/* ============================================================
   engineering.css - Nimbus ∆P engineering expression layer
   Phase 2, 2026-06-03. Restrained "Cool Dark" accents,
   Apple-style data presentation, and the engineering aesthetic
   (registration marks + technical annotations).
   Depends on tokens.css. Opt-in via classes - adds nothing
   unless the markup uses it.
   ============================================================ */

/* ---- Dark expression band (one restrained moment per page) ---- */
.eng-band {
  position: relative;
  background: var(--expr-bg);
  color: var(--expr-text);
  overflow: hidden;
}
.eng-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--expr-glow);
  pointer-events: none;
}
.eng-band > .container { position: relative; }
.eng-band .section-label { color: var(--bronze); }
.eng-band .section-heading { color: var(--expr-text); }
.eng-band .section-sub { color: var(--expr-text-dim); }

/* ---- Data strip - big numbers (number + unit + label) ---- */
.data-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-xl);
}
.data-card {
  padding: var(--space-xl) var(--space-lg);
  background: var(--expr-surface);
  border: 1px solid var(--expr-border);
  border-radius: var(--r-md);
  transition: transform var(--dur-hover) var(--ease-out-smooth),
              border-color var(--dur-hover) var(--ease-out-smooth);
}
.data-card:hover { transform: translateY(-3px); border-color: var(--bronze); }
.data-num {
  font-size: clamp(38px, 4.4vw, 60px);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 0.95;
  color: var(--expr-text);
  font-variant-numeric: tabular-nums;
}
.data-num .unit {
  font-size: 0.32em;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bronze);
  margin-left: 6px;
}
.data-label { margin: 14px 0 0; font-size: 13px; color: var(--expr-text-dim); letter-spacing: 0.02em; }
.data-code {
  margin: 5px 0 0;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--expr-text-dim);
  opacity: 0.62;
}

/* ---- Spec table, dark variant (inside .eng-band) ---- */
.eng-band .spec-table { background: transparent; border-color: var(--expr-border); }
.eng-band .spec-table tr { border-color: var(--expr-border); }
.eng-band .spec-table td:first-child { color: var(--expr-text-dim); }
.eng-band .spec-table td:last-child { color: var(--expr-text); }

/* ---- Registration-mark frame (engineering aesthetic) ---- */
.eng-frame { position: relative; }
.eng-reg {
  position: absolute;
  width: 16px;
  height: 16px;
  pointer-events: none;
  opacity: 0.45;
  z-index: 2;
  transition: opacity var(--dur-hover) var(--ease-out-smooth);
}
.eng-reg::before, .eng-reg::after { content: ""; position: absolute; background: var(--bronze); }
.eng-reg::before { top: 50%; left: 0; width: 100%; height: 1px; transform: translateY(-50%); }
.eng-reg::after { left: 50%; top: 0; width: 1px; height: 100%; transform: translateX(-50%); }
.eng-reg.tl { top: 12px; left: 12px; }
.eng-reg.tr { top: 12px; right: 12px; }
.eng-reg.bl { bottom: 12px; left: 12px; }
.eng-reg.br { bottom: 12px; right: 12px; }
.eng-frame:hover .eng-reg { opacity: 0.8; }

/* ---- Technical annotation caption ---- */
.eng-caption {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 2px 10px;
}

/* ---- Responsive ---- */
@media (max-width: 900px) { .data-strip { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) {
  .data-strip { gap: var(--space-sm); }
  .data-card { padding: var(--space-lg) var(--space-md); }
  .data-num { font-size: clamp(26px, 7.6vw, 36px); white-space: nowrap; }
  .data-num .unit { white-space: nowrap; font-size: 0.34em; margin-left: 4px; }
  .data-label { font-size: 12px; }
  .eng-caption { font-size: 9px; letter-spacing: 0.12em; }
}
@media (max-width: 360px) { .data-strip { grid-template-columns: 1fr; } }

/* ---- Respect reduced motion ---- */
@media (prefers-reduced-motion: reduce) {
  .data-card, .eng-reg { transition: none; }
  .data-card:hover { transform: none; }
}