@import url("/assets/walkthroughs.css");

/* ------------------------------------------------------------------
   Hack & Learn reading layer.
   Tokens come from walkthroughs.css (cyanotype palette, both themes).
   Rule of the room: prose in the sans, mono only when the machine said it.
   No literal colors below this block; everything is a token.
   ------------------------------------------------------------------ */

:root {
  --sans: ui-sans-serif, system-ui, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --prose: 68ch;
  --pic-ink: var(--blue);
  --pic-paper: var(--fg);
  --pic-dim: var(--dim);
  --pic-line: var(--line);
  --pic-hi: var(--accent);
  --pic-ok: var(--green);
  --pic-bad: var(--red);
  --pic-bg: var(--panel);
  --hi-soft: color-mix(in srgb, var(--accent) 12%, transparent);
  --cyan-soft: color-mix(in srgb, var(--blue) 12%, transparent);
  --green-soft: color-mix(in srgb, var(--green) 12%, transparent);
  --red-soft: color-mix(in srgb, var(--red) 12%, transparent);
  --purple-soft: color-mix(in srgb, var(--purple) 14%, transparent);
}

.learn-page-body,
.learn-hub-page {
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.65;
}

.learn-main {
  width: min(100% - 2rem, 52rem);
  margin: 0 auto;
  padding: 0.5rem 0 4rem;
}

.learn-hub-page .learn-main { width: min(100% - 2rem, 56rem); }

.learn-page-body .site-header,
.learn-page-body .site-footer,
.learn-hub-page .site-header,
.learn-hub-page .site-footer { font-family: var(--mono); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Slot labels: the skeleton of every page reads in mono. */
.slot-label {
  margin: 0 0 0.9rem;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--dim);
}

.slot-label::before { content: "// "; color: var(--line); }

/* ---------- lesson header ---------- */

.lesson { max-width: 100%; }
.lesson-head { margin-top: 1.5rem; }
.lesson-head .back-link { font-family: var(--mono); color: var(--dim); font-size: 12px; text-decoration: none; }
.lesson-head .back-link::before { content: "← "; }
.lesson-head .back-link:hover { color: var(--accent); }

.lesson-crumb {
  margin: 0.6rem 0 0;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.lesson-head h1 {
  margin: 0.35rem 0 0;
  font-family: var(--sans);
  font-size: clamp(1.7rem, 3.6vw, 2.35rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

.lesson-blurb { margin: 0.55rem 0 0; max-width: var(--prose); font-size: 1.12rem; color: var(--dim); }

.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem;
  margin: 0.9rem 0 0;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--dim);
}

.status-badge {
  display: inline-block;
  border: 1px solid var(--line);
  padding: 0.05rem 0.45rem;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--dim);
}

.status-badge.is-ready { color: var(--green); border-color: color-mix(in srgb, var(--green) 50%, var(--line)); }

.lesson-attack {
  margin: 0.5rem 0 0;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--purple);
}

.path-attack {
  grid-column: 2;
  margin-top: 0.15rem;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.03em;
  color: var(--purple);
}

.lesson-needs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.6rem;
  align-items: baseline;
  margin: 0.8rem 0 0;
  font-size: 0.92rem;
}

.lesson-needs-label,
.related-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--dim);
}

.lesson-needs a,
.related a {
  border: 1px solid var(--line);
  padding: 0.1rem 0.5rem;
  color: var(--fg);
  text-decoration: none;
}

.lesson-needs a:hover,
.related a:hover { border-color: var(--blue); color: var(--blue); }

/* ---------- slots ---------- */

.outcomes,
.lesson-list,
.terms,
.quiz,
.try-it { margin-top: 3rem; }

.outcome-list {
  margin: 0;
  padding: 0;
  list-style: none;
  max-width: var(--prose);
}

.outcome-list li {
  position: relative;
  padding: 0.35rem 0 0.35rem 1.8rem;
  border-top: 1px solid var(--line);
}

.outcome-list li:last-child { border-bottom: 1px solid var(--line); }

.outcome-list li::before {
  content: "";
  position: absolute;
  left: 0.2rem;
  top: 0.85rem;
  width: 0.7rem;
  height: 0.7rem;
  border: 1px solid var(--accent);
}

.lesson-list ol,
.path-units,
.unit-lessons ol { list-style: none; margin: 0; padding: 0; }

.lesson-list li a,
.path-lesson a {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.2rem 0.9rem;
  align-items: baseline;
  padding: 0.7rem 0.2rem;
  border-top: 1px solid var(--line);
  color: inherit;
  text-decoration: none;
}

