/* SenseBridge docs — "technical instrument panel" register.
   Tokens mirror .agents/context/DESIGN.md. Dark is the default theme;
   [data-theme="light"] and the prefers-color-scheme fallback both apply the
   light set so "System" works with zero JS. */

/* ---------------------------------------------------------------------
   Fonts — self-hosted, zero third-party requests.
   --------------------------------------------------------------------- */
@font-face {
  font-family: "Fraunces Variable";
  src: url("../fonts/fraunces-variable-latin.woff2") format("woff2");
  font-weight: 300 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Geist Variable";
  src: url("../fonts/geist-variable-latin.woff2") format("woff2");
  font-weight: 300 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Geist Mono Variable";
  src: url("../fonts/geist-mono-variable-latin.woff2") format("woff2");
  font-weight: 400 600;
  font-style: normal;
  font-display: swap;
}

/* ---------------------------------------------------------------------
   Tokens
   --------------------------------------------------------------------- */
:root {
  --color-bg: #080a10;
  --color-bg-elevated: #0f131c;
  --color-surface: #161b28;
  --color-glass: rgba(15, 19, 28, 0.6);
  --color-text: #e8ebf2;
  --color-text-muted: #a7afc2;
  --color-signal: #5eb1ff;
  --color-perception: #ffb37a;
  --color-hairline: #2a3145;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 64px;
  --space-6: 96px;
  --space-7: 128px;

  --font-display: "Fraunces Variable", ui-serif, Georgia, serif;
  --font-body: "Geist Variable", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "Geist Mono Variable", ui-monospace, SFMono-Regular, Menlo, monospace;

  --measure: 72ch;
  --sidebar-width: 260px;
  --toc-width: 240px;

  color-scheme: dark;
}

/* "System" fallback: only applies when no explicit dark/light choice was
   persisted (data-theme absent or JS never ran). */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --color-bg: #f7f8fb;
    --color-bg-elevated: #ffffff;
    --color-surface: #eef1f7;
    --color-glass: rgba(255, 255, 255, 0.6);
    --color-text: #101422;
    --color-text-muted: #4d5468;
    --color-signal: #145fc4;
    --color-perception: #a8480d;
    --color-hairline: #d4d9e4;
    color-scheme: light;
  }
}

:root[data-theme="light"] {
  --color-bg: #f7f8fb;
  --color-bg-elevated: #ffffff;
  --color-surface: #eef1f7;
  --color-glass: rgba(255, 255, 255, 0.6);
  --color-text: #101422;
  --color-text-muted: #4d5468;
  --color-signal: #145fc4;
  --color-perception: #a8480d;
  --color-hairline: #d4d9e4;
  color-scheme: light;
}

/* ---------------------------------------------------------------------
   Reset & base
   --------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 100%;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
}

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

a {
  color: var(--color-signal);
}

/* Visually hidden but still available to screen readers. */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---------------------------------------------------------------------
   Focus — never suppressed, always ≥3:1 against adjacent colors.
   --------------------------------------------------------------------- */
:focus {
  outline: none;
}

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

/* ---------------------------------------------------------------------
   Skip link
   --------------------------------------------------------------------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-2);
  z-index: 100;
  padding: var(--space-1) var(--space-2);
  background: var(--color-signal);
  color: var(--color-bg-elevated);
  font-family: var(--font-mono);
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  top: var(--space-2);
}

/* ---------------------------------------------------------------------
   Header
   --------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--color-glass);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-hairline);
}

.site-header__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2);
  max-width: 1400px;
  margin: 0 auto;
}

.site-header__brand {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--color-text);
  text-decoration: none;
  min-height: 44px;
}

.site-header__mark {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-signal);
}

.site-header__controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.search-trigger {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  min-height: 44px;
  padding: 0 var(--space-2);
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-signal);
  border-radius: var(--radius-sm);
  font: inherit;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  cursor: pointer;
}

.search-trigger__kbd {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-sm);
  padding: 1px 5px;
}

.theme-switch {
  display: flex;
  gap: 2px;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-sm);
  padding: 2px;
  margin: 0;
}

