/* eventline site. Tokens first: six colours, two faces, one accent.
   frontstage.css supplies the floor; this file is the page's own composition. */

@font-face {
  font-family: "Bricolage Grotesque";
  src: url("assets/fonts/bricolage-grotesque.woff2") format("woff2");
  font-weight: 200 800;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("assets/fonts/jetbrains-mono.woff2") format("woff2");
  font-weight: 100 800;
  font-display: swap;
}

:root {
  --sc-canvas: #0a0e1a;
  --sc-surface: #121a2e;
  --sc-ink: #f3f5fa;
  --sc-ink-soft: #c2cadd;
  --sc-accent: #ffd400;
  --sc-accent-ink: #0a0e1a;
  --sc-font-display: "Bricolage Grotesque", system-ui, sans-serif;
  --sc-font-text: "Bricolage Grotesque", system-ui, sans-serif;
  --sc-font-mono: "JetBrains Mono", ui-monospace, monospace;
  --sc-shadow-color: 224 50% 3%;

  --bar-h: 3.5rem;
  --code-dim: #9ba6c2;
  --r: 10px; /* one radius for the page */
  --page-pad: max(var(--sc-gutter), calc((100vw - 96rem) / 2)); /* keeps the stages readable on ultrawide screens */
}

body { background: var(--sc-canvas); font-weight: 400; }
.sc-display { font-weight: 650; }
.sc-lede { font-weight: 450; }
code, pre, kbd { font-family: var(--sc-font-mono); }

/* ------------------------------------------------------------- scenes -- */
.scene { color: var(--sc-ink); background: var(--sc-canvas); position: relative; }
.scene--dark  { --sc-canvas: #0a0e1a; }
.scene--mid   { --sc-canvas: #0f1a38; --sc-surface: #17244a; }
.scene--deep  { --sc-canvas: #05070d; --sc-surface: #0d1220; --code-dim: #98a3c0; }
.scene--light {
  --sc-canvas: #eef2f8; --sc-surface: #ffffff;
  --sc-ink: #0a0e1a; --sc-ink-soft: #38425f;
  --sc-hairline: rgba(10, 14, 26, 0.16);
  --sc-hairline-strong: rgba(10, 14, 26, 0.32);
  --sc-shadow-color: 224 30% 20%;
  color: var(--sc-ink);
}
.scene--hit {
  --sc-canvas: #ffd400; --sc-surface: #0a0e1a;
  --sc-ink: #0a0e1a; --sc-ink-soft: #2a3150;
  --sc-hairline: rgba(10, 14, 26, 0.28);
  --sc-hairline-strong: rgba(10, 14, 26, 0.6);
  --sc-shadow-color: 45 80% 12%;
  color: var(--sc-ink);
}
.scene--light :focus-visible, .scene--hit :focus-visible { outline-color: #0a0e1a; }
.scene--light ::selection, .scene--hit ::selection { background: #0a0e1a; color: #ffd400; }

/* -------------------------------------------------------------- chrome -- */
.bar {
  position: fixed; inset: 0 0 auto 0; z-index: var(--sc-z-chrome);
  height: var(--bar-h);
  display: flex; align-items: center; gap: var(--sc-5);
  padding-inline: var(--page-pad);
  background: #0a0e1a; color: #f3f5fa;
  border-bottom: 1px solid rgba(243, 245, 250, 0.12);
}
.bar__mark { display: inline-flex; align-items: center; gap: var(--sc-2); text-decoration: none; font-weight: 700; letter-spacing: var(--sc-track-snug); min-height: 44px; }
.bar__nav { display: flex; gap: var(--sc-5); margin-left: var(--sc-5); }
.bar__nav a {
  position: relative; text-decoration: none; color: #c2cadd;
  display: inline-flex; align-items: center; min-height: 44px;
  font-size: var(--sc-t-sm);
  transition: color var(--sc-d-fast) var(--sc-ease-out);
}
.bar__nav a[aria-current] { color: #f3f5fa; }
.bar__nav a[aria-current]::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 6px; height: 2px;
  background: #ffd400; border-radius: 2px;
}
.bar__ev {
  margin-left: auto; font-family: var(--sc-font-mono); font-size: var(--sc-t-xs);
  color: #c2cadd; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  max-width: 24rem; min-width: 0;
}
.bar__ev.is-pulse { animation: ev-pulse 360ms var(--sc-ease-out); }
@keyframes ev-pulse { from { color: #ffd400; transform: translateX(6px); opacity: 0.4; } to { color: #c2cadd; transform: none; opacity: 1; } }
.bar__log {
  min-height: 44px; padding: 0 var(--sc-3); background: transparent; color: #f3f5fa;
  border: 1px solid rgba(243, 245, 250, 0.28); border-radius: var(--r); cursor: pointer;
  font-size: var(--sc-t-sm);
  transition: transform var(--sc-d-fast) var(--sc-ease-out), border-color var(--sc-d-fast) var(--sc-ease-out);
}
@media (hover: hover) and (pointer: fine) { .bar__log:hover { border-color: #ffd400; } }
.bar__log:active { transform: scale(0.97); }

.cta {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 0 1.5em; border-radius: var(--r); border: 2px solid transparent; white-space: nowrap;
  background: var(--sc-accent); color: var(--sc-accent-ink);
  font-weight: 700; text-decoration: none; letter-spacing: var(--sc-track-snug);
  transition: transform var(--sc-d-fast) var(--sc-ease-out);
}
.cta--bar { min-height: 40px; padding: 0 1.1em; background: #ffd400; color: #0a0e1a; }
.bar__log { white-space: nowrap; }
@media (hover: hover) and (pointer: fine) { .cta:hover { transform: translateY(-2px); } }
.cta:active { transform: scale(0.97); }

