/* scrolly.css - the insight kit (R1, 2026-10-23): the scroll scaffold, the
 * charts drawn into it, the clip component, the takeaways and the stamp.
 *
 * A page that uses the kit links this after style.css. Every colour and size
 * is a token from style.css :root; nothing here introduces a colour, and
 * there are no gradients (HANDOFF section 4).
 *
 * THE OLD RAIL IS NOT IN THE KIT. aside.marginalia stays in style.css only
 * for the pages that still carry it; a page that links this file uses
 * .takeaways instead, and tests/test_kit.js fails a page that has both.
 */

/* ------------------------------------------------------------- scrolly --- */
/* Without JS, or with reduced motion, a .scrolly is a column of steps, each
   with its own static figure (built from the same chart code at build time).
   scrolly.js adds .is-live only when it can animate; then the stage shows,
   sticks, and the per-step figures hide. Nothing on the page depends on the
   live state to be read. */
/* The section spans main's wide track and inherits main's tracks as a
   subgrid, so the steps sit on the text track itself. max-width: var(--text)
   centred is NOT the same thing: below about 1100px main squeezes the text
   track narrower than --text, and steps held to --text had a second left edge
   (tests/test_layout.js, 34px off at 1024 and 960, 2026-10-23). */
.scrolly { position: relative; margin: 28px 0; display: grid; grid-template-columns: subgrid; }
.scrolly > .scrolly-steps { grid-column: text; min-width: 0; }
.scrolly > .scrolly-stage { grid-column: wide; min-width: 0; }
.scrolly-stage { display: none; }
.scrolly .step { margin: 0 0 30px; }
.scrolly .step > p:first-child { margin-top: 0; }
.step-fig { margin: 14px 0 0; container-type: inline-size; }
/* Two static widths ship (charts.js WIDE and PHONE); the wider one shows only
   when its container is at least that wide, so a figure is never scaled up
   and its text stays at the size it was drawn at. */
.step-fig .snap-wide { display: none; }
@container (min-width: 720px) {
  .step-fig .snap-wide { display: block; }
  .step-fig .snap-phone { display: none; }
}
.step-fig svg { display: block; max-width: 100%; height: auto; }

.scrolly.is-live .step-fig { display: none; }
.scrolly.is-live .scrolly-stage {
  display: block;
  position: sticky;
  top: 0;
  z-index: 2;
  background: var(--bg);
  padding: 14px 0 12px;
  border-bottom: 1px solid var(--faint);
}
.scrolly.is-live .scrolly-stage svg { display: block; margin: 0 auto; max-width: 100%; height: auto; }
/* Steps scroll up beneath the stage. Each sits on a card so its text never
   lies over the chart's lines, and the gap between them is what gives the
   chart room to move. */
.scrolly.is-live .scrolly-steps { position: relative; z-index: 1; padding: 24vh 0 30vh; }
.scrolly.is-live .step {
  margin-bottom: 55vh;
  background: var(--card);
  border: 1px solid var(--rule);
  padding: 16px 20px;
}
.scrolly.is-live .step:last-child { margin-bottom: 0; }

/* -------------------------------------------------------------- charts --- */
/* charts.js lays text out with these sizes (FS 12, FS_BIG 14.5, Plex Mono)
   and test_kit.js measures the rendered widths against them. Change one and
   change the other, or labels collide. */
.chart text { font-family: var(--mono); font-size: var(--fs-2); fill: var(--ink); }
.chart .ch-tick { fill: var(--dim); }
.chart .ch-now { font-size: var(--fs-1); fill: var(--ink); font-weight: 600; }
.chart .ch-grid { stroke: var(--faint); stroke-width: 1; }
.chart .ch-axis { stroke: var(--rule); stroke-width: 1; }
.chart .ch-line { fill: none; stroke-width: 2.25; stroke-linejoin: round; stroke-linecap: round; }
.chart .ch-band { stroke: none; opacity: .28; }
.chart .ch-ann line { stroke: var(--dim); stroke-width: 1; stroke-dasharray: 2 3; }
.chart .ch-ann, .chart .ch-plab, .chart [data-k="tot"] { transition: opacity .35s; }
.chart .ch-plab line { stroke: var(--rule); stroke-width: 1; }
.chart .ch-plab .ch-v { fill: var(--dim); }
.chart .c-acc  { stroke: var(--acc); }
.chart .c-moss { stroke: var(--moss); }
.chart .c-ink  { stroke: var(--ink); }
.chart .f-acc  { fill: var(--acc); }
.chart .f-moss { fill: var(--moss); }
.chart .f-ink  { fill: var(--ink); }
.chart .f-rule { fill: var(--rule); }
.chart rect.ch-band.f-acc, .chart rect.ch-band.f-moss { opacity: .28; }
:root[data-motion="off"] .chart * { transition: none !important; }

