/* vhrd.tech site layer, on top of the brand's tokens.css and vhrd.css (both pulled from vhrd_brand by `just brand`,
   never edited here). Colours only through tokens. The look: a faint drawing grid, a framed column with crosshair
   marks where the section rules meet it, mono caps labels, FIG. captions with the datasheet's corner marks, and PCB
   traces in the signal colours between sections. */

:root {
  --grid: 24px;
  --grid-line: color-mix(in oklch, var(--text) 4%, transparent);
  --frame-line: var(--line);
  --mark: color-mix(in oklch, var(--text) 35%, transparent);
  --header-h: 3.5rem;
  scroll-padding-top: calc(var(--header-h) + 1rem);
}

html { -webkit-text-size-adjust: 100%; overflow-x: clip; }
/* The toggle's choice also steers light-dark(), which the code highlighting uses. */
:root[data-theme="dark"] { color-scheme: dark; }
:root[data-theme="light"] { color-scheme: light; }
.giallo-l { display: inline-block; min-height: 1lh; width: 100%; }

/* The drawing grid: a fine line every --grid, fixed to the page so sections slide over it. */
body {
  background-color: var(--bg);
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: var(--grid) var(--grid);
  background-position: center top;
  overflow-x: clip;
}

img, svg { max-width: 100%; }
img { height: auto; }
a:focus-visible, button:focus-visible, summary:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius);
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 100;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: var(--on-accent);
  font-weight: 600;
}
.skip:focus { top: 0.5rem; }

/* The column: hairline sides like the brand's .v-page, on the page background so the grid stays behind. */
.frame {
  max-width: var(--page);
  margin-inline: auto;
  border-inline: 1px solid var(--frame-line);
  position: relative;
}
main.frame { background: color-mix(in oklch, var(--bg) 70%, transparent); }

/* Sections: hairline on top, a crosshair where it meets each side of the frame. */
.section {
  position: relative;
  padding: clamp(2.5rem, 7vw, 5rem) var(--gutter);
  border-top: 1px solid var(--line);
}
.section::before, .section::after, .bus::before, .bus::after {
  content: "";
  position: absolute;
  top: -6px;
  width: 11px;
  height: 11px;
  background:
    linear-gradient(var(--mark), var(--mark)) center / 1px 100% no-repeat,
    linear-gradient(var(--mark), var(--mark)) center / 100% 1px no-repeat;
  pointer-events: none;
}
.section::before, .bus::before { left: -6px; }
.section::after, .bus::after { right: -6px; }
main > .section:first-child { border-top: 0; }
main > .section:first-child::before, main > .section:first-child::after { display: none; }

/* Labels: "01 · PRODUCTS" with the number boxed. */
.sec-label { display: flex; align-items: center; gap: 0.6em; margin-bottom: 1rem; }
.sec-no {
  display: inline-block;
  padding: 0.15em 0.4em;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  color: var(--text);
}

/* Header: sticky, hairline below, the frame continues through it. */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in oklch, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-row {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-height: var(--header-h);
  padding-inline: var(--gutter);
}
.brand { display: inline-flex; align-items: center; color: var(--text); text-decoration: none; }
.wordmark { height: 1rem; width: auto; display: block; }
.wordmark .wm-word { fill: var(--accent); }
.wordmark .wm-dot { fill: var(--muted); }
.nav ul, .menu-panel ul, .footer-col ul { list-style: none; margin: 0; padding: 0; }
.nav ul { display: flex; gap: 1.5rem; }
.nav a, .menu-panel a {
  font: 500 0.75rem/1 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
  padding-block: 0.5rem;
}
.nav a:hover, .menu-panel a:hover, .nav a[aria-current="page"], .menu-panel a[aria-current="page"] { color: var(--text); }
.nav a[aria-current="page"] { box-shadow: inset 0 -1px 0 var(--accent); }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 0.5rem; }
.theme-toggle, .menu summary {
  display: inline-grid;
  place-items: center;
  width: 2.25rem;
  height: 2.25rem;
  padding: 0;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  cursor: pointer;
}
.theme-toggle:hover, .menu summary:hover { color: var(--text); border-color: var(--accent); }
.notify-btn { white-space: nowrap; }

