/* Paper, ink, and hairlines.
 *
 * There are no shadows anywhere in this stylesheet, and that is deliberate.
 * Separation is done with one-pixel rules and with fills, never with elevation,
 * because a printed page has no elevation. There is also no pure white and no
 * pure black: the paper is #f2f1e8 and the ink is #2b2b2b, and the small
 * distance each of them keeps from the extremes is most of the reason the thing
 * looks printed rather than rendered.
 *
 * Parameters are labelled with the identifiers they have in the source and in
 * the papers — `mu`, `sigma`, `F`, `k`, `tau`, `chiR` — in lowercase monospace.
 * Sentence-casing them into "Growth Centre" would be friendlier and would
 * quietly cut the control off from the literature it came from.
 *
 * Every number is set in tabular figures. A generation counter in proportional
 * figures visibly wobbles as it ticks, and once you have noticed it you cannot
 * stop noticing it.
 */

@font-face {
  font-family: 'IBM Plex Mono';
  font-style: normal; font-weight: 400; font-display: swap;
  src: local('IBM Plex Mono'), local('IBMPlexMono');
}

:root {
  --paper:      #f2f1e8;
  --ink:        #2b2b2b;
  --ink-70:     #2b2b2bb3;
  --ink-55:     #2b2b2b8c;
  --ink-35:     #2b2b2b59;
  --ink-18:     #2b2b2b2e;
  --hairline:   #dedcd0;
  --fill:       #e7e5d9;
  --fill-hover: #dfddd0;
  --fill-press: #d4d2c4;
  --accent:     #81acec;

  --font-ui: 'Inter Tight', Inter, system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', 'Menlo', 'Consolas', monospace;

  --rail-w: 302px;
  --status-h: 34px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  height: 100%;
  overflow: hidden;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 13px;
  -webkit-font-smoothing: antialiased;
}

/* the canvas is the page */
#sim {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  background: var(--paper);
  touch-action: none;
  cursor: crosshair;
}

/* Film grain over the whole sheet. Static: a live simulation is already moving,
 * and animating this would cost a full-screen composite every frame for nothing. */
.grain {
  position: fixed; inset: 0;
  pointer-events: none;
  z-index: 5;
  opacity: 0.10;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.82' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  background-size: 220px 220px;
  transform: translateZ(0);
}

/* ── the rail ─────────────────────────────────────────────────────────── */

.rail {
  position: fixed;
  top: 16px; right: 16px;
  bottom: calc(var(--status-h) + 16px);
  width: var(--rail-w);
  z-index: 20;
  display: flex;
  flex-direction: column;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(14px) saturate(1.05);
  -webkit-backdrop-filter: blur(14px) saturate(1.05);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  box-shadow: none;
  overflow: hidden;
  transition: opacity .15s, transform .15s;
}
.rail[hidden] { display: none; }
.rail.gone { opacity: 0; transform: translateX(8px); pointer-events: none; }

.rail-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 9px 10px 9px 12px;
  border-bottom: 1px solid var(--hairline);
  flex: none;
}
.wordmark {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .02em;
  color: var(--ink);
}
.rail-btns { display: flex; gap: 4px; }

.rail-body {
  padding: 4px 12px 16px;
  overflow-y: auto;
  overscroll-behavior: contain;
  flex: 1;
}
.rail-body::-webkit-scrollbar { width: 5px; }
.rail-body::-webkit-scrollbar-thumb { background: var(--ink-18); border-radius: 3px; }

.section {
  margin: 16px 0 8px;
  font-size: 9.5px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .13em;
  color: var(--ink-35);
}

.tagline {
  margin: 8px 0 0;
  font-size: 12px;
  line-height: 1.45;
  color: var(--ink-70);
}
.fine {
  margin: 10px 0 0;
  font-size: 11px;
  line-height: 1.5;
  color: var(--ink-55);
}

/* ── a parameter row ──────────────────────────────────────────────────── */
/* label | track | value. Drag anywhere on the track to scrub; the number on the
 * right is editable, because sometimes you know exactly what you want. */

