:root {
  --bg: #0d1117;
  --panel: #161b22;
  --panel2: #1c2430;
  --fg: #e6edf3;
  --muted: #8b949e;
  --accent: #3fb6d0;
  --accent2: #e69f00;
  --border: #30363d;
  --ok: #2ea043;
  --warn: #d29922;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.45;
}
header { padding: 18px 24px 8px; border-bottom: 1px solid var(--border); }
h1 { font-size: 20px; margin: 0 0 4px; }
.sub { margin: 0; color: var(--muted); font-size: 13px; max-width: 1100px; }
code { background: #21262d; padding: 1px 4px; border-radius: 4px; font-size: 12px; }

/* ---- site header + nav ---- */
.site-header { display: flex; flex-wrap: wrap; align-items: flex-start; justify-content: space-between; gap: 12px; }
.brand { display: flex; align-items: flex-start; gap: 12px; }
.brand .logo {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 10px; flex: none;
  background: #12333d; color: var(--accent); border: 1px solid var(--accent);
  font-size: 22px; font-weight: 700;
}
.site-nav { display: flex; flex-wrap: wrap; gap: 4px; }
.site-nav .nav-link {
  font-size: 13px; color: var(--muted); text-decoration: none;
  padding: 6px 11px; border-radius: 6px; border: 1px solid transparent;
}
.site-nav .nav-link:hover { color: var(--fg); border-color: var(--border); background: var(--panel2); }
.site-nav .nav-link.ext::after { content: " \2197"; }

/* ---- tabs ---- */
.tabs { display: flex; gap: 6px; padding: 12px 24px 0; flex-wrap: wrap; }
.tab {
  font-size: 13px; cursor: pointer; padding: 8px 14px; border-radius: 8px 8px 0 0;
  background: var(--panel); color: var(--muted); border: 1px solid var(--border); border-bottom: none;
}
.tab:hover { color: var(--fg); }
.tab.active { color: var(--accent); background: var(--panel2); border-color: var(--accent); }
.tabpanel { display: none; }
.tabpanel.active { display: block; }

.status {
  margin: 12px 24px 0;
  padding: 8px 12px;
  background: var(--panel2);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  color: var(--muted);
}
.status.ok { color: var(--ok); border-color: var(--ok); }
.status.err { color: #f85149; border-color: #f85149; }

.engine-badge {
  display: inline-block;
  margin: 8px 24px 0;
  padding: 5px 12px;
  border-radius: 14px;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  background: var(--panel2);
  border: 1px solid var(--accent);
  color: var(--accent);
}
.engine-badge.warn { border-color: var(--warn); color: var(--warn); }
.engine-badge.err { border-color: #f85149; color: #f85149; }

button.primary {
  width: 100%; padding: 9px 12px; border-radius: 6px; cursor: pointer;
  background: #12333d; color: var(--accent); border: 1px solid var(--accent);
  font-size: 13px;
}
button.primary:hover { background: #17414e; }
button.primary:disabled { opacity: .55; cursor: default; }

main {
  padding: 14px 24px 40px;
}
.split {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 18px;
}
.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
}
.controls { align-self: start; position: sticky; top: 12px; }
h2 { font-size: 14px; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin: 16px 0 10px; }
h2:first-child { margin-top: 0; }

.field { display: block; margin-bottom: 14px; font-size: 13px; }
.field select {
  width: 100%; margin-top: 5px; padding: 7px; border-radius: 6px;
  background: var(--panel2); color: var(--fg); border: 1px solid var(--border); font-size: 13px;
}
.slider-row { margin-bottom: 14px; }
.slider-head { display: flex; justify-content: space-between; font-size: 13px; margin-bottom: 2px; }
.slider-head output { color: var(--accent); font-variant-numeric: tabular-nums; }
input[type=range] { width: 100%; accent-color: var(--accent); }

.derived { display: grid; grid-template-columns: 1fr; gap: 3px; margin: 10px 0 6px; font-size: 13px; }
.derived div { display: flex; justify-content: space-between; }
.derived output { color: var(--fg); font-variant-numeric: tabular-nums; }

.ood-flags { display: flex; flex-wrap: wrap; gap: 5px; margin: 6px 0 4px; min-height: 20px; }
.badge { font-size: 11px; padding: 2px 7px; border-radius: 10px; border: 1px solid var(--border); color: var(--muted); }
.badge.id { color: var(--ok); border-color: var(--ok); }
.badge.ood { color: var(--warn); border-color: var(--warn); }

.hint { font-size: 12px; color: var(--muted); margin: 0 0 8px; }
.presets { display: flex; flex-direction: column; gap: 6px; margin-bottom: 12px; }
.presets button {
  text-align: left; padding: 7px 10px; border-radius: 6px; cursor: pointer;
  background: var(--panel2); color: var(--fg); border: 1px solid var(--border); font-size: 12.5px;
}
.presets button:hover { border-color: var(--accent); }
.presets button.active { border-color: var(--accent); background: #12333d; }
.toggle { display: flex; align-items: center; gap: 8px; font-size: 12.5px; color: var(--muted); cursor: pointer; }

.readouts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 16px; }
.big { background: var(--panel2); border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; }
.big span { display: block; font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: .03em; }
.big output { font-size: 22px; font-variant-numeric: tabular-nums; color: var(--accent); }
#out_refI { color: var(--accent2); font-size: 18px; }

.maps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
figure { margin: 0; }
figcaption { font-size: 12px; color: var(--muted); margin-bottom: 6px; }
canvas { width: 100%; height: auto; background: #06090d; border: 1px solid var(--border); border-radius: 6px; display: block; }
.wide { margin-top: 18px; }
.axis-note, .footer-note { font-size: 11.5px; color: var(--muted); margin: 10px 0 0; }

@media (max-width: 980px) {
  .split { grid-template-columns: 1fr; }
  .controls { position: static; }
  .maps { grid-template-columns: repeat(2, 1fr); }
}