/* Colours are tokens: dark by default, light when the viewer asks for it. */
:root {
  color-scheme: dark;
  --page: #0e0e10;
  --surface: #161618;
  --surface-2: #1d1d20;
  --border: rgba(255, 255, 255, 0.08);
  --grid: #26262a;
  --axis: #3a3a3f;
  --ink: #f0efec;
  --ink-2: #c3c2b7;
  --muted: #8a8984;
  --stable: #3987e5;
  --truth: #d95926;
  --other: #55555b;
  --spectrum: rgba(57, 135, 229, 0.07);
  --spectrum-line: rgba(57, 135, 229, 0.35);
  --focus: rgba(57, 135, 229, 0.45);
}
:root[data-theme="light"] {
  color-scheme: light;
  --page: #f4f4f1;
  --surface: #fcfcfb;
  --surface-2: #f1f1ee;
  --border: rgba(11, 11, 11, 0.09);
  --grid: #e8e7e1;
  --axis: #c3c2b7;
  --ink: #0b0b0b;
  --ink-2: #52514e;
  --muted: #7d7c77;
  --stable: #2a78d6;
  --truth: #eb6834;
  --other: #c4c3bd;
  --spectrum: rgba(42, 120, 214, 0.07);
  --spectrum-line: rgba(42, 120, 214, 0.35);
  --focus: rgba(42, 120, 214, 0.35);
}

* { box-sizing: border-box; }

html, body { margin: 0; }

body {
  background: var(--page);
  color: var(--ink);
  font: 14px/1.5 Inter, system-ui, -apple-system, "Segoe UI", sans-serif;
  -webkit-font-smoothing: antialiased;
}

h1, h2 { margin: 0; font-weight: 600; }
a { color: inherit; }
button { font: inherit; color: inherit; }

.mono, output, td, .tick, .panel-note, .status, .fineprint {
  font-family: "JetBrains Mono", ui-monospace, Consolas, monospace;
  font-variant-numeric: tabular-nums;
}

/* ---------- top bar ---------- */

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 24px;
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand h1 { font-size: 15px; letter-spacing: -0.01em; }
.logo { width: 22px; height: 22px; fill: none; stroke: var(--stable); stroke-width: 2.6; stroke-linecap: round; }
.links { display: flex; align-items: center; gap: 6px; }

.status { display: inline-flex; align-items: center; gap: 8px; font-size: 12px; color: var(--muted); margin-right: 8px; }
.status .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--muted); }
.status.busy .dot { background: var(--stable); animation: pulse 1s ease-in-out infinite; }
.status.ready .dot { background: var(--stable); }
.status.error .dot { background: var(--truth); }
@keyframes pulse { 50% { opacity: 0.25; } }

.icon-button {
  display: inline-grid; place-items: center;
  width: 32px; height: 32px;
  border: 1px solid transparent; border-radius: 8px;
  background: none; cursor: pointer; color: var(--ink-2);
}
.icon-button:hover { background: var(--surface-2); color: var(--ink); }
.icon-button svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; }

/* ---------- layout ---------- */

.layout {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: 20px;
  max-width: 1440px;
  margin: 0 auto;
  padding: 20px 24px 40px;
}

.controls {
  position: sticky; top: 20px;
  align-self: start;
  display: flex; flex-direction: column; gap: 22px;
}
.intro { margin: 0; color: var(--ink-2); font-size: 13px; }

.group { display: flex; flex-direction: column; gap: 10px; }
.group h2 { font-size: 11px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 500; }
.group-head { display: flex; justify-content: space-between; align-items: baseline; }
.hint { font-size: 11px; color: var(--muted); }