.theme-switch__option {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.theme-switch__option input {
  position: absolute;
  inset: 0;
  opacity: 0;
  margin: 0;
  cursor: pointer;
}

.theme-switch__option:has(input:checked) {
  background: var(--color-signal);
  color: var(--color-bg-elevated);
}

.theme-switch__option:has(input:focus-visible) {
  outline: 3px solid var(--color-signal);
  outline-offset: 2px;
}

/* ---------------------------------------------------------------------
   Layout grid
   --------------------------------------------------------------------- */
.layout {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-2);
}

main {
  min-width: 0;
  padding-block: var(--space-3);
}

main:focus-visible {
  outline: none;
}

@media (min-width: 900px) {
  .layout {
    display: grid;
    grid-template-columns: var(--sidebar-width) minmax(0, 1fr) var(--toc-width);
    gap: var(--space-4);
    align-items: start;
  }

  main {
    padding-block: var(--space-4);
  }
}

/* ---------------------------------------------------------------------
   Sidebar — native <details>/<summary>, forced open at desktop widths so
   the nav is never trapped behind JS.
   --------------------------------------------------------------------- */
.sidebar {
  border-bottom: 1px solid var(--color-hairline);
}

.sidebar__toggle {
  display: block;
  min-height: 44px;
  padding: var(--space-2) 0;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.875rem;
  cursor: pointer;
}

.sidebar__content {
  padding-bottom: var(--space-3);
}

.sidebar__group + .sidebar__group {
  margin-top: var(--space-3);
}

.sidebar__heading {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-1);
}

.sidebar__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar__list a {
  position: relative;
  display: block;
  min-height: 40px;
  display: flex;
  align-items: center;
  padding: 0 var(--space-1);
  color: var(--color-text-muted);
  text-decoration: none;
  border-radius: var(--radius-sm);
  border-left: 3px solid transparent;
}

.sidebar__list a:hover {
  color: var(--color-text);
}

.sidebar__list a[aria-current="page"] {
  color: var(--color-signal);
  border-left-color: var(--color-signal);
  font-weight: 600;
}

@media (min-width: 900px) {
  .sidebar {
    border-bottom: none;
    position: sticky;
    top: calc(var(--space-2) + 60px);
    max-height: calc(100vh - 80px);
    overflow-y: auto;
  }

  .sidebar__toggle {
    display: none;
  }

  /* Force the drawer's content visible regardless of the [open] attribute
     so desktop never depends on JS to show the nav. */
  .sidebar__drawer:not([open]) > .sidebar__content {
    display: block !important;
  }
}

/* ---------------------------------------------------------------------
   Table of contents
   --------------------------------------------------------------------- */
.toc {
  display: none;
}

@media (min-width: 900px) {
  .toc:not([hidden]) {
    display: block;
    position: sticky;
    top: calc(var(--space-2) + 60px);
    max-height: calc(100vh - 80px);
    overflow-y: auto;
  }
}

.toc__heading {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-1);
}

.toc__list-wrap {
  position: relative;
}

.toc__indicator {
  position: absolute;
  top: 0;
  left: 0;
  width: 2px;
  height: 20px;
  background: var(--color-signal);
  opacity: 0;
  transform: translateY(0);
}

.toc__indicator.is-active {
  opacity: 1;
}

@media (prefers-reduced-motion: no-preference) {
  .toc__indicator {
    transition: transform 200ms ease;
  }
}

.toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--color-hairline);
}

.toc__list ul {
  list-style: none;
  margin: 0;
  padding-left: var(--space-2);
}

.toc__list a {
  display: block;
  min-height: 32px;
  display: flex;
  align-items: center;
  padding-left: var(--space-2);
  color: var(--color-text-muted);
  font-size: 0.875rem;
  text-decoration: none;
}

.toc__list a:hover {
  color: var(--color-text);
}

.toc__list a[aria-current="true"] {
  color: var(--color-signal);
  font-weight: 600;
}

/* ---------------------------------------------------------------------
   Reading progress
   --------------------------------------------------------------------- */
.reading-progress {
  position: sticky;
  top: 0;
  z-index: 5;
  height: 2px;
  width: 0%;
  background: var(--color-signal);
  margin-bottom: var(--space-2);
}

