/* ============================================================
   Siyu Interactive — siyuhudong.net
   Static stylesheet. No build step, no framework.
   ============================================================ */

/* ── Tokens ─────────────────────────────────────────────── */
:root {
  /* Ink (dark surfaces) */
  --ink-900: #0E1013;
  --ink-800: #15181C;
  --ink-700: #1C2126;

  /* Paper (light surfaces) */
  --paper-000: #FAF8F4;
  --paper-100: #F4F1EA;
  --paper-200: #E9E4DA;

  /* Signal */
  --signal: #E2600F;
  --signal-dark: #C4520A;
  --signal-wash: rgba(226, 96, 15, 0.10);

  /* Verified */
  --jade: #2F7A63;
  --jade-on-ink: #5FBE9E;
  --jade-wash: rgba(47, 122, 99, 0.10);

  /* Text on paper */
  --text-strong: #0E1013;
  --text: #24282D;
  --text-muted: #5F5950;
  --text-faint: #6B655B;

  /* Text on ink */
  --on-ink-strong: #FAF8F4;
  --on-ink: #D8D3CA;
  --on-ink-muted: #9A948A;
  --on-ink-faint: #6A655D;

  /* Lines */
  --line: rgba(14, 16, 19, 0.13);
  --line-strong: rgba(14, 16, 19, 0.26);
  --line-ink: rgba(250, 248, 244, 0.13);
  --line-ink-strong: rgba(250, 248, 244, 0.24);

  /* Type */
  --font-sans: "Archivo", "Helvetica Neue", Helvetica, Arial, "Noto Sans", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* Spacing (4px base, 1-4-9 rhythm) */
  --s1: 4px;
  --s2: 8px;
  --s3: 12px;
  --s4: 16px;
  --s5: 24px;
  --s6: 36px;
  --s7: 48px;
  --s8: 72px;
  --s9: 96px;
  --s10: 144px;

  /* Radius */
  --r-xs: 2px;
  --r-sm: 4px;
  --r-md: 8px;

  /* Layout */
  --shell-max: 1280px;
  --gutter: clamp(20px, 5vw, 48px);
  --section-y: clamp(72px, 9vw, 136px);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  margin: 0;
  background: var(--paper-100);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.6;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, p, dl, dd, figure { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; }

a {
  color: inherit;
  text-decoration-color: rgba(226, 96, 15, 0.45);
  text-underline-offset: 0.22em;
  text-decoration-thickness: 1px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ── Focus ──────────────────────────────────────────────── */
:focus { outline: none; }

:focus-visible {
  outline: 2px dashed var(--signal);
  outline-offset: 3px;
  border-radius: var(--r-xs);
}

.section-ink :focus-visible,
.site-footer :focus-visible,
.site-header :focus-visible {
  outline-color: var(--signal);
}

/* ── Utilities ──────────────────────────────────────────── */
.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--gutter);
  z-index: 200;
  padding: 12px 20px;
  background: var(--signal);
  color: var(--ink-900);
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: var(--r-sm);
  text-decoration: none;
  transition: top 0.2s ease;
}
.skip-link:focus { top: 12px; }

.cn {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}

/* ── Type scale ─────────────────────────────────────────── */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--signal);
  margin-bottom: var(--s5);
}

.hero-title {
  font-size: clamp(2.4rem, 1.5rem + 3.9vw, 4.75rem);
  line-height: 1.04;
  letter-spacing: -0.032em;
  font-weight: 700;
  color: var(--on-ink-strong);
  max-width: 17ch;
}

.section-title {
  font-size: clamp(1.85rem, 1.35rem + 2.1vw, 3rem);
  line-height: 1.1;
  letter-spacing: -0.026em;
  font-weight: 700;
  color: var(--text-strong);
  max-width: 22ch;
}

.section-ink .section-title { color: var(--on-ink-strong); }

.lead {
  font-size: clamp(1.05rem, 0.97rem + 0.36vw, 1.3rem);
  line-height: 1.55;
  color: var(--on-ink);
  max-width: 46ch;
}

.section-lead {
  font-size: clamp(1rem, 0.95rem + 0.3vw, 1.1875rem);
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 56ch;
  margin-top: var(--s5);
}