/* ------------------------------------------------------------- counter --- */
/* A number that is a link to its source. scrolly.js counts it up once when
   it first scrolls into view; the markup already holds the final value, so
   without JS or with reduced motion it simply reads correctly. */
a.counter { font-family: var(--mono); font-variant-numeric: tabular-nums; white-space: nowrap; }

/* ---------------------------------------------------------- takeaways --- */
/* At most three, each a full sentence (insight.py refuses anything else).
   In the flow, under the standfirst, in the text column: one left edge. */
.takeaways { margin: 22px 0 8px; }
.takeaways ol { list-style: none; margin: 0; padding: 0; }
.takeaways li {
  margin: 0 0 12px;
  padding: 2px 0 2px 16px;
  border-left: 2px solid var(--acc);
  font-size: var(--fs0);
  line-height: 1.5;
}

/* --------------------------------------------------------------- stamp --- */
p.stamp { font: var(--fs-2)/1.4 var(--mono); color: var(--dim); margin: 6px 0 0; letter-spacing: .02em; }

/* ---------------------------------------------------------------- clip --- */
/* A Manim clip: poster first, nothing downloads until asked (preload=none).
   Without JS the native controls show. With JS a play button sits on the
   poster; a loop of ten seconds or less plays muted while in view, unless the
   reader has asked for less motion, in which case it waits for a click like
   any other clip. */
figure.clip { margin: 22px 0; }
.clip-frame { position: relative; border: 1px solid var(--rule); background: var(--card); line-height: 0; }
.clip-frame video { display: block; width: 100%; height: auto; }
.clip-play {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  font: 600 var(--fs-1) var(--mono);
  color: var(--acc-ink); background: var(--acc-fill); border: 1px solid var(--acc-fill);
  padding: 10px 16px; cursor: pointer; line-height: 1;
}
.clip-play:hover { background: var(--acc-fill-hover); }
.clip-play:focus-visible { outline: 2px solid var(--acc); outline-offset: 3px; }
.clip-play[hidden] { display: none; }
figure.clip figcaption { font: var(--fs-1)/1.5 var(--sans); color: var(--dim); margin-top: 8px; }

/* --------------------------------------------------------------- strip --- */
/* charts.js "strip" (R3): the unlit bars, and the range's label. */
.chart .f-dim  { fill: var(--dim); }
.chart rect.ch-bar.f-dim { opacity: .45; }
.chart .ch-light, .chart .ch-rl { transition: opacity .35s; }
.chart .ch-rl { fill: var(--ink); }

/* ---------------------------------------------------------------- pick --- */
/* The one control a page may carry (pick.js). Without JS the buttons stay
   hidden and every block shows. */
.pick-ctl { font: var(--fs-1)/1.4 var(--mono); }
.pick-ctl button {
  font: inherit; color: var(--ink); background: var(--bg); border: 1px solid var(--rule);
  padding: 6px 12px; margin: 0 4px 4px 0; cursor: pointer;
}
.pick-ctl button[aria-pressed="true"] { color: var(--acc-ink); background: var(--acc-fill); border-color: var(--acc-fill); }
.pick-ctl button:focus-visible { outline: 2px solid var(--acc); outline-offset: 2px; }
.pick-ctl[hidden], .pick [data-when][hidden] { display: none; }