.param {
  display: grid;
  grid-template-columns: 84px 1fr 54px;
  align-items: center;
  gap: 7px;
  height: 22px;
  margin-bottom: 5px;
}
.param > label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-70);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  cursor: help;
}
.track {
  position: relative;
  height: 20px;
  border-radius: 4px;
  background: var(--fill);
  cursor: ew-resize;
  overflow: hidden;
}
.track .fill {
  position: absolute; inset: 0;
  width: 0%;
  background: var(--ink);
  opacity: .16;
}
.track .tick {
  position: absolute; top: 3px; bottom: 3px;
  width: 1px;
  background: var(--ink);
  opacity: .5;
}
.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: 'tnum' 1, 'zero' 1;
  font-size: 11px;
  text-align: right;
  height: 20px;
  padding: 0 5px;
  color: var(--ink);
  background: var(--fill);
  border: 0;
  border-radius: 4px;
  outline: 0;
  width: 100%;
}
.num:focus-visible { background: #f8f8f4; outline: 1.5px solid var(--accent); outline-offset: -1px; }

.select, .mono-input {
  width: 100%;
  height: 24px;
  padding: 0 7px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink);
  background: var(--fill);
  border: 0;
  border-radius: 4px;
  outline: 0;
  appearance: none;
  cursor: pointer;
}
.select:focus-visible, .mono-input:focus-visible { outline: 1.5px solid var(--accent); }
.mono-input { font-variant-numeric: tabular-nums; cursor: text; }

.param select.select { height: 20px; cursor: pointer; }

.seedrow { display: grid; grid-template-columns: 1fr auto; gap: 6px; }

/* ── buttons ──────────────────────────────────────────────────────────── */

.btn, .icon {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink);
  background: var(--fill);
  border: 0;
  border-radius: 4px;
  cursor: pointer;
  box-shadow: none;
  transition: background .15s cubic-bezier(.4,0,.2,1);
}
.btn { height: 24px; padding: 0 9px; }
.icon { width: 22px; height: 22px; line-height: 1; display: inline-grid; place-items: center; }
.icon.wide { width: 28px; }
.btn:hover, .icon:hover { background: var(--fill-hover); }
.btn:active, .icon:active { background: var(--fill-press); }
.btn:focus-visible, .icon:focus-visible { outline: 1.5px solid var(--accent); outline-offset: 1px; }

/* the "try this" recipes: the most valuable thing on the panel, so they are
 * buttons rather than a paragraph telling you what to type */
.recipes { display: flex; flex-direction: column; gap: 4px; }
.recipe {
  text-align: left;
  padding: 7px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.35;
  color: var(--ink);
  background: var(--fill);
  border: 0; border-radius: 5px;
  cursor: pointer;
  transition: background .15s;
}
.recipe:hover { background: var(--fill-hover); }
.recipe .rn {
  display: block;
  margin-top: 3px;
  font-family: var(--font-ui);
  font-size: 11px;
  line-height: 1.45;
  color: var(--ink-55);
}

/* Same anatomy as a recipe button: this rail has one kind of thing you press. */
.paperlink {
  display: block;
  margin-bottom: 4px;
  padding: 7px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.35;
  color: var(--ink);
  text-decoration: none;
  background: var(--fill);
  border-radius: 5px;
  transition: background .15s;
}
.paperlink:hover { background: var(--fill-hover); }
.paperlink:focus-visible { outline: 1.5px solid var(--accent); outline-offset: 1px; }
.paperlink .rn {
  display: block;
  margin-top: 3px;
  font-family: var(--font-ui);
  font-size: 11px;
  line-height: 1.45;
  color: var(--ink-55);
}

.show-rail[hidden] { display: none; }
.show-rail {
  position: fixed;
  top: 16px; right: 16px;
  z-index: 21;
  width: 30px; height: 30px;
  display: grid; place-items: center;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(14px);
  border: 1px solid var(--hairline);
  border-radius: 8px;
  color: var(--ink);
  cursor: pointer;
}

/* ── the info drawer ──────────────────────────────────────────────────── */
/* It replaces the rail's contents rather than covering the canvas. The
 * simulation must stay visible while you read about it; that is the whole
 * point of reading about it. */

.info h1 { margin: 10px 0 0; font-size: 17px; font-weight: 500; letter-spacing: -.01em; }
.back {
  margin-top: 4px;
  padding: 0; border: 0; background: none;
  font-family: var(--font-mono); font-size: 11px;
  color: var(--ink-55); cursor: pointer;
}
.back:hover { color: var(--ink); }
.prose { font-size: 12.5px; line-height: 1.58; color: var(--ink-70); }
.prose p { margin: 0 0 9px; }
.prose code, .eq {
  display: block;
  margin: 8px 0;
  padding: 7px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--fill);
  border-radius: 4px;
  overflow-x: auto;
}
.refs {
  margin: 0; padding-left: 16px;
  font-size: 11px; line-height: 1.5;
  color: var(--ink-55);
}
.refs li { margin-bottom: 7px; }

