/* /decision-mesh, "How the Gate Decides": the illustrated gate as a section of the page. The story layout and the
   paper-and-pencil inks are the dissertation's (dissertation/opening.css), copied here and scoped to .gatehow, since
   that sheet's unscoped .stage and .cards would restyle the live fit and the race. This adds the controls, the
   engine-specific paragraphs and the colors the run is drawn in. */
.gatehow {
  --paper: #fffff0;
  --sheet: #fffdf6;
  --ink: #1b1b20;
  --ink-2: #4a4a55;
  --ink-3: #8a8a93;
  --rule: rgba(20, 20, 30, 0.1);
  --accent: #1f3fd0;
  --warm: #b4461f;
  color: var(--ink);
  padding: 2rem 0 0;
}
.dark .gatehow {
  --paper: #1f2022;
  --sheet: #25262a;
  --ink: #ecedf1;
  --ink-2: #b2b3bc;
  --ink-3: #7c7d86;
  --rule: rgba(255, 255, 255, 0.12);
  --accent: #8fb0ff;
  --warm: #ee8a5e;
  color-scheme: dark;   /* the controls' native parts (a select's list and arrow) in dark too, or WebKit draws them white */
}
.gatehow[data-engine="tri"] [data-engine="rect"],
.gatehow[data-engine="rect"] [data-engine="tri"] { display: none; }
.gatehow a { color: var(--accent); text-decoration: none; }

/* the head and foot of the section, on the page's column */
.gatehow .howhead, .gatehow .howfoot { max-width: 1120px; margin: 0 auto; padding: 0 16px; box-sizing: border-box; }
.gatehow .howhead .lede { font-family: Newsreader, Georgia, serif; font-size: 1.2rem; line-height: 1.5; color: var(--ink-2); max-width: 40rem; margin: 0; }
.gatehow .howfoot { padding-bottom: 2rem; }
.gatehow .howfoot .note { font: 0.84rem/1.55 ui-sans-serif, system-ui, sans-serif; color: var(--ink-3); max-width: 44rem; margin: 0; }

/* the story: text on the left, the drawing held on the right */
.gatehow .story { position: relative; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); width: min(1100px, calc(100% - 40px)); margin: 0 auto; }
.gatehow .stage { grid-column: 2; grid-row: 1; position: sticky; top: 0; height: 100vh; height: 100svh; display: flex; align-items: center; justify-content: center; }
.gatehow .stage > svg { width: min(100%, 78vh); height: auto; overflow: visible; }
.gatehow .steps { grid-column: 1; grid-row: 1; padding: 30vh 0 40vh; }
.gatehow .step { min-height: 88vh; display: flex; flex-direction: column; justify-content: center; max-width: 30rem; opacity: 0.22; transition: opacity 0.5s; }
.gatehow .step.on { opacity: 1; }
.gatehow .step p { font-family: Newsreader, Georgia, serif; font-size: clamp(1.45rem, 2.6vw, 2.05rem); line-height: 1.3; letter-spacing: -0.01em; margin: 0 0 0.8rem; }
.gatehow .step p.small { font-size: clamp(1.05rem, 1.7vw, 1.25rem); color: var(--ink-2); }
.gatehow .step em { font-style: italic; color: var(--accent); }
.gatehow [data-v] { font-variant-numeric: tabular-nums; }

