/* ==========================================================================
   ChessVision Engine — design system
   --------------------------------------------------------------------------
   Ivory & Ink: a light, editorial, acquisition-prospectus aesthetic.
   Warm paper ground, ink text, deep forest-green primary, brass detail.
   Serif display, sans body, mono data. Sharp corners, hairline rules.
   No external resources of any kind.
   ========================================================================== */

/* ---------- Tokens ---------------------------------------------------- */
:root {
  /* Paper */
  --paper-0: #f7f3ea;         /* page ground — warm ivory */
  --paper-1: #f0eadb;        /* raised panels */
  --paper-2: #e8e0c9;        /* inset wells, chips */
  --rule-0: #d9d0b8;         /* hairlines */
  --rule-1: #a89c7c;         /* strong rules */

  /* Ink */
  --ink-0: #1c1e1c;          /* primary text */
  --ink-1: #383d37;          /* secondary text */
  --ink-2: #666b60;          /* muted text */
  --ink-3: #93927f;          /* faint labels */

  /* Accents */
  --green: #0e5a3c;          /* deep forest green — primary accent */
  --green-deep: #0b4229;     /* hover / band ground */
  --green-tint: rgba(14, 90, 60, 0.10);
  --brass: #8a6420;          /* figure numerals, detail marks */
  --board-light: #ece4cc;    /* chessboard buff */
  --board-dark: #76855f;     /* chessboard sage */

  /* Type */
  --font-serif: Georgia, "Iowan Old Style", "Times New Roman", Times, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "Cascadia Mono", Consolas, "SF Mono", Menlo, monospace;

  /* Metrics */
  --container: 1160px;
  --content-w: 860px;
  --section-pad: clamp(64px, 8vw, 110px);

  /* Motion */
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- Reset ---------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}
body {
  margin: 0;
  background: var(--paper-0);
  color: var(--ink-1);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--green); text-decoration: none; }
a:hover { color: var(--green-deep); text-decoration: underline; text-underline-offset: 3px; }
:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 3px;
  border-radius: 1px;
}

/* ---------- Type ------------------------------------------------------ */
h1, h2, h3 {
  font-family: var(--font-serif);
  color: var(--ink-0);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.01em;
  margin: 0 0 18px 0;
  text-wrap: balance;
}
h1 { font-size: clamp(34px, 4.8vw, 58px); letter-spacing: -0.015em; }
h2 { font-size: clamp(25px, 3vw, 33px); }
h3 { font-size: 18.5px; margin-bottom: 8px; }
p { margin: 0 0 16px 0; }
p:last-child { margin-bottom: 0; }
strong { color: var(--ink-0); font-weight: 600; }
code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--paper-2);
  border: 1px solid var(--rule-0);
  border-radius: 1px;
  padding: 1px 5px;
  color: var(--green-deep);
  overflow-wrap: break-word;
}

/* ---------- Utilities -------------------------------------------------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--ink-0);
  color: var(--paper-0);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 18px;
}
.skip-link:focus { left: 0; }

.container { width: min(var(--container), calc(100% - 48px)); margin-inline: auto; }
.narrow { max-width: 760px; }
.u-mt-0 { margin-top: 0; }
.u-mt-28 { margin-top: 28px; }
.u-mt-32 { margin-top: 32px; }
.u-mb-0 { margin-bottom: 0; }
.u-muted { color: var(--ink-2); }
.u-small { font-size: 14px; }
.u-centered { justify-content: center; }
.u-lede { font-size: 18px; color: var(--ink-1); }
.u-h1 { font-size: clamp(28px, 4vw, 42px); }
.u-h1-sm { font-size: clamp(23px, 3vw, 32px); }
.u-measure { max-width: 44ch; color: var(--ink-1); }

/* ---------- Rules ------------------------------------------------------ */
.rule-double { border-top: 1px solid var(--rule-1); border-bottom: 3px double var(--rule-1); height: 5px; }
.rule-hair { border: 0; border-top: 1px solid var(--rule-0); margin: 0; }

