sky); }
.tag--write { color: var(--amber); }
.tag--exec { color: var(--rose); }
.tag--meta { color: var(--ink-faint); }

/* ---------- 13. Two-column split ---------- */

.split {
  display: grid;
  gap: 1.6rem 2.4rem;
  grid-template-columns: 1fr;
  margin: 2rem 0 2.4rem;
}
@media (min-width: 860px) {
  .split { grid-template-columns: 1fr 1fr; }
}
.split section {
  padding: 1.15rem 1.3rem;
  border: 1px solid var(--rule-soft);
  border-radius: 5px;
  background: color-mix(in srgb, var(--panel) 55%, transparent);
}
.split h3 { margin-top: 0; }
.split > section > :last-child { margin-bottom: 0; }
.split ul { padding-left: 1.15rem; font-size: 0.92rem; }

/* ---------- 14. Page header block ---------- */

.masthead {
  padding: clamp(1.6rem, 4vw, 3rem) 0 0.5rem;
  max-width: 74ch;
}
.masthead h1 { margin-bottom: 0.45rem; }

.meta-line {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
  margin: 1.4rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem 1.2rem;
}

/* ---------- 15. Footer / edges ---------- */

.edges {
  margin-top: 4.5rem;
  padding-top: 1.8rem;
  border-top: 1px solid var(--rule);
}
.edges h2 {
  margin: 0 0 1rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 500;
}
.edges ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.55rem 2rem;
  grid-template-columns: 1fr;
}
@media (min-width: 720px) {
  .edges ul { grid-template-columns: 1fr 1fr; }
}
.edges li { margin: 0; display: flex; gap: 0.6rem; align-items: baseline; }
.edges .arrow { color: var(--ink-faint); font-family: var(--mono); flex: none; }
.edges .why { color: var(--ink-faint); font-size: 0.86rem; }

.colophon {
  margin-top: 3rem;
  padding: 1.4rem 0 0;
  border-top: 1px solid var(--rule-soft);
  font-size: 0.8rem;
  color: var(--ink-faint);
  line-height: 1.6;
}
.colophon p { margin: 0 0 0.4em; max-width: 70ch; }

/* ---------- 16. Small screens ---------- */

@media (max-width: 560px) {
  .minimap { padding-top: 1rem; }
  .term-body { font-size: 0.735rem; }
  figure.diagram > svg { padding: 0.35rem; }
  .pull { font-size: 1.02rem; }
}