.lesson-list li:last-child a { border-bottom: 1px solid var(--line); }
.lesson-list li a:hover .lesson-list-title,
.path-lesson a:hover .lesson-list-title { color: var(--accent); }

.lesson-num,
.path-num {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent);
  letter-spacing: 0.08em;
}

.lesson-list-title { font-weight: 600; }
.lesson-list-blurb { grid-column: 2; font-size: 0.9rem; color: var(--dim); }

/* ---------- body prose ---------- */

.lesson-body { margin-top: 3rem; }
.lesson-body > * { max-width: var(--prose); }
.lesson-body > .picture { max-width: 32rem; margin-inline: auto; }
.lesson-body > .artifact,
.lesson-body > .table-scroll,
.lesson-body > .hl-timeline { max-width: 100%; }

.lesson-body p { margin: 0 0 1.1rem; }
.lesson-body h2 {
  margin: 2.6rem 0 0.8rem;
  font-family: var(--sans);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--fg);
}

.lesson-body h2::before { content: none; }
.lesson-body h3 { margin: 1.8rem 0 0.5rem; font-size: 1.05rem; font-weight: 700; }
.lesson-body ul,
.lesson-body ol { margin: 0 0 1.1rem; padding-left: 1.4rem; }
.lesson-body li { margin: 0.3rem 0; }
.lesson-body li p { margin: 0; }
.lesson-body strong { font-weight: 700; }
.lesson-body a { color: var(--blue); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--blue) 45%, transparent); text-underline-offset: 0.15em; }
.lesson-body a:hover { text-decoration-color: var(--blue); }
.lesson-body a.tool-ref { font-family: var(--mono); font-size: 0.92em; }
.lesson-body blockquote { margin: 0 0 1.1rem; padding-left: 1rem; border-left: 2px solid var(--line); color: var(--dim); }

.lesson-body code,
.lesson-body kbd { font-family: var(--mono); font-size: 0.86em; }

.lesson-body dfn {
  font-style: normal;
  font-weight: 700;
  border-bottom: 1px dotted var(--blue);
}

.lesson-body pre { font-family: var(--mono); }

.table-scroll { overflow-x: auto; margin: 0 0 1.2rem; }
.lesson-body table { width: 100%; max-width: var(--prose); border-collapse: collapse; font-size: 0.93rem; }
.lesson-body th,
.lesson-body td { border-top: 1px solid var(--line); padding: 0.5rem 0.6rem 0.5rem 0; text-align: left; vertical-align: top; }
.lesson-body tr:last-child td { border-bottom: 1px solid var(--line); }
.lesson-body th { font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--dim); font-weight: 500; }

.lesson-body img { display: block; max-width: 100%; height: auto; border: 1px solid var(--line); }

/* ---------- callouts ---------- */

.callout {
  margin: 1.4rem 0 1.6rem;
  padding: 0.85rem 1rem 0.2rem;
  border: 1px solid var(--line);
  border-left-width: 3px;
  background: color-mix(in srgb, var(--panel) 60%, transparent);
}

.callout p:last-child { margin-bottom: 0.7rem; }

.callout-label,
.try-kind {
  display: block;
  margin-bottom: 0.3rem;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.callout-idea { border-left-color: var(--blue); }
.callout-idea .callout-label { color: var(--blue); }
.callout-later { border-left-color: var(--purple); }
.callout-later .callout-label { color: var(--purple); }
.callout-careful { border-left-color: var(--accent); background: var(--hi-soft); }
.callout-careful .callout-label { color: var(--accent); }
.callout-note { border-left-color: var(--dim); font-style: italic; }
.callout-note .callout-label { color: var(--dim); font-style: normal; }
.callout-draft { border-left-color: var(--dim); border-style: dashed; margin-top: 1.5rem; }
.callout-draft .callout-label { color: var(--dim); }

.predict {
  margin: 1.4rem 0 1.6rem;
  border: 1px solid var(--line);
  border-left: 3px solid var(--green);
  background: color-mix(in srgb, var(--panel) 60%, transparent);
}

.predict summary {
  cursor: pointer;
  padding: 0.85rem 1rem;
  list-style: none;
  font-weight: 600;
}

.predict summary::-webkit-details-marker { display: none; }
.predict summary .callout-label { color: var(--green); }
.predict summary::after { content: " ▸"; color: var(--green); font-family: var(--mono); }
.predict[open] summary::after { content: " ▾"; }
.predict-reveal { padding: 0 1rem 0.2rem; border-top: 1px solid var(--line); }
.predict-reveal > :first-child { margin-top: 0.8rem; }