.btn {
  min-height: 44px; padding: 0 1.1em; border-radius: var(--r);
  background: var(--sc-surface); color: var(--sc-ink);
  border: 1px solid var(--sc-hairline-strong);
  font-family: var(--sc-font-mono); font-size: var(--sc-t-sm); font-weight: 500;
  cursor: pointer;
  transition: transform var(--sc-d-fast) var(--sc-ease-out), border-color var(--sc-d-fast) var(--sc-ease-out), background-color var(--sc-d-fast) var(--sc-ease-out);
}
@media (hover: hover) and (pointer: fine) { .btn:hover:not(:disabled) { border-color: var(--sc-accent); } }
.btn:active:not(:disabled) { transform: scale(0.97); }
.btn:disabled { cursor: not-allowed; color: var(--code-dim); border-style: dashed; }
.btn--quiet { background: transparent; font-family: var(--sc-font-text); min-height: 36px; padding: 0 0.9em; font-size: var(--sc-t-xs); }
.btn--quiet[aria-pressed="true"] { border-color: var(--sc-accent); }
.btn--quiet { min-width: 24px; }
.btn--ink { background: #0a0e1a; color: #ffd400; border-color: #0a0e1a; font-family: var(--sc-font-text); font-weight: 700; }

/* ---------------------------------------------------------------- hero -- */
.pf-hero {
  min-height: 100vh; min-height: 100svh;
  padding: calc(var(--bar-h) + var(--sc-6)) 0 0;
  display: grid; grid-template-rows: minmax(0, 1fr) auto;
  overflow: clip;
}
.pf-hero__top {
  padding-inline: var(--page-pad);
  display: grid; gap: var(--sc-5) var(--sc-9); align-content: center; align-items: center;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
}
.pf-hero__copy h1 { max-width: 15ch; font-size: clamp(2.6rem, 1.1rem + 4.6vw, 4.9rem); }
.pf-hero__copy .sc-lede { max-width: 38ch; }
.pf-actions { display: flex; flex-wrap: wrap; gap: var(--sc-3); align-items: center; margin-top: var(--sc-5); }
.pf-copy {
  display: inline-flex; align-items: center; gap: var(--sc-3); min-height: 48px; padding: 0 var(--sc-3) 0 var(--sc-4);
  background: transparent; border: 1px solid var(--sc-hairline-strong); border-radius: var(--r); cursor: pointer;
  transition: transform var(--sc-d-fast) var(--sc-ease-out), border-color var(--sc-d-fast) var(--sc-ease-out);
}
.pf-copy code { font-size: var(--sc-t-sm); }
.pf-copy span { font-size: var(--sc-t-xs); font-weight: 600; padding: 0.25rem 0.55rem; border-radius: 5px; background: color-mix(in oklab, var(--sc-ink) 12%, transparent); min-width: 4.4rem; text-align: center; }
@media (hover: hover) and (pointer: fine) { .pf-copy:hover { border-color: var(--sc-accent); } }
.pf-copy:active { transform: scale(0.97); }
.pf-console { align-self: center; display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--sc-3); min-width: 0; }
.pf-console__btns { display: flex; flex-wrap: wrap; gap: var(--sc-2); }
.pf-console__code {
  background: var(--sc-surface); border: 1px solid var(--sc-hairline); border-radius: var(--r);
  box-shadow: var(--sc-e2), var(--sc-edge); padding: var(--sc-4); min-height: 9.5rem;
}
.pf-code { margin: 0; font-size: var(--sc-t-xs); line-height: 1.65; overflow-x: auto; white-space: pre; }
.pf-code[hidden] { display: none; }
.pf-code .ln { display: block; padding-inline: 0.5ch; margin-inline: -0.5ch; border-radius: 3px; }
.pf-code .ln.is-hit { background: color-mix(in oklab, var(--sc-accent) 16%, transparent); box-shadow: inset 2px 0 0 var(--sc-accent); }
.pf-code .ln.is-hit::before { content: "\25B8 "; position: absolute; margin-left: -2ch; color: var(--sc-accent); }
.pf-status { margin: 0; font-size: var(--sc-t-sm); color: var(--sc-ink-soft); min-height: 3.2em; max-width: 52ch; }
.pf-views { display: flex; flex-wrap: wrap; gap: var(--sc-2) var(--sc-5); margin: 0; font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); }
.pf-views div { display: flex; gap: var(--sc-2); align-items: baseline; }
.pf-views dt { color: var(--sc-ink-soft); }
.pf-views dt::after { content: " ="; }
.pf-views dd { margin: 0; color: var(--sc-ink); font-variant-numeric: tabular-nums; }

/* syntax roles carry meaning through weight and shape as well as colour */
.t-kw { color: #c3cbe0; font-weight: 700; }
.t-ev { color: var(--sc-accent); }
.t-cmd { font-weight: 700; }
.t-an { color: #c3cbe0; font-style: italic; }
.t-str { color: #b8c2dc; }