/* ---------- Eyebrow / section numbering --------------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--green);
  margin: 0 0 16px 0;
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--brass);
  flex: none;
}

.sec-head {
  border-top: 3px double var(--rule-1);
  padding-top: 18px;
  margin-bottom: 44px;
  max-width: 720px;
}
.sec-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--brass);
  margin: 0 0 10px 0;
}
.sec-head > p.lede-note { color: var(--ink-1); margin-top: -6px; }

/* ---------- Header ------------------------------------------------------ */
.site-header {
  background: var(--paper-0);
  padding-block: 18px 16px;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink-0);
}
.brand:hover { color: var(--ink-0); text-decoration: none; }
.brand-name {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.01em;
  line-height: 1.1;
  white-space: nowrap;
}
.brand-name small {
  display: block;
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--ink-2);
  margin-top: 3px;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  flex-wrap: wrap;
}
.site-nav a {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--ink-1);
}
.site-nav a:hover { color: var(--green); text-decoration: none; }
.nav-cta {
  border: 1px solid var(--ink-0);
  background: var(--ink-0);
  color: var(--paper-0) !important;
  padding: 7px 14px;
  font-size: 11px !important;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  transition: background 0.16s var(--ease), border-color 0.16s var(--ease);
}
.nav-cta:hover { background: var(--green); border-color: var(--green); color: var(--paper-0) !important; }

/* ---------- Hero --------------------------------------------------------- */
.hero { padding-block: clamp(48px, 6vw, 84px) clamp(56px, 7vw, 96px); }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: clamp(36px, 5vw, 72px);
  align-items: start;
}
.hero-copy { max-width: 620px; }
.hero-copy .lede {
  font-size: clamp(16.5px, 1.4vw, 18.5px);
  color: var(--ink-1);
  max-width: 54ch;
  margin-bottom: 26px;
}

/* spec strip — datasheet line, not pills */
.spec-strip {
  display: flex;
  flex-wrap: wrap;
  border-top: 1px solid var(--rule-1);
  border-bottom: 1px solid var(--rule-1);
  margin: 0 0 30px;
  padding: 10px 0;
}
.spec-item {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ink-2);
  padding: 2px 14px;
  border-left: 1px solid var(--rule-0);
}
.spec-item:first-child { border-left: 0; padding-left: 0; }
.spec-item.is-accent { color: var(--green); }

.cta-row { display: flex; flex-wrap: wrap; align-items: center; gap: 20px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 50px;
  padding: 0 28px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  border-radius: 1px;
  transition: background 0.16s var(--ease), border-color 0.16s var(--ease), color 0.16s var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn-solid { background: var(--ink-0); color: var(--paper-0); border-color: var(--ink-0); }
.btn-solid:hover { background: var(--green); border-color: var(--green); color: var(--paper-0); text-decoration: none; }
.btn-text {
  min-height: auto;
  padding: 0;
  background: none;
  border: 0;
  color: var(--ink-0);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
}
.btn-text::after { content: "\2192"; margin-left: 8px; transition: margin-left 0.16s var(--ease); }
.btn-text:hover { color: var(--green); text-decoration: none; }
.btn-text:hover::after { margin-left: 12px; }
/* Pending acquisition CTA (no listing URL configured yet) */
.btn.is-pending {
  background: none;
  border: 1px dashed var(--ink-2);
  color: var(--ink-2);
  cursor: default;
  font-weight: 500;
}
.btn.is-pending:hover { background: none; border-color: var(--ink-2); color: var(--ink-2); }

/* ---------- Hero figure: board + readout ---------------------------------- */
.figure { position: relative; }
.fig-frame {
  position: relative;
  border: 1px solid var(--rule-1);
  background: var(--paper-1);
  padding: 18px;
}
.fig-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
}
.fig-title {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-2);
}
.fig-title b { color: var(--brass); font-weight: 700; }
.fig-status {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--green);
  white-space: nowrap;
}
.fig-status::before {
  content: "";
  display: inline-block;
  width: 7px; height: 7px;
  background: var(--brass);
  margin-right: 8px;
  vertical-align: 0;
}

