/* ════════════════════════════════════════════════════════════
   Was That AI? - public site
   "The examination bench": ledger paper, pencil-blue ink,
   grease-pencil red verdicts, black screens for the footage.
   Type: Spectral (display + body) · IBM Plex Mono (data/labels)
   ════════════════════════════════════════════════════════════ */

:root {
  --paper:        #eeede5;
  --paper-2:      #e5e4d9;
  --paper-3:      #d9d8cb;
  --sheet:        #f7f6ef;   /* raised, actionable surfaces */
  --line:         #cfcec0;
  --line-strong:  #a9a898;
  --ink:          #20221c;
  --ink-2:        #4c4f45;
  --ink-3:        #5d6156;   /* ≥4.5:1 on --paper - AA for metadata */
  --blue:         #2b3fa8;   /* pencil blue - the interactive voice */
  --blue-deep:    #1e2f85;
  --blue-soft:    rgba(43, 63, 168, 0.07);
  --mark:         #b3301c;   /* grease-pencil red - reveal marks only */
  --mark-soft:    rgba(179, 48, 28, 0.06);
  --green:        #4e7247;
  --amber:        #97701f;
  --bronze:       #9a5a34;   /* logo mark bronze - avatar rings only */
  --stage:        #000;      /* video letterbox */
  --chrome:       #171814;   /* monitor chrome around footage */
  --chrome-text:  #9a9c8f;

  --serif: 'Spectral', 'Iowan Old Style', Georgia, serif;
  --mono:  'IBM Plex Mono', ui-monospace, 'SF Mono', monospace;

  --col: 1080px;
  --col-read: 780px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; background: var(--paper-3); }

body {
  font-family: var(--serif);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.75;
  font-size: 1.0625rem;     /* 17px base - kinder to older eyes */
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; }
img, video { max-width: 100%; display: block; }

::selection { background: var(--blue); color: var(--sheet); }

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
  border-radius: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

.container {
  width: 100%;
  max-width: var(--col);
  margin: 0 auto;
  padding: 0 28px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 12px;
  z-index: 200;
  background: var(--blue);
  color: var(--sheet);
  font-family: var(--mono);
  font-size: 0.9rem;
  padding: 8px 16px;
  border-radius: 3px;
}
.skip-link:focus { left: 12px; }

/* shared type utilities */
.mono {
  font-family: var(--mono);
  font-size: 0.8rem;
}
/* Section label - small mono, the register of a log sheet heading */
.overline {
  font-family: var(--mono);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}

/* Even line breaks on headings; orphan control on prose. */
h1, h2, h3 { text-wrap: balance; }
p { text-wrap: pretty; }

/* ── Header ──────────────────────────────────────────────── */

.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 22px;
  padding-bottom: 22px;
}
.wordmark {
  font-family: var(--serif);
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  display: inline-flex;
  align-items: center;
  gap: 12px;
}
.wordmark-logo {
  width: 45px;
  height: 45px;
  display: block;
  flex-shrink: 0;
}
.wordmark em { font-style: italic; }

