/* =========================================================================
   InfraWhisperer — theme
   Palette + type carry the identity. Boldness is spent in one place: the
   trace hero. Everything else stays quiet and disciplined.
   ========================================================================= */

:root {
  /* light (default) */
  --base:        #F7F8FA;   /* cool off-white page */
  --surface:     #FFFFFF;   /* cards / raised */
  --surface-2:   #F1F3F7;   /* inset */
  --ink:         #0B0E14;   /* deep blue-black */
  --ink-soft:    #3A4150;
  --ink-faint:   #6B7280;
  --line:        #E4E7EE;   /* hairline */
  --line-strong: #CDD2DD;
  --accent:      #2F44FF;   /* electric cobalt — the one chrome accent */
  --accent-ink:  #1B2ECC;
  --accent-wash: #EBEDFF;

  /* trace viz only — the color budget lives here */
  --trace-track: #D4D8E0;
  --trace-teal:  #00A6A6;
  --trace-amber: #E8A13A;
  --trace-blue:  #2F44FF;

  --font-display: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-body:    "IBM Plex Sans", ui-sans-serif, system-ui, sans-serif;
  --font-mono:    "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --maxw: 1080px;
  --maxw-prose: 46rem;
  --radius: 10px;
  --radius-lg: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --base:        #0A0C11;
    --surface:     #12151C;
    --surface-2:   #171B24;
    --ink:         #EAECF1;
    --ink-soft:    #AEB4C2;
    --ink-faint:   #7C828F;
    --line:        #232833;
    --line-strong: #333A47;
    --accent:      #7C8BFF;
    --accent-ink:  #A3AEFF;
    --accent-wash: #191E33;
    --trace-track: #2A3040;
    --trace-teal:  #38C7C7;
    --trace-amber: #F0B65A;
    --trace-blue:  #7C8BFF;
  }
}

/* ---- reset-ish ---------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--base);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-ink); }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: 600; line-height: 1.15; letter-spacing: -0.02em; color: var(--ink); margin: 0; }

::selection { background: var(--accent-wash); color: var(--ink); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 3px; }

/* ---- layout ------------------------------------------------------------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 1.5rem; }
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: none;
  color: var(--accent);
}

/* ---- header ------------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--base) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: inline-flex; align-items: center; gap: 0.6rem; font-family: var(--font-display); font-weight: 600; font-size: 1.05rem; letter-spacing: -0.01em; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand .sig {
  width: 16px; height: 16px; flex: none;
  border-radius: 3px;
  background:
    linear-gradient(var(--accent), var(--accent)) center/2px 10px no-repeat,
    linear-gradient(90deg, var(--trace-teal), var(--accent)) center/10px 2px no-repeat;
  border: 1px solid var(--line-strong);
}
.nav { display: flex; align-items: center; gap: 1.5rem; }
.nav a { font-size: 0.9rem; color: var(--ink-soft); font-weight: 500; }
.nav a:hover { color: var(--ink); }
.nav a.gh { color: var(--ink-faint); }

/* ---- hero --------------------------------------------------------------- */
.hero { padding: 5.5rem 0 3.5rem; }
.hero .eyebrow { display: block; margin-bottom: 1.1rem; }
.hero h1 {
  font-size: clamp(2.4rem, 5.2vw, 4rem);
  font-weight: 600;
  max-width: 16ch;
  margin-bottom: 1.1rem;
}
.hero .lede {
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  color: var(--ink-soft);
  max-width: 52ch;
  margin: 0 0 2.5rem;
}

/* ---- signature: the trace hero ----------------------------------------- */
.trace {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.4rem 1.5rem 1.6rem;
  box-shadow: 0 1px 0 var(--line), 0 18px 40px -28px rgba(11,14,20,0.35);
}
.trace .trace-head {
  display: flex; justify-content: space-between; align-items: center;
  font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint);
  margin-bottom: 1.1rem;
}
.trace .trace-head .dot-row { display: inline-flex; gap: 6px; }
.trace .trace-head .dot-row i { width: 9px; height: 9px; border-radius: 50%; background: var(--line-strong); display: inline-block; }

