:root {
  --bg: #f7f7f5;
  --panel: #ffffff;
  --text: #1d1f21;
  --muted: #666b70;
  --border: #d8dadc;
  --accent: #2a78c2;
  --readonly: #eef1f4;
  --grid: #e6e8ea;
  --error-bg: #fdecea;
  --error: #9b2c1f;
  --opt: #7a4fc0;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17191b;
    --panel: #212427;
    --text: #e4e6e8;
    --muted: #9aa0a6;
    --border: #3a3e42;
    --accent: #6aa9e6;
    --readonly: #2a2e32;
    --grid: #30343a;
    --error-bg: #3b1f1c;
    --error: #f2a196;
    --opt: #b48ef0;
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 0 16px 40px;
  background: var(--bg);
  color: var(--text);
  font: 14px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
header { max-width: 1400px; margin: 0 auto; padding: 18px 0 6px; }
h1 { font-size: 1.5em; margin: 0; }
header p { margin: 4px 0 0; color: var(--muted); }
h2 { font-size: 1.1em; margin: 26px 0 8px; display: flex; align-items: center; gap: 10px; }

main {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}
@media (max-width: 820px) { main { grid-template-columns: minmax(0, 1fr); } }

/* The sidebar scrolls independently of the results. */
form {
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 0 6px 12px 0;
}
@media (max-width: 820px) { form { position: static; max-height: none; overflow: visible; } }
fieldset {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin: 12px 0 0;
  padding: 8px 12px 10px;
}
legend { font-weight: 600; padding: 0 4px; }
form label { display: block; margin: 6px 0; font-size: 0.93em; }
.unit { color: var(--muted); font-size: 0.9em; }
input[type=number], select, output {
  display: block;
  width: 100%;
  margin-top: 2px;
  padding: 4px 6px;
  font: inherit;
  color: inherit;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 4px;
}
input[readonly] { background: var(--readonly); color: var(--muted); }
.pair { display: flex; align-items: center; gap: 6px; }
.pair input { flex: 1; min-width: 0; }
.mode label, label.check { display: flex; gap: 6px; align-items: center; }

.outputs {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 8px 14px;
  margin-top: 12px;
}
.outputs label { font-size: 0.88em; color: var(--muted); }
.outputs output { background: var(--readonly); color: var(--text); font-size: 1.07em; min-height: 1.9em; font-variant-numeric: tabular-nums; }

.empty { color: var(--muted); text-align: center; padding: 60px 12px; margin: 0; }
.error {
  margin-top: 12px;
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--error-bg);
  color: var(--error);
}

.plots {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
  gap: 12px;
}
@media (max-width: 500px) { .plots { grid-template-columns: minmax(0, 1fr); } }
figure {
  margin: 0;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
}
figcaption { font-weight: 600; font-size: 0.93em; margin-bottom: 4px; }
.plotbox { position: relative; width: 100%; }
svg.plot { display: block; max-width: 100%; height: auto; font-size: 11px; }
svg.plot text { fill: var(--muted); }
svg.plot .label { fill: var(--text); font-size: 12px; }
svg.plot .legend { fill: var(--text); }
svg.plot .grid { stroke: var(--grid); }
svg.plot .frame { fill: none; stroke: var(--border); }
svg.plot .line { fill: none; stroke-width: 1.8; }
svg.plot .vline { stroke: var(--muted); stroke-dasharray: 4 3; }
svg.plot .vlabel { fill: var(--muted); font-size: 10px; }
svg.plot .vline.opt { stroke: var(--opt); stroke-dasharray: none; stroke-width: 1.5; }
svg.plot .vlabel.opt { fill: var(--opt); font-weight: 600; }
svg.plot .vline.opt2 { stroke-dasharray: 6 4; }
tr.opt2 td { font-weight: 600; color: var(--opt); font-style: italic; }
#reelBox h2 { margin-top: 18px; }
.optnote { margin: -2px 0 8px; color: var(--muted); }
.optnote b { color: var(--opt); }
svg.plot .cursor { stroke: var(--muted); stroke-width: 1; }
.tip {
  position: absolute;
  pointer-events: none;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 8px;
  font-size: 12px;
  white-space: nowrap;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  z-index: 2;
}

.tablewrap {
  overflow-x: auto;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
}
table { border-collapse: collapse; width: 100%; font-variant-numeric: tabular-nums; font-size: 0.92em; }
th, td { padding: 4px 10px; text-align: right; white-space: nowrap; border-bottom: 1px solid var(--grid); }
th { position: sticky; top: 0; background: var(--panel); font-weight: 600; vertical-align: bottom; }
tr.geo td { font-weight: 600; }
tr.opt td { font-weight: 600; color: var(--opt); }
td.index { color: var(--muted); }
button.csv {
  font: inherit;
  font-size: 0.8em;
  font-weight: normal;
  padding: 2px 8px;
  color: var(--accent);
  background: none;
  border: 1px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
}
.tabs { margin-top: 26px; }
.tabbar { display: flex; flex-wrap: wrap; gap: 4px; border-bottom: 1px solid var(--border); }
.tabbar button {
  font: inherit;
  font-weight: 600;
  color: var(--muted);
  background: none;
  border: 1px solid transparent;
  border-bottom: none;
  border-radius: 6px 6px 0 0;
  padding: 6px 12px;
  margin-bottom: -1px;
  cursor: pointer;
}
.tabbar button[aria-selected="true"] { color: var(--text); background: var(--panel); border-color: var(--border); }
.tabpanel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 8px 8px;
  padding: 4px 16px 12px;
}
.notes { color: var(--muted); }
.notes li { margin: 4px 0; }
#specText { white-space: pre-wrap; font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace; margin: 10px 0; }