/* ---------- artifact blocks ---------- */

.artifact { margin: 1.4rem 0 1.8rem; border: 1px solid var(--line); background: var(--card); }

.artifact pre {
  margin: 0;
  border: 0;
  border-radius: 0;
  padding: 0.85rem 1rem;
  background: transparent;
  font-size: 12.5px;
  line-height: 1.6;
  overflow-x: auto;
}

.artifact pre code { color: var(--fg); background: transparent; padding: 0; }
.artifact-sh pre code { color: var(--green); }

.artifact mark.part {
  background: var(--cyan-soft);
  color: var(--blue);
  border-bottom: 1px solid var(--blue);
  padding: 0 0.1em;
  cursor: default;
}

.artifact mark.part sup { font-size: 0.7em; color: var(--accent); margin-left: 0.15em; }
.artifact mark.part.is-active { background: var(--hi-soft); color: var(--accent); border-bottom-color: var(--accent); }

.artifact-notes {
  margin: 0;
  padding: 0.6rem 1rem 0.7rem 2.2rem;
  border-top: 1px solid var(--line);
  font-size: 0.9rem;
  color: var(--dim);
}

.artifact-notes li { margin: 0.2rem 0; padding-left: 0.2rem; }
.artifact-notes li::marker { font-family: var(--mono); color: var(--accent); }
.artifact-notes li.is-active { color: var(--fg); }

/* ---------- the picture ---------- */

.picture { margin: 1.6rem 0 2rem; }

.picture-frame {
  border: 1px solid var(--line);
  background: var(--pic-bg);
  padding: 0.6rem;
}

.picture-frame svg { display: block; width: 100%; height: auto; }
.picture svg text { font-family: var(--mono); font-size: 12px; fill: var(--pic-paper); }
.picture svg .t-dim { fill: var(--pic-dim); }
.picture svg .t-hi { fill: var(--pic-hi); }
.picture svg .t-ok { fill: var(--pic-ok); }
.picture svg .t-bad { fill: var(--pic-bad); }
.picture svg .t-small { font-size: 10.5px; }
.picture svg .actor { fill: none; stroke: var(--pic-ink); stroke-width: 1.4; }
.picture svg .actor-fill { fill: color-mix(in srgb, var(--pic-ink) 10%, transparent); }
.picture svg .boundary { fill: none; stroke: var(--pic-dim); stroke-width: 1; stroke-dasharray: 5 4; }
.picture svg .edge { fill: none; stroke: var(--pic-ink); stroke-width: 1.4; }
.picture svg .edge-dim { fill: none; stroke: var(--pic-dim); stroke-width: 1; stroke-dasharray: 3 3; }
.picture svg .hi { stroke: var(--pic-hi); }
.picture svg .hi-fill { fill: var(--hi-soft); }
.picture svg .ok { stroke: var(--pic-ok); }
.picture svg .bad { stroke: var(--pic-bad); }
.picture svg .arrow { fill: var(--pic-ink); }
.picture svg .arrow-hi { fill: var(--pic-hi); }
.picture svg .arrow-ok { fill: var(--pic-ok); }
.picture svg .arrow-bad { fill: var(--pic-bad); }
.picture svg .node-hi { fill: var(--hi-soft); stroke: var(--pic-hi); }

/* Steps: without JS only step 1 shows. JS toggles .is-on. */
.picture svg [data-step]:not([data-step="1"]) { display: none; }
.picture.is-enhanced svg [data-step] { display: none; }
.picture.is-enhanced svg [data-step].is-on { display: inline; }

.picture figcaption {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  margin-top: 0.55rem;
  font-size: 0.92rem;
  color: var(--dim);
}

.picture-cap::before { content: "▲ "; font-family: var(--mono); color: var(--accent); }

.picture-controls { display: inline-flex; gap: 0.35rem; align-items: center; font-family: var(--mono); font-size: 11.5px; }
.picture-controls button {
  min-height: 30px;
  min-width: 30px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--fg);
  font: inherit;
  cursor: pointer;
}

.picture-controls button:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
.picture-controls button:disabled { opacity: 0.4; cursor: default; }
.picture-controls .picture-step-n { color: var(--dim); padding: 0 0.3rem; }

/* ---------- terms ---------- */

.term-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0; }
.term-chip {
  border: 1px solid var(--line);
  padding: 0.15rem 0.55rem;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--fg);
  text-decoration: none;
}

