/* zeno.center - "HARD SIGNAL" neo-brutalist design system (static site).
   See docs/BRAND.md. Light paper ground, pure-black thick borders, hard offset
   shadows, sharp corners, mono-first data voice + Archivo Black display.
   Self-hosts Archivo Black + Space Mono (+ legacy Geist kept as fallback);
   Newsreader (research serif) loads via <link>. */

@font-face {
  font-family: "Archivo Black";
  src: url("/fonts/ArchivoBlack-400.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "Space Mono";
  src: url("/fonts/SpaceMono-400.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "Space Mono";
  src: url("/fonts/SpaceMono-700.woff2") format("woff2");
  font-weight: 700;
  font-display: swap;
}
@font-face {
  font-family: "Geist";
  src: url("/fonts/Geist-Variable.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
}
/* Newsreader (self-hosted variable) - the research/whitepaper long-form serif */
@font-face {
  font-family: "Newsreader";
  src: url("/fonts/Newsreader-normal.woff2") format("woff2");
  font-weight: 200 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Newsreader";
  src: url("/fonts/Newsreader-italic.woff2") format("woff2");
  font-weight: 200 800;
  font-style: italic;
  font-display: swap;
}

:root {
  --bg: #ffffff;
  --panel: #0b0b0b;
  --raised: #f2f1ec;
  --fg: #000000;
  --fg-strong: #000000;
  --fg-muted: #52525b;
  --signal: #ffe500;
  --signal-ink: #8a6a00;
  --phosphor: #00e676;
  --oxidized: #2d5bff;
  --hair: #000000;
  --hair-strong: #000000;
  --good: #00e676;
  --watch: #ffe500;
  --critical: #ff2d2d;
  /* brutalist accent set */
  --red: #ff2d2d;
  --yellow: #ffe500;
  --cyan: #FFE500;
  --blue: #2d5bff;
  --coral: #ff6f61;
  --green: #00e676;
  --violet: #a855f7;
  --paper: #ffffff;
  --ink: #000000;

  --display: "Archivo Black", "Arial Black", "Helvetica Neue", sans-serif;
  --sans: "Geist", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "Space Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;

  --maxw: 1120px;
  --step-h1: clamp(2.6rem, 6.5vw, 5rem);
  --step-h2: clamp(1.5rem, 3.4vw, 2.3rem);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 5rem; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--mono);
  font-weight: 400;
  line-height: 1.6;
  font-variant-numeric: tabular-nums;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: var(--yellow); color: #000; }

a { color: var(--signal-ink); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
/* links inside running text must not rely on color alone (WCAG 1.4.1) */
p a, li a { text-decoration: underline; text-decoration-thickness: 1.5px; text-underline-offset: 3px; }
:focus-visible { outline: 3px solid #000; outline-offset: 2px; }

h1, h2, h3 { font-family: var(--display); color: var(--fg-strong); line-height: 1.02; letter-spacing: -0.02em; font-weight: 400; text-wrap: balance; margin: 0; }
h1 { font-size: var(--step-h1); max-width: 18ch; }
h2 { font-size: var(--step-h2); }
p { margin: 0; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(1.1rem, 4vw, 2.2rem); }
.measure { max-width: 62ch; }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin: 0 0 1rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.eyebrow .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--green); border: 1.5px solid #000; }
.mono { font-family: var(--mono); }
.serif { font-family: var(--serif); }
/* skip-to-content link (WCAG 2.4.1) - visually hidden until focused. Pages on
   this sheet (index/research/prosoche/sclt) carry no common.css copy. */
.skip-link { position: absolute; left: -9999px; top: 8px; z-index: 100; background: var(--ink); color: #fff; padding: 8px 12px; font: 700 11px/1 var(--mono); letter-spacing: 0.14em; text-transform: uppercase; }
.skip-link:focus { left: 16px; }
.sig { color: var(--signal-ink); }
/* yellow-only: the hero accent word gets the brand highlighter (black on yellow),
   since yellow fails as text; links + inline .sig elsewhere use the amber signal-ink. */
h1 .sig { background: var(--yellow); color: #000; padding: 0 0.08em; -webkit-box-decoration-break: clone; box-decoration-break: clone; }
.tnum { font-variant-numeric: tabular-nums; }