/* the river: events travel left from "now". The right of the playhead is the future, hatched and empty. */
.pf-river { margin-top: var(--sc-5); min-width: 0; }
.pf-river__head { display: flex; flex-wrap: wrap; align-items: center; gap: var(--sc-2) var(--sc-6); padding: 0 var(--page-pad) var(--sc-3); }
.pf-river__head .sc-label { margin-right: auto; }
.pf-river__tools { display: flex; align-items: center; gap: var(--sc-3); }
.pf-asof { font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); font-variant-numeric: tabular-nums; min-width: 9ch; text-align: right; }
.pf-asof.is-live::before { content: ""; display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--sc-accent); margin-right: 0.6ch; vertical-align: 0.05em; animation: live-dot 1.6s var(--sc-ease-in-out) infinite; }
@keyframes live-dot { 50% { opacity: 0.25; } }
.btn--go { background: var(--sc-accent); color: var(--sc-accent-ink); border-color: var(--sc-accent); font-family: var(--sc-font-text); font-weight: 700; min-height: 36px; font-size: var(--sc-t-xs); }
.btn--go[hidden], .pf-lane__cue[hidden] { display: none; }
.pf-lane__view {
  position: relative; height: 12.5rem; contain: paint; touch-action: pan-y; cursor: grab; user-select: none; -webkit-user-select: none;
  border-block: 1px solid var(--sc-hairline);
  /* a ruler along the bottom edge, scrolled with the river */
  background:
    linear-gradient(to right, var(--sc-hairline-strong) 0 1px, transparent 1px) calc(var(--off, 0) * -1px) 100% / 200px 12px repeat-x,
    linear-gradient(to right, var(--sc-hairline) 0 1px, transparent 1px) calc(var(--off, 0) * -1px) 100% / 40px 6px repeat-x;
  -webkit-mask-image: linear-gradient(to right, transparent, #000 7%);
  mask-image: linear-gradient(to right, transparent, #000 7%);
}
.pf-lane__view.is-drag { cursor: grabbing; }
.pf-lane__track { position: absolute; inset: 0; will-change: transform; }
.pf-lane__future {
  position: absolute; top: 0; bottom: 0; left: calc(var(--ph, 66) * 1%); right: 0; pointer-events: none;
  background: repeating-linear-gradient(135deg, transparent 0 8px, color-mix(in oklab, var(--sc-ink) 6%, transparent) 8px 9px);
}
.pf-play {
  position: absolute; top: 0; bottom: 0; left: calc(var(--ph, 66) * 1%); width: 44px; margin-left: -22px; z-index: 3; cursor: ew-resize; outline: none;
}
.pf-play::before { content: ""; position: absolute; top: 0; bottom: 0; left: 50%; width: 2px; margin-left: -1px; background: var(--sc-accent); }
.pf-play__tag {
  position: absolute; top: 8px; left: 50%; transform: translateX(-50%);
  padding: 0.2rem 0.55rem; border-radius: 5px; background: var(--sc-accent); color: var(--sc-accent-ink);
  font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); font-weight: 700; white-space: nowrap; font-variant-numeric: tabular-nums;
}
.pf-play:focus-visible .pf-play__tag { outline: 2px solid var(--sc-ink); outline-offset: 3px; }
.pf-lane__cue {
  position: absolute; left: calc(var(--ph, 66) * 1% + 1.6rem); top: 10px; margin: 0;
  font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); pointer-events: none; white-space: nowrap;
}
.pf-lane__cue::before { content: "\2190\00a0"; color: var(--sc-accent); }
.chip {
  position: absolute; display: flex; flex-direction: column; justify-content: center; gap: 1px; width: 208px; height: 46px;
  padding: 0 0.8rem; border-radius: 6px;
  background: var(--sc-accent); color: var(--sc-accent-ink);
  font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); line-height: 1.25; white-space: nowrap;
  animation: zip 260ms var(--sc-ease-out) backwards;
  transition: opacity 180ms var(--sc-ease-out);
}
.chip b { font-weight: 700; overflow: hidden; text-overflow: ellipsis; }
.chip i { font-style: normal; opacity: 0.8; font-size: 0.85em; }
/* the trail: speed shown as a smear behind the event, not as glow */
.chip::before {
  content: ""; position: absolute; left: 100%; top: 0; bottom: 0; width: 110px;
  background: linear-gradient(to right, color-mix(in oklab, var(--sc-accent) 70%, transparent), transparent);
  border-radius: 0 6px 6px 0; pointer-events: none;
}
.chip--no { background: transparent; color: var(--sc-ink); border: 1.5px dashed var(--sc-accent); }
.chip--no::before { background: linear-gradient(to right, color-mix(in oklab, var(--sc-accent) 22%, transparent), transparent); }
.chip.is-future { opacity: 0.22; }
.is-scrub .chip::before { display: none; }
@keyframes zip { from { opacity: 0; transform: translateX(40px) scale(0.95); } to { opacity: 1; transform: none; } }
.pf-lane__view.is-static { height: auto; padding-block: var(--sc-3); -webkit-mask-image: none; mask-image: none; background: none; cursor: auto; touch-action: auto; }
.pf-lane__view.is-static .pf-lane__track { position: static; display: flex; flex-wrap: wrap; gap: var(--sc-2); padding-inline: var(--page-pad); }
.pf-lane__view.is-static .chip { position: static; animation: none; width: auto; height: auto; padding: 0.35rem 0.7rem; }
.pf-lane__view.is-static .chip::before { display: none; }