.section-ink .section-lead { color: var(--on-ink-muted); }

.sub-title {
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: var(--s5);
}

/* ── Buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s2);
  min-height: 50px;
  padding: 0 26px;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.22s ease, border-color 0.22s ease, color 0.22s ease, transform 0.12s ease;
}

.btn-sm { min-height: 40px; padding: 0 18px; font-size: 0.9375rem; }
.btn-block { width: 100%; }

.btn-primary {
  background: var(--signal);
  color: var(--ink-900);
}
.btn-primary:hover { background: #F0701E; }
.btn-primary:active { transform: translateY(1px); }

.btn-ghost {
  background: transparent;
  color: var(--on-ink-strong);
  border-color: var(--line-ink-strong);
}
.btn-ghost:hover {
  background: rgba(250, 248, 244, 0.06);
  border-color: var(--on-ink-muted);
}
.btn-ghost:active { transform: translateY(1px); }

/* ── Header ─────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(14, 16, 19, 0.88);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease;
}
.site-header.is-stuck { border-bottom-color: var(--line-ink); }

.header-inner {
  display: flex;
  align-items: center;
  gap: var(--s5);
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  margin-right: auto;
  padding: 6px 0;
}

.brand-mark {
  flex: none;
  width: 30px;
  height: 30px;
  color: var(--ink-900);
}
.brand-mark svg { width: 100%; height: 100%; }
.brand-mark rect { fill: var(--signal); }

.brand-text { display: flex; flex-direction: column; line-height: 1.15; }

.brand-name {
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -0.018em;
  color: var(--on-ink-strong);
}

.brand-sub {
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  color: var(--on-ink-faint);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

.site-nav {
  display: flex;
  align-items: center;
}

.site-nav ul {
  display: flex;
  align-items: center;
  gap: var(--s5);
}

.site-nav a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--on-ink-muted);
  text-decoration: none;
  transition: color 0.2s ease;
  padding: 6px 0;
}
.site-nav a:hover { color: var(--on-ink-strong); }

.nav-cta { margin-left: var(--s5); }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  background: none;
  border: 1px solid var(--line-ink-strong);
  border-radius: var(--r-sm);
  padding: 9px 13px;
  cursor: pointer;
  color: var(--on-ink);
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-toggle-bars {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}
.nav-toggle-bars span {
  display: block;
  height: 1.5px;
  background: currentColor;
  border-radius: 1px;
  transition: transform 0.24s ease, opacity 0.24s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:first-child {
  transform: translateY(2.75px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:last-child {
  transform: translateY(-2.75px) rotate(-45deg);
}

/* ── Hero ───────────────────────────────────────────────── */
.hero {
  position: relative;
  background: var(--ink-900);
  padding-top: clamp(72px, 10vw, 128px);
  padding-bottom: clamp(48px, 6vw, 80px);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(74% 58% at 82% 4%, rgba(226, 96, 15, 0.14), transparent 64%),
    radial-gradient(58% 48% at 4% 96%, rgba(47, 122, 99, 0.10), transparent 62%);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(to right, rgba(250, 248, 244, 0.05) 1px, transparent 1px);
  background-size: clamp(72px, 8.5vw, 118px) 100%;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.85), transparent 78%);
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.85), transparent 78%);
}

.hero .shell { position: relative; z-index: 1; }

.hero-lower {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--s6);
  margin-top: var(--s6);
  padding-top: var(--s6);
  border-top: 1px solid var(--line-ink);
  max-width: 62ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s3);
}

/* ── Live operations board (proof object) ───────────────── */
.board {
  margin-top: clamp(40px, 6vw, 72px);
  border: 1px solid var(--line-ink);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--ink-900);
}

.board-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s3);
  padding: 15px var(--s5);
  border-bottom: 1px solid var(--line-ink);
  background: var(--ink-800);
}

.board-title {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--on-ink);
}

.board-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--on-ink-faint);
}

.live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--signal);
  animation: pulse 2.2s ease-out infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(226, 96, 15, 0.55); }
  70% { box-shadow: 0 0 0 7px rgba(226, 96, 15, 0); }
  100% { box-shadow: 0 0 0 0 rgba(226, 96, 15, 0); }
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-ink);
}