/* header / nav */
.site-head { position: sticky; top: 0; z-index: 40; background: rgba(255, 255, 255, 0.9); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px); border-bottom: 2px solid var(--hair); }
.site-head .wrap { display: flex; align-items: center; gap: 1.2rem; padding-top: 0.8rem; padding-bottom: 0.8rem; }
.nav { display: flex; gap: 0.3rem; margin-left: auto; align-items: center; flex-wrap: wrap; }
.nav a { font-family: var(--mono); font-size: 0.76rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; color: var(--fg-muted); padding: 0.4rem 0.6rem; }
.nav a:hover { color: var(--fg-strong); text-decoration: none; background: var(--yellow); }
.nav a[aria-current="page"] { color: var(--fg-strong); box-shadow: inset 0 -3px 0 0 var(--yellow); }
/* header CTA - dedicated class so page-local .btn styles never collide */
.nav-cta { display: inline-flex; align-items: center; font-family: var(--mono); font-size: 0.76rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; padding: 0.5rem 0.9rem; margin-left: 0.3rem; border: 2px solid #000; background: var(--yellow); color: #000; box-shadow: 3px 3px 0 0 #000; text-decoration: none; transition: transform 120ms ease, box-shadow 120ms ease; }
.nav-cta:hover { color: #000; text-decoration: none; transform: translate(-2px, -2px); box-shadow: 5px 5px 0 0 #000; }
.nav-cta:active { transform: translate(0, 0); box-shadow: 2px 2px 0 0 #000; }
@media (max-width: 560px) {
  /* the wrapped two-row nav would pin ~150px of a phone screen if left sticky */
  .site-head { position: static; }
  .site-head .wrap { gap: 0.5rem; }
  .nav { gap: 0.1rem; }
  .nav a { font-size: 0.7rem; padding: 0.35rem 0.45rem; letter-spacing: 0.02em; }
  .nav-cta { font-size: 0.7rem; padding: 0.45rem 0.6rem; margin-left: 0.1rem; }
}

/* buttons - solid fill, black border, hard offset shadow, sharp corners */
.btn { display: inline-flex; align-items: center; gap: 0.5rem; font-family: var(--mono); font-size: 0.85rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; padding: 0.72rem 1.15rem; border: 2px solid #000; cursor: pointer; box-shadow: 3px 3px 0 0 #000; transition: transform 120ms ease, box-shadow 120ms ease, background 120ms ease; }
.btn:hover { text-decoration: none; transform: translate(-2px, -2px); box-shadow: 5px 5px 0 0 #000; }
.btn:active { transform: translate(0, 0); box-shadow: 2px 2px 0 0 #000; }
.btn-primary { background: var(--signal); color: #000; }
.btn-primary:hover { background: var(--signal); }
.btn-ghost { background: #fff; color: var(--fg); }
.btn-ghost:hover { background: var(--yellow); }

/* layout / sections */
section { padding: clamp(3rem, 7vw, 5.5rem) 0; border-bottom: 2px solid var(--hair); }
.sec-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; flex-wrap: wrap; margin-bottom: 2rem; }
.sec-no { font-family: var(--mono); font-size: 0.72rem; font-weight: 700; color: var(--fg-muted); letter-spacing: 0.12em; }

/* cards / panels - thick black border + hard shadow, sharp corners */
.card { border: 3px solid var(--hair); background: #fff; padding: 1.4rem 1.5rem; box-shadow: 4px 4px 0 0 #000; }
.card h3 { font-size: 1.05rem; }
.grid { display: grid; gap: 0.9rem; }
.cols-2 { grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr)); }
.cols-3 { grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr)); }

/* metric readout */
.readout { font-family: var(--mono); }
.readout .v { font-family: var(--display); color: var(--fg-strong); font-size: 1.8rem; font-weight: 400; }
.readout .v.sig { color: var(--signal-ink); }
.readout .k { color: var(--fg-muted); font-size: 0.66rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; }

/* chips / pills - square, solid fill, black border */
.chip { display: inline-flex; align-items: center; gap: 0.4rem; font-family: var(--mono); font-size: 0.68rem; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; padding: 0.25rem 0.6rem; border: 2px solid #000; color: var(--fg); background: #fff; }
.chip.live { color: #000; background: var(--good); }
.chip.soon { color: #000; background: var(--watch); }