/* pipeline rail */
.rail { position: relative; display: flex; align-items: center; justify-content: space-between; margin: 0.3rem 0 1.4rem; }
.rail::before {
  content: ""; position: absolute; left: 6%; right: 6%; top: 50%;
  height: 2px; background: var(--trace-track); transform: translateY(-50%); border-radius: 2px;
}
.rail .signal {
  position: absolute; top: 50%; left: 6%; width: 10px; height: 10px; border-radius: 50%;
  background: var(--accent); transform: translate(-50%, -50%);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 22%, transparent);
  animation: travel 3.6s cubic-bezier(.65,0,.35,1) 0.3s 1 forwards;
}
@keyframes travel {
  0% { left: 6%; opacity: 0; }
  8% { opacity: 1; }
  92% { opacity: 1; }
  100% { left: 94%; opacity: 0; }
}
.node {
  position: relative; z-index: 1; background: var(--surface);
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 0.4rem 0.9rem; font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink);
  white-space: nowrap;
}
.node.gateway {
  border-radius: 12px; padding: 0.5rem 0.75rem; border-color: var(--accent);
  background: var(--accent-wash);
  display: inline-flex; gap: 0.35rem; align-items: center;
}
.node.gateway .stage { font-size: 0.7rem; color: var(--accent-ink); padding: 0.1rem 0.35rem; border-radius: 5px; background: color-mix(in srgb, var(--accent) 10%, transparent); }
.node.gateway .stage + .stage { margin-left: 0; }
.node .cap { display: block; font-size: 0.62rem; color: var(--ink-faint); margin-top: 1px; }

/* span waterfall */
.spans { display: grid; gap: 6px; font-family: var(--font-mono); font-size: 0.72rem; }
.span-row { display: grid; grid-template-columns: 12ch 1fr 7ch; align-items: center; gap: 0.6rem; color: var(--ink-soft); }
.span-row .label { color: var(--ink); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.span-track { position: relative; height: 10px; background: var(--surface-2); border-radius: 3px; }
.span-bar { position: absolute; top: 0; height: 10px; border-radius: 3px; transform-origin: left; animation: grow 0.7s ease-out both; }
.span-bar.blue  { background: var(--trace-blue); }
.span-bar.teal  { background: var(--trace-teal); }
.span-bar.amber { background: var(--trace-amber); }
.span-row .ms { text-align: right; color: var(--ink-faint); }
@keyframes grow { from { transform: scaleX(0.02); } to { transform: scaleX(1); } }

/* ---- section scaffolding ------------------------------------------------ */
section { padding: 3.5rem 0; }
/* Adjacent sections were stacking 3.5rem + 3.5rem into a 7rem hole. */
section + section { padding-top: 1rem; }
.crumb { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); margin: 0 0 1.2rem; }
.crumb a { color: var(--ink-faint); }
.crumb a:hover { color: var(--accent); }
.crumb span { padding: 0 0.35rem; color: var(--line-strong); }
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; margin-bottom: 2rem; border-bottom: 1px solid var(--line); padding-bottom: 0.9rem; }
.section-head h2 { font-size: clamp(1.4rem, 2.4vw, 1.9rem); }
.section-head .more { font-family: var(--font-mono); font-size: 0.8rem; }