/* the drawing's inks */
#stage { color: var(--ink); font-family: Newsreader, Georgia, serif; }
#stage .pencil { fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; }
#stage .soft { opacity: 0.35; }
#stage .accent { stroke: var(--accent); }
#stage .warm { stroke: var(--warm); }
#stage .fillacc { fill: var(--accent); }
#stage .fillink { fill: var(--ink-2); }
#stage .fillwarm { fill: var(--warm); }
#stage text { fill: currentColor; font-size: 17px; }
#stage text.label { font-size: 15px; }
#stage text.mono { font-family: ui-monospace, Menlo, monospace; font-size: 11px; letter-spacing: 0.08em; fill: var(--ink-3); }
#stage text.src { font: 11px ui-sans-serif, system-ui, sans-serif; fill: var(--ink-3); }
#stage text.acc { fill: var(--accent); }
#stage text.warmt { fill: var(--warm); }
#stage text.halo { paint-order: stroke; stroke: var(--paper); stroke-width: 6px; stroke-linejoin: round; }
#stage .box { fill: var(--sheet); }
#stage .pos { fill: var(--accent); }
#stage .neg { fill: var(--warm); }
#stage .posS { stroke: var(--accent); }
#stage .negS { stroke: var(--warm); }
#stage .ink { fill: currentColor; }
#stage .sheet { fill: var(--sheet); }
#stage .frame { fill: none; stroke: var(--rule); stroke-width: 1; }
#stage .meshline { fill: none; stroke: currentColor; stroke-width: 0.6; stroke-opacity: 0.3; }
#stage .shade { fill: var(--accent); fill-opacity: 0.13; }
#stage .shadew { fill: var(--warm); fill-opacity: 0.13; }
#stage text.small { font-size: 12px; }
#stage text.tiny { font: 10px ui-monospace, Menlo, monospace; fill: var(--ink-3); }
#stage text.tiny.acc { fill: var(--accent); }
#stage text.tiny.halo { paint-order: stroke; stroke: var(--paper); stroke-width: 4px; stroke-linejoin: round; }
#stage .stagebusy { font: 12px ui-monospace, Menlo, monospace; letter-spacing: 0.08em; fill: var(--ink-3); }

/* the controls */
.gatehow .howbar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 18px; margin: 1.2rem 0 0; font: 0.9rem ui-sans-serif, system-ui, sans-serif; color: var(--ink-2); }
.gatehow .howbar label { display: inline-flex; align-items: center; gap: 8px; }
.gatehow .howbar select, .gatehow .howbar button { font: inherit; color: var(--ink); background: var(--sheet); border: 1px solid var(--rule); border-radius: 999px; padding: 0.35rem 0.8rem; }
.gatehow .howbar button { cursor: pointer; }
.gatehow .howbar button:hover { border-color: var(--accent); }
.gatehow .howbar input[type=range] { width: 120px; accent-color: var(--accent); }
.gatehow .howbar .val { font: 0.8rem ui-monospace, Menlo, monospace; color: var(--ink); min-width: 2.2em; }
.gatehow .howstatus { font: 0.78rem ui-monospace, Menlo, monospace; letter-spacing: 0.06em; color: var(--ink-3); }
.gatehow .howstatus.busy::before { content: ""; display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--accent); margin-right: 7px; animation: howpulse 1s infinite ease-in-out; }
@keyframes howpulse { 50% { opacity: 0.2; } }
.gatehow :is(button, select, input, a):focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* phones: the drawing on top, the text scrolls over it. The drawing is shown at about half its size, so its labels
   are set larger to stay readable. */
@media (max-width: 820px) {
  .gatehow .story { grid-template-columns: 1fr; width: 100%; }
  .gatehow .stage { grid-column: 1; height: 52vh; height: 52svh; top: 3.5rem; z-index: 1; background: linear-gradient(var(--paper) 88%, transparent); }
  .gatehow .stage > svg { width: min(92vw, 46vh); }
  .gatehow .steps { grid-column: 1; grid-row: 1; padding: 58vh 20px 30vh; position: relative; z-index: 2; pointer-events: none; }
  .gatehow .step { min-height: 70vh; justify-content: flex-end; padding-bottom: calc(6vh + 3rem); }
  .gatehow .step p { font-size: 1.3rem; background: color-mix(in srgb, var(--paper) 92%, transparent); padding: 0.4rem 0.2rem; border-radius: 4px; }
  .gatehow .step p.small { font-size: 1.02rem; }
  .gatehow #stage text { font-size: 19px; }
  .gatehow #stage text.label { font-size: 18px; }
  .gatehow #stage text.mono { font-size: 13px; letter-spacing: 0.02em; }
  .gatehow #stage text.small { font-size: 15px; }
  .gatehow #stage text.tiny { font-size: 13px; }
}
@media (prefers-reduced-motion: reduce) {
  .gatehow .step { transition: none; }
  .gatehow .howstatus.busy::before { animation: none; }
}