:root {
  --bg: #0a0b0d;
  --panel: #121418;
  --panel-edge: #23262d;
  --text: #e8e9ec;
  --muted: #8b9099;
  --ok: #4ade80;
  --no: #f87171;
  --edge: #2c3038;
  --accent: #7dd3fc;
  --sans: "Inter Tight", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
  color-scheme: dark;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 var(--sans);
}

main {
  max-width: 1040px;
  margin: 0 auto;
  padding: 48px 16px 64px;
}

.eyebrow, dt, output, code, pre {
  font-family: var(--mono);
  font-size: 13px;
}

.eyebrow { color: var(--accent); margin: 0 0 8px; }
h1 { font-size: clamp(28px, 5vw, 44px); line-height: 1.1; margin: 0 0 12px; letter-spacing: -0.02em; }
h2 { font-size: 20px; margin: 0 0 8px; }
h3 { font: 500 14px var(--mono); margin: 0; color: var(--text); }
.lede { color: var(--muted); max-width: 64ch; margin: 0 0 28px; }
.lede strong { color: var(--text); }

.panel {
  background: var(--panel);
  border: 1px solid var(--panel-edge);
  border-radius: 10px;
  box-shadow: inset 0 1px 0 rgb(255 255 255 / 0.04);
}

#controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px 24px;
  padding: 18px 20px;
  margin-bottom: 16px;
}

label { display: grid; gap: 6px; color: var(--muted); font-size: 14px; }
output { color: var(--text); justify-self: end; margin-top: -26px; }

select, button {
  font: inherit;
  color: var(--text);
  background: #1a1d22;
  border: 1px solid var(--panel-edge);
  border-radius: 6px;
  padding: 8px 10px;
}

button { cursor: pointer; font-weight: 600; }
button:hover:not(:disabled) { border-color: var(--accent); }
button:disabled { opacity: 0.5; cursor: progress; }
input[type="range"] { accent-color: var(--accent); width: 100%; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

dl {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 24px;
  margin: 0;
}

dl div { display: flex; gap: 8px; align-items: baseline; }
dt { color: var(--muted); }
dd { margin: 0; font: 500 14px var(--mono); }
dl .bad dd { color: var(--no); }

.api {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr);
  gap: 20px;
  padding: 20px;
}

.api p { color: var(--muted); margin: 0 0 14px; }
code { color: var(--text); }

pre {
  margin: 0;
  padding: 12px;
  min-height: 120px;
  background: #0d0f12;
  border: 1px solid var(--panel-edge);
  border-radius: 6px;
  overflow-x: auto;
  white-space: pre;
}

@media (max-width: 640px) {
  .api { grid-template-columns: 1fr; }
}

/* idempotency-lab additions */
.pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.mode { padding: 16px; display: grid; gap: 12px; align-content: start; }
.mode header { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
.mode .tag { font: 500 12px var(--mono); color: var(--muted); }
.big { display: flex; align-items: baseline; gap: 10px; }
.big strong { font: 600 40px/1 var(--sans); letter-spacing: -0.02em; }
.big span { color: var(--muted); font-size: 14px; }
.mode.bad .big strong { color: var(--no); }
.mode.good .big strong { color: var(--ok); }
.mode canvas { width: 100%; height: 72px; display: block; }
.trace { padding: 16px; margin-top: 10px; }
.trace .pair pre { min-height: 0; font-size: 12px; line-height: 1.6; }
.trace p { color: var(--muted); margin: 0 0 12px; }
.section-h { margin: 36px 0 12px; }
.fields { display: grid; grid-template-columns: minmax(0, 2fr) minmax(0, 1fr); gap: 10px; margin-bottom: 12px; }
.buttons { display: flex; flex-wrap: wrap; gap: 8px; }
input[type="text"], input[type="number"] {
  font: 14px var(--mono);
  color: var(--text);
  background: #1a1d22;
  border: 1px solid var(--panel-edge);
  border-radius: 6px;
  padding: 8px 10px;
  width: 100%;
  min-width: 0;
}
.s2 { color: var(--ok); }
.s4 { color: #fbbf24; }
.s5 { color: var(--no); }

@media (max-width: 640px) {
  .pair, .fields { grid-template-columns: 1fr; }
}