.fineprint { margin: 0; font-size: 11px; color: var(--muted); }

/* mode rows */
.mode-list { display: flex; flex-direction: column; gap: 6px; }
.mode-row {
  display: grid;
  grid-template-columns: 22px 1fr 1fr 26px;
  align-items: center;
  gap: 6px;
}
.mode-index { font: 500 12px "JetBrains Mono", monospace; color: var(--muted); text-align: center; }
.mode-row input {
  width: 100%;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--surface);
  color: var(--ink);
  font: 13px "JetBrains Mono", monospace;
  font-variant-numeric: tabular-nums;
  outline: none;
  -moz-appearance: textfield;
}
.mode-row input::-webkit-inner-spin-button { -webkit-appearance: none; }
.mode-row input:focus { border-color: var(--stable); box-shadow: 0 0 0 3px var(--focus); }
.mode-row input.invalid { border-color: var(--truth); }
.remove {
  width: 26px; height: 26px; border: none; border-radius: 6px;
  background: none; color: var(--muted); cursor: pointer; font-size: 16px; line-height: 1;
}
.remove:hover { background: var(--surface-2); color: var(--ink); }
.remove:disabled { visibility: hidden; }

.ghost-button {
  align-self: flex-start;
  padding: 4px 0; border: none; background: none; cursor: pointer;
  color: var(--ink-2); font-size: 13px;
}
.ghost-button:hover { color: var(--ink); }
.ghost-button:disabled { opacity: 0.35; cursor: default; }

/* sliders */
.slider {
  display: grid;
  grid-template-columns: 1fr auto;
  row-gap: 4px;
  font-size: 13px;
  color: var(--ink-2);
}
.slider output { font-size: 12px; color: var(--ink); }
.slider input { grid-column: 1 / -1; }

input[type="range"] {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 18px; margin: 0;
  background: transparent; cursor: pointer;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 3px; border-radius: 3px;
  background: linear-gradient(to right, var(--stable) var(--fill, 50%), var(--grid) var(--fill, 50%));
}
input[type="range"]::-moz-range-track { height: 3px; border-radius: 3px; background: var(--grid); }
input[type="range"]::-moz-range-progress { height: 3px; border-radius: 3px; background: var(--stable); }
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px; height: 14px; margin-top: -5.5px;
  border-radius: 50%; border: 2px solid var(--page);
  background: var(--ink);
}
input[type="range"]::-moz-range-thumb {
  width: 12px; height: 12px; border-radius: 50%;
  border: 2px solid var(--page); background: var(--ink);
}
input[type="range"]:focus-visible { outline: none; }
input[type="range"]:focus-visible::-webkit-slider-thumb { box-shadow: 0 0 0 4px var(--focus); }

/* buttons */
.actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.button {
  padding: 9px 12px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--surface); cursor: pointer;
  font-size: 13px; font-weight: 500;
}
.button:hover { background: var(--surface-2); }
.button.primary { background: var(--ink); color: var(--page); border-color: var(--ink); }
.button.primary:hover { opacity: 0.88; }
.button:disabled { opacity: 0.4; cursor: default; }
.run-info { min-height: 1.5em; }

/* ---------- panels ---------- */

.results { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.results .chart, .results .shapes, .results table { transition: opacity 0.25s; }
.results.stale .chart, .results.stale .shapes, .results.stale table { opacity: 0.45; }

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px 12px;
  min-width: 0;
}
.panel-head {
  display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between;
  gap: 6px 16px; margin-bottom: 8px;
}
.panel-head h2 { font-size: 13px; }
.panel-note { font-size: 11px; color: var(--muted); }

.two-up { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

.legend { display: flex; flex-wrap: wrap; gap: 4px 14px; margin: 0; padding: 0; list-style: none; font-size: 12px; color: var(--ink-2); }
.legend li { display: inline-flex; align-items: center; gap: 6px; }
.key { display: inline-block; }
.key-stable { width: 8px; height: 8px; border-radius: 50%; background: var(--stable); }
.key-other { width: 6px; height: 6px; border-radius: 50%; background: var(--other); }
.key-true { width: 2px; height: 12px; background: var(--truth); }
.key-true-h { width: 14px; height: 2px; background: var(--truth); }
.key-mean { width: 14px; height: 2px; background: var(--ink); }
.key-line { width: 14px; height: 2px; background: var(--ink-2); }
.key-spectrum { width: 14px; height: 9px; border-radius: 2px; background: var(--spectrum); border-top: 1.5px solid var(--spectrum-line); }