/* Small screens: the links fold into a menu (a <details>, no script). */
.menu { position: relative; display: none; }
.menu summary { list-style: none; }
.menu summary::-webkit-details-marker { display: none; }
.menu-bars, .menu-bars::before, .menu-bars::after {
  display: block;
  width: 16px;
  height: 1.5px;
  background: currentColor;
  position: relative;
}
.menu-bars::before, .menu-bars::after { content: ""; position: absolute; left: 0; }
.menu-bars::before { top: -5px; }
.menu-bars::after { top: 5px; }
.menu[open] .menu-bars { background: transparent; }
.menu[open] .menu-bars::before { top: 0; transform: rotate(45deg); }
.menu[open] .menu-bars::after { top: 0; transform: rotate(-45deg); }
.menu-panel {
  position: absolute;
  right: 0;
  top: calc(100% + 0.5rem);
  min-width: 12rem;
  padding: 0.5rem 1rem;
  background: var(--raised);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
}
.menu-panel a { display: block; padding-block: 0.75rem; }

@media (max-width: 52rem) {
  .nav { display: none; }
  .menu { display: block; }
}
@media (max-width: 26rem) {
  .header-row { gap: 0.75rem; }
  .notify-btn { padding-inline: 0.65rem; }
  .wordmark { height: 0.8rem; }
}

/* Hero: text left, FIG. 1 right; stacked on a phone. */
.hero { display: grid; gap: 2.5rem; align-items: center; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); }
.hero h1 { font-size: clamp(2.5rem, 6.5vw, 4.5rem); }
.ctas { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1.75rem; }
@media (max-width: 52rem) { .hero { grid-template-columns: minmax(0, 1fr); } }

.draft-note { margin-top: 1.25rem; font-size: 0.8125rem; color: var(--muted); }

/* Figures: corner marks in the brand red like the datasheet frame, the caption in mono caps. */
.fig { margin: 0; }
.fig-frame {
  position: relative;
  padding: 0.75rem;
  --c: 14px;
  background:
    linear-gradient(var(--accent), var(--accent)) top left / var(--c) 1px no-repeat,
    linear-gradient(var(--accent), var(--accent)) top left / 1px var(--c) no-repeat,
    linear-gradient(var(--accent), var(--accent)) top right / var(--c) 1px no-repeat,
    linear-gradient(var(--accent), var(--accent)) top right / 1px var(--c) no-repeat,
    linear-gradient(var(--accent), var(--accent)) bottom left / var(--c) 1px no-repeat,
    linear-gradient(var(--accent), var(--accent)) bottom left / 1px var(--c) no-repeat,
    linear-gradient(var(--accent), var(--accent)) bottom right / var(--c) 1px no-repeat,
    linear-gradient(var(--accent), var(--accent)) bottom right / 1px var(--c) no-repeat;
}
.fig-frame img { display: block; width: 100%; }
.fig-placeholder {
  display: grid;
  place-items: center;
  aspect-ratio: 4 / 3;
  border: 1px dashed var(--line-strong);
  background: repeating-linear-gradient(-45deg, transparent 0 9px, var(--line) 9px 10px);
  color: var(--muted);
  font: 500 0.75rem/1.4 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: center;
  padding: 1rem;
}
.fig-placeholder span { background: var(--bg); padding: 0.25em 0.5em; }
.fig figcaption {
  display: flex;
  align-items: center;
  gap: 0.75em;
  margin-top: 0.6rem;
  font: 500 0.6875rem/1.4 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.fig-no { padding: 0.15em 0.45em; border: 1px solid var(--line-strong); color: var(--text); white-space: nowrap; }

/* Cards in a ruled grid; each card's top edge is wired in its signal colour. */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 2rem;
}
.card { background: var(--bg); display: flex; flex-direction: column; box-shadow: inset 0 2px 0 var(--sig); }
.card .fig { padding: 1rem 1rem 0; }
.card .fig-placeholder { aspect-ratio: 16 / 10; }
.card-body { padding: 1rem 1.25rem 1.25rem; }
.card h3 { font-size: 1.25rem; display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem; }
.card h3 a { text-decoration: none; }
.card h3 a::after { content: " →"; color: var(--sig); }
.card h3 a:hover { text-decoration: underline; text-decoration-color: var(--sig); }

/* Spec list: mono, hairline rows, the key muted. */
.specs { margin: 0.75rem 0 0; font: 400 0.8125rem/1.4 var(--font-mono); }
.specs > div { display: flex; justify-content: space-between; gap: 1rem; padding: 0.4rem 0; border-top: 1px solid var(--line); }
.specs dt { color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; font-size: 0.6875rem; padding-top: 0.15em; }
.specs dd { margin: 0; text-align: right; overflow-wrap: anywhere; }

