/* Engram — "modern journal reprint"
   Type: STIX Two Text (journal serif) · IBM Plex Mono (labels, captions, data)
   Accent: marginalia violet on paper white; night-lab dark mode. */

:root {
  --paper: #FDFDFB;
  --ink: #1C1E26;
  --ink2: #5B5E6B;
  --line: #E3E2DC;
  --violet: #6D28D9;
  --violet-soft: #EDE7FB;
  --amber: #B45309;
  --fig-bg: #FBFAF7;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #12141C;
    --ink: #E8E6F0;
    --ink2: #A2A1B3;
    --line: #2B2D3A;
    --violet: #A78BFA;
    --violet-soft: #251D3D;
    --amber: #E5A050;
    --fig-bg: #171A24;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 18px/1.65 "STIX Two Text", Georgia, serif;
  -webkit-font-smoothing: antialiased;
}

.mono {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: .72rem;
  letter-spacing: .04em;
}

a { color: var(--violet); text-decoration-thickness: 1px; text-underline-offset: 2px; }

:focus-visible { outline: 2px solid var(--violet); outline-offset: 2px; }

.paper {
  max-width: 720px;
  margin: 0 auto;
  padding: 4.5rem 1.4rem 3rem;
}

/* ---- masthead ---- */
.masthead { margin-bottom: 3.5rem; }
.eyebrow { color: var(--violet); margin: 0 0 1.2rem; }
h1 {
  font-size: clamp(2rem, 5.5vw, 3rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -.01em;
  margin: 0 0 1.1rem;
}
.lede { font-size: 1.12rem; color: var(--ink); }
.byline { color: var(--ink2); margin-top: 1.2rem; }

/* ---- sections ---- */
section { margin-bottom: 3.2rem; }
h2 {
  font-size: 1.45rem;
  font-weight: 600;
  margin: 0 0 .8rem;
  display: flex;
  align-items: baseline;
  gap: .7rem;
}
.secno {
  color: var(--violet);
  font-size: .8rem;
  border: 1px solid var(--violet);
  border-radius: 50%;
  width: 1.7em; height: 1.7em;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  transform: translateY(-.15em);
}
p { margin: 0 0 1rem; }

/* ---- figures: the numbered plates ---- */
figure { margin: 1.6rem 0 0; }
.fig-frame {
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--fig-bg);
  overflow: hidden;
}
.fig-pad { padding: 1rem; }
#net { display: block; width: 100%; height: auto; cursor: crosshair; }
figcaption {
  color: var(--ink2);
  margin-top: .6rem;
  line-height: 1.6;
}
.figno { color: var(--violet); font-weight: 500; margin-right: .35em; }
sup { font-size: .7em; }

/* Fig 2 — curve */
.curve-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: .8rem;
  color: var(--ink2);
}
.curve-controls label { display: flex; align-items: center; gap: .5rem; }
input[type=range] { accent-color: var(--violet); width: 140px; }
.fig-btn {
  background: none;
  border: 1px solid var(--line);
  border-radius: 3px;
  color: var(--ink);
  padding: .3rem .7rem;
  cursor: pointer;
}
.fig-btn:hover { border-color: var(--violet); color: var(--violet); }
.curve-readout { color: var(--violet); }
#curve { display: block; width: 100%; height: auto; cursor: pointer; }

/* Fig 3 — digit span */
#span-display {
  font-size: 2.6rem;
  letter-spacing: .1em;
  text-align: center;
  min-height: 4.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink);
}
#span-display.dim { color: var(--ink2); font-size: 1rem; }
.span-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .8rem;
  flex-wrap: wrap;
}
#span-input {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  color: var(--ink);
  font-size: 1rem;
  padding: .4rem .7rem;
  width: 12em;
  text-align: center;
}
#span-status { color: var(--violet); }

/* ---- table ---- */
.table-wrap { overflow-x: auto; margin: 1.4rem 0; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: .92rem;
}
th {
  font-family: "IBM Plex Mono", monospace;
  font-size: .68rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  font-weight: 500;
  color: var(--ink2);
  text-align: left;
  padding: .5rem .8rem .5rem 0;
  border-bottom: 1px solid var(--ink2);
}
td {
  padding: .55rem .8rem .55rem 0;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
td:first-child { color: var(--violet); }

/* ---- colophon ---- */
.colophon {
  border-top: 1px solid var(--line);
  padding-top: 1.4rem;
  margin-top: 3rem;
  color: var(--ink2);
  font-size: .85rem;
}
.colophon .mono { display: block; margin-bottom: .8rem; line-height: 1.7; }

@media (max-width: 560px) {
  body { font-size: 16.5px; }
  .paper { padding-top: 3rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}