.chart { position: relative; width: 100%; }
.chart svg { display: block; width: 100%; overflow: visible; }
.chart-trace { height: 132px; }
.chart-stab { height: 440px; }
.chart-damping { height: 300px; }

.loading-text { fill: var(--muted); font-size: 12px; }

/* svg marks */
.pole-stable { fill: var(--stable); stroke: var(--surface); stroke-width: 1.2; }
.pole-stable.faded { opacity: 0.8; }
.pole-other { fill: var(--other); }
.true-line { stroke: var(--truth); stroke-width: 1; opacity: 0.75; }
.true-mark { stroke: var(--truth); stroke-width: 2; stroke-linecap: round; }
.mean-mark { stroke: var(--ink); stroke-width: 2; stroke-linecap: round; }
.hover-ring { fill: none; stroke: var(--ink); stroke-width: 1.5; pointer-events: none; }
.spectrum-area { fill: var(--spectrum); }
.spectrum-line { fill: none; stroke: var(--spectrum-line); stroke-width: 1.2; }
.trace-line { fill: none; stroke: var(--ink-2); stroke-width: 1; stroke-linejoin: round; opacity: 0.9; }
.trace-zero { stroke: var(--grid); stroke-width: 1; shape-rendering: crispEdges; }
.shape-true { fill: none; stroke: var(--ink-2); stroke-width: 1.5; opacity: 0.7; }

/* svg chrome */
.grid line { stroke: var(--grid); stroke-width: 1; shape-rendering: crispEdges; }
.axis-line { stroke: var(--axis); stroke-width: 1; shape-rendering: crispEdges; }
.tick { fill: var(--muted); font-size: 10.5px; }
.axis-title { fill: var(--muted); font-size: 11px; }

/* mode shape small multiples */
.shapes { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.shape-card { background: var(--surface-2); border-radius: 8px; padding: 8px 10px 6px; }
.shape-title { display: flex; justify-content: space-between; font-size: 12px; color: var(--ink-2); }
.shape-title .mono { font-size: 11px; color: var(--muted); }
.shape-card svg { display: block; width: 100%; height: 64px; overflow: visible; }
.shape-missing { fill: var(--muted); font-size: 11px; }

/* table */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
th {
  text-align: right; font-weight: 500; color: var(--muted); font-size: 11.5px;
  padding: 6px 10px; border-bottom: 1px solid var(--grid); white-space: nowrap;
}
td { text-align: right; padding: 7px 10px; border-bottom: 1px solid var(--grid); white-space: nowrap; color: var(--ink); }
th:first-child, td:first-child { text-align: left; }
tbody tr:last-child td { border-bottom: none; }
td.muted { color: var(--muted); }

.notes { color: var(--muted); font-size: 12px; max-width: 860px; padding: 4px 2px; }
.notes p { margin: 0 0 8px; }
.notes a { color: var(--ink-2); text-underline-offset: 2px; }

/* tooltip */
.tooltip {
  position: fixed; z-index: 10; pointer-events: none;
  padding: 7px 10px; border-radius: 8px;
  background: var(--surface-2); border: 1px solid var(--border);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.25);
  font: 12px/1.5 "JetBrains Mono", monospace; color: var(--ink);
  opacity: 0; transition: opacity 0.08s;
  white-space: nowrap;
}
.tooltip.show { opacity: 1; }
.tooltip .tt-muted { color: var(--muted); }

/* ---------- small screens ---------- */

@media (max-width: 1040px) {
  .two-up { grid-template-columns: 1fr; }
}
@media (max-width: 820px) {
  .layout { grid-template-columns: 1fr; padding: 16px 16px 32px; }
  .controls { position: static; }
  .top { padding: 12px 16px; }
  .chart-stab { height: 340px; }
  .status { display: none; }
}