/* Code panel with tabs. Without the script every panel shows under its own title. */
.code-tabs { margin-top: 2rem; border: 1px solid var(--line-strong); border-radius: var(--radius); background: var(--raised); }
.code-tabs-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  padding: 0 0.75rem;
  border-bottom: 1px solid var(--line);
  min-height: 2.75rem;
}
.tablist { display: flex; gap: 0.25rem; }
.tablist [role="tab"] {
  font: 500 0.75rem/1 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  background: none;
  border: 0;
  padding: 0.9rem 0.6rem;
  cursor: pointer;
  box-shadow: inset 0 -2px 0 transparent;
}
.tablist [role="tab"]:hover { color: var(--text); }
.tablist [role="tab"][aria-selected="true"] { color: var(--text); box-shadow: inset 0 -2px 0 var(--accent); }
.tabpanel pre { margin: 0; border: 0; border-radius: 0; background: transparent; padding: 1rem 1.25rem; }
.tabpanel-title { margin: 0; padding: 0.75rem 1.25rem 0; }
.code-tabs.js-tabs .tabpanel-title { display: none; }

/* Traces between sections: a track leaves the section above at --from and enters the one below at --to, with a
   pad (via) at each end. The SVG stretches to the frame width; the stroke keeps its width. */
.trace { position: relative; height: 96px; color: var(--sig); }
.trace svg { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.trace-line {
  fill: none;
  stroke: var(--sig, currentColor);
  stroke-width: 2;
  stroke-linejoin: round;
  vector-effect: non-scaling-stroke;
}
.pad {
  position: absolute;
  width: 9px;
  height: 9px;
  margin-left: -4.5px;
  border: 2px solid var(--sig);
  border-radius: 50%;
  background: var(--bg);
}
.pad-top { left: var(--from); top: -4.5px; }
.pad-bottom { left: var(--to); bottom: -4.5px; }
.trace-label {
  position: absolute;
  top: 50%;
  left: calc((var(--from) + var(--to)) / 2);
  transform: translate(0.9rem, -50%);
  font: 500 0.625rem/1 var(--font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted); /* the signal colours are too light for small text on the light background */
  white-space: nowrap;
  padding-left: 0.5em;
  border-left: 2px solid var(--sig);
}
.trace + .section { border-top-color: transparent; }
.trace + .section::before, .trace + .section::after { display: none; }

/* The bus over the footer: the four signal colours side by side. */
.bus { position: relative; height: 48px; border-top: 1px solid var(--line); }
.bus-lines { position: absolute; inset: 0; width: 100%; height: 100%; }

/* Drawn in as they scroll into view, with CSS scroll-driven animations (no script): the track is uncovered from
   its top pad down. Browsers without them, and everyone who asks for reduced motion, see the traces already drawn. */
@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .trace svg, .bus-lines {
      animation: draw linear both;
      animation-timeline: view();
      animation-range: entry 20% cover 50%;
    }
    .bus-lines { animation-name: draw-across; }
    .pad-bottom, .trace-label { animation: fade linear both; animation-timeline: view(); animation-range: cover 40% cover 50%; }
  }
}
@keyframes draw { from { clip-path: inset(0 0 100% 0); } to { clip-path: inset(0 0 0 0); } }
@keyframes draw-across { from { clip-path: inset(0 100% 0 0); } to { clip-path: inset(0 0 0 0); } }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

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

/* Pages and prose. */
.page h1 { font-size: clamp(2.25rem, 6vw, 3.75rem); }
.prose { max-width: 42rem; margin-top: 1.5rem; }
.prose h2 { margin-top: 2.5rem; }
.prose ul { padding-left: 1.25rem; }
.post-list { list-style: none; padding: 0; margin-top: 2rem; }
.post-list li { display: flex; justify-content: space-between; gap: 1rem; padding: 0.75rem 0; border-top: 1px solid var(--line); }

/* Footer: columns of links, the build stamp like the one on our PDFs. */
.site-footer { border-top: 1px solid var(--line); font-size: 0.875rem; color: var(--muted); }
.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 1fr));
  padding: 2.5rem var(--gutter);
}
.footer-brand .wordmark { height: 0.9rem; margin-bottom: 1rem; }
.footer-col .v-label { margin-bottom: 0.75rem; }
.footer-col li { margin-bottom: 0.5rem; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--text); }
.footer-stamp {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding: 1rem var(--gutter) 1.5rem;
  border-top: 1px solid var(--line);
  font: 400 0.75rem/1.4 var(--font-mono);
}
.footer-stamp code { font-size: 1em; color: var(--text); }
@media (max-width: 52rem) { .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } .footer-brand { grid-column: 1 / -1; } }
.section .section { padding-inline: 0; }
.section .section::before, .section .section::after { display: none; }

/* Highlighted code: giallo pins color-scheme inline; follow the page (and so the theme toggle) instead, on the
   page's own surface. */
pre.giallo { color-scheme: inherit !important; background-color: var(--surface) !important; }
.tabpanel pre.giallo { background-color: transparent !important; }