/* -------------------------------------------------------------- premise -- */
/* Two full-bleed lenses on one system, laid out on the same grid. The wipe moves the edge of "events" across "boxes". */
.pf-lens__a, .pf-lens__b {
  position: absolute; inset: 0; background: var(--sc-canvas); color: var(--sc-ink);
  padding: calc(var(--bar-h) + var(--sc-7)) var(--page-pad) var(--sc-7);
  display: grid; grid-template-rows: auto 1fr auto; gap: var(--sc-6); align-items: center;
}
.pf-lens__b {
  --sc-canvas: #0a0e1a; --sc-surface: #121a2e; --sc-ink: #f3f5fa; --sc-ink-soft: #c2cadd;
  --sc-hairline: rgba(243, 245, 250, 0.16); --sc-hairline-strong: rgba(243, 245, 250, 0.32);
}
.pf-lens__copy h2 { max-width: 12ch; font-size: clamp(3rem, 1rem + 6.2vw, 7.6rem); line-height: 0.92; letter-spacing: var(--sc-track-tight); }
.pf-lens__b .pf-lens__copy h2 { max-width: 16ch; }
.pf-lens__copy .sc-lede { margin-top: var(--sc-4); max-width: 34ch; color: var(--sc-ink-soft); }
.pf-lens__row { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0 var(--sc-6); align-self: center; }
.pf-lens__row li { position: relative; display: grid; gap: var(--sc-3); align-content: start; min-width: 0; }
.pf-lens__row li:not(:last-child)::after {
  content: ""; position: absolute; top: 3.2rem; left: 100%; width: var(--sc-6); height: 2px; background: var(--sc-ink);
}
.pf-lens__row code { font-size: var(--sc-t-sm); color: var(--sc-ink-soft); text-wrap: balance; }
.pf-lens__note { font-size: var(--sc-t-sm); color: var(--sc-ink-soft); line-height: 1.4; text-wrap: balance; }
.lens-node {
  display: grid; align-items: center; min-height: 6.4rem; padding: 0.8rem 1.1rem; border-radius: 10px;
  border: 2px solid var(--sc-ink); font-size: var(--sc-t-lg); line-height: 1.15; overflow-wrap: anywhere;
}
.lens-node--box { background: var(--sc-surface); font-weight: 650; letter-spacing: var(--sc-track-snug); box-shadow: 5px 5px 0 -1px var(--sc-canvas), 5px 5px 0 0 var(--sc-ink); }
.lens-node--ev { background: var(--sc-accent); color: var(--sc-accent-ink); border-color: var(--sc-accent); font-family: var(--sc-font-mono); font-size: var(--sc-t-base); font-weight: 650; }
.lens-node--view { background: var(--sc-surface); border-style: double; border-width: 5px; font-family: var(--sc-font-mono); font-size: var(--sc-t-base); font-weight: 650; }
.pf-lens__cap { margin: 0; align-self: end; }
.pf-lens__edge { position: absolute; top: 0; bottom: 0; left: 0; width: 3px; background: var(--sc-accent); box-shadow: 0 0 0 1px #0a0e1a; z-index: 2; pointer-events: none; will-change: transform; }

/* ---------------------------------------------------------------- board -- */
/* The board is an image derived by eventline-axi from twitter-pure.dsl (scripts/build-site.js). */
.pf-board { display: flex; align-items: center; padding: calc(var(--bar-h) + var(--sc-5)) 0 4.5rem; }
.pf-board__rail { display: flex; align-items: center; height: 100%; padding-left: var(--page-pad); }
.pf-board__lead { flex: 0 0 min(26rem, 78vw); padding-right: var(--sc-7); }
.pf-board__lead h2 { max-width: 10ch; }
.pf-board__lead p { max-width: 36ch; }
.pf-board__lead code { font-size: 0.86em; color: var(--sc-accent); overflow-wrap: anywhere; }
.pf-board__fig { flex: none; margin: 0; padding-right: var(--page-pad); }
.pf-board__fig :is(img, svg) { display: block; width: auto; max-width: none; height: min(calc(100svh - var(--bar-h) - 7rem), 52rem); border-radius: var(--r); }
/* trace: pointing at a box lights its whole lineage and dims the rest */
.pf-board__fig svg .nd, .pf-board__fig svg .ed { transition: opacity 200ms var(--sc-ease-out); }
.pf-board__fig svg.is-tracing .nd:not(.is-on), .pf-board__fig svg.is-tracing .ed:not(.is-on) { opacity: 0.14; }
.pf-board__fig svg.is-tracing .ed.is-on path { stroke: #ffd400; stroke-width: 2.4; }
.pf-board__fig svg .nd { cursor: crosshair; }
.pf-trace {
  position: absolute; left: var(--page-pad); right: var(--page-pad); bottom: var(--sc-5); margin: 0; z-index: 4; pointer-events: none;
  font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); max-width: 70ch; line-height: 1.55;
  text-shadow: 0 0 12px #0a0e1a, 0 0 4px #0a0e1a;
}
.pf-trace b { color: var(--sc-accent); font-weight: 700; }
/* When the board already fits the screen there is nothing to pan, so it stops pinning and simply lays out. */
.pf-board--flat { position: relative; height: 100vh; height: 100svh; }
.pf-board--flat .pf-board__rail { justify-content: center; padding-inline: var(--page-pad); }
.pf-board--flat .pf-board__fig { padding-right: 0; }

/* --------------------------------------------------------------- proof -- */
.pf-proof {
  padding: calc(var(--bar-h) + var(--sc-5)) var(--page-pad) var(--sc-5);
  display: grid; gap: var(--sc-4) var(--sc-7); min-height: 0;
  grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
  grid-template-rows: auto minmax(0, 1fr);
  grid-template-areas: "title title" "code out";
}
.pf-proof__title { grid-area: title; }
.pf-proof__code {
  grid-area: code; position: relative; contain: paint; min-height: 0;
  background: var(--sc-surface); border: 1px solid var(--sc-hairline); border-radius: var(--r); box-shadow: var(--sc-e2), var(--sc-edge);
  -webkit-mask-image: linear-gradient(to bottom, transparent 0, #000 7%, #000 93%, transparent 100%);
  mask-image: linear-gradient(to bottom, transparent 0, #000 7%, #000 93%, transparent 100%);
}
.pf-code__inner {
  padding: var(--sc-6) var(--sc-5); font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); line-height: 1.7;
  transition: transform 280ms var(--sc-ease-out), opacity 240ms var(--sc-ease-out); will-change: transform;
}
.blk { margin: 0 0 var(--sc-4); padding-inline: 0.75rem; margin-inline: -0.75rem; border-radius: 4px; color: var(--code-dim); white-space: pre; transition: color 240ms var(--sc-ease-out); }
.blk .ln { display: block; }
.blk :is(.t-kw, .t-an, .t-str, .t-cmd) { color: inherit; }
.blk .t-ev { color: inherit; }
.blk.is-active { color: var(--sc-ink); background: color-mix(in oklab, var(--sc-accent) 10%, transparent); box-shadow: inset 3px 0 0 var(--sc-accent); }
.blk.is-active .t-ev { color: var(--sc-accent); }
.blk.is-active .t-kw, .blk.is-active .t-an { color: #c3cbe0; }
.blk.is-active .t-str { color: #b8c2dc; }
.pf-proof__final {
  grid-area: code; align-self: center; z-index: 2; opacity: 0; pointer-events: none; padding: var(--sc-4) var(--sc-3);
  transition: opacity 280ms var(--sc-ease-out);
}
.pf-proof__final .sc-display { max-width: 12ch; }
.pf-proof__final .sc-lede { margin-top: var(--sc-4); color: var(--sc-ink-soft); }
.pf-proof[data-final="1"] .pf-proof__final { opacity: 1; }
.pf-proof[data-final="1"] .pf-proof__code { opacity: 0; transition: opacity 240ms var(--sc-ease-out); }
.pf-proof__code { transition: opacity 240ms var(--sc-ease-out); }