.term-chip:hover { border-color: var(--blue); color: var(--blue); }

.glossary-controls { margin: 1.6rem 0 0; }
.glossary-search-input {
  width: 100%; max-width: var(--prose); box-sizing: border-box;
  padding: 0.55rem 0.8rem; font: inherit; color: var(--fg);
  background: var(--surface, transparent); border: 1px solid var(--line); border-radius: 6px;
}
.glossary-search-input:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
.glossary-empty { margin: 1rem 0 0; color: var(--dim); }
.glossary-list { margin: 1.2rem 0 0; padding: 0; }
.glossary-entry { padding: 0.9rem 0; border-top: 1px solid var(--line); scroll-margin-top: 5rem; }
.glossary-entry dt { font-family: var(--mono); font-weight: 700; }
.glossary-aka { margin-left: 0.5rem; font-family: var(--mono); font-weight: 400; font-size: 11.5px; color: var(--dim); }
.glossary-entry dd { margin: 0.3rem 0 0; max-width: var(--prose); color: var(--fg); }
.glossary-from { margin: 0.35rem 0 0; font-family: var(--mono); font-size: 11.5px; color: var(--dim); }
.glossary-from a { color: var(--dim); text-decoration: none; }
.glossary-from a:hover { color: var(--accent); }
.glossary-entry:target { background: var(--hi-bg, rgba(127,127,127,0.08)); }
.glossary-credit { margin: 2.4rem 0 0; max-width: var(--prose); font-size: 12.5px; color: var(--dim); }
.glossary-credit a { color: var(--dim); }
.glossary-credit a:hover { color: var(--accent); }

/* ---------- quiz ---------- */

.quiz-list { list-style: none; margin: 0; padding: 0; counter-reset: q; }

.q { margin: 0 0 1rem; padding: 0.9rem 1rem 0.8rem; border: 1px solid var(--line); background: color-mix(in srgb, var(--panel) 60%, transparent); }
.q-prompt { margin: 0 0 0.7rem; font-weight: 600; max-width: var(--prose); }
.q-prompt::before { counter-increment: q; content: counter(q) "  "; font-family: var(--mono); color: var(--accent); font-weight: 500; }

.q-choices { display: grid; gap: 0.35rem; }
.q-choices button {
  display: block;
  width: 100%;
  text-align: left;
  font: inherit;
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--fg);
  background: transparent;
  border: 1px solid var(--line);
  padding: 0.5rem 0.7rem;
  cursor: pointer;
}

.q-choices button:hover,
.q-choices button:focus-visible { border-color: var(--blue); }
.q-choices button[aria-pressed="true"] { border-color: var(--accent); background: var(--hi-soft); }
.q.is-correct .q-choices button[data-correct="true"] { border-color: var(--green); background: var(--green-soft); }
.q.is-wrong .q-choices button[aria-pressed="true"] { border-color: var(--red); background: var(--red-soft); }
.q.is-wrong .q-choices button[data-correct="true"] { border-color: color-mix(in srgb, var(--green) 45%, var(--line)); }

.q-feedback { margin: 0.7rem 0 0; font-size: 0.93rem; color: var(--dim); max-width: var(--prose); }
.q-feedback.is-ok { color: var(--green); }
.q-feedback.is-no { color: var(--fg); }
.q-feedback b { font-family: var(--mono); font-weight: 500; font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; margin-right: 0.4rem; }
.q-feedback.is-ok b { color: var(--green); }
.q-feedback.is-no b { color: var(--red); }

.q-nojs { margin-top: 0.6rem; font-size: 0.93rem; color: var(--dim); }
.q-nojs summary { cursor: pointer; font-family: var(--mono); font-size: 12px; }
.quiz.is-enhanced .q-nojs { display: none; }
.quiz-score { margin: 0.3rem 0 0; font-family: var(--mono); font-size: 12px; color: var(--dim); }

/* ---------- try it ---------- */

.try-list { list-style: none; margin: 0; padding: 0; max-width: var(--prose); }
.try-list > li { padding: 0.8rem 0; border-top: 1px solid var(--line); }
.try-list > li:last-child { border-bottom: 1px solid var(--line); }
.try-list p { margin: 0.4rem 0 0; }
.try-gym a { font-weight: 700; color: var(--fg); text-decoration: none; }
.try-gym a:hover { color: var(--accent); }
.try-goal { display: block; margin-top: 0.25rem; color: var(--dim); }
.try-goal b { font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); font-weight: 500; }
.try-os { font-family: var(--mono); font-size: 11.5px; color: var(--dim); margin-left: 0.4rem; }
.try-kind.try-kind { margin-bottom: 0.35rem; color: var(--dim); }

.diff {
  display: inline-block;
  margin-left: 0.4rem;
  border: 1px solid var(--line);
  padding: 0.02rem 0.4rem;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--dim);
  vertical-align: middle;
}

