/* agent-bridge site — "wire schematic" design system.
   Engineering-drawing voice: cool blueprint paper, ink navy, signal blue for
   live wires, amber for the approval theme. IBM Plex Mono carries display &
   data, Plex Sans carries prose. Zero JS: theme follows the system via
   light-dark(), hero motion is SVG + CSS only and respects reduced-motion. */

@layer theme, base, components;

/* ---- fonts (self-hosted, latin subset; CJK falls back to system) -------- */
@font-face {
  font-family: 'Plex Mono';
  src: url('fonts/ibm-plex-mono-400.woff2') format('woff2');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'Plex Mono';
  src: url('fonts/ibm-plex-mono-600.woff2') format('woff2');
  font-weight: 600;
  font-display: swap;
}
@font-face {
  font-family: 'Plex Sans';
  src: url('fonts/ibm-plex-sans-var.woff2') format('woff2');
  font-weight: 400 700;
  font-display: swap;
}

@layer theme {
  :root {
    color-scheme: light dark;

    /* raw palette */
    --paper-light: #f5f7fa;
    --paper-dark: #0e1420;
    --ink-light: #17233a;
    --ink-dark: #e6ecf5;
    --muted-light: #5a6b85;
    --muted-dark: #8fa1bb;
    --line-light: #d5deea;
    --line-dark: #2a3852;
    --slab-light: #eaeff6;
    --slab-dark: #131c2c;
    --wire-light: #2563eb;
    --wire-dark: #7da7ff;
    --amber-light: #b45309;
    --amber-dark: #f59e0b;

    /* tokens (resolve late, per modern-web-guidance dark-mode rules) */
    --paper: light-dark(var(--paper-light), var(--paper-dark));
    --ink: light-dark(var(--ink-light), var(--ink-dark));
    --muted: light-dark(var(--muted-light), var(--muted-dark));
    --line: light-dark(var(--line-light), var(--line-dark));
    --slab: light-dark(var(--slab-light), var(--slab-dark));
    --wire: light-dark(var(--wire-light), var(--wire-dark));
    --amber: light-dark(var(--amber-light), var(--amber-dark));

    /* terminal ink: code slabs stay dark in BOTH schemes */
    --code-bg: #0b1220;
    --code-ink: #dce5f2;
    --code-dim: #7f93b2;
    --code-wire: #7da7ff;
    --code-amber: #f5b74a;
    --code-green: #6fcf97;

    --font-display: 'Plex Mono', ui-monospace, 'SF Mono', Menlo, Consolas,
      'PingFang SC', 'Hiragino Sans GB', 'Noto Sans CJK SC', 'Microsoft YaHei',
      monospace;
    --font-body: 'Plex Sans', system-ui, -apple-system, 'Segoe UI', Roboto,
      'PingFang SC', 'Hiragino Sans GB', 'Noto Sans CJK SC', 'Microsoft YaHei',
      sans-serif;
    --font-mono: 'Plex Mono', ui-monospace, 'SF Mono', Menlo, Consolas,
      'PingFang SC', 'Noto Sans CJK SC', monospace;

    --measure: 46rem;
    --wide: 60rem;
    --radius: 6px;
  }
}

@layer base {
  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }
  html {
    color-scheme: light dark;
    accent-color: var(--wire);
    scrollbar-color: var(--muted) transparent;
  }
  body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-body);
    font-size: clamp(1rem, 0.96rem + 0.2vw, 1.0625rem);
    line-height: 1.7;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
  }
  a {
    color: var(--wire);
    text-underline-offset: 0.18em;
    text-decoration-thickness: from-font;
  }
  a:hover {
    text-decoration-thickness: 2px;
  }
  :focus-visible {
    outline: 2px solid var(--wire);
    outline-offset: 2px;
    border-radius: 2px;
  }
  h1,
  h2,
  h3 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.25;
    text-wrap: balance;
  }
  h2 {
    font-size: 1.375rem;
    margin: 3.25rem 0 0.25rem;
    letter-spacing: -0.01em;
  }
  h3 {
    font-size: 1.0625rem;
    margin: 2.25rem 0 0.25rem;
  }
  p {
    margin: 0.85rem 0;
  }
  code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--slab);
    border: 1px solid var(--line);
    border-radius: 4px;
    padding: 0.08em 0.35em;
  }
  pre code {
    background: none;
    border: none;
    padding: 0;
    white-space: pre;
    font-size: 0.8125rem;
    line-height: 1.65;
    color: inherit;
  }
  pre {
    background: var(--code-bg);
    color: var(--code-ink);
    border-radius: var(--radius);
    padding: 1rem 1.15rem;
    overflow-x: auto;
    font-family: var(--font-mono);
    margin: 1.15rem 0;
    tab-size: 2;
    color-scheme: dark;
  }
  table {
    border-collapse: collapse;
    width: 100%;
    margin: 1.15rem 0;
    font-size: 0.9375rem;
    line-height: 1.55;
  }
  th {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted);
    text-align: left;
    padding: 0.55rem 0.85rem;
    border-bottom: 1.5px solid var(--line);
    white-space: nowrap;
  }
  td {
    padding: 0.65rem 0.85rem;
    border-bottom: 1px solid var(--line);
    vertical-align: top;
  }
  td code {
    white-space: nowrap;
  }
  blockquote {
    margin: 1.15rem 0;
    padding: 0.15rem 0 0.15rem 1.15rem;
    border-left: 3px solid var(--amber);
    color: var(--muted);
  }
  hr {
    border: none;
    border-top: 1px solid var(--line);
    margin: 3rem 0;
  }
  ::selection {
    background: light-dark(#c7d8ff, #23406e);
  }
}