.pf-proof__out { grid-area: out; display: grid; grid-template-rows: auto auto minmax(0, 1fr) auto; gap: var(--sc-3); min-height: 0; min-width: 0; }
.pf-out__head { display: flex; align-items: center; justify-content: space-between; gap: var(--sc-3); }
.pf-stream { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; overflow: hidden; min-height: 0; }
.pf-stream li {
  display: flex; flex-wrap: wrap; gap: 0.15rem 0.75rem; align-items: baseline;
  padding: 0.45rem 0.7rem; border-radius: 6px; background: var(--sc-accent); color: var(--sc-accent-ink);
  font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); line-height: 1.3; animation: row-in 240ms var(--sc-ease-out) both;
}
.pf-stream li b { font-weight: 700; }
.pf-stream li code { opacity: 0.85; overflow-wrap: anywhere; }
.pf-stream li.is-no { background: transparent; color: var(--sc-ink); border: 1.5px dashed var(--sc-accent); }
.pf-stream li.is-meta { background: var(--sc-surface); color: var(--sc-ink); border: 1px solid var(--sc-hairline-strong); }
@keyframes row-in { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: none; } }
.pf-views--proof { flex-direction: column; gap: var(--sc-2); padding-block: var(--sc-2); border-block: 1px solid var(--sc-hairline); }
.pf-stream:empty::before { content: "No events yet. The stream fills as each command runs."; color: var(--sc-ink-soft); font-size: var(--sc-t-sm); }