.diff-easy { color: var(--green); border-color: color-mix(in srgb, var(--green) 50%, var(--line)); }
.diff-medium { color: var(--yellow); border-color: color-mix(in srgb, var(--yellow) 50%, var(--line)); }
.diff-hard { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 50%, var(--line)); }
.diff-insane { color: var(--red); border-color: color-mix(in srgb, var(--red) 50%, var(--line)); }

.try-legacy h2,
.try-legacy h3 { font-size: 1rem; margin: 0.4rem 0; }
.try-legacy ul { padding-left: 1.2rem; }

/* ---------- pager, related, references ---------- */

.article-pager { font-family: var(--mono); }
.related { display: flex; flex-wrap: wrap; gap: 0.4rem 0.6rem; align-items: baseline; margin: 1.2rem 0 0; font-size: 0.92rem; }

.references { margin-top: 2rem; font-size: 0.92rem; color: var(--dim); }
.references summary { cursor: pointer; font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; }
.references summary::before { content: "// "; color: var(--line); }
.references ul { padding-left: 1.2rem; }
.references a { color: var(--blue); }

/* ---------- timeline ---------- */

.hl-timeline { margin: 2rem 0 1rem; border: 1px solid var(--line); background: var(--panel); padding: 0.85rem 0.9rem 0.9rem; }
.hl-timeline-hint { margin: 0 0 0.6rem; font-family: var(--mono); font-size: 11px; letter-spacing: 0.06em; color: var(--dim); }
.hl-timeline-scroller { overflow-x: auto; scrollbar-color: var(--accent) transparent; padding-bottom: 0.3rem; }
.hl-timeline-track { list-style: none; margin: 0; padding: 0.3rem 0.2rem 0; position: relative; display: flex; align-items: flex-start; min-width: max-content; }
.hl-timeline-track::before { content: ""; position: absolute; left: 1.2rem; right: 1.2rem; top: 2.45rem; height: 2px; background: linear-gradient(90deg, transparent, var(--accent) 8%, var(--accent) 92%, transparent); opacity: 0.55; }
.hl-era { position: relative; width: 9.5rem; flex: 0 0 auto; padding: 0 0.3rem; }
.hl-era-btn { display: flex; flex-direction: column; align-items: center; gap: 0.35rem; width: 100%; padding: 0.2rem 0.25rem 0.35rem; border: 1px solid transparent; background: transparent; color: inherit; font: inherit; cursor: pointer; text-align: center; }
.hl-era-btn:hover,
.hl-era-btn:focus-visible { border-color: var(--line); color: var(--accent); }
.hl-era-btn[aria-expanded="true"] { border-color: var(--accent); background: var(--hi-soft); }
.hl-era-when { font-family: var(--mono); font-size: 11px; letter-spacing: 0.06em; color: var(--purple); text-transform: uppercase; }
.hl-era-dot { width: 12px; height: 12px; border-radius: 50%; border: 2px solid var(--accent); background: var(--bg); box-shadow: 0 0 0 3px var(--hi-soft); }
.hl-era-btn[aria-expanded="true"] .hl-era-dot { background: var(--accent); }
.hl-era-what { font-size: 0.85rem; font-weight: 700; line-height: 1.3; }
.hl-era-line { font-family: var(--mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; border: 1px solid var(--line); padding: 0.05rem 0.35rem; color: var(--blue); }
.hl-era[data-line="windows"] .hl-era-line { color: var(--accent); }
.hl-era[data-line="mac"] .hl-era-line { color: var(--green); }
.hl-era[data-line="mobile"] .hl-era-line { color: var(--purple); }
.hl-era[data-line="langs"] .hl-era-line { color: var(--dim); }
.hl-era-callout .hl-era-dot { border-color: var(--green); box-shadow: 0 0 0 3px var(--green-soft); }
.hl-era-panel { margin: 0.5rem 0 0; padding: 0.6rem 0.7rem; border: 1px solid var(--line); background: var(--card); text-align: left; }
/* Panels must not sit clipped inside the horizontal scroller (D6). */
.hl-era-panel { display: none; }
.hl-timeline:not(.is-enhanced) .hl-timeline-track .hl-era-panel[hidden] {
  display: block;
  position: static;
  width: auto;
  margin: 0.45rem 0 0;
}
.hl-timeline.is-enhanced .hl-era-panel { display: none; }
.hl-timeline-detail {
  margin-top: 0.7rem;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--accent);
  background: var(--card);
  overflow: visible;
}
.hl-timeline-scroller { overflow-x: auto; overflow-y: visible; }