@layer components {
  /* ---- layout ---------------------------------------------------------- */
  .wrap {
    max-width: var(--wide);
    margin: 0 auto;
    padding: 0 1.25rem;
  }
  .prose {
    max-width: var(--measure);
  }
  .skip-link {
    position: absolute;
    left: -9999px;
    background: var(--wire);
    color: #fff;
    padding: 0.5rem 1rem;
    z-index: 10;
  }
  .skip-link:focus {
    left: 1rem;
    top: 1rem;
  }

  /* ---- header ---------------------------------------------------------- */
  .site-header {
    border-bottom: 1px solid var(--line);
    background: var(--paper);
  }
  .site-header .wrap {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    min-height: 3.75rem;
    flex-wrap: wrap;
  }
  .brand {
    display: flex;
    align-items: baseline;
    gap: 0.65rem;
    text-decoration: none;
    color: var(--ink);
  }
  .brand .logo {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.0625rem;
    letter-spacing: -0.02em;
  }
  .brand .tag {
    font-family: var(--font-display);
    font-size: 0.6875rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
    border: 1px solid var(--line);
    border-radius: 99px;
    padding: 0.15rem 0.55rem;
    white-space: nowrap;
  }
  .site-nav {
    display: flex;
    gap: 1.15rem;
    margin-left: auto;
    align-items: center;
    flex-wrap: wrap;
  }
  .site-nav a {
    color: var(--ink);
    text-decoration: none;
    font-family: var(--font-display);
    font-size: 0.8125rem;
    letter-spacing: 0.04em;
  }
  .site-nav a:hover {
    color: var(--wire);
  }
  .site-nav a[aria-current='page'] {
    color: var(--wire);
  }

  /* ---- hero ------------------------------------------------------------ */
  .hero {
    padding: 4.5rem 0 1rem;
  }
  .hero .kicker {
    font-family: var(--font-display);
    font-size: 0.75rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--wire);
    margin: 0 0 1.1rem;
  }
  .hero h1 {
    font-size: clamp(1.85rem, 1.35rem + 2.2vw, 3.05rem);
    letter-spacing: -0.025em;
    margin: 0 0 1.15rem;
    max-width: 21ch;
  }
  .hero .lede {
    font-size: clamp(1.0625rem, 1rem + 0.35vw, 1.25rem);
    color: var(--muted);
    max-width: 38rem;
  }
  .hero .lede strong {
    color: var(--ink);
    font-weight: 500;
  }
  .hero-actions {
    display: flex;
    gap: 0.85rem;
    margin-top: 1.75rem;
    flex-wrap: wrap;
  }

  /* ---- buttons --------------------------------------------------------- */
  .btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius);
    padding: 0.62rem 1.15rem;
    border: 1px solid transparent;
  }
  .btn-primary {
    background: var(--wire);
    color: light-dark(#fff, #0b1220);
  }
  .btn-primary:hover {
    filter: brightness(1.08);
  }
  .btn-ghost {
    border-color: var(--line);
    color: var(--ink);
  }
  .btn-ghost:hover {
    border-color: var(--wire);
    color: var(--wire);
  }