/* ---- series cards (one card per SERIES, not per part) ------------------- */
/* Sized so 1 series doesn't look lonely and 3+ tile cleanly. */
.series-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(20rem, 1fr)); gap: 1rem; }
.series-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 1.5rem 1.6rem 1.3rem; display: flex; flex-direction: column; gap: 0.7rem;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.series-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.series-card-head { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.series-card .kicker {
  font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.08em; color: var(--accent);
}
.series-card .state {
  font-family: var(--font-mono); font-size: 0.66rem; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--trace-amber); border: 1px solid var(--line); border-radius: 999px; padding: 0.1rem 0.55rem;
}
.series-card .state.done { color: var(--trace-teal); }
.series-card h3 { font-size: 1.35rem; }
.series-card h3 a { color: var(--ink); }
.series-card:hover h3 a { color: var(--accent); }
.series-card .tagline { margin: 0; color: var(--ink-soft); font-size: 0.95rem; max-width: 46ch; }
.series-card .progress { display: flex; align-items: center; gap: 0.7rem; margin-top: 0.2rem; }
.series-card .progress-bar {
  flex: 1; height: 5px; border-radius: 999px; background: var(--surface-2);
  border: 1px solid var(--line); overflow: hidden;
}
.series-card .progress-fill { display: block; height: 100%; background: var(--accent); border-radius: 999px; }
.series-card .progress-label { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint); white-space: nowrap; }
.series-card .foot {
  margin-top: auto; padding-top: 0.7rem; border-top: 1px solid var(--line);
  font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-faint);
}
.series-card .foot a { color: var(--ink-soft); }
.series-card .foot a:hover { color: var(--accent); }

/* ---- series (earned 01–04 sequence) ------------------------------------ */
.series { display: grid; gap: 0; border-top: 1px solid var(--line); }
.series-item {
  display: grid; grid-template-columns: 4.5rem 1fr auto; gap: 1.5rem; align-items: start;
  padding: 1.6rem 0.5rem; border-bottom: 1px solid var(--line);
  transition: background 0.15s ease;
}
.series-item:hover { background: var(--surface); }
.series-item .num { font-family: var(--font-mono); font-size: 1.5rem; color: var(--line-strong); font-weight: 500; }
.series-item:hover .num { color: var(--accent); }
.series-item h3 { font-size: 1.2rem; margin-bottom: 0.35rem; }
.series-item h3 a { color: var(--ink); }
.series-item h3 a:hover { color: var(--accent); }
.series-item .thesis { color: var(--ink-soft); font-size: 0.97rem; margin: 0; max-width: 60ch; }
.series-item .tag { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint); white-space: nowrap; padding-top: 0.4rem; }
.series-item .flag { display: inline-block; font-family: var(--font-mono); font-size: 0.68rem; color: var(--trace-teal); border: 1px solid var(--line); border-radius: 5px; padding: 0.05rem 0.4rem; margin-top: 0.6rem; }

/* ---- deep dives (standalone cards; no false sequence) ------------------- */
.dives { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
@media (max-width: 900px) { .dives { grid-template-columns: repeat(2, 1fr); } }
.dive {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.3rem 1.4rem; display: flex; flex-direction: column; gap: 0.55rem;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.dive:hover { border-color: var(--accent); transform: translateY(-2px); }
.dive .topic { font-family: var(--font-mono); font-size: 0.72rem; color: var(--accent); }
.dive h3 { font-size: 1.12rem; }
.dive h3 a { color: var(--ink); }
.dive:hover h3 a { color: var(--accent); }
.dive p { margin: 0; color: var(--ink-soft); font-size: 0.95rem; }
.dive .foot { margin-top: auto; padding-top: 0.4rem; font-family: var(--font-mono); font-size: 0.7rem; color: var(--ink-faint); }
@media (max-width: 720px) { .dives { grid-template-columns: 1fr; } }

/* ---- placeholder skeletons: show structure, reveal no topics ------------ */
.skel { display: grid; gap: 0.55rem; }
.skel-bar { display: block; height: 0.72rem; border-radius: 4px; background: var(--surface-2); border: 1px solid var(--line); }
.dive.skeleton, .series-item.skeleton { pointer-events: none; }
.dive.skeleton:hover { transform: none; border-color: var(--line); }
.series-item.skeleton:hover { background: transparent; }
.series-item.skeleton:hover .num { color: var(--line-strong); }
/* Planned parts show their title and thesis but read as not-yet-there. */
.series-item.skeleton h3 { color: var(--ink-faint); font-weight: 500; }
.series-item.skeleton .thesis { color: var(--ink-faint); }