/* code block (telemetry) - stays dark for real-terminal authenticity */
.cli { background: #0b0b0b; border: 3px solid #000; box-shadow: 4px 4px 0 0 #000; padding: 1rem 1.1rem; font-family: var(--mono); font-size: 0.85rem; color: #e6eaf0; white-space: pre; overflow-x: auto; }
.cli .pr { color: #8b93a0; } /* 6.35:1 on #0b0b0b - AA (was #6b7480, 4.16:1) */
.cli .ok { color: var(--phosphor); }
.cursor { display: inline-block; width: 8px; height: 1em; background: var(--phosphor); vertical-align: -2px; margin-left: 2px; animation: blink 1.1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }

/* footer */
.site-foot { padding: 2.6rem 0 3.4rem; color: var(--fg-muted); font-family: var(--mono); font-size: 0.76rem; border-top: 2px solid var(--hair); }
.site-foot a { color: var(--fg-muted); display: inline-block; padding: 0.25rem 0; }
.site-foot a:hover { color: var(--signal-ink); }

/* waitlist form (index #waitlist) */
.wl-form { display: grid; gap: 0.8rem; }
.wl-form label { display: grid; gap: 0.35rem; font-family: var(--mono); font-size: 0.66rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--fg-muted); }
/* 1rem (16px) floor: anything smaller makes iOS Safari zoom the page on focus */
.wl-form input, .wl-form select { appearance: none; -webkit-appearance: none; border: 2px solid #000; border-radius: 0; background: #fff; color: var(--fg); padding: 0.65rem 0.7rem; font-family: var(--mono); font-size: 1rem; }
.wl-form select { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%23000' stroke-width='2'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.7rem center; padding-right: 2.2rem; }
.wl-form button[disabled] { opacity: 0.7; cursor: not-allowed; }
.wl-form .hp-field { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.wl-status { min-height: 1.3em; font-family: var(--mono); font-size: 0.78rem; color: var(--fg-muted); margin: 0; }
.wl-status.error { color: var(--critical); }
.wl-fine { margin: 0.2rem 0 0; font-family: var(--mono); font-size: 0.66rem; line-height: 1.55; color: var(--fg-muted); }
.wl-fine a { color: var(--signal-ink); text-decoration: underline; text-underline-offset: 2px; }
#waitlist-thanks { display: none; margin-top: 0.8rem; border: 2px solid #000; background: var(--yellow); color: #000; padding: 0.6rem 0.8rem; font-family: var(--mono); font-size: 0.8rem; }
#waitlist-thanks:target { display: block; }

/* motion - the .reveal hidden state lives ONLY inside the no-preference
   gate below (V2), keyed on :not(.in) so the revealed state can never lose
   a specificity fight against the html.js no-JS guard. */
@media (prefers-reduced-motion: reduce) {
  .cursor { animation: none; }
}

/* inline SVG charts: their viewBox text (10-12px) turns illegible when the
   chart shrinks below ~350px rendered width, so scale label type up there */
@media (max-width: 640px) {
  .chart-curve text { font-size: 15px; }
}