  /* ---- schematic (the signature) --------------------------------------- */
  .schematic {
    margin: 3.25rem 0 1rem;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background:
      linear-gradient(var(--line) 1px, transparent 1px) 0 0 / 100% 2.25rem,
      linear-gradient(90deg, var(--line) 1px, transparent 1px) 0 0 / 2.25rem 100%;
    background-color: var(--paper);
    overflow: hidden;
  }
  .schematic svg {
    display: block;
    width: 100%;
    height: auto;
  }
  .schematic .wire {
    stroke: var(--line);
    stroke-width: 1.5;
    fill: none;
  }
  .schematic .wire-live {
    stroke: var(--wire);
    stroke-width: 2;
  }
  .schematic .wire-opt {
    stroke-dasharray: 5 5;
  }
  .schematic .node-box {
    fill: var(--paper);
    stroke: var(--line);
    stroke-width: 1.25;
  }
  .schematic .node-box.accent {
    stroke: var(--wire);
  }
  .schematic text {
    font-family: var(--font-mono);
    fill: var(--ink);
  }
  .schematic .label {
    font-size: 11px;
  }
  .schematic .label-dim {
    fill: var(--muted);
    font-size: 10px;
    letter-spacing: 0.08em;
  }
  .schematic .pulse {
    fill: var(--wire);
  }
  .schematic .pulse-amber {
    fill: var(--amber);
  }
  .schematic-caption {
    display: flex;
    gap: 1.35rem;
    flex-wrap: wrap;
    padding: 0.75rem 1.15rem;
    border-top: 1px solid var(--line);
    font-family: var(--font-display);
    font-size: 0.6875rem;
    letter-spacing: 0.09em;
    text-transform: uppercase;
    color: var(--muted);
  }
  .legend-line {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
  }
  .legend-line i {
    display: inline-block;
    width: 26px;
    border-top: 2px solid var(--wire);
  }
  .legend-line.dashed i {
    border-top-style: dashed;
    border-top-color: var(--muted);
    border-top-width: 1.5px;
  }
  .legend-line.plain i {
    border-top-color: var(--line);
  }

  @media (prefers-reduced-motion: reduce) {
    .pulse {
      display: none;
    }
  }

  /* ---- eyebrow sections ------------------------------------------------ */
  .eyebrow {
    font-family: var(--font-display);
    font-size: 0.75rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--muted);
    margin: 0 0 0.35rem;
  }

  /* ---- step list (quick start: a true sequence) ------------------------ */
  .steps {
    counter-reset: step;
    list-style: none;
    margin: 1.35rem 0;
    padding: 0;
  }
  .steps > li {
    counter-increment: step;
    display: grid;
    grid-template-columns: 2.25rem 1fr;
    gap: 0.35rem 1rem;
    padding: 1.05rem 0;
    border-top: 1px solid var(--line);
  }
  .steps > li:last-child {
    border-bottom: 1px solid var(--line);
  }
  .steps > li::before {
    content: counter(step, decimal-leading-zero);
    font-family: var(--font-display);
    font-weight: 600;
    color: var(--wire);
    font-size: 0.9375rem;
  }
  .steps h3 {
    margin: 0;
  }
  .steps p {
    margin: 0.35rem 0 0;
    grid-column: 2;
    color: var(--muted);
  }
  .steps pre {
    grid-column: 2;
    margin: 0.65rem 0 0;
  }

  /* ---- code caption ---------------------------------------------------- */
  .code-cap {
    font-family: var(--font-display);
    font-size: 0.6875rem;
    letter-spacing: 0.11em;
    text-transform: uppercase;
    color: var(--muted);
    margin: 1.35rem 0 -0.85rem;
  }
  /* keyword / string / comment tints inside terminal slabs */
  .tok-key {
    color: var(--code-wire);
  }
  .tok-str {
    color: var(--code-green);
  }
  .tok-num {
    color: var(--code-amber);
  }
  .tok-com {
    color: var(--code-dim);
    font-style: italic;
  }

  /* ---- chips & callouts ------------------------------------------------ */
  .chip {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    line-height: 1.5;
    padding: 0.02rem 0.45rem;
    border-radius: 4px;
    border: 1px solid var(--line);
    background: var(--slab);
    white-space: nowrap;
  }
  .chip-enum {
    color: var(--wire);
    border-color: color-mix(in srgb, var(--wire) 35%, var(--line));
  }
  .chip-amber {
    color: var(--amber);
    border-color: color-mix(in srgb, var(--amber) 45%, var(--line));
    background: color-mix(in srgb, var(--amber) 8%, var(--paper));
  }
  .chip-codex {
    letter-spacing: 0.06em;
    text-transform: uppercase;
    font-size: 0.6875rem;
    color: var(--muted);
  }
  .note {
    border: 1px solid var(--line);
    border-left: 3px solid var(--wire);
    border-radius: 0 var(--radius) var(--radius) 0;
    background: var(--slab);
    padding: 0.95rem 1.15rem;
    margin: 1.35rem 0;
  }
  .note.warn {
    border-left-color: var(--amber);
  }
  .note .note-title {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.8125rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin: 0 0 0.35rem;
    color: var(--wire);
  }
  .note.warn .note-title {
    color: var(--amber);
  }
  .note p {
    margin: 0.35rem 0;
    font-size: 0.9375rem;
  }