/* ------------------------------------------------------------ playground -- */
.pg { padding: calc(var(--bar-h) + var(--sc-7)) var(--page-pad) var(--sc-8); display: grid; gap: var(--sc-5); }
.pg__head { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: var(--sc-4) var(--sc-7); align-items: end; }
.pg__title h2 { max-width: 14ch; }
.pg__title .sc-lede { max-width: 46ch; color: var(--sc-ink-soft); }
.pg__presets { display: flex; flex-wrap: wrap; gap: var(--sc-2); justify-content: flex-end; max-width: 34rem; }
.pg__tab {
  min-height: 44px; padding: 0 1.1em; border-radius: 999px; background: transparent; color: var(--sc-ink);
  border: 1px solid var(--sc-hairline-strong); cursor: pointer; font-size: var(--sc-t-sm); font-weight: 600;
  transition: transform var(--sc-d-fast) var(--sc-ease-out), background-color var(--sc-d-fast) var(--sc-ease-out), border-color var(--sc-d-fast) var(--sc-ease-out);
}
@media (hover: hover) and (pointer: fine) { .pg__tab:hover { border-color: var(--sc-accent); } }
.pg__tab:active { transform: scale(0.97); }
.pg__tab[aria-pressed="true"] { background: var(--sc-accent); color: var(--sc-accent-ink); border-color: var(--sc-accent); }
.pg__grid { display: grid; grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr); gap: var(--sc-4); height: min(72svh, 46rem); min-height: 30rem; }
.pg__ed, .pg__bd {
  display: grid; grid-template-columns: minmax(0, 1fr); grid-template-rows: auto minmax(0, 1fr); min-width: 0; min-height: 0;
  background: #0a0e1a; border: 1px solid var(--sc-hairline-strong); border-radius: var(--r); overflow: hidden;
  box-shadow: var(--sc-e3), var(--sc-edge);
}
.pg__bar { display: flex; justify-content: space-between; align-items: center; gap: var(--sc-3); padding: 0 var(--sc-4); min-height: 3rem; border-bottom: 1px solid var(--sc-hairline); background: #0f1630; }
.pg__bar--kinds { padding-inline: var(--sc-2) var(--sc-4); min-height: 3.2rem; }
.pg__kinds { display: flex; gap: 2px; overflow-x: auto; flex: 1 1 0; min-width: 0; scrollbar-width: none; }
.pg__kinds::-webkit-scrollbar { display: none; }
.pg__kind {
  flex: none; min-height: 44px; padding: 0 0.85em; background: transparent; color: var(--sc-ink-soft); border: 0; border-radius: 8px; cursor: pointer;
  font-size: var(--sc-t-sm); font-weight: 600; white-space: nowrap; position: relative;
  transition: color var(--sc-d-fast) var(--sc-ease-out), background-color var(--sc-d-fast) var(--sc-ease-out);
}
@media (hover: hover) and (pointer: fine) { .pg__kind:hover:not(:disabled) { color: var(--sc-ink); } }
.pg__kind[aria-selected="true"] { color: var(--sc-ink); }
.pg__kind[aria-selected="true"]::after { content: ""; position: absolute; left: 0.85em; right: 0.85em; bottom: 4px; height: 2px; border-radius: 1px; background: var(--sc-accent); }
.pg__kind:disabled { opacity: 0.4; cursor: not-allowed; }
.pg__kind:focus-visible { outline: 2px solid var(--sc-accent); outline-offset: -2px; }
.pg__hint { font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); }
.pg__code { position: relative; min-height: 0; display: grid; }
/* the selected block: a band under the text, moved with the editor's scroll */
.pg__hl { grid-area: 1 / 1; position: relative; overflow: hidden; pointer-events: none; }
.pg__hl-in { position: absolute; inset: 0; will-change: transform; }
.pg__hl-in i {
  position: absolute; left: 0; right: 0; background: color-mix(in oklab, var(--sc-accent) 13%, transparent);
  box-shadow: inset 3px 0 0 var(--sc-accent); transition: opacity 160ms var(--sc-ease-out);
  animation: hl-in 200ms var(--sc-ease-out);
}
@keyframes hl-in { from { opacity: 0; } to { opacity: 1; } }
.pg__mirror, .pg__area {
  grid-area: 1 / 1; margin: 0; padding: var(--sc-4); border: 0; min-width: 0; min-height: 0;
  font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); line-height: 1.7; letter-spacing: 0; tab-size: 2;
  white-space: pre; overflow: auto; overflow-wrap: normal; word-break: normal; font-variant-ligatures: none;
}
.pg__mirror { pointer-events: none; color: var(--sc-ink); overflow: hidden; }
.pg__mirror code { font: inherit; display: block; }
.pg__area { background: transparent; color: transparent; caret-color: var(--sc-accent); resize: none; outline: none; -webkit-text-fill-color: transparent; }
.pg__area::selection { background: color-mix(in oklab, var(--sc-accent) 38%, transparent); -webkit-text-fill-color: transparent; }
.pg__code:focus-within { box-shadow: inset 0 0 0 2px var(--sc-accent); }
/* a mark in the editor's left margin for each line a check is about: shape and weight say how serious, not colour alone */
.pg__marks b { position: absolute; left: 3px; width: 11px; display: grid; place-items: center; font: 700 9px/1 var(--sc-font-mono); }
.pg__marks b[data-s="error"] { color: var(--sc-accent); font-size: 11px; }
.pg__marks b[data-s="warn"] { color: var(--sc-accent); }
.pg__marks b[data-s="info"] { color: var(--sc-ink-soft); opacity: 0.8; }
.pg__board svg .issue-badge { pointer-events: none; }
.t-cm { color: #7f8aa8; font-style: italic; }
.pg__board { min-height: 0; overflow: auto; display: grid; place-items: start; cursor: grab; overscroll-behavior: contain; }
.pg__board.is-drag { cursor: grabbing; user-select: none; }
.pg__board.is-fit { cursor: default; }
.pg__board svg { display: block; flex: none; max-width: none; }
.pg__board.is-fit { place-items: center; }
.pg__board.is-fit svg { width: 100%; height: auto; max-height: 100%; }
.pg__board svg .nd { cursor: pointer; outline: none; }
.pg__board svg a { cursor: pointer; }
.pg__board svg .gp.is-flash { animation: gp-flash 1.4s var(--sc-ease-out); }
@keyframes gp-flash { from { filter: drop-shadow(0 0 8px #ffd400) drop-shadow(0 0 2px #ffd400); } to { filter: drop-shadow(0 0 0 transparent); } }
.pg__board svg a.lnk-badge:hover rect { fill: #fff; }
.pg__board svg a.lnk-badge:focus-visible rect { stroke-width: 2.5; stroke: #f3f5fa; }
.pg__board svg .nd.is-sel { filter: drop-shadow(0 0 3px #ffd400); }
.pg__board svg .nd:focus-visible { filter: drop-shadow(0 0 4px #f3f5fa); }
.pg__board svg .nd, .pg__board svg .ed { transition: opacity 200ms var(--sc-ease-out); }
.pg__board svg.is-tracing .nd:not(.is-on), .pg__board svg.is-tracing .ed:not(.is-on) { opacity: 0.14; }
.pg__board svg.is-tracing .nd:not(.is-on) .lnk-badge { pointer-events: none; }
.pg__board svg.is-tracing .ed.is-on path { stroke: #ffd400; stroke-width: 2.4; }
.pg__empty { margin: auto; color: var(--sc-ink-soft); font-size: var(--sc-t-sm); padding: var(--sc-5); }
.pg__grid[data-state="error"] .pg__board svg { opacity: 0.35; }
.pg__foot { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: var(--sc-4) var(--sc-6); align-items: start; }
.pg__read { display: grid; gap: var(--sc-2); min-width: 0; }
.pg__status, .pg__trace { margin: 0; font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); line-height: 1.6; }
.pg__status { color: var(--sc-ink); }
.pg__status.is-error { color: #ffd400; }
.pg__trace { color: var(--sc-ink-soft); }
.pg__trace b { color: var(--sc-accent); }
.pg__issues { list-style: none; margin: var(--sc-2) 0 0; padding: 0; display: grid; gap: 4px; font-size: var(--sc-t-sm); color: var(--sc-ink-soft); max-width: 90ch; }
.pg__issues li { display: grid; grid-template-columns: 1.4rem minmax(0, 1fr); gap: 0 var(--sc-2); align-items: baseline; }
.pg__checks { display: flex; flex-wrap: wrap; align-items: center; gap: var(--sc-2); margin-top: var(--sc-3); }
.pg__checks-label { font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); margin-right: var(--sc-1); }
.pg__check {
  min-height: 36px; padding: 0 0.9em; border-radius: 999px; background: transparent; color: var(--sc-ink); border: 1px solid var(--sc-hairline-strong); cursor: pointer;
  font-size: var(--sc-t-xs); font-weight: 600; transition: background-color var(--sc-d-fast) var(--sc-ease-out), border-color var(--sc-d-fast) var(--sc-ease-out), transform var(--sc-d-fast) var(--sc-ease-out);
}
@media (hover: hover) and (pointer: fine) { .pg__check:hover { border-color: var(--sc-accent); } }
.pg__check:active { transform: scale(0.97); }
.pg__check[aria-pressed="true"] { background: var(--sc-accent); color: var(--sc-accent-ink); border-color: var(--sc-accent); }
.pg__check:focus-visible, .pg__checks-more:focus-visible, .pg__more:focus-visible { outline: 2px solid var(--sc-accent); outline-offset: 2px; }
.pg__checks-more { font-size: var(--sc-t-xs); color: var(--sc-ink-soft); margin-left: var(--sc-2); }
.pg__summary { margin: var(--sc-2) 0 0; font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); min-height: 1.4em; }
.pg__more { all: unset; margin-top: var(--sc-2); cursor: pointer; font-size: var(--sc-t-sm); text-decoration: underline; text-underline-offset: 0.2em; color: var(--sc-ink-soft); }
.pg__more[hidden] { display: none; }
.pg__issues .pg__cat { font-family: var(--sc-font-mono); font-size: 0.78em; color: var(--sc-ink-soft); border: 1px solid var(--sc-hairline); border-radius: 4px; padding: 0 0.4em; margin-left: 0.6ch; white-space: nowrap; }
.pg__issues .pg__why { margin-left: 0.8ch; font-size: 0.9em; color: var(--sc-ink-soft); }
.pg__issue { all: unset; margin-left: 0.8ch; cursor: pointer; text-decoration: underline; text-underline-offset: 0.2em; text-decoration-color: var(--sc-hairline-strong); }
.pg__issue:hover { color: var(--sc-ink); }
.pg__issue:focus-visible { outline: 2px solid var(--sc-accent); outline-offset: 2px; }
.pg__issues li::before { font-family: var(--sc-font-mono); font-weight: 700; color: var(--sc-accent); }
.pg__issues li[data-s="error"]::before { content: "\25CF"; }
.pg__issues li[data-s="warn"]::before { content: "\25B2"; }
.pg__issues li[data-s="info"]::before { content: "i"; color: var(--sc-ink-soft); }
.pg__tools { display: flex; flex: none; align-items: center; gap: var(--sc-2); }
/* zoom floats over the board's corner, like a map's controls, so the tab strip keeps the bar */
.pg__bd { position: relative; }
.pg__zoom {
  position: absolute; right: var(--sc-3); bottom: var(--sc-3); display: flex; align-items: center; gap: 2px; padding: 3px;
  background: color-mix(in oklab, #0a0e1a 88%, transparent); border: 1px solid var(--sc-hairline-strong); border-radius: 10px; box-shadow: var(--sc-e2);
}
.pg__z {
  min-width: 40px; min-height: 40px; padding: 0 0.6em; background: transparent; color: var(--sc-ink); border: 0; border-radius: 7px; cursor: pointer;
  font-size: var(--sc-t-sm); font-weight: 600; transition: background-color var(--sc-d-fast) var(--sc-ease-out);
}
@media (hover: hover) and (pointer: fine) { .pg__z:hover { background: color-mix(in oklab, var(--sc-ink) 12%, transparent); } }
.pg__z:active { transform: scale(0.96); }
.pg__z:focus-visible { outline: 2px solid var(--sc-accent); outline-offset: -2px; }
.pg__z--fit[aria-pressed="true"] { color: var(--sc-accent); }
.pg__zv { min-width: 3.4rem; text-align: center; font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); color: var(--sc-ink-soft); font-variant-numeric: tabular-nums; }
.pg__out { display: flex; flex-wrap: wrap; gap: var(--sc-2); justify-content: flex-end; }
.pg__out .btn[data-done]::after { content: " \2713"; color: var(--sc-accent); }