.fig-board {
  position: relative;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  aspect-ratio: 1 / 1;
  width: min(100%, 460px);
  border: 1px solid var(--ink-0);
  margin-inline: auto;
}
.sq {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(18px, 2.4vw, 28px);
  line-height: 1;
}
.sq::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--green);
  opacity: 0;
  pointer-events: none;
}
.sq-light { background: var(--board-light); }
.sq-dark { background: var(--board-dark); }
.pc { position: relative; z-index: 2; line-height: 1; }
.pc-w { color: #faf6ea; text-shadow: 0 1px 2px rgba(20, 22, 20, 0.55); }
.pc-b { color: #23251f; text-shadow: 0 1px 1px rgba(250, 246, 234, 0.35); }

/* Rank-ripple recognition sweep: each rank flashes in sequence,
   once per cycle. r0 (top) leads; delays via classes (no inline styles). */
.sq::after { animation: ripple 7s var(--ease) infinite; }
.sq.r0::after { animation-delay: 0s; }
.sq.r1::after { animation-delay: 0.22s; }
.sq.r2::after { animation-delay: 0.44s; }
.sq.r3::after { animation-delay: 0.66s; }
.sq.r4::after { animation-delay: 0.88s; }
.sq.r5::after { animation-delay: 1.1s; }
.sq.r6::after { animation-delay: 1.32s; }
.sq.r7::after { animation-delay: 1.54s; }
@keyframes ripple {
  0%, 2.4%, 100% { opacity: 0; }
  1.2% { opacity: 0.22; }
}

/* Registration brackets over the figure corners */
.brackets {
  position: absolute;
  inset: -9px;
  width: calc(100% + 18px);
  height: calc(100% + 18px);
  pointer-events: none;
}
.brackets path {
  stroke: var(--green);
  stroke-width: 2.5;
  fill: none;
  stroke-linecap: square;
  stroke-dasharray: 100;
  animation: brdraw 7s var(--ease) infinite;
}
@keyframes brdraw {
  0% { stroke-dashoffset: 100; opacity: 0.25; }
  7% { stroke-dashoffset: 0; opacity: 1; }
  88% { stroke-dashoffset: 0; opacity: 1; }
  100% { stroke-dashoffset: -100; opacity: 0.25; }
}

.fig-caption {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-top: 14px;
}
.fig-caption b { color: var(--brass); font-weight: 700; }

/* Reconstruction readout */
.readout {
  margin-top: 16px;
  border-top: 1px solid var(--rule-1);
  display: grid;
  grid-template-columns: 1fr 1fr;
}
.readout-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 9px 2px;
  border-bottom: 1px solid var(--rule-0);
}
.readout-label {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.readout-value { font-size: 13.5px; color: var(--ink-0); font-weight: 600; text-align: right; }
.readout-value.is-ok { color: var(--green); }
.readout-fen {
  grid-column: 1 / -1;
  margin-top: 4px;
  background: var(--paper-2);
  border: 1px solid var(--rule-0);
  padding: 10px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--green-deep);
  overflow-wrap: anywhere;
}

/* ---------- Document layout: contents rail + content ---------------------- */
.layout {
  display: grid;
  grid-template-columns: 208px minmax(0, 1fr);
  gap: clamp(40px, 5vw, 80px);
  align-items: start;
}
.toc {
  position: sticky;
  top: 28px;
  border-top: 3px double var(--rule-1);
  padding-top: 14px;
}
.toc-title {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--brass);
  margin: 0 0 10px;
}
.toc ol { list-style: none; margin: 0; padding: 0; }
.toc li { border-bottom: 1px solid var(--rule-0); }
.toc a {
  display: flex;
  gap: 10px;
  padding: 8px 2px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.05em;
  color: var(--ink-2);
}
.toc a:hover { color: var(--green); text-decoration: none; }
.toc a i {
  font-style: normal;
  color: var(--ink-3);
  min-width: 20px;
}
.toc a.is-active { color: var(--green); font-weight: 700; }
.toc a.is-active i { color: var(--green); }