/* ---- writing list ------------------------------------------------------- */
.post-list { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--line); }
.post-list li { border-bottom: 1px solid var(--line); }
.post-list a { display: grid; grid-template-columns: 8.5rem 1fr; gap: 1.2rem; padding: 1.1rem 0.5rem; align-items: baseline; }
.post-list a:hover { background: var(--surface); }
.post-list .date { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); }
.post-list .title { color: var(--ink); font-family: var(--font-display); font-weight: 500; font-size: 1.08rem; }
.post-list a:hover .title { color: var(--accent); }
.post-list .in-series {
  display: block; font-family: var(--font-mono); font-size: 0.7rem; font-weight: 400;
  color: var(--ink-faint); letter-spacing: 0.04em; margin-top: 0.2rem;
}

/* ---- pagination --------------------------------------------------------- */
.pager {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  margin-top: 1.6rem; font-family: var(--font-mono); font-size: 0.8rem;
}
.pager .step { color: var(--accent); }
.pager .step.disabled { color: var(--line-strong); }
.pager-pages { display: flex; gap: 0.35rem; }
.pager-pages a, .pager-pages .here {
  min-width: 1.9rem; padding: 0.25rem 0.45rem; text-align: center;
  border: 1px solid var(--line); border-radius: 6px;
}
.pager-pages a { color: var(--ink-faint); }
.pager-pages a:hover { color: var(--accent); border-color: var(--accent); }
.pager-pages .here { color: var(--ink); background: var(--surface-2); border-color: var(--line-strong); }

/* Section headings that link to their own index page. */
.section-head h2 a { color: inherit; }
.section-head h2 a:hover { color: var(--accent); }

/* ---- prose (post pages) ------------------------------------------------- */
.post { padding: 3.5rem 0 4rem; }
.post-head { max-width: var(--maxw-prose); margin: 0 auto 2.5rem; }
.post-head .meta { font-family: var(--font-mono); font-size: 0.8rem; color: var(--ink-faint); margin-bottom: 1rem; }
.post-head h1 { font-size: clamp(2rem, 4vw, 3rem); }
.prose { max-width: var(--maxw-prose); margin: 0 auto; }
.prose > * + * { margin-top: 1.3rem; }
.prose h2 { font-size: 1.6rem; margin-top: 2.6rem; }
.prose h3 { font-size: 1.25rem; margin-top: 2rem; }
.prose p, .prose li { color: var(--ink-soft); }
.prose strong { color: var(--ink); }
.prose a { text-decoration: underline; text-decoration-color: var(--line-strong); text-underline-offset: 3px; }
.prose a:hover { text-decoration-color: var(--accent); }
.prose ul, .prose ol { padding-left: 1.3rem; }
.prose blockquote { border-left: 3px solid var(--accent); margin: 1.6rem 0; padding: 0.2rem 0 0.2rem 1.2rem; color: var(--ink-soft); font-style: italic; }
.prose code { font-family: var(--font-mono); font-size: 0.86em; background: var(--surface-2); padding: 0.12em 0.38em; border-radius: 5px; }
.prose pre { background: var(--surface-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem 1.1rem; overflow-x: auto; font-size: 0.86rem; line-height: 1.55; }
.prose pre code { background: none; padding: 0; font-size: inherit; }
.prose img { border-radius: var(--radius); border: 1px solid var(--line); margin: 1.6rem auto; }
.prose hr { border: none; border-top: 1px solid var(--line); margin: 2.5rem 0; }

/* Source line under a code block — sits tight to the <pre> it belongs to. */
.prose .src { display: block; font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-faint); }
.prose pre + p > .src:only-child, .prose pre + .src { margin-top: -0.9rem; }
.prose .src a { color: var(--ink-faint); text-decoration-color: var(--line); }
.prose .src a:hover { color: var(--accent); }