/* ── Hero: the title frame ───────────────────────────────── */

.hero {
  padding: 48px 0 60px;
  border-bottom: 1px solid var(--line);
}

/* A paused screen sitting on the bench. The one black surface
   above the fold, and it's diegetic - it is the footage. */
.title-frame {
  position: relative;
  background: var(--stage);
  border-radius: 2px;
  padding: clamp(64px, 10vw, 120px) clamp(24px, 6vw, 80px);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: clamp(280px, 38vw, 420px);
  overflow: hidden;
}
/* SMPTE test-signal bars glowing behind the footage. A radial scrim keeps
   the centre dark so the title card stays crisp; colour breathes at the
   edges. The bars are the brand's own mark, here as diegetic screen colour. */
.title-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 70% 62% at center,
      rgba(0, 0, 0, 0.94) 34%, rgba(0, 0, 0, 0.62) 72%, rgba(0, 0, 0, 0.42) 100%),
    linear-gradient(90deg,
      #b4b4b4 0 14.28%, #b4b410 0 28.57%, #10b4b4 0 42.85%,
      #10b410 0 57.14%, #b410b4 0 71.42%, #b41010 0 85.71%, #1010b4 0 100%);
}
.frame-title { position: relative; z-index: 1; }
.frame-meta, .frame-bar { z-index: 1; }
.frame-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2.2rem, 5.4vw, 4rem);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: #f2f1e8;
  text-align: center;
  max-width: 18ch;
  text-wrap: balance;
}
.frame-meta {
  position: absolute;
  top: 18px;
  left: 22px;
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 500;
  color: #f2f1e8;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.55);
}
/* The controls bar: a solid black strip across the foot of the frame,
   overlaying the footage like a real video player's chrome. */
.frame-bar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 11px 18px;
  background: rgba(0, 0, 0, 0.9);
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--chrome-text);
}
.frame-tc { min-width: 8ch; }
.frame-tc-right { text-align: right; }

/* Transport: one play/pause toggle on the far left of the controls bar.
   Shows pause while playing, play when paused. */
.frame-btn {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  padding: 0;
  border: none;
  background: none;
  color: #f2f1e8;
  opacity: 0.85;
  cursor: pointer;
  transition: opacity 0.15s ease;
}
.frame-btn:hover { opacity: 1; }
.frame-btn svg { width: 18px; height: 18px; display: block; fill: currentColor; }
.frame-btn .ic-pause { display: none; }
.frame-btn.is-playing .ic-play { display: none; }
.frame-btn.is-playing .ic-pause { display: block; }
.frame-btn:focus-visible {
  outline: 2px solid rgba(242, 241, 232, 0.75);
  outline-offset: 2px;
  border-radius: 2px;
  opacity: 1;
}

/* The scrubber: a real range input drawn as the thin scrub line.
   00:33:30 is the true frame; everything else is off-air. */
.frame-scrub {
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  height: 26px;
  margin: 0;
  background: transparent;
  cursor: pointer;
  --p: 50%;
}
.frame-scrub::-webkit-slider-runnable-track {
  height: 2px;
  border-radius: 1px;
  background: linear-gradient(to right,
    rgba(242, 241, 232, 0.75) var(--p),
    rgba(242, 241, 232, 0.22) var(--p));
}
.frame-scrub::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: none;
  background: #f2f1e8;
  margin-top: -4.5px;
  transition: transform 0.15s ease;
}
.frame-scrub:hover::-webkit-slider-thumb { transform: scale(1.35); }
.frame-scrub::-moz-range-track {
  height: 2px;
  border-radius: 1px;
  background: rgba(242, 241, 232, 0.22);
}
.frame-scrub::-moz-range-progress {
  height: 2px;
  border-radius: 1px;
  background: rgba(242, 241, 232, 0.75);
}
.frame-scrub::-moz-range-thumb {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: none;
  background: #f2f1e8;
  transition: transform 0.15s ease;
}
.frame-scrub:hover::-moz-range-thumb { transform: scale(1.35); }
.frame-scrub:focus-visible {
  outline: 2px solid rgba(242, 241, 232, 0.75);
  outline-offset: 4px;
}

/* Scrub damage: per-letter spans so each glyph can drift and tilt.
   Word wrappers keep line breaks at spaces, not mid-word. */
.frame-title .w { display: inline-block; white-space: nowrap; }
.frame-title .g {
  display: inline-block;
  transition: transform 0.08s linear;
}

/* Below the player: title, then the description box - the anatomy of a
   video page, set in this system's materials. */
.video-title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.35rem, 2.7vw, 1.75rem);
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-top: 20px;
  text-wrap: balance;
}
.video-desc {
  margin-top: 16px;
  background: var(--paper-2);
  border-radius: 3px;
  padding: 16px 20px;
  width: fit-content;
  max-width: 100%;
}
.hero .lede {
  font-size: 1.1rem;
  color: var(--ink-2);
  max-width: 58ch;
  line-height: 1.7;
  margin-top: 10px;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--ink-2);
  font-weight: 500;
}
.hero-meta .sep { color: var(--line-strong); }