.content { max-width: var(--content-w); }

/* ---------- Sections ------------------------------------------------------ */
.section { padding-block: clamp(48px, 6vw, 84px); }
.section + .section { border-top: 1px solid var(--rule-0); }

/* ---------- Recognition stack: hanging index list -------------------------- */
.index-group {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--brass);
  margin: 34px 0 6px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--rule-1);
}
.index-group:first-child { margin-top: 0; }
.index-item {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 0 18px;
  padding: 16px 0 15px;
  border-bottom: 1px solid var(--rule-0);
}
.index-item .idx {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--green);
  padding-top: 2px;
}
.index-item h3 { margin: 0 0 5px; font-size: 17px; }
.index-item p { margin: 0; font-size: 14.5px; color: var(--ink-2); max-width: 62ch; }

/* ---------- Architecture pipeline ------------------------------------------ */
.pipeline { max-width: 640px; }
.pl-node {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule-0);
}
.pl-node .pl-idx {
  font-family: var(--font-serif);
  font-size: 21px;
  font-weight: 700;
  color: var(--green);
  line-height: 1;
  padding-top: 2px;
}
.pl-node h3 { margin: 0 0 4px; font-size: 16.5px; }
.pl-node p { margin: 0; font-size: 13.5px; color: var(--ink-2); }
.pl-node.is-gate { background: var(--green-tint); border-inline: 1px solid var(--rule-0); padding-inline: 16px; }
.pl-node.is-gate .pl-idx { color: var(--brass); }
.pl-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 26px;
  margin-top: 22px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-2);
}
.pl-legend span { display: inline-flex; align-items: center; gap: 8px; }
.pl-legend i { width: 16px; height: 2px; display: inline-block; }
.lg-rec { background: var(--green); }
.lg-gate { background: var(--brass); }
.lg-ana { background: var(--ink-0); }

/* ---------- Spec table (engine datasheet) ---------------------------------- */
.spec-table { border-top: 3px double var(--rule-1); }
.spec-row {
  display: grid;
  grid-template-columns: 168px 1fr;
  gap: 18px;
  padding: 12px 0;
  border-bottom: 1px solid var(--rule-0);
}
.spec-k {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-2);
  padding-top: 3px;
}
.spec-v { font-size: 14.5px; color: var(--ink-1); }
.spec-v b { color: var(--ink-0); }

/* ---------- Pull quote ------------------------------------------------------ */
.pull {
  font-family: var(--font-serif);
  font-size: clamp(21px, 2.6vw, 27px);
  line-height: 1.3;
  color: var(--ink-0);
  max-width: 26ch;
  border-left: 3px solid var(--green);
  padding-left: 22px;
  margin: 0 0 34px;
}

/* ---------- Prose columns ---------------------------------------------------- */
.prose-cols { columns: 2; column-gap: 44px; }
.prose-cols > * { break-inside: avoid; }
.prose-cols h3 { margin-top: 0; }
.tick-list { list-style: none; margin: 14px 0 0; padding: 0; }
.tick-list li {
  padding: 9px 0 9px 22px;
  font-size: 14.5px;
  color: var(--ink-1);
  border-bottom: 1px solid var(--rule-0);
  position: relative;
}
.tick-list li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  top: 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--green);
}
.tick-list b { color: var(--ink-0); font-weight: 600; }

/* ---------- Brass note ------------------------------------------------------ */
.brass-note {
  border-left: 2px solid var(--brass);
  padding: 4px 0 4px 22px;
  color: var(--ink-1);
  font-size: 14.5px;
  max-width: 74ch;
}

/* ---------- Panels ----------------------------------------------------------- */
.panel {
  border: 1px solid var(--rule-1);
  background: var(--paper-1);
  padding: 32px 30px;
}
.panel h3 { margin-top: 22px; }
.panel h3:first-child { margin-top: 0; }
.panel p { font-size: 15px; }