/* ---- hero pulse-field: the aura instrument (replaced the dark gap chart).
   Cognition as a beacon the instrument reads: an att core heartbeats at 2.4s
   while yellow aura rings + halos radiate and a sensor tick orbits the gauge.
   CSS-only; transform/opacity animations; dignified freeze under reduced motion. */
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.04fr) minmax(0, 0.96fr); gap: clamp(2rem, 4.5vw, 4rem); align-items: center; }
/* the copy shares the row with the instrument, so the display scale steps down
   from the full-width h1 - "Agents scale." and "Your attention" hold one line each */
.hero-copy h1 { font-size: clamp(2.3rem, 3.9vw, 3.6rem); max-width: none; }
.hero-copy .measure { font-size: 1.02rem; }
.hero-rig { width: 100%; max-width: 560px; justify-self: end; }
.rig-card { border: 3px solid #000; background: #fff; box-shadow: 8px 8px 0 0 #000; }
.rig-head { display: flex; justify-content: space-between; align-items: center; border-bottom: 3px solid #000; padding: 0.55rem 0.85rem; font-family: var(--mono); font-size: 0.66rem; font-weight: 700; letter-spacing: 0.18em; text-transform: uppercase; }
.rig-live { display: inline-flex; align-items: center; gap: 0.45rem; color: var(--fg-muted); }
.rig-live i { width: 8px; height: 8px; background: var(--green); border: 2px solid #000; display: inline-block; animation: rig-blink 2.4s steps(1) infinite; }
@keyframes rig-blink { 0%, 100% { opacity: 1; } 55% { opacity: 0.25; } }
.rig-field { position: relative; aspect-ratio: 1 / 1; max-height: 470px; margin: 0 auto; overflow: hidden; background: linear-gradient(#f1f1f3 1px, transparent 1px), linear-gradient(90deg, #f1f1f3 1px, transparent 1px); background-size: 32px 32px; background-position: center center; }
.rig-field::before, .rig-field::after { content: ""; position: absolute; background: #d4d4d8; }
.rig-field::before { left: 0; right: 0; top: 50%; height: 1px; }
.rig-field::after { top: 0; bottom: 0; left: 50%; width: 1px; }
.rig-tick { position: absolute; z-index: 1; font-family: var(--mono); font-size: 0.6rem; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase; color: var(--fg-muted); background: #fff; padding: 0.15rem 0.35rem; }
.rig-tick.tl { top: 0.55rem; left: 0.6rem; }
.rig-tick.br { bottom: 0.55rem; right: 0.6rem; }
.rig-gauge { position: absolute; inset: 7%; border: 2px dashed #000; border-radius: 50%; opacity: 0.85; }
.rig-gauge i { position: absolute; width: 9px; height: 9px; background: #000; }
.rig-gauge i.n { top: -6px; left: 50%; margin-left: -4.5px; }
.rig-gauge i.s { bottom: -6px; left: 50%; margin-left: -4.5px; }
.rig-gauge i.e { right: -6px; top: 50%; margin-top: -4.5px; }
.rig-gauge i.w { left: -6px; top: 50%; margin-top: -4.5px; }
.rig-sweep { position: absolute; inset: 7%; animation: rig-rot 16s linear infinite; }
.rig-sweep i { position: absolute; top: -8px; left: 50%; margin-left: -6px; width: 12px; height: 12px; background: var(--yellow); border: 2px solid #000; }
@keyframes rig-rot { to { transform: rotate(360deg); } }
.rig-halo { position: absolute; inset: 0; margin: auto; width: 74%; aspect-ratio: 1 / 1; border-radius: 50%; background: var(--yellow); opacity: 0; animation: rig-halo 2.4s cubic-bezier(0.22, 0.61, 0.36, 1) infinite; }
.rig-halo.h2 { animation-delay: 1.2s; }
@keyframes rig-halo { 0% { transform: scale(0.22); opacity: 0.6; } 60% { opacity: 0.22; } 100% { transform: scale(1.02); opacity: 0; } }
.rig-ring { position: absolute; inset: 0; margin: auto; width: 82%; aspect-ratio: 1 / 1; border-radius: 50%; border: 7px solid var(--yellow); outline: 2px solid #000; opacity: 0; animation: rig-aura 2.4s cubic-bezier(0.22, 0.61, 0.36, 1) infinite; }