/* ---------------------------------------------------------------------
   Content typography
   --------------------------------------------------------------------- */
main > h1,
main > h2,
main > h3,
main > h4,
main > p,
main > ul,
main > ol,
main > table,
main > blockquote,
main > pre,
main > .table-wrapper {
  max-width: var(--measure);
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.15;
  scroll-margin-top: 80px;
}

h1 {
  font-size: clamp(2rem, 1.5rem + 2vw, 2.75rem);
  margin-top: 0;
}

/* h2/h3's clamp() endpoints (1.5rem, 1.25rem) are deliberate: they're the
   fluid heading scale, and the design-system detector can only compare
   literal values against DESIGN.md's fixed steps — it can't evaluate a
   clamp() as a range. Flagged and left visible on purpose; see TODO.md's
   docs.css entry. */
h2 {
  font-size: clamp(1.5rem, 1.3rem + 1vw, 2rem);
  margin-top: var(--space-4);
}

h3 {
  font-size: clamp(1.25rem, 1.1rem + 0.6vw, 1.5rem);
  margin-top: var(--space-3);
}

p,
li {
  font-size: 1rem;
}

.heading-anchor {
  margin-left: var(--space-1);
  color: var(--color-text-muted);
  text-decoration: none;
  opacity: 0;
  font-size: 0.85em;
}

h1:hover .heading-anchor,
h2:hover .heading-anchor,
h3:hover .heading-anchor,
h4:hover .heading-anchor,
.heading-anchor:focus-visible {
  opacity: 1;
}

/* ---------------------------------------------------------------------
   Code
   --------------------------------------------------------------------- */
code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-surface);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
}

.code-block {
  position: relative;
}

pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  background: var(--color-surface);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-2);
  overflow-x: auto;
  white-space: pre;
  max-width: var(--measure);
}

pre code {
  background: none;
  padding: 0;
}

.copy-code {
  position: absolute;
  top: var(--space-1);
  right: var(--space-1);
  min-height: 32px;
  padding: 0 var(--space-1);
  background: var(--color-bg-elevated);
  color: var(--color-text-muted);
  /* currentColor, not --color-hairline: this is a real control, and the
     hairline token sits at ~1.4:1. Matching the label colour keeps the
     border at the label's own ratio (8.45:1 dark / 7.54:1 light) and makes
     it brighten with the text on hover. */
  border: 1px solid currentColor;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  cursor: pointer;
}

.copy-code:hover {
  color: var(--color-text);
}

/* ---------------------------------------------------------------------
   Tables
   --------------------------------------------------------------------- */
table {
  border-collapse: collapse;
  width: 100%;
}

th,
td {
  text-align: left;
  padding: var(--space-1) var(--space-2);
  border-bottom: 1px solid var(--color-hairline);
}

th {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--color-text-muted);
}

.table-wrapper {
  overflow-x: auto;
  max-width: var(--measure);
}

.table-wrapper.is-scrollable {
  /* Flat-by-default: DESIGN.md builds depth from a surface step and a 1px
     border, never a blur radius, so the "more to scroll" affordance is a
     hairline right edge rather than the inset shadow this used to carry.
     Screen-reader users get the same cue from the wrapper's "Scrollable
     table" label, set in docs.js. */
  border-right: 1px solid var(--color-hairline);
}

.table-wrapper.is-scrollable thead th {
  position: sticky;
  top: 0;
  background: var(--color-bg-elevated);
}

/* ---------------------------------------------------------------------
   Callouts — blockquotes whose first run of text is Note/Warning/
   Important/Doctrine, classed by JS (docs.js) since markdown carries no
   HTML for this.
   --------------------------------------------------------------------- */
blockquote {
  margin: var(--space-3) 0;
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface);
  /* A full hairline, not a thick left rule. DESIGN.md builds depth from a
     surface step plus a 1px border and nothing else, and a heavy one-sided
     accent is the "side-tab" pattern its detector flags. Callout variants
     differentiate by border colour rather than border width. */
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-sm);
  max-width: var(--measure);
}

blockquote p:first-child {
  margin-top: 0;
}

blockquote p:last-child {
  margin-bottom: 0;
}

.callout {
  border-color: var(--color-signal);
}

.callout-warning,
.callout-important {
  border-color: var(--color-perception);
}