/* ── Method strip ────────────────────────────────────────── */

.method {
  border-bottom: 1px solid var(--line);
  background: var(--paper-2);
}
.method-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}
.method-step {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 14px;
  align-items: baseline;
  padding: 32px 28px 32px 0;
}
.method-step + .method-step {
  border-left: 1px solid var(--line);
  padding-left: 28px;
}
.method-step .num {
  grid-column: 1;
  grid-row: 1;
  font-family: var(--mono);
  font-size: 1rem;
  color: var(--ink-3);
}
.method-step h2 {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--serif);
  font-size: 1.4rem;
  font-weight: 600;
}
.method-step p {
  grid-column: 2;
  grid-row: 2;
  margin-top: 6px;
  font-size: 1rem;
  color: var(--ink-2);
  line-height: 1.65;
  max-width: 38ch;
}

/* ── Contents (category index) ───────────────────────────── */

.contents { padding: 56px 0 12px; }
.contents .overline { display: block; margin-bottom: 18px; }
.contents-list {
  columns: 2;
  column-gap: 56px;
}
.contents-list li { break-inside: avoid; }
.contents-list a {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
  transition: color 0.15s ease;
}
.contents-list a:hover .c-name { color: var(--blue); }
.contents-list .c-num {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--ink-3);
  min-width: 1.8em;
}
.contents-list .c-num-star { color: var(--blue); }
.contents-list .c-name {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--ink);
  transition: color 0.15s ease;
}
.contents-list .c-count {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-3);
}

/* ── Search ──────────────────────────────────────────────── */

.search-row {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 44px 0 8px;
}
.search-row label { flex: 1; display: flex; align-items: center; gap: 12px; }
.search-row .search-glyph { display: none; }
#search {
  flex: 1;
  background: var(--sheet);
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  outline: none;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.05rem;
  padding: 12px 16px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
#search::placeholder { color: var(--ink-3); }
#search:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px var(--blue-soft);
}
#search-count {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--ink-3);
  white-space: nowrap;
}
.search-hint {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-3);
  white-space: nowrap;
}
.search-hint kbd {
  font-family: var(--mono);
  font-size: 0.78rem;
  border: 1px solid var(--line-strong);
  background: var(--sheet);
  padding: 1px 7px;
  border-radius: 3px;
  margin: 0 1px;
}
@media (max-width: 700px) { .search-hint { display: none; } }

/* ── Comments section (the catalog as a comment thread) ──── */

.comments-head {
  margin-top: 44px;
  padding-bottom: 14px;
  margin-bottom: 4px;
  border-bottom: 1px solid var(--line);
}
.comments-count {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.2rem;
  color: var(--ink);
}

/* Top-level comment = a category, voiced by a viewer who caught something. */
.thread { padding: 22px 0; border-bottom: 1px solid var(--line); }
.thread:last-child { border-bottom: none; }
.thread.hidden { display: none; }
.comment-top {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  align-items: start;
}
.comment-main { min-width: 0; }
.cmt-user {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--ink);
}
.cmt-when {
  margin-left: 8px;
  font-weight: 400;
  color: var(--ink-3);
}
.cmt-text {
  margin-top: 6px;
  font-size: 1.08rem;
  line-height: 1.5;
  color: var(--ink);
  max-width: 64ch;
}