.hl-era-detail { margin: 0; color: var(--fg); font-size: 0.93rem; }
.hl-era-why { margin: 0.5rem 0 0; font-size: 0.93rem; }
.hl-era-why-label { display: block; margin-bottom: 0.15rem; font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); }

@media (max-width: 720px) {
  .hl-timeline-scroller { overflow: visible; }
  .hl-timeline-track { flex-direction: column; min-width: 0; }
  .hl-timeline-track::before { left: 1.05rem; right: auto; top: 0.6rem; bottom: 0.6rem; width: 2px; height: auto; background: var(--accent); opacity: 0.35; }
  .hl-era { width: 100%; padding: 0 0 0.9rem 2.2rem; }
  .hl-era-btn { align-items: flex-start; text-align: left; }
  .hl-era-dot { position: absolute; left: 0.75rem; top: 1.5rem; }
}

/* ---------- hub ---------- */

.hub-hero { margin-top: 2.5rem; }
.hub-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; list-style: none; margin: 0; padding: 0; }
.hub-chip { border: 1px solid var(--line); padding: 0.2rem 0.6rem; font-family: var(--mono); font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--dim); }
.hub-hero h1 { margin: 1rem 0 0; font-family: var(--sans); font-size: clamp(2.2rem, 6vw, 3.6rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.02; }
.hub-hero h1 .n1 { color: var(--accent); }
.hub-hero .lede { margin: 1.1rem 0 0; max-width: 60ch; font-size: 1.12rem; color: var(--dim); }
.hub-partial { margin: 0.9rem 0 0; max-width: 60ch; font-size: 0.95rem; color: var(--dim); }
.hub-cta-row { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-top: 1.5rem; }
.hub-cta { display: inline-flex; align-items: center; gap: 0.35rem; min-height: 42px; padding: 0 1rem; border: 1px solid var(--line); color: var(--fg); text-decoration: none; font-family: var(--mono); font-size: 13px; }
.hub-cta:hover { border-color: var(--accent); color: var(--accent); }
.hub-cta-primary { background: var(--accent); border-color: var(--accent); color: var(--button-text); font-weight: 700; }
.hub-cta-primary:hover { color: var(--button-text); background: color-mix(in srgb, var(--accent) 88%, white); }
.hub-cta-continue span { color: var(--dim); }
.hub-cta-lang { color: var(--blue); }

.hub-path { margin-top: 3.5rem; }
.hub-controls { display: grid; gap: 0.7rem; margin-bottom: 1.5rem; }
.hub-search input { width: 100%; min-height: 42px; border: 1px solid var(--line); padding: 0 0.8rem; background: var(--card); color: var(--fg); font: inherit; }
.hub-search input:focus { outline: 2px solid color-mix(in srgb, var(--blue) 55%, transparent); outline-offset: 1px; }
.hub-filters { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.hub-filter,
.hub-text-btn { appearance: none; border: 1px solid var(--line); background: transparent; color: var(--dim); min-height: 32px; padding: 0 0.7rem; font-family: var(--mono); font-size: 11.5px; cursor: pointer; }
.hub-filter.is-active,
.hub-filter[aria-pressed="true"] { border-color: var(--blue); color: var(--blue); background: var(--cyan-soft); }
.hub-filter:hover,
.hub-text-btn:hover { color: var(--fg); border-color: color-mix(in srgb, var(--fg) 25%, var(--line)); }
.hub-import-label { display: inline-flex; align-items: center; }

.path-track { margin-top: 2.2rem; }
.path-track-label { margin: 0; font-family: var(--mono); font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--fg); }
.path-track-why { margin: 0.25rem 0 0.7rem; font-size: 0.92rem; color: var(--dim); }

.path-unit { border-top: 1px solid var(--line); }
.path-units > li:last-child { border-bottom: 1px solid var(--line); }
.path-unit-link { display: grid; grid-template-columns: 2.6rem 1fr auto; gap: 0.2rem 0.6rem; align-items: baseline; padding: 0.85rem 0.2rem; color: inherit; text-decoration: none; }
.path-unit-link:hover .path-title { color: var(--accent); }
.path-title { font-weight: 700; font-size: 1.05rem; }
.path-why { grid-column: 2; font-size: 0.92rem; color: var(--dim); }
.path-meta { display: inline-flex; gap: 0.6rem; align-items: baseline; font-family: var(--mono); font-size: 11.5px; color: var(--dim); white-space: nowrap; }
.path-unit.is-done .path-num { color: var(--green); }