/* ---------- Application plates ----------------------------------------------- */
.plates {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--rule-1);
  border-left: 1px solid var(--rule-1);
}
.plate {
  border-right: 1px solid var(--rule-1);
  border-bottom: 1px solid var(--rule-1);
  padding: 24px 22px 26px;
  background: var(--paper-0);
  transition: background 0.18s var(--ease);
}
.plate:hover { background: var(--paper-1); }
.plate .plate-num {
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 700;
  font-style: italic;
  color: var(--brass);
  display: block;
  margin-bottom: 10px;
}
.plate h3 { margin: 0 0 8px; font-size: 17px; }
.plate p { margin: 0; font-size: 14px; color: var(--ink-2); }

/* ---------- Acquisition ledger ------------------------------------------------ */
.ledger {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 3px double var(--rule-1);
}
.ledger-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 14px;
  padding: 15px 10px 15px 0;
  border-bottom: 1px solid var(--rule-0);
}
.ledger-item:nth-child(odd) { padding-right: 26px; }
.ledger-item .lg-idx {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  color: var(--green);
  padding-top: 2px;
}
.ledger-item .lg-term { font-size: 15px; font-weight: 600; color: var(--ink-0); }
.ledger-item small { display: block; font-size: 12.5px; color: var(--ink-2); margin-top: 2px; font-weight: 400; }

/* ---------- Validation ledger table -------------------------------------------- */
.vtable { border-top: 3px double var(--rule-1); }
.vt-head, .vt-row {
  display: grid;
  grid-template-columns: 74px 172px 1fr;
  gap: 18px;
}
.vt-head {
  padding: 10px 0 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-3);
  border-bottom: 1px solid var(--rule-1);
}
.vt-row { padding: 14px 0 13px; border-bottom: 1px solid var(--rule-0); align-items: baseline; }
.vt-check {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--green);
}
.vt-area { font-size: 14px; font-weight: 600; color: var(--ink-0); }
.vt-detail { font-size: 13.5px; color: var(--ink-2); }

/* ---------- Principles ----------------------------------------------------------- */
.terms {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  border-top: 1px solid var(--rule-1);
  border-left: 1px solid var(--rule-1);
}
.term {
  border-right: 1px solid var(--rule-1);
  border-bottom: 1px solid var(--rule-1);
  padding: 18px 16px 20px;
}
.term h3 {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--green);
  margin: 0 0 8px;
}
.term p { font-size: 13px; color: var(--ink-2); margin: 0; }

/* ---------- FAQ --------------------------------------------------------------------- */
.faq-list { max-width: 780px; border-top: 3px double var(--rule-1); }
details.faq { border-bottom: 1px solid var(--rule-0); }
details.faq summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 18px;
  padding: 18px 2px;
  font-family: var(--font-serif);
  font-size: 17.5px;
  font-weight: 700;
  color: var(--ink-0);
}
details.faq summary::-webkit-details-marker { display: none; }
details.faq summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 19px;
  color: var(--brass);
  transition: transform 0.2s var(--ease);
  flex: none;
}
details.faq[open] summary::after { transform: rotate(45deg); }
details.faq[open] summary { color: var(--green); }
details.faq .faq-body { padding: 0 2px 20px; font-size: 14.5px; color: var(--ink-1); max-width: 68ch; }

/* ---------- Inverted band (final CTA) ---------------------------------------------- */
.band { background: var(--green-deep); color: var(--paper-0); }
.band-inner {
  padding-block: clamp(56px, 7vw, 96px);
  text-align: center;
  max-width: 760px;
}
.band .eyebrow { color: var(--brass); justify-content: center; }
.band .eyebrow::before { background: var(--brass); }
.band h2 { color: var(--paper-0); }
.band p { color: rgba(247, 243, 234, 0.82); font-size: 17px; margin-bottom: 32px; }
.band .cta-row { justify-content: center; }
.btn-band {
  background: var(--paper-0);
  color: var(--green-deep);
  border-color: var(--paper-0);
}
.btn-band:hover { background: var(--paper-1); border-color: var(--paper-1); color: var(--green-deep); text-decoration: none; }
.btn-text-band {
  min-height: auto;
  padding: 0;
  background: none;
  border: 0;
  color: var(--paper-0);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
}
.btn-text-band::after { content: "\2192"; margin-left: 8px; }
.btn-text-band:hover { color: var(--brass); text-decoration: none; }
.band .btn.is-pending {
  background: none;
  border: 1px dashed rgba(247, 243, 234, 0.5);
  color: rgba(247, 243, 234, 0.72);
  cursor: default;
}
.band .btn.is-pending:hover { background: none; border-color: rgba(247, 243, 234, 0.5); color: rgba(247, 243, 234, 0.72); }