.board-cell {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 15px 16px 17px;
  background: var(--ink-800);
  min-height: 106px;
}

.cell-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s2);
}

.cell-code {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: var(--on-ink-faint);
}

.cell-dot {
  flex: none;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--on-ink-faint);
  opacity: 0.55;
}

.board-cell.is-open .cell-dot,
.cell-dot.is-on {
  background: var(--jade-on-ink);
  opacity: 1;
}

.board-cell.is-open { background: var(--ink-700); }

.cell-city {
  font-size: 0.8125rem;
  color: var(--on-ink-muted);
  line-height: 1.3;
}

.cell-time {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 1.375rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  color: var(--on-ink-strong);
  line-height: 1.1;
}

.board-cell.is-open .cell-time { color: #FFFFFF; }

.board-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s5);
  padding: 13px var(--s5);
  border-top: 1px solid var(--line-ink);
  background: var(--ink-800);
  font-size: 0.75rem;
  color: var(--on-ink-faint);
}

.legend { display: inline-flex; align-items: center; gap: 7px; }
.board-note { margin-left: auto; }

/* ── Sections ───────────────────────────────────────────── */
.section {
  padding-block: var(--section-y);
  background: var(--paper-100);
  color: var(--text);
}

.section-alt { background: var(--paper-000); }

.section-ink {
  background: var(--ink-900);
  color: var(--on-ink);
}

.section-head { margin-bottom: clamp(44px, 5vw, 72px); }

/* ── Regions ────────────────────────────────────────────── */
.regions {
  border-top: 1px solid var(--line-strong);
}

.region {
  display: grid;
  grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
  gap: var(--s5);
  padding-block: var(--s6);
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.region-name {
  font-size: 1.375rem;
  font-weight: 600;
  letter-spacing: -0.018em;
  color: var(--text-strong);
}

.region-body { display: flex; flex-direction: column; gap: var(--s4); }

.region-markets {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s2) var(--s6);
  font-size: 1.0625rem;
  color: var(--text);
}

.region-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.meta-key {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-right: 9px;
}

.figures {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s5) clamp(32px, 6vw, 88px);
  margin-top: var(--s7);
  padding-top: var(--s5);
  border-top: 1px solid var(--line-strong);
}

.figure {
  font-size: 0.875rem;
  color: var(--text-muted);
  letter-spacing: 0.01em;
}

.figure b {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--text-strong);
  margin-bottom: 2px;
}

/* ── Pipeline stages ────────────────────────────────────── */
.stages {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid var(--line-strong);
}

.stage {
  position: relative;
  padding: var(--s6) var(--s6) var(--s2) 0;
}

.stage + .stage {
  padding-left: var(--s6);
  border-left: 1px solid var(--line);
}

.stage::before {
  content: "";
  position: absolute;
  top: -3.5px;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--signal);
}
.stage + .stage::before { left: var(--s6); }

.stage-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--signal);
  margin-bottom: var(--s6);
}

.stage-title {
  font-size: 1.3125rem;
  font-weight: 600;
  letter-spacing: -0.018em;
  color: var(--text-strong);
  margin-bottom: var(--s3);
}

.stage-body {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 34ch;
}

/* ── Operations ─────────────────────────────────────────── */
.ops-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-ink);
  border: 1px solid var(--line-ink);
  border-radius: var(--r-md);
  overflow: hidden;
}

.op {
  padding: clamp(24px, 3vw, 40px);
  background: var(--ink-900);
}

.op-title {
  font-size: 1.1875rem;
  font-weight: 600;
  letter-spacing: -0.016em;
  color: var(--on-ink-strong);
  margin-bottom: var(--s3);
  padding-left: var(--s4);
  border-left: 2px solid var(--signal);
  line-height: 1.35;
}

.op-body {
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--on-ink-muted);
  max-width: 46ch;
}

/* ── Lead quality ───────────────────────────────────────── */
.quality {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(36px, 5vw, 88px);
  align-items: start;
}