/* "X replies" disclosure - the tells in this category. */
.replies { margin-top: 10px; }
.replies > summary {
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--blue);
  transition: color 0.15s ease;
}
.replies > summary::-webkit-details-marker { display: none; }
.replies > summary:hover { color: var(--blue-deep); }
.replies > summary .twist {
  display: inline-block;
  color: var(--blue);
  transition: transform 0.18s ease;
}
.replies[open] > summary .twist { transform: rotate(90deg); }
.reply-list { margin-top: 2px; }
.reply-list .cmt-avatar { width: 32px; height: 32px; font-size: 0.95rem; }
.reply-list .tell-row > a { grid-template-columns: 32px 1fr; gap: 14px; padding: 14px 10px; }

/* Reply rows: avatar, difficulty (where a timestamp would sit), then the
   tell title + summary as the comment body. */
.tell-rows { border-top: 1px solid var(--line); }
.tell-row { border-bottom: 1px solid var(--line); }
.tell-row.hidden { display: none; }
.tell-row > a {
  display: grid;
  grid-template-columns: 40px 1fr;
  align-items: start;
  gap: 16px;
  padding: 18px 12px;
  margin: 0 -12px;
  border-radius: 3px;
  transition: background 0.15s ease;
}
.tell-row > a:hover { background: var(--sheet); }
/* Identicon avatar: a deterministic pixel mark per user, ink on paper. */
.cmt-avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  margin-top: 1px;
  flex-shrink: 0;
  border-radius: 50%;
  overflow: hidden;
  background: var(--paper-2);
  border: 2px solid var(--bronze);
  transition: border-color 0.15s ease;
}
.cmt-avatar svg {
  width: 66%;
  height: 66%;
  display: block;
}
.row-main { min-width: 0; }
.cmt-byline {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-3);
}
.row-title {
  display: block;
  font-weight: 600;
  font-size: 1.13rem;
  line-height: 1.45;
  color: var(--ink);
  margin-top: 3px;
  transition: color 0.15s ease;
}
.tell-row > a:hover .row-title { color: var(--blue); }
.row-summary {
  display: block;
  font-size: 0.98rem;
  color: var(--ink-2);
  line-height: 1.55;
  margin-top: 2px;
}
.cmt-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 16px;
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 0.8rem;
}
/* Quiet content badge; "Learn more" is the primary, obviously-clickable cue. */
.flag-video { color: var(--ink-3); }
.learn-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--blue);
  font-weight: 500;
}
.lm-arrow { transition: transform 0.15s ease; }
.tell-row > a:hover .learn-more { color: var(--blue-deep); }
.tell-row > a:hover .lm-arrow { transform: translateX(3px); }

.diff {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-3);
}
.diff::before {
  content: '●';
  font-size: 0.6em;
  margin-right: 6px;
  vertical-align: 2px;
}
.diff-beginner::before     { color: var(--green); }
.diff-intermediate::before { color: var(--amber); }
.diff-advanced::before     { color: var(--mark); }

.catalog-empty {
  padding: 56px 0;
  text-align: center;
  color: var(--ink-3);
  font-size: 1.02rem;
  display: none;
}
.catalog-empty.show { display: block; }

/* ── About ───────────────────────────────────────────────── */

.about {
  margin-top: 64px;
  border-top: 1px solid var(--line);
  padding: 68px 0 84px;
  background: var(--paper-2);
}
.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.5fr) minmax(0, 1.5fr);
  gap: 40px;
}
.about h2 {
  font-family: var(--serif);
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.2;
  max-width: 16ch;
}
.about-body p {
  color: var(--ink-2);
  margin-bottom: 18px;
  max-width: 82ch;
  font-size: 1.05rem;
}
.about-body p:last-child { margin-bottom: 0; }