/* ---- series badge ------------------------------------------------------- */
.series-badge {
  font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--accent); margin: 0.7rem 0 0;
}

/* ---- figures & diagrams ------------------------------------------------- */
/* Diagrams break the prose column on purpose: they carry structure the text
   can only describe serially, so they get the full grid width. */
.figure {
  margin: 2.2rem auto; max-width: min(var(--maxw), 100%);
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 1.4rem 1.4rem 1.1rem;
}
.figure svg, .figure .mermaid svg { display: block; width: 100%; height: auto; }
.figure figcaption {
  font-family: var(--font-mono); font-size: 0.76rem; line-height: 1.6;
  color: var(--ink-faint); margin-top: 1rem;
  border-top: 1px solid var(--line); padding-top: 0.75rem;
}
.figure figcaption b { color: var(--ink-soft); font-weight: 500; }
.figure-mermaid { padding: 1.6rem 1rem; overflow-x: auto; }
.figure-mermaid pre.mermaid { background: none; border: none; padding: 0; margin: 0; text-align: center; }
/* Pre-render state: hide the raw source so a slow CDN never flashes DSL text. */
pre.mermaid:not([data-processed]) { visibility: hidden; min-height: 2rem; }
.figure-scroll { overflow-x: auto; }
.figure-scroll > svg { min-width: 640px; }

/* SVG diagram type scale — set here so diagrams inherit the site's palette
   and stay legible when the browser zooms text. */
.dg-label  { font-family: var(--font-body); font-size: 13px; fill: var(--ink); }
.dg-mono   { font-family: var(--font-mono); font-size: 11.5px; fill: var(--ink-soft); }
.dg-small  { font-family: var(--font-mono); font-size: 10px; fill: var(--ink-faint); letter-spacing: 0.04em; }
.dg-title  { font-family: var(--font-display); font-size: 13px; font-weight: 600; fill: var(--ink); }
.dg-box    { fill: var(--surface-2); stroke: var(--line-strong); }
.dg-line   { stroke: var(--ink-faint); fill: none; }
.dg-track  { fill: var(--trace-track); opacity: 0.35; }
.dg-prefill { fill: var(--trace-amber); }
.dg-decode  { fill: var(--trace-teal); }
.dg-idle    { fill: var(--trace-track); }
.dg-accent  { fill: var(--trace-blue); }
/* Cell text sits on amber/teal fills, which stay light in both schemes, so it
   is deliberately NOT var(--ink) — that would invert to near-white on dark. */
.dg-cell-txt { font-family: var(--font-mono); font-size: 10.5px; fill: #0B0E14; fill-opacity: 0.82; text-anchor: middle; }

/* ---- footer ------------------------------------------------------------- */
.site-footer { border-top: 1px solid var(--line); margin-top: 2rem; padding: 2.5rem 0; }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: space-between; align-items: center; }
.site-footer .cols { display: flex; gap: 1.5rem; font-family: var(--font-mono); font-size: 0.8rem; }
.site-footer a { color: var(--ink-faint); }
.site-footer a:hover { color: var(--accent); }
.site-footer .whoami { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); }

/* ---- responsive --------------------------------------------------------- */
@media (max-width: 720px) {
  .rail { flex-direction: column; gap: 0.7rem; align-items: stretch; }
  .rail::before, .rail .signal { display: none; }
  .node { text-align: center; }
  .node.gateway { flex-wrap: wrap; justify-content: center; }
  .span-row { grid-template-columns: 9ch 1fr 5ch; font-size: 0.68rem; }
  .series-item { grid-template-columns: 2.5rem 1fr; }
  .series-item .tag { grid-column: 2; padding-top: 0.5rem; }
  .post-list a { grid-template-columns: 1fr; gap: 0.2rem; }
  .nav { gap: 1rem; }
  .nav a:not(.gh) { display: none; }
}

/* ---- motion / a11y ------------------------------------------------------ */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .rail .signal { left: 94%; opacity: 0; }
  .span-bar { transform: scaleX(1); }
}