.unit-lessons { margin: -0.3rem 0 0.9rem 2.6rem; }
.unit-lessons > summary { cursor: pointer; list-style: none; font-family: var(--mono); font-size: 11.5px; color: var(--blue); padding: 0.2rem 0; }
.unit-lessons > summary::-webkit-details-marker { display: none; }
.unit-lessons > summary::before { content: "▸ "; }
.unit-lessons[open] > summary::before { content: "▾ "; }
.unit-lessons ol { margin-top: 0.3rem; counter-reset: lesson; }
.path-lesson a { grid-template-columns: 1fr auto; padding: 0.5rem 0.2rem; }
.path-lesson .lesson-list-blurb { grid-column: 1; }
.path-lesson .lesson-list-title::before { counter-increment: lesson; content: counter(lesson) "  "; font-family: var(--mono); font-size: 12px; color: var(--accent); }

.hub-mark { min-width: 1.1em; font-family: var(--mono); color: var(--dim); }
.hub-mark.is-done { color: var(--green); }
.hub-mark.is-seen { color: var(--accent); }

.hub-missing { margin-top: 2.2rem; }
.hub-missing ul { margin: 0.5rem 0 0; padding-left: 1.2rem; font-size: 0.95rem; }
.hub-empty { margin-top: 1rem; font-family: var(--mono); font-size: 12px; color: var(--dim); }

.hub-how { margin-top: 3.5rem; }
.hub-how-list { margin: 0; padding: 0; list-style: none; counter-reset: how; max-width: var(--prose); }
.hub-how-list li { padding: 0.45rem 0; border-top: 1px solid var(--line); }
.hub-how-list li:last-child { border-bottom: 1px solid var(--line); }
.hub-how-list li::before { counter-increment: how; content: counter(how) "  "; font-family: var(--mono); color: var(--accent); }
.hub-progress-note { margin: 1.2rem 0 0; font-size: 0.9rem; color: var(--dim); display: flex; flex-wrap: wrap; gap: 0.5rem 0.7rem; align-items: center; }

/* ---------- small screens ---------- */

@media (max-width: 560px) {
  .learn-page-body,
  .learn-hub-page { font-size: 16px; }
  .learn-main { width: min(100% - 1.5rem, 52rem); }
  .path-unit-link { grid-template-columns: 2.2rem 1fr; }
  .path-meta { grid-column: 2; }
  .unit-lessons { margin-left: 2.2rem; }
  .lesson-list li a { grid-template-columns: auto 1fr; }
  .lesson-list li a .hub-mark { grid-column: 2; }
}

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

/* --- Tool finder --- */
.tools .lesson-blurb { max-width: 60ch; }
.tool-cat-grid {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr));
  gap: 0.6rem;
}
.tool-cat-card a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.6rem;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  text-decoration: none;
  color: var(--fg);
  background: color-mix(in srgb, var(--panel) 60%, transparent);
  transition: border-color 120ms ease, background 120ms ease;
}
.tool-cat-card a:hover { border-color: var(--blue); background: color-mix(in srgb, var(--blue) 8%, transparent); }
.tool-cat-name { font-weight: 600; }
.tool-cat-count { font-family: var(--mono); font-size: 11px; color: var(--dim); }

.tool-controls { margin: 1.2rem 0 0.6rem; }
.tool-controls input {
  width: 100%;
  box-sizing: border-box;
  min-height: 42px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: color-mix(in srgb, var(--panel) 70%, transparent);
  color: var(--fg);
  font: inherit;
  font-size: 14px;
}
.tool-controls input:focus { outline: 2px solid color-mix(in srgb, var(--blue) 55%, transparent); outline-offset: 1px; }

.tool-list { list-style: none; margin: 1rem 0 0; padding: 0; display: grid; gap: 0.7rem; }
.tool-card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.75rem 0.85rem;
  background: color-mix(in srgb, var(--panel) 55%, transparent);
}
.tool-card[hidden] { display: none; }
.tool-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.5rem; }
.tool-name { font-family: var(--mono); font-weight: 700; font-size: 15px; color: var(--fg); }
.tool-bin { font-family: var(--mono); font-size: 11.5px; color: var(--accent); }
.tool-links { margin-left: auto; display: flex; gap: 0.7rem; }
.tool-link { font-family: var(--mono); font-size: 11.5px; color: var(--blue); text-decoration: none; }
.tool-link:hover { text-decoration: underline; }
.tool-desc { margin: 0.4rem 0 0; color: var(--dim); font-size: 13.5px; line-height: 1.55; }
.tool-help { margin-top: 0.5rem; }
.tool-help > summary {
  cursor: pointer;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--green);
  list-style: none;
}
.tool-help > summary::before { content: "help ▸ "; color: var(--dim); }
.tool-help[open] > summary::before { content: "help ▾ "; }
.tool-help-pre {
  margin: 0.5rem 0 0;
  max-height: 22rem;
  overflow: auto;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--bg) 78%, black);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.5;
  white-space: pre;
}
.tool-help-pre code { font-family: inherit; color: var(--green); background: none; padding: 0; }
.tool-source { margin-top: 1.5rem; color: var(--faint); font-size: 12px; }