.rig-ring.base { opacity: 1; border-width: 9px; animation: rig-basebeat 2.4s cubic-bezier(0.3, 0, 0.4, 1) infinite; }
.rig-ring.r2 { animation-delay: 0.6s; border-width: 5px; }
.rig-ring.r3 { animation-delay: 1.2s; border-width: 4px; outline: none; }
.rig-ring.r4 { animation-delay: 1.8s; border-width: 3px; outline: none; }
@keyframes rig-aura { 0% { transform: scale(0.18); opacity: 0; } 9% { opacity: 1; } 60% { opacity: 0.55; } 100% { transform: scale(1.06); opacity: 0; } }
@keyframes rig-basebeat { 0%, 100% { transform: scale(0.48); } 7% { transform: scale(0.515); } 18% { transform: scale(0.48); } }
.rig-core { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); z-index: 2; text-align: center; background: #fff; border: 3px solid #000; box-shadow: 6px 6px 0 0 #000; padding: 0.9rem 1.35rem 0.8rem; animation: rig-beat 2.4s cubic-bezier(0.3, 0, 0.4, 1) infinite; }
@keyframes rig-beat { 0%, 100% { transform: translate(-50%, -50%) scale(1); } 7% { transform: translate(-50%, -50%) scale(1.045); } 18% { transform: translate(-50%, -50%) scale(1); } }
.rig-core .lbl { font-family: var(--mono); font-size: 0.62rem; font-weight: 700; letter-spacing: 0.3em; text-transform: uppercase; color: var(--fg-muted); }
.rig-core .val { font-family: var(--display); font-size: clamp(2.6rem, 4.2vw, 3.4rem); line-height: 1; letter-spacing: -0.02em; color: var(--fg-strong); }
.rig-core .trend { margin-top: 0.3rem; font-family: var(--mono); font-size: 0.62rem; font-weight: 700; letter-spacing: 0.12em; color: #067647; }
.rig-foot { display: grid; grid-template-columns: 1fr 1fr 1fr; border-top: 3px solid #000; }
.rig-driver { padding: 0.6rem 0.85rem 0.7rem; border-right: 3px solid #000; }
.rig-driver:last-child { border-right: 0; }
.rig-driver .dk { display: flex; justify-content: space-between; align-items: baseline; font-family: var(--mono); font-size: 0.64rem; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase; color: var(--fg-muted); margin-bottom: 0.4rem; }
.rig-driver .dk b { color: var(--fg-strong); font-size: 0.82rem; }
.rig-bar { height: 8px; border: 2px solid #000; position: relative; overflow: hidden; }
.rig-bar i { position: absolute; inset: 0; background: var(--yellow); transform-origin: left center; }
.rig-delta { font-family: var(--mono); font-size: 0.6rem; font-weight: 700; letter-spacing: 0.1em; margin-top: 0.35rem; }
.rig-delta.up { color: #067647; }
.rig-delta.dn { color: #c81e1e; }
.rig-delta.fl { color: var(--fg-muted); }
.rig-cap { margin-top: 1rem; font-family: var(--mono); font-size: 0.64rem; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase; color: var(--fg-muted); text-align: right; }
@media (prefers-reduced-motion: reduce) {
  .rig-ring, .rig-ring.base, .rig-halo, .rig-core, .rig-sweep, .rig-live i { animation: none; }
  .rig-halo { transform: scale(0.3); opacity: 0.35; }
  .rig-halo.h2 { opacity: 0; }
  .rig-ring.base { transform: scale(0.48); }
  .rig-ring.r1 { transform: scale(0.62); opacity: 0.8; }
  .rig-ring.r2 { transform: scale(0.75); opacity: 0.55; }
  .rig-ring.r3 { transform: scale(0.88); opacity: 0.35; }
  .rig-ring.r4 { transform: scale(1); opacity: 0.18; }
  .rig-sweep { transform: rotate(38deg); }
}
@media (max-width: 880px) {
  .hero-grid { grid-template-columns: 1fr; gap: 2.2rem; }
  .hero-rig { justify-self: stretch; max-width: 100%; }
  .rig-field { max-height: 340px; }
  .rig-card { box-shadow: 6px 6px 0 0 #000; }
  .rig-driver { padding: 0.5rem 0.55rem 0.6rem; }
  .rig-cap { text-align: left; }
}