/* --------------------------------------------------------------- answers -- */
.pf-faq { padding-block: var(--sc-section); }
.pf-faq__wrap { display: grid; gap: var(--sc-8); grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr); align-items: start; }
.pf-faq__wrap h2 { max-width: 10ch; font-size: var(--sc-t-2xl); position: sticky; top: calc(var(--bar-h) + var(--sc-6)); }
.pf-faq__list { border-top: 1px solid var(--sc-hairline-strong); }
.pf-faq details { border-bottom: 1px solid var(--sc-hairline-strong); }
.pf-faq summary {
  display: flex; justify-content: space-between; align-items: center; gap: var(--sc-4);
  min-height: 4rem; padding-block: var(--sc-4); cursor: pointer; list-style: none;
  font-size: var(--sc-t-lg); font-weight: 600; letter-spacing: var(--sc-track-snug); line-height: 1.2;
}
.pf-faq summary::-webkit-details-marker { display: none; }
.pf-faq summary::after {
  content: ""; flex: none; width: 0.6rem; height: 0.6rem; margin-right: 0.4rem;
  border-right: 2px solid currentColor; border-bottom: 2px solid currentColor; transform: rotate(45deg);
  transition: transform var(--sc-d-base) var(--sc-ease-out);
}
.pf-faq details[open] summary::after { transform: rotate(-135deg); }
.pf-faq details p { margin: 0 0 var(--sc-5); max-width: 60ch; color: var(--sc-ink-soft); line-height: 1.6; text-wrap: pretty; }
.pf-faq code { font-size: 0.88em; background: rgba(10, 14, 26, 0.07); padding: 0.1em 0.35em; border-radius: 4px; }