/* ── Footer ──────────────────────────────────────────────── */

.site-footer {
  border-top: 1px solid var(--line);
  padding: 52px 0 44px;
  background: var(--paper-2);
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 32px;
  flex-wrap: wrap;
}
.footer-brand .wordmark { font-size: 1.25rem; display: inline; }
.footer-tagline {
  color: var(--ink-2);
  font-size: 0.98rem;
  margin-top: 6px;
  max-width: 38ch;
}
.footer-support { margin-top: 18px; }
.bmc-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  border-radius: 3px;
  border: 1px solid var(--blue);
  background: transparent;
  color: var(--blue);
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  transition: color 0.15s ease, background 0.15s ease;
}
.bmc-button:hover {
  background: var(--blue);
  color: var(--sheet);
}
.bmc-button svg { width: 17px; height: 17px; }
.bmc-note {
  margin-top: 8px;
  font-size: 0.9rem;
  color: var(--ink-3);
  max-width: 38ch;
}
.footer-links { text-align: right; }
.footer-links .overline { display: block; margin-bottom: 12px; }
.footer-links ul {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}
.footer-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 3px;
  border: 1px solid var(--line-strong);
  background: var(--sheet);
  color: var(--ink-2);
  transition: color 0.15s ease, border-color 0.15s ease;
}
.footer-links a:hover {
  color: var(--blue);
  border-color: var(--blue);
}
.footer-links a svg { width: 20px; height: 20px; }
.footer-bottom {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-3);
}

/* ════════════════════════════════════════════════════════════
   Tell page
   ════════════════════════════════════════════════════════════ */

.tell-page {
  max-width: var(--col-read);
  margin: 0 auto;
  padding: 52px 28px 96px;
}

.tell-topline {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--ink-3);
  margin-bottom: 38px;
}
.tell-topline a { color: var(--ink-2); border-bottom: 1px dotted var(--line-strong); }
.tell-topline a:hover { color: var(--blue); border-color: var(--blue); }
.tell-topline .sep { margin: 0 8px; color: var(--line-strong); }

.tell-page h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2.1rem, 5vw, 3rem);
  line-height: 1.14;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
}
.tell-lede {
  font-size: 1.22rem;
  color: var(--ink-2);
  line-height: 1.65;
  margin-bottom: 46px;
  max-width: 56ch;
}

.tell-section { margin-bottom: 44px; }
.section-label {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
  font-size: 1rem;      /* neutralize <h2> defaults; the .overline child owns type */
  font-weight: 400;
  line-height: 1.4;
}
.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--line);
}
/* The verdict: the one place the grease pencil comes out. */
.section-label-answer .overline { color: var(--mark); }
.section-label-answer::after {
  height: 0;
  background: none;
  border-top: 1px dashed rgba(179, 48, 28, 0.45);
}

.tell-section .prose p {
  color: var(--ink-2);
  line-height: 1.8;
  margin-bottom: 16px;
  font-size: 1.05rem;
}
.tell-section .prose p:last-child { margin-bottom: 0; }
.prose strong { color: var(--ink); font-weight: 600; }
.prose em { font-style: italic; }
.prose ul { margin: 4px 0 16px; }
.prose ul li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 9px;
  color: var(--ink-2);
  line-height: 1.7;
  font-size: 1.05rem;
}
.prose ul li::before {
  content: '–';
  position: absolute;
  left: 0;
  color: var(--ink-3);
}

/* "What to look for" list (reference layout, no video yet) */
.looklist { border-top: 1px solid var(--line); }
.looklist li {
  display: flex;
  gap: 18px;
  padding: 15px 4px;
  border-bottom: 1px solid var(--line);
  color: var(--ink-2);
  line-height: 1.7;
  font-size: 1.05rem;
}
.looklist .li-num {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--ink-3);
  padding-top: 4px;
}

/* ── Challenge panel: the screening room ─────────────────── */

.challenge {
  position: relative;
  border: 1px solid var(--line-strong);
  background: var(--sheet);
  border-radius: 3px;
  margin: 56px 0;
  overflow: hidden;
}
/* Colour bars across the top: the test-signal strip that says
   "footage is examined here". The single saturated moment. */
.challenge::before {
  content: '';
  display: block;
  height: 6px;
  background: linear-gradient(90deg,
    #b4b4b4 0 14.28%, #b4b410 0 28.57%, #10b4b4 0 42.85%,
    #10b410 0 57.14%, #b410b4 0 71.42%, #b41010 0 85.71%, #1010b4 0 100%);
}
.challenge-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 18px 26px;
  border-bottom: 1px solid var(--line);
  background: var(--paper-2);
}
.challenge-head .tag {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--ink-3);
  white-space: nowrap;
}
.challenge-question {
  font-family: var(--serif);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--ink);
}
.challenge-body { padding: 26px; }

