/* ─────────────────────────────────────────────
   AMPACITIES · cable-sizing variants (wave II)
   shared tokens, grain, topbar, theme toggle
   ───────────────────────────────────────────── */

:root,
[data-theme="night"] {
  --bg:           #0a0e14;
  --bg-deep:      #10151e;
  --bg-card:      #131923;
  --bg-deepest:   #060910;
  --ink:          #e8e2d0;
  --ink-soft:     #c8c0aa;
  --ink-mute:     #7a7363;
  --accent:       #c8895e;
  --accent-bright:#e6a672;
  --voltage:      #6f9aff;
  --rule:         #e8e2d022;
  --rule-strong:  #e8e2d044;
  --grain:        0.04;
}

[data-theme="day"] {
  --bg:           #ece4d2;
  --bg-deep:      #e2d9c4;
  --bg-card:      #e7dec7;
  --bg-deepest:   #d6caaf;
  --ink:          #14171a;
  --ink-soft:     #2c3036;
  --ink-mute:     #6a6055;
  --accent:       #a8623c;
  --accent-bright:#c47b4f;
  --voltage:      #1b3a8c;
  --rule:         #14171a25;
  --rule-strong:  #14171a48;
  --grain:        0.08;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  background: var(--bg);
  color: var(--ink);
  font-family: 'Manrope', system-ui, -apple-system, sans-serif;
  font-size: 14.5px;
  line-height: 1.55;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "ss01", "kern";
  transition: background 0.5s ease, color 0.5s ease;
}

a { color: inherit; text-decoration: none; }

::selection { background: var(--accent); color: var(--bg); }

/* film grain (same as landing) */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 200;
  opacity: var(--grain);
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 0  0 0 0 0 0  0 0 0 0 0  0 0 0 0.5 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* topbar — compact, no megamenu */
.topbar {
  position: sticky;
  top: 0;
  z-index: 80;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 40px;
  border-bottom: 1px solid var(--rule);
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.topbar .brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
}
.topbar .brand .mark {
  font-family: 'Antonio', sans-serif;
  font-weight: 500;
  font-size: 17px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink);
}
.topbar .brand .mark em {
  font-family: 'Instrument Serif', serif;
  font-style: italic;
  color: var(--accent);
  font-size: 17px;
  letter-spacing: 0;
}
.topbar .brand .sub {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.topbar .right {
  display: inline-flex;
  align-items: center;
  gap: 14px;
}
.topbar a.back,
.topbar button.theme {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--ink-mute);
  background: transparent;
  border: 1px solid var(--rule);
  padding: 7px 12px;
  cursor: pointer;
  transition: color 0.4s, border-color 0.4s;
}
.topbar a.back:hover,
.topbar button.theme:hover {
  color: var(--accent);
  border-color: var(--accent);
}
.topbar button.theme span.dot {
  display: inline-block;
  width: 6px; height: 6px;
  background: var(--accent);
  border-radius: 50%;
  margin-right: 6px;
  vertical-align: middle;
}

/* footer strip (one-line) */
.foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 40px;
  border-top: 1px solid var(--rule);
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--ink-mute);
  background: var(--bg-deepest);
}
.foot em {
  font-family: 'Instrument Serif', serif;
  font-style: italic;
  color: var(--accent);
  letter-spacing: 0;
  text-transform: none;
  font-size: 13px;
}
.foot .exports {
  display: inline-flex;
  gap: 14px;
}
.foot .exports a {
  border-bottom: 1px solid transparent;
  transition: color 0.4s, border-color 0.4s;
  padding-bottom: 1px;
}
.foot .exports a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* shared type primitives */
.eyebrow {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.it {
  font-family: 'Instrument Serif', serif;
  font-style: italic;
  color: var(--accent);
  letter-spacing: -0.005em;
}
.mono { font-family: 'IBM Plex Mono', monospace; }

/* focus rings (accessibility) */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* draft / issued / superseded stamps */
.stamp {
  display: inline-block;
  border: 1.5px solid var(--accent);
  color: var(--accent);
  padding: 3px 9px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 9.5px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  transform: rotate(-2deg);
  opacity: 0.85;
}
.stamp[data-status="issued"] { border-color: var(--voltage); color: var(--voltage); }
.stamp[data-status="superseded"] { border-color: var(--ink-mute); color: var(--ink-mute); }

/* warning callout (when calc combo isn't in our table) */
.warn {
  border-left: 2px solid var(--accent);
  padding: 8px 14px;
  background: color-mix(in srgb, var(--accent) 8%, transparent);
  font-family: 'Instrument Serif', serif;
  font-style: italic;
  color: var(--ink-soft);
  font-size: 14px;
}