/* ---------- Footer ------------------------------------------------------------------- */
.site-footer { padding: 30px 0 44px; font-size: 13.5px; color: var(--ink-2); }
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 15px;
  color: var(--ink-0);
}
.footer-links { display: flex; flex-wrap: wrap; gap: 22px; }
.footer-links a {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-2);
}
.footer-links a:hover { color: var(--green); }
.footer-legal { width: 100%; margin-top: 16px; color: var(--ink-3); font-size: 12.5px; }

/* ---------- 404 ------------------------------------------------------------------------ */
.error-wrap { min-height: 56vh; display: flex; align-items: center; }
.error-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 48px;
  align-items: center;
  width: 100%;
}
.error-code {
  font-family: var(--font-serif);
  font-size: clamp(90px, 13vw, 170px);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--green);
}
.error-code small {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--brass);
  margin-top: 14px;
  font-weight: 700;
}

/* ---------- Reveal ----------------------------------------------------------------------- */
/* Hidden pre-reveal applies ONLY when JS marks the document;
   without JavaScript every section is fully visible. */
.js [data-cve-reveal] {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.js [data-cve-reveal].is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  [data-cve-reveal] { opacity: 1 !important; transform: none !important; transition: none !important; }
  .sq::after { animation: none; opacity: 0; }
  .brackets path { animation: none; stroke-dashoffset: 0; opacity: 1; }
}

/* ---------- Responsive ---------------------------------------------------------------------- */
@media (max-width: 1220px) {
  .layout { grid-template-columns: 1fr; }
  .toc { display: none; }
  .content { max-width: 100%; }
  .hero-grid { grid-template-columns: 1fr; }
  .figure { max-width: 620px; }
}
@media (max-width: 900px) {
  .plates { grid-template-columns: repeat(2, 1fr); }
  .terms { grid-template-columns: repeat(2, 1fr); }
  .ledger { grid-template-columns: 1fr; }
  .ledger-item:nth-child(odd) { padding-right: 10px; }
  .prose-cols { columns: 1; }
  .vt-head { display: none; }
  .vt-row { grid-template-columns: 74px 1fr; }
  .vt-row .vt-detail { grid-column: 2; margin-top: 4px; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .container { width: calc(100% - 32px); }
  .plates { grid-template-columns: 1fr; }
  .terms { grid-template-columns: 1fr; }
  .spec-row { grid-template-columns: 1fr; gap: 2px; }
  .spec-v { margin-bottom: 8px; }
  .readout { grid-template-columns: 1fr; }
  .error-grid { grid-template-columns: 1fr; gap: 24px; }
  .site-nav { gap: 12px; font-size: 12px; }
  .nav-cta { padding: 5px 10px; font-size: 10px !important; }
  .spec-item { padding: 2px 8px; font-size: 10px; }
  .spec-item:first-child { padding-left: 0; }
  .index-item { grid-template-columns: 36px 1fr; }
  .hero-grid { gap: 28px; }
  .btn { min-height: 46px; padding: 0 22px; font-size: 14px; }
  .cta-row { gap: 14px; }
  h1 { font-size: clamp(26px, 8vw, 34px); }
  .brand-name { font-size: 18px; }
  .brand-name small { font-size: 8px; letter-spacing: 0.18em; }
  .brand-mark { width: 28px; height: 28px; }
}