.callout-doctrine {
  border-color: var(--color-text);
}

/* ---------------------------------------------------------------------
   Footer
   --------------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--color-hairline);
  padding: var(--space-3) var(--space-2);
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.site-footer a {
  color: var(--color-text-muted);
}

/* ---------------------------------------------------------------------
   Search palette
   --------------------------------------------------------------------- */
.search-overlay {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 10vh;
  /* The scrim is the documented ink at partial alpha, not pure black, so the
     dimmed page stays on-palette in both themes. */
  background: rgba(8, 10, 16, 0.72);
}

.search-overlay[hidden] {
  display: none;
}

.search-panel {
  width: min(600px, 90vw);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-2);
  max-height: 70vh;
  display: flex;
  flex-direction: column;
}

.search-panel__input {
  width: 100%;
  min-height: 44px;
  padding: 0 var(--space-2);
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-signal);
  border-radius: var(--radius-sm);
  font: inherit;
}

.search-panel__list {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0;
  overflow-y: auto;
}

.search-panel__list li {
  border-radius: var(--radius-sm);
}

.search-panel__option {
  display: block;
  padding: var(--space-1) var(--space-2);
  color: var(--color-text);
  text-decoration: none;
  border-radius: var(--radius-sm);
}

.search-panel__option-title {
  font-weight: 600;
}

.search-panel__option-snippet {
  display: block;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.search-panel__list li[aria-selected="true"] .search-panel__option {
  background: var(--color-surface);
  outline: 2px solid var(--color-signal);
}

/* ---------------------------------------------------------------------
   Signal Path hero (home page only)
   --------------------------------------------------------------------- */
.signal-hero {
  margin-bottom: var(--space-4);
}

.signal-hero__svg {
  width: 100%;
  height: auto;
  max-width: 880px;
}

.signal-hero__track {
  fill: none;
  stroke: var(--color-hairline);
  stroke-width: 2;
}

.signal-hero__node circle {
  fill: var(--color-bg-elevated);
  stroke: var(--color-signal);
  stroke-width: 2;
}

.signal-hero__node--glow circle {
  stroke: var(--color-perception);
}

.signal-hero__node text {
  fill: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 13px;
  text-anchor: middle;
}

.signal-hero__pulse {
  fill: var(--color-signal);
  offset-path: path("M40,70 L220,70 L400,70 L580,70 L760,70");
  offset-distance: 0%;
}

@media (prefers-reduced-motion: no-preference) {
  .signal-hero__pulse {
    animation: signal-travel 4s ease-in-out infinite;
  }
}

@keyframes signal-travel {
  0% {
    offset-distance: 0%;
  }
  100% {
    offset-distance: 100%;
  }
}

/* ---------------------------------------------------------------------
   Section reveal — resting state is fully visible by default; the
   animated (hidden-then-revealed) state only exists under
   prefers-reduced-motion: no-preference, and JS never applies it to
   content already in the first viewport.
   --------------------------------------------------------------------- */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 400ms ease-out, transform 400ms ease-out;
  }

  .reveal.in-view {
    opacity: 1;
    transform: none;
  }
}

/* ---------------------------------------------------------------------
   Print
   --------------------------------------------------------------------- */
@media print {
  .site-header,
  .sidebar,
  .toc,
  .site-footer,
  .skip-link,
  .reading-progress,
  .signal-hero,
  .copy-code,
  .heading-anchor {
    display: none !important;
  }

  /* #fff/#000 here (and on `a` below) are deliberate: this is a print
     stylesheet, and pure black on white is correct for print regardless of
     DESIGN.md's screen palette. Flagged and left visible on purpose; see
     TODO.md's docs.css entry. */
  body {
    background: #fff;
    color: #000;
  }

  .layout {
    display: block;
  }

  a {
    color: #000;
    text-decoration: underline;
  }
}