/* research / "field notes" light register (used on /research surfaces) */
.field { background: var(--paper); color: var(--ink); }
.field a { color: var(--signal-ink); }
.field .serif { font-family: var(--serif); }

/* ============================================================
   MEASURED MOTION - adoption spec v1 ("HARD SIGNAL, MEASURED MOTION")
   The vocabulary is capped at 5 verbs: V1 LIFT/PRESS, V2 STAGGER,
   V3 TRACE-DRAW, V4 STAMP-SNAP, V5 TICK. Everything animates in once
   and ends still. All @keyframes use steps(); hover transitions run
   <= 150ms ease/linear. The ONLY infinite loop sitewide stays the
   .cursor blink above. Resting/final states live OUTSIDE the
   no-preference gate so reduced-motion and no-JS users always see the
   finished state, never a hidden one. Never add a blanket
   `* { animation: none !important }`.
   ============================================================ */

/* ---- resting states (outside any media query) ---- */
.stamp {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: 2.5px solid #000;
  padding: 0.3rem 0.6rem;
  background: #fff;
  color: #000;
  transform: rotate(-3deg);
}
/* .trace carries no dash props at rest: SVG paths render fully drawn by
   default, so no-JS and reduced-motion both see the finished plot. Put
   pathLength="1000" on every animated path so the CSS constant below
   needs zero JS measurement. */
.hud .fill { transform-origin: left; } /* full width at rest */

@media (prefers-reduced-motion: no-preference) {

  /* V1 LIFT/PRESS - extends the shipped .btn/.nav-cta verb to every
     clickable card, pricing tier, and chip-link. No hover colors, no scale. */
  a.card, .tier, a.chip { transition: transform 120ms ease, box-shadow 120ms ease; }
  a.card:hover, .tier:hover { transform: translate(-2px, -2px); box-shadow: 6px 6px 0 0 #000; }
  a.card:active, .tier:active { transform: none; box-shadow: 2px 2px 0 0 #000; }
  a.chip:hover { transform: translate(-2px, -2px); box-shadow: 3px 3px 0 0 #000; }
  a.chip:active { transform: none; box-shadow: none; }

  /* V2 STAGGER - html.js-gated so no-JS users always see content; the
     hidden state keys on :not(.in) so .in always wins regardless of
     specificity. Usage: <div class="card reveal" style="--i:1"> ...
     cap groups at 5; translateY stays 12px. */
  html.js .reveal { transition: opacity 0.35s ease, transform 0.35s ease; transition-delay: calc(var(--i, 0) * 60ms); }
  html.js .reveal:not(.in) { opacity: 0; transform: translateY(12px); }

  /* V3 TRACE-DRAW - a chart recorder plotting, not a tween. steps(24)
     quantization reads as sampling. .in comes from the IO in
     js/instrument.js (on the .trace itself or a container). */
  .in .trace, .trace.in { stroke-dasharray: 1000; stroke-dashoffset: 1000; animation: plot 0.9s steps(24, end) forwards; }
  @keyframes plot { to { stroke-dashoffset: 0; } }

  /* V4 STAMP-SNAP - the rubber stamp presses flat on hover; never spins. */
  .stamp { transition: transform 120ms linear; }
  .stamp:hover { transform: rotate(0deg); }

  /* V5 TICK - HUD bar fills draw once on reveal, end still. The count-up
     twin lives in js/instrument.js (its reduce guard prints the final
     number; every data-count element must carry the real target in
     markup or aria-label). */
  .hud.in .fill { animation: fill 0.6s steps(12, end) backwards; }
  @keyframes fill { from { transform: scaleX(0); } }
}

/* ---- hyperlink apparatus (not motion; lives outside the gate) ---- */
/* .cite = annotated citation link. Dotted underline signals a tooltip;
   data-note carries the one-line claim, build-injected from
   research/claims-map.json. The tooltip is CSS-only: zero JS. */
.cite { position: relative; font-family: var(--mono); font-size: 0.74rem; color: var(--signal-ink); text-decoration: underline dotted 1.5px; text-underline-offset: 3px; }
.cite:hover { text-decoration-style: solid; background: var(--yellow); color: #000; }
.cite[data-note]:hover::after,
.cite[data-note]:focus-visible::after {
  content: attr(data-note);
  position: absolute;
  left: 0;
  bottom: calc(100% + 0.5rem);
  z-index: 60;
  width: max-content;
  max-width: 34ch;
  padding: 0.45rem 0.6rem;
  border: 2px solid #000;
  background: #fff;
  color: #000;
  box-shadow: 3px 3px 0 0 #000;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 400;
  line-height: 1.45;
  letter-spacing: normal;
  text-transform: none;
  text-align: left;
  white-space: normal;
  text-decoration: none;
  pointer-events: none;
}
/* .ext = external-destination marker (U+2197 north-east arrow) */
.ext::after { content: " \2197"; font-size: 0.85em; }