/* ── the status strip ─────────────────────────────────────────────────── */

.status {
  position: fixed;
  inset: auto 0 0 0;
  height: var(--status-h);
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 0 12px;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-top: 1px solid var(--hairline);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: 'tnum' 1, 'zero' 1;
  font-size: 11px;
  color: var(--ink-70);
  white-space: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}
.status::-webkit-scrollbar { display: none; }
.transport { display: flex; gap: 3px; }
.stat { display: inline-flex; gap: 5px; align-items: baseline; }
.status .k { color: var(--ink-35); }
.status .v { color: var(--ink); }
.spacer { margin-left: auto; }

.speedbox { display: inline-flex; align-items: center; gap: 6px; }
.speedbox input[type=range] {
  -webkit-appearance: none; appearance: none;
  width: 62px; height: 3px;
  background: var(--ink-18);
  border-radius: 2px;
  cursor: ew-resize;
}
.speedbox input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 9px; height: 13px;
  background: var(--ink);
  border-radius: 2px;
  cursor: ew-resize;
}
.speedbox input[type=range]::-moz-range-thumb {
  width: 9px; height: 13px; border: 0;
  background: var(--ink); border-radius: 2px;
}

/* ── the readout ──────────────────────────────────────────────────────── */

.readout {
  position: fixed;
  left: 16px;
  bottom: calc(var(--status-h) + 16px);
  z-index: 20;
  width: 320px;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  overflow: hidden;
}
.readout[hidden] { display: none; }
.readout-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 6px 8px 6px 12px;
  border-bottom: 1px solid var(--hairline);
}
.readout-head .section { margin: 0; }
.plots { padding: 10px 12px 12px; }

.plot { margin-bottom: 12px; }
.plot:last-child { margin-bottom: 0; }
.plot-head {
  display: flex; justify-content: space-between; align-items: baseline;
  font-family: var(--font-mono);
  font-size: 10.5px;
  margin-bottom: 3px;
}
.plot-head .pk { color: var(--ink-35); }
.plot-head .pv {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  font-feature-settings: 'tnum' 1, 'zero' 1;
}
.plot canvas { display: block; width: 100%; height: 34px; }

/* ── the sweep ────────────────────────────────────────────────────────── */
/* Sits opposite the rail, so a phase diagram and the run it came from are on
 * screen at the same time. That co-visibility is the point: the curve is an
 * abstraction of the thing moving next to it. */

.sweep {
  position: fixed;
  left: 16px; top: 16px;
  z-index: 20;
  width: 380px;
  background: color-mix(in srgb, var(--paper) 93%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  overflow: hidden;
}
.sweep[hidden] { display: none; }
.sweep .readout-head .btn { margin-right: 4px; }
#sweep-canvas {
  display: block;
  width: 100%;
  height: 210px;
}
.sweep-bar {
  height: 2px;
  background: var(--fill);
}
.sweep-fill {
  height: 100%;
  width: 0%;
  background: var(--ink);
  transition: width .12s linear;
}
.sweep-note {
  margin: 0;
  padding: 10px 12px 12px;
  font-size: 11.5px;
  line-height: 1.5;
  color: var(--ink-55);
}

@media (max-width: 760px) {
  .sweep { left: 8px; right: 8px; width: auto; }
}

.toast {
  position: fixed;
  left: 50%; bottom: calc(var(--status-h) + 20px);
  transform: translateX(-50%);
  z-index: 40;
  padding: 7px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--paper);
  background: var(--ink);
  border-radius: 5px;
}
.toast[hidden] { display: none; }

/* ── small screens ────────────────────────────────────────────────────── */
/* The reference simply deletes its control panel below a breakpoint. We do not:
 * a laboratory you cannot operate is not a laboratory. The rail becomes a sheet. */

@media (max-width: 760px) {
  .rail {
    top: auto;
    left: 8px; right: 8px;
    bottom: calc(var(--status-h) + 8px);
    width: auto;
    max-height: 52vh;
  }
  .readout { left: 8px; right: 8px; width: auto; bottom: calc(var(--status-h) + 8px); }
  .status { gap: 10px; }
  .speedbox { display: none; }
}