  /* ---- approve-card motif ---------------------------------------------- */
  .approve-card {
    border: 1px solid color-mix(in srgb, var(--amber) 55%, var(--line));
    border-radius: var(--radius);
    background: color-mix(in srgb, var(--amber) 7%, var(--paper));
    margin: 1.15rem 0;
    overflow: hidden;
    max-width: var(--measure);
  }
  .approve-card .ac-head {
    display: flex;
    gap: 0.55rem;
    align-items: center;
    font-family: var(--font-display);
    font-size: 0.6875rem;
    letter-spacing: 0.11em;
    text-transform: uppercase;
    color: var(--amber);
    padding: 0.55rem 0.95rem;
    border-bottom: 1px solid color-mix(in srgb, var(--amber) 35%, var(--line));
  }
  .approve-card pre {
    margin: 0;
    border-radius: 0;
    font-size: 0.78rem;
  }
  .ac-choices {
    display: flex;
    gap: 0.55rem;
    padding: 0.75rem 0.95rem;
    flex-wrap: wrap;
    border-top: 1px solid color-mix(in srgb, var(--amber) 35%, var(--line));
    font-family: var(--font-mono);
    font-size: 0.8125rem;
  }
  .ac-choices .choice {
    border: 1px solid color-mix(in srgb, var(--amber) 45%, var(--line));
    border-radius: 4px;
    padding: 0.22rem 0.65rem;
  }

  /* ---- field table tuning ---------------------------------------------- */
  .fields td:first-child {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    white-space: nowrap;
    font-weight: 600;
  }
  .fields td:nth-child(2),
  .fields td:nth-child(3) {
    white-space: nowrap;
    color: var(--muted);
    font-family: var(--font-mono);
    font-size: 0.8125rem;
  }
  .fields .grp td {
    background: var(--slab);
    font-family: var(--font-display);
    font-size: 0.6875rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
    padding: 0.45rem 0.85rem;
    border-bottom: 1px solid var(--line);
  }

  /* ---- three-doors compare --------------------------------------------- */
  .door-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: 1.35rem 0;
  }
  .door {
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.15rem 1.2rem;
    background: var(--paper);
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
  }
  .door h3 {
    margin: 0;
    font-size: 0.9375rem;
  }
  .door .door-proto {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--wire);
  }
  .door p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--muted);
  }
  .door .door-open {
    margin-top: auto;
    padding-top: 0.65rem;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--ink);
    border-top: 1px dashed var(--line);
  }
  @media (max-width: 720px) {
    .door-grid {
      grid-template-columns: 1fr;
    }
  }

  /* ---- page hero (inner pages) ----------------------------------------- */
  .page-hero {
    padding: 3.25rem 0 0.5rem;
  }
  .page-hero h1 {
    font-size: clamp(1.65rem, 1.35rem + 1.4vw, 2.35rem);
    letter-spacing: -0.02em;
    margin: 0.35rem 0 0.85rem;
  }
  .page-hero .lede {
    color: var(--muted);
    max-width: var(--measure);
  }

  /* ---- config page: sticky section nav --------------------------------- */
  .with-nav {
    display: grid;
    grid-template-columns: 11.5rem 1fr;
    gap: 2.5rem;
    align-items: start;
    padding-bottom: 4rem;
  }
  .toc {
    position: sticky;
    top: 1.25rem;
    padding-top: 3.25rem;
    font-family: var(--font-display);
    font-size: 0.75rem;
    line-height: 2.1;
    letter-spacing: 0.04em;
    border-right: 1px solid var(--line);
    align-self: stretch;
  }
  .toc a {
    display: block;
    color: var(--muted);
    text-decoration: none;
    padding-right: 1.15rem;
  }
  .toc a:hover {
    color: var(--wire);
  }
  @media (max-width: 900px) {
    .with-nav {
      grid-template-columns: 1fr;
      gap: 0;
    }
    .toc {
      position: static;
      border-right: none;
      border-bottom: 1px solid var(--line);
      padding: 1.25rem 0;
      display: flex;
      flex-wrap: wrap;
      gap: 0 1.15rem;
      line-height: 2.4;
    }
  }

  /* ---- footer ---------------------------------------------------------- */
  .site-footer {
    border-top: 1px solid var(--line);
    margin-top: 4.5rem;
    padding: 2.25rem 0 3rem;
    color: var(--muted);
    font-size: 0.875rem;
  }
  .site-footer .wrap {
    display: flex;
    gap: 1.5rem;
    justify-content: space-between;
    flex-wrap: wrap;
    align-items: baseline;
  }
  .site-footer a {
    color: var(--muted);
  }
  .site-footer a:hover {
    color: var(--wire);
  }
  .foot-links {
    display: flex;
    gap: 1.15rem;
    flex-wrap: wrap;
    font-family: var(--font-display);
    font-size: 0.75rem;
    letter-spacing: 0.05em;
  }
}