/* Monitor chrome: black stage + live timecode readout beneath. */
.challenge-video {
  background: var(--stage);
  border-radius: 2px 2px 0 0;
  overflow: hidden;
}
.challenge-video video { width: 100%; max-height: 70vh; }
.tc-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 8px 14px;
  background: var(--chrome);
  border-radius: 0 0 2px 2px;
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--chrome-text);
}
.challenge-support {
  color: var(--ink-2);
  font-size: 1.02rem;
  margin-top: 18px;
  line-height: 1.7;
}
/* Neutral source credit shown under the clip. */
.clip-credit {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-3);
  line-height: 1.5;
}

.hints { margin-top: 22px; border-top: 1px solid var(--line); }
.hints summary {
  list-style: none;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 2px;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  color: var(--ink-2);
  transition: color 0.15s ease;
}
.hints summary::-webkit-details-marker { display: none; }
.hints summary:hover { color: var(--blue); }
.hints summary .twist {
  display: inline-block;
  transition: transform 0.18s ease;
  color: var(--blue);
}
.hints[open] summary .twist { transform: rotate(90deg); }
.hints ul { padding: 2px 2px 18px; }
.hints li {
  display: flex;
  gap: 12px;
  padding: 7px 0;
  color: var(--ink-2);
  font-size: 1rem;
  line-height: 1.65;
}
.hints li::before {
  content: '·';
  color: var(--ink-3);
  font-weight: 700;
}

/* ── Reveal ──────────────────────────────────────────────── */

.reveal-cta {
  display: block;
  width: 100%;
  margin-top: 24px;
  padding: 15px 24px;
  background: var(--blue);
  border: none;
  border-radius: 3px;
  color: var(--sheet);
  font-family: var(--mono);
  font-size: 0.95rem;
  font-weight: 500;
  transition: background 0.15s ease;
}
.reveal-cta:hover { background: var(--blue-deep); }
.reveal-cta-note {
  margin-top: 12px;
  text-align: center;
  font-family: var(--serif);
  font-style: italic;
  font-size: 0.98rem;
  color: var(--ink-3);
}

.reveal-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.4s ease;
}
.reveal-panel.open { grid-template-rows: 1fr; }
.reveal-inner {
  overflow: hidden;
  visibility: hidden;            /* keeps collapsed content out of tab order */
  transition: visibility 0.4s;
}
.reveal-panel.open .reveal-inner { visibility: visible; }
.reveal-content {
  margin-top: 34px;
}
/* Programmatic focus target after reveal; the "The answer" heading announces
   the region, so no focus ring is needed on the container itself. */
.reveal-content:focus { outline: none; }
.reveal-content .section-label { margin-bottom: 14px; }

.timestamps { margin: 18px 0 8px; border-top: 1px solid var(--line); }
.timestamps li { border-bottom: 1px solid var(--line); }
.ts-btn {
  display: flex;
  width: 100%;
  align-items: baseline;
  gap: 16px;
  padding: 13px 4px;
  background: none;
  border: none;
  text-align: left;
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: 1rem;
  line-height: 1.6;
  border-radius: 3px;
  transition: color 0.15s ease, background 0.15s ease;
}
.ts-btn:hover { color: var(--ink); background: var(--mark-soft); }
.ts-btn .ts-time {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--mark);
  white-space: nowrap;
  border-bottom: 1px dotted var(--mark);
}
.ts-static .ts-time { border-bottom: none; }

