:root {
  color-scheme: light;
  --bg: #f4f3ef;
  --surface: #fcfcfb;
  --border: #e2e0d8;
  --text: #0b0b0b;
  --text-2: #52514e;
  --muted: #8a8880;
  --grid: #ebe9e2;
  --accent: #2a78d6;
  --accent-ink: #ffffff;
  --series-1: #2a78d6; /* measured */
  --series-2: #eb6834; /* fit */
  --error: #c62828;
  --code-bg: #f7f6f2;
  --mono: ui-monospace, 'Cascadia Code', 'SF Mono', Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #111110;
    --surface: #1a1a19;
    --border: #2e2e2c;
    --text: #ffffff;
    --text-2: #c3c2b7;
    --muted: #8f8e86;
    --grid: #262624;
    --accent: #3987e5;
    --series-1: #3987e5;
    --series-2: #d95926;
    --error: #ef6b6b;
    --code-bg: #151514;
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #111110;
  --surface: #1a1a19;
  --border: #2e2e2c;
  --text: #ffffff;
  --text-2: #c3c2b7;
  --muted: #8f8e86;
  --grid: #262624;
  --accent: #3987e5;
  --series-1: #3987e5;
  --series-2: #d95926;
  --error: #ef6b6b;
  --code-bg: #151514;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, 'Segoe UI', sans-serif;
}

header, main, footer { max-width: 1200px; margin: 0 auto; padding: 0 16px; }
header { padding-top: 32px; padding-bottom: 8px; }
h1 { margin: 0; font-size: 28px; letter-spacing: -0.02em; }
header p { margin: 4px 0 0; color: var(--text-2); max-width: 60ch; }
h2 { font-size: 17px; margin: 0 0 8px; }

main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
  gap: 16px;
  padding-top: 16px;
  padding-bottom: 16px;
}
.explainer { grid-column: 1 / -1; }
@media (max-width: 860px) {
  main { grid-template-columns: minmax(0, 1fr); }
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  min-width: 0;
}

.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.editor { display: flex; flex-direction: column; gap: 12px; }
.editor > .row:first-child select { flex: 1; min-width: 0; }
label { color: var(--text-2); font-size: 13px; }
.controls label { display: flex; flex-direction: column; gap: 4px; flex: 1; min-width: 180px; }

select, input, button, textarea {
  font: inherit;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 10px;
}
select:focus-visible, input:focus-visible, button:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
textarea {
  font: 13.5px/1.55 var(--mono);
  background: var(--code-bg);
  min-height: 320px;
  resize: vertical;
  tab-size: 2;
  font-variant-ligatures: none;
  white-space: pre;
  overflow: auto;
}
button { cursor: pointer; }
button:hover { border-color: var(--muted); }
button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  font-weight: 600;
  min-width: 80px;
}
button.primary:hover { filter: brightness(1.08); }

.status { color: var(--text-2); font-size: 13px; flex: 1 1 200px; }
.status.error { color: var(--error); }

.eyebrow { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; }
.verdict-row { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.verdict { font: 700 44px/1.1 var(--mono); letter-spacing: -0.02em; margin-top: 4px; }
.verdict-sub { color: var(--text-2); font-size: 13px; margin-top: 4px; }
.ranked-wrap { min-width: 180px; }
.ranked { list-style: none; margin: 6px 0 0; padding: 0; font: 13px/1.8 var(--mono); }
.ranked li { display: flex; justify-content: space-between; gap: 16px; color: var(--text-2); }
.ranked li.chosen { color: var(--text); font-weight: 700; }
.ranked .err { color: var(--muted); font-weight: 400; }

.legend { display: flex; gap: 16px; font-size: 13px; color: var(--text-2); margin: 16px 0 4px; }
.swatch { display: inline-block; vertical-align: middle; margin-right: 6px; }
.swatch-point { width: 9px; height: 9px; border-radius: 50%; background: var(--series-1); }
.swatch-fit { width: 16px; height: 2px; background: var(--series-2); }

.chart-wrap { position: relative; }
#chart { width: 100%; height: auto; display: block; overflow: visible; }
#chart .grid { stroke: var(--grid); stroke-width: 1; }
#chart .axis { stroke: var(--muted); stroke-width: 1; }
#chart .tick { fill: var(--muted); font-size: 11px; }
#chart .axis-label { fill: var(--text-2); font-size: 11px; }
#chart .fit-line { fill: none; stroke: var(--series-2); stroke-width: 2; stroke-linecap: round; }
#chart .direct-label { fill: var(--text-2); font: 600 12px var(--mono); }
#chart .point { fill: var(--series-1); stroke: var(--surface); stroke-width: 2; }
#chart .hit { fill: transparent; cursor: default; }

.tooltip {
  position: absolute;
  pointer-events: none;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 12.5px;
  box-shadow: 0 4px 16px rgb(0 0 0 / 0.12);
  white-space: nowrap;
  z-index: 2;
}
.tip-n { font-weight: 600; margin-bottom: 2px; }

details { margin-top: 12px; }
summary { cursor: pointer; color: var(--text-2); font-size: 13px; }
table { border-collapse: collapse; width: 100%; margin-top: 8px; font: 13px var(--mono); }
th, td { text-align: right; padding: 4px 8px; border-bottom: 1px solid var(--border); }
th { color: var(--muted); font-weight: 500; }

.explainer ol { padding-left: 20px; margin: 0; color: var(--text-2); }
.explainer li { margin-bottom: 6px; }
.explainer b { color: var(--text); }
.caveat { color: var(--text-2); font-size: 14px; margin: 12px 0 0; }
code { font-family: var(--mono); font-size: 0.92em; background: var(--code-bg); padding: 1px 5px; border-radius: 4px; }

footer { padding-bottom: 32px; color: var(--muted); font-size: 13px; }
footer a { color: var(--text-2); }