.check-list { display: flex; flex-direction: column; }

.check-list li {
  padding: var(--s4) 0 var(--s4) var(--s5);
  border-bottom: 1px solid var(--line);
  font-size: 0.9375rem;
  line-height: 1.62;
  color: var(--text-muted);
  position: relative;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 23px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--jade);
}

.check-list b {
  display: block;
  color: var(--text-strong);
  font-weight: 600;
  margin-bottom: 3px;
}

.tier-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.tier-table th,
.tier-table td {
  text-align: left;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.tier-table thead th {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding-bottom: 11px;
  border-bottom-color: var(--line-strong);
}

.tier-table tbody th {
  width: 106px;
  font-weight: 600;
  padding-right: var(--s4);
}

.tier-table td { color: var(--text-muted); }

.tier {
  display: inline-block;
  padding: 3px 10px;
  border-radius: var(--r-xs);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.tier-high { background: var(--jade-wash); color: var(--jade); }
.tier-mid { background: var(--signal-wash); color: var(--signal-dark); }
.tier-low { background: rgba(14, 16, 19, 0.06); color: var(--text-muted); }
.tier-out {
  background: transparent;
  color: var(--text-faint);
  border: 1px solid var(--line-strong);
  padding: 2px 9px;
}

/* ── Contact ────────────────────────────────────────────── */
.contact-shell {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(40px, 6vw, 96px);
  align-items: start;
}

.contact-panel {
  border: 1px solid var(--line-ink);
  border-radius: var(--r-md);
  padding: clamp(24px, 3vw, 36px);
  background: var(--ink-800);
}

.contact-list { display: flex; flex-direction: column; }

.contact-row {
  display: grid;
  grid-template-columns: 104px minmax(0, 1fr);
  gap: var(--s4);
  padding: var(--s4) 0;
  border-bottom: 1px solid var(--line-ink);
}

.contact-row:first-child { padding-top: 0; }

.contact-row dt {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--on-ink-faint);
  padding-top: 4px;
}

.contact-row dd {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--on-ink);
}

.contact-row a {
  color: var(--on-ink-strong);
  font-weight: 500;
}
.contact-row a:hover { color: var(--signal); }

.contact-panel .btn { margin-top: var(--s5); }

/* ── Footer ─────────────────────────────────────────────── */
.site-footer {
  background: var(--ink-900);
  border-top: 1px solid var(--line-ink);
  padding-block: var(--s8) var(--s6);
  color: var(--on-ink-muted);
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s7);
  justify-content: space-between;
  padding-bottom: var(--s7);
  border-bottom: 1px solid var(--line-ink);
}

.footer-brand {
  display: flex;
  align-items: flex-start;
  gap: 13px;
}

.footer-name {
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -0.016em;
  color: var(--on-ink-strong);
  margin-bottom: 5px;
}

.footer-name .cn {
  font-weight: 400;
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  color: var(--on-ink-faint);
  margin-left: 8px;
}

.footer-legal {
  font-size: 0.8125rem;
  color: var(--on-ink-faint);
  max-width: 44ch;
  line-height: 1.5;
}

.footer-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s3) var(--s5);
  max-width: 40ch;
}

.footer-nav a {
  font-size: 0.9375rem;
  color: var(--on-ink-muted);
  text-decoration: none;
}
.footer-nav a:hover { color: var(--on-ink-strong); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s3) var(--s5);
  justify-content: space-between;
  padding-top: var(--s5);
  font-size: 0.8125rem;
  color: var(--on-ink-faint);
}

.footer-note { color: var(--on-ink-faint); }

/* ── Reveal ─────────────────────────────────────────────────
   Fail-open: the hidden state only applies while <html> carries
   `anim`, which is added by an inline head script only when
   IntersectionObserver works and motion is allowed. If anything
   goes wrong, the class is absent and all content is visible.  */
.anim [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
}

.anim [data-reveal].is-in {
  opacity: 1;
  transform: none;
  transition:
    opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ── Legal pages ────────────────────────────────────────── */
.page-hero {
  background: var(--ink-900);
  padding-top: clamp(56px, 7vw, 88px);
  padding-bottom: clamp(40px, 5vw, 64px);
  border-bottom: 1px solid var(--line-ink);
}