.reveal-figures { display: grid; gap: 22px; margin: 22px 0; }
.reveal-figures figure {
  border: 1px solid var(--line);
  border-radius: 2px;
  overflow: hidden;
  background: var(--sheet);
}
.reveal-figures img { width: 100%; }
.reveal-figures video { width: 100%; background: var(--stage); }
.reveal-figures figcaption {
  padding: 12px 16px;
  font-size: 0.95rem;
  color: var(--ink-2);
  border-top: 1px solid var(--line);
  line-height: 1.6;
}

.commentary {
  margin: 26px 0 8px;
  padding: 20px 24px;
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  background: var(--paper);
}
.commentary .overline { display: block; margin-bottom: 6px; }
.commentary p { color: var(--ink-2); font-size: 1.02rem; line-height: 1.75; }

.coming-soon {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.02rem;
  color: var(--ink-3);
}

/* ── Prev / next ─────────────────────────────────────────── */

.tell-pagenav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--line-strong);
  margin-top: 64px;
}
.pagenav-link {
  padding: 24px 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-radius: 3px;
  transition: background 0.15s ease;
}
.pagenav-link:hover { background: var(--sheet); }
.pagenav-link.next { text-align: right; border-left: 1px solid var(--line); padding-left: 22px; }
.pagenav-link.prev { padding-right: 22px; }
.pagenav-dir {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-3);
}
.pagenav-title {
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.35;
}
.pagenav-link:hover .pagenav-title { color: var(--blue); }
.pagenav-empty { opacity: 0.45; pointer-events: none; }

.kbd-hint {
  margin-top: 20px;
  text-align: center;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-3);
}
.kbd-hint kbd {
  font-family: var(--mono);
  font-size: 0.78rem;
  border: 1px solid var(--line-strong);
  background: var(--sheet);
  padding: 1px 7px;
  border-radius: 3px;
  margin: 0 2px;
}

/* ── Preview banner (admin draft preview) ────────────────── */

.preview-banner {
  position: sticky;
  top: 0;
  z-index: 300;
  background: var(--blue);
  color: var(--sheet);
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  text-align: center;
  padding: 9px 16px;
}

/* ── Error state ─────────────────────────────────────────── */

.tell-error { padding: 96px 28px; text-align: center; }
.tell-error h2 {
  font-family: var(--serif);
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 12px;
}
.tell-error p { color: var(--ink-2); }
.tell-error a { color: var(--blue); border-bottom: 1px dotted var(--blue); }

/* ── Responsive ──────────────────────────────────────────── */

@media (max-width: 860px) {
  .method-grid { grid-template-columns: 1fr; }
  .method-step { padding: 28px 0; }
  .method-step + .method-step {
    border-left: none;
    border-top: 1px solid var(--line);
    padding-left: 0;
  }
  .contents-list { columns: 1; }
  .about-grid { grid-template-columns: 1fr; gap: 24px; }
  .footer-links { text-align: left; }
  .footer-links ul { justify-content: flex-start; }
}

@media (max-width: 640px) {
  .container { padding: 0 20px; }
  .hero { padding: 28px 0 44px; }
  .title-frame { min-height: 240px; padding: 56px 20px; }
  .frame-meta { top: 14px; left: 16px; }
  .frame-bar { padding: 9px 12px; gap: 10px; }
  .frame-bar .frame-tc-right { display: none; }
  .tell-page { padding: 40px 20px 72px; }
  .tell-row > a { padding: 15px 8px; margin: 0 -8px; grid-template-columns: 34px 1fr; gap: 12px; }
  .cmt-avatar { width: 32px; height: 32px; font-size: 0.95rem; }
  .challenge-body { padding: 18px 16px; }
  .challenge-head { padding: 16px; flex-direction: column; gap: 6px; }
  .pagenav-link { padding: 18px 6px; }
  .pagenav-link.next { padding-left: 14px; }
  .pagenav-link.prev { padding-right: 14px; }
  .kbd-hint { display: none; }
}