/* ------------------------------------------------------------------ close -- */
.pf-run { min-height: 100vh; min-height: 100svh; display: grid; grid-template-rows: 1fr auto; padding-top: var(--sc-section); }
.pf-run__wrap { display: grid; gap: var(--sc-8); grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr); align-items: center; padding-bottom: var(--sc-8); }
.pf-run__copy h2 { max-width: 10ch; }
.pf-run .sc-lede { color: var(--sc-ink); }
.pf-cmd { display: flex; gap: var(--sc-2); align-items: stretch; max-width: 40rem; margin-bottom: var(--sc-3); }
.pf-cmd code {
  flex: 1; min-width: 0; padding: var(--sc-4); display: block;
  background: #0a0e1a; color: #f3f5fa; border: 2px solid #0a0e1a; border-radius: var(--r);
  font-size: var(--sc-t-xs); line-height: 1.6; overflow-wrap: anywhere; font-variant-ligatures: none; user-select: all;
}
.pf-cmd code::before { content: "$ "; color: #ffd400; }
.pf-cmd code:focus-visible { outline: 3px solid #0a0e1a; outline-offset: 3px; }
.pf-cmd .btn { min-height: 52px; align-self: flex-start; }
.pf-run__hint { margin: 0; font-size: var(--sc-t-sm); color: var(--sc-ink); max-width: 46ch; }
.pf-run__hint a { font-weight: 700; }
.pf-cli { margin: 0; }
.pf-cli figcaption { margin-bottom: var(--sc-2); color: var(--sc-ink); }
.pf-cli__out {
  margin: 0; padding: var(--sc-5); background: #0a0e1a; color: #f3f5fa; border-radius: var(--r);
  box-shadow: var(--sc-e2); font-size: var(--sc-t-sm); line-height: 1.7; overflow-x: auto;
}
.pf-cli__ps { color: #98a3c0; }
.pf-cli__ps::before { content: ""; }
.pf-cli__out [data-sc-count] { color: #ffd400; font-weight: 700; }
.pf-foot { display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--sc-3) var(--sc-6); padding: var(--sc-5) var(--page-pad); border-top: 1px solid var(--sc-hairline-strong); font-size: var(--sc-t-sm); }
.pf-foot p { margin: 0; }

/* ----------------------------------------------------------------- log -- */
.pf-log {
  width: min(44rem, calc(100vw - 2rem)); max-height: min(80vh, 44rem); padding: var(--sc-5);
  background: #0a0e1a; color: #f3f5fa; border: 1px solid rgba(243, 245, 250, 0.24); border-radius: var(--r);
  box-shadow: var(--sc-e3); overflow: auto;
}
.pf-log::backdrop { background: rgba(5, 7, 13, 0.7); }
.pf-log__bar { display: flex; justify-content: space-between; align-items: center; gap: var(--sc-3); }
.pf-log__bar h2 { margin: 0; font-size: var(--sc-t-xl); font-weight: 650; letter-spacing: var(--sc-track-snug); }
.pf-log .btn { color: #f3f5fa; border-color: rgba(243, 245, 250, 0.4); }
.pf-log__note { margin: var(--sc-3) 0 var(--sc-4); color: #c2cadd; font-size: var(--sc-t-sm); max-width: 56ch; }
.pf-log__list { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px; font-family: var(--sc-font-mono); font-size: var(--sc-t-xs); }
.pf-log__list li { display: grid; grid-template-columns: 3.2rem 4.2rem minmax(0, 1fr); gap: 0 var(--sc-3); padding: 0.3rem 0.5rem; border-radius: 4px; background: #121a2e; align-items: baseline; }
.pf-log__list li > span { color: #c2cadd; }
.pf-log__list li b { color: #ffd400; font-weight: 600; }
.pf-log__list li code { grid-column: 3; color: #c2cadd; overflow-wrap: anywhere; }

/* ------------------------------------------------------------- responsive -- */
@media (max-width: 1000px) {
  .bar__nav { display: none; }
  .pf-hero__top { grid-template-columns: minmax(0, 1fr); align-content: start; padding-top: var(--sc-4); }
  .pf-hero__copy h1 { max-width: 14ch; font-size: var(--sc-t-3xl); }
  .pf-lens__row { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--sc-4) var(--sc-5); }
  .pf-lens__row li:nth-child(2)::after, .pf-lens__row li:last-child::after { display: none; }
  .lens-node { min-height: 4.6rem; }
  .pf-proof { grid-template-columns: minmax(0, 1fr); grid-template-rows: auto minmax(0, 1.1fr) minmax(0, 1fr); grid-template-areas: "title" "code" "out"; gap: var(--sc-3); }
  .pf-proof__out { grid-template-rows: auto auto minmax(0, 1fr) auto; }
  .pf-faq__wrap, .pf-run__wrap { grid-template-columns: minmax(0, 1fr); gap: var(--sc-6); }
  .pg__head, .pg__foot { grid-template-columns: minmax(0, 1fr); }
  .pg__presets, .pg__out { justify-content: flex-start; }
  .pg__grid { grid-template-columns: minmax(0, 1fr); grid-template-rows: minmax(16rem, 22rem) minmax(18rem, 26rem); height: auto; }
  .pf-faq__wrap h2 { position: static; max-width: 14ch; }
}
@media (max-width: 640px) {
  .bar { gap: var(--sc-3); }
  .bar__ev { display: none; }
  .bar__log { margin-left: auto; }
  .pf-board__lead { padding-right: var(--sc-5); }
  .pf-cmd { flex-wrap: wrap; }
  .pf-cmd input { flex: 1 1 100%; font-size: var(--sc-t-xs); }
  .pf-cmd .btn { flex: 1 1 100%; }
  .pf-hero__copy h1 { font-size: var(--sc-t-2xl); }
  .pf-console__code { min-height: 0; padding: var(--sc-3); }
  .pf-river__head { gap: var(--sc-2) var(--sc-4); }
  .pf-river__tools { width: 100%; justify-content: space-between; }
  .pf-proof__code .pf-code__inner { padding: var(--sc-4) var(--sc-3); }
  .pf-proof__final .sc-display { font-size: var(--sc-t-2xl); }
  .pf-views--proof div { flex-wrap: wrap; }
}
@media (max-height: 760px) and (min-width: 1001px) {
  .pf-hero__copy h1 { font-size: var(--sc-t-3xl); }
}

/* --------------------------------------------------------- reduced motion -- */
@media (prefers-reduced-motion: reduce) {
  .chip, .pf-stream li, .bar__ev.is-pulse { animation: none; }
  .pf-code__inner { transition: none; }
}