.page-hero .eyebrow { margin-bottom: var(--s4); }

.page-title {
  font-size: clamp(2rem, 1.5rem + 2.2vw, 3.125rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 700;
  color: var(--on-ink-strong);
}

.page-sub {
  margin-top: var(--s4);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.03em;
  color: var(--on-ink-faint);
}

.prose {
  max-width: 72ch;
  padding-block: clamp(48px, 6vw, 84px) var(--section-y);
}

.prose h2 {
  font-size: 1.375rem;
  font-weight: 600;
  letter-spacing: -0.018em;
  color: var(--text-strong);
  margin-top: var(--s6);
  margin-bottom: var(--s4);
  padding-top: var(--s6);
  border-top: 1px solid var(--line);
}

.prose h2:first-of-type { margin-top: 0; padding-top: 0; border-top: 0; }

.prose h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text-strong);
  margin-top: var(--s6);
  margin-bottom: var(--s3);
}

.prose p,
.prose li {
  font-size: 1rem;
  line-height: 1.72;
  color: var(--text-muted);
  margin-bottom: var(--s4);
}

.prose ul {
  list-style: none;
  margin-bottom: var(--s4);
}

.prose ul li {
  position: relative;
  padding-left: var(--s5);
  margin-bottom: var(--s2);
}

.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--signal);
}

.prose a {
  color: var(--signal-dark);
  font-weight: 500;
}

.prose strong { color: var(--text-strong); font-weight: 600; }

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
  margin-bottom: var(--s5);
}

.prose th,
.prose td {
  text-align: left;
  padding: 13px 16px 13px 0;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.prose th {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  border-bottom-color: var(--line-strong);
}

.prose td { color: var(--text-muted); }

/* ── Responsive ─────────────────────────────────────────── */

/* Board collapses first: 5 → 4 columns */
@media (max-width: 1180px) {
  .board-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* Nav collapses to a panel */
@media (max-width: 1000px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: fixed;
    inset: 68px 0 auto;
    display: grid;
    gap: 0;
    background: var(--ink-900);
    border-bottom: 1px solid var(--line-ink);
    padding: var(--s4) var(--gutter) var(--s6);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s;
    max-height: calc(100dvh - 68px);
    overflow-y: auto;
  }

  .site-nav.is-open {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .site-nav ul {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav a {
    display: block;
    padding: 15px 0;
    font-size: 1.0625rem;
    border-bottom: 1px solid var(--line-ink);
  }

  .nav-cta {
    margin: var(--s5) 0 0;
    width: 100%;
  }

  .quality { grid-template-columns: minmax(0, 1fr); }
  .contact-shell { grid-template-columns: minmax(0, 1fr); }
  .stages { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .stage:nth-child(odd) { padding-left: 0; border-left: 0; }
  .stage:nth-child(odd)::before { left: 0; }
  .stage:nth-child(n + 3) { border-top: 1px solid var(--line); padding-top: var(--s6); }
}

@media (max-width: 860px) {
  .board-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .ops-grid { grid-template-columns: minmax(0, 1fr); }
  .region { grid-template-columns: minmax(0, 1fr); gap: var(--s3); }
}

@media (max-width: 640px) {
  body { font-size: 1rem; }

  .board-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .board-cell { min-height: 92px; padding: 13px 13px 15px; }
  .cell-time { font-size: 1.1875rem; }

  .board-head,
  .board-foot { padding-inline: var(--s4); }

  .board-note { margin-left: 0; flex-basis: 100%; }

  .stages { grid-template-columns: minmax(0, 1fr); }
  .stage,
  .stage + .stage { padding: var(--s5) 0 0; border-left: 0; }
  .stage::before,
  .stage + .stage::before { left: 0; }
  .stage + .stage { border-top: 1px solid var(--line); margin-top: var(--s5); }
  .stage-index { margin-bottom: var(--s4); }

  .hero-actions .btn { width: 100%; }

  .figures { gap: var(--s4) var(--s6); }

  .contact-row { grid-template-columns: minmax(0, 1fr); gap: 5px; }
  .footer-top { flex-direction: column; gap: var(--s6); }
}

/* iOS: keep form/input text at 16px to avoid focus zoom */
@media (max-width: 640px) {
  input, select, textarea { font-size: 1rem; }
}