/* ---------- interactives (D7) ---------- */
.ix {
  margin: 1.6rem 0 1.8rem;
  padding: 1rem 1rem 1.1rem;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--panel) 70%, transparent);
}
.ix-title {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  font-weight: 700;
}
.ix-lede { margin: 0 0 0.9rem; color: var(--dim); max-width: 60ch; }
.ix-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0 0 0.9rem;
}
.ix-chip,
.ix-choice,
.ix-reset {
  font: inherit;
  cursor: pointer;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--fg);
  padding: 0.45rem 0.7rem;
  min-height: 40px;
}
.ix-chip:hover,
.ix-choice:hover,
.ix-reset:hover { border-color: var(--blue); }
.ix-chip[aria-selected="true"],
.ix-chip[aria-pressed="true"] {
  border-color: var(--blue);
  background: color-mix(in srgb, var(--blue) 12%, transparent);
}
.ix-chip:focus-visible,
.ix-choice:focus-visible,
.ix-reset:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}
.ix-results { list-style: none; margin: 0 0 1rem; padding: 0; }
.ix-result-label { margin: 0 0 0.35rem; font-weight: 600; }
.ix-result-list { margin: 0; padding-left: 1.2rem; }
.ix-fallback { margin: 0.8rem 0 0; }
.ix-ethics-q { margin: 0 0 0.7rem; font-weight: 600; }
.ix-choice-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.45rem; }
.ix-choice { width: 100%; text-align: left; }
.ix-terminal { margin: 0.8rem 0 0; font-weight: 700; }
.ix-terminal-go { color: var(--green); }
.ix-terminal-stop { color: var(--red); }
.ix-reset { margin-top: 0.8rem; }
.ix-payload { margin: 0 0 0.8rem; }
.ix-payload-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--dim);
  margin-right: 0.5rem;
}
.ix-enc-sample {
  margin: 0 0 0.6rem;
  padding: 0.7rem 0.8rem;
  overflow-x: auto;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 80%, transparent);
}
.ix-enc-note { margin: 0; color: var(--dim); max-width: 60ch; }

.ix-cw-strip {
  list-style: none;
  margin: 0 0 0.9rem;
  padding: 0;
  display: grid;
  gap: 0.35rem;
}
.ix-cw-slot {
  border: 1px solid var(--line);
  background: var(--card);
  padding: 0.55rem 0.7rem;
  cursor: pointer;
}
.ix-cw-slot.is-active { border-color: var(--blue); }
.ix-cw-slot-label {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--dim);
  margin-bottom: 0.2rem;
}
.ix-cw-slot-text { font-family: var(--mono); font-size: 0.85rem; }
.ix-cw-trust-untrusted { border-left: 3px solid var(--red); }
.ix-cw-trust-high { border-left: 3px solid var(--green); }
.ix-cw-trust-user { border-left: 3px solid var(--blue); }
.ix-cw-trust-model { border-left: 3px solid var(--accent); }
.ix-cw-note { margin: 0.6rem 0 0; color: var(--dim); max-width: 60ch; }

.ix-buf-nav { display: flex; gap: 0.45rem; margin: 0 0 0.8rem; }
.ix-buf-stack {
  list-style: none;
  margin: 0 0 0.7rem;
  padding: 0;
  display: grid;
  gap: 0.35rem;
  max-width: 28rem;
}
.ix-buf-cell {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  border: 1px solid var(--line);
  padding: 0.45rem 0.65rem;
  background: var(--card);
}
.ix-buf-label { color: var(--dim); font-size: 0.85rem; }
.ix-buf-hit { border-color: var(--red); }
.ix-buf-ret { border-style: dashed; }
.ix-buf-caption { margin: 0; color: var(--dim); max-width: 60ch; }

.ix-acl-nodes { margin: 0 0 0.8rem; padding-left: 1.2rem; }
.ix-acl-notes { list-style: none; margin: 0 0 0.8rem; padding: 0; }
.ix-acl-notes li { margin: 0.35rem 0; color: var(--dim); max-width: 60ch; }
.ix-acl-pathline { margin: 0 0 0.8rem; font-weight: 600; }

.ix-pivot-map {
  list-style: none;
  margin: 0 0 0.9rem;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
  font-family: var(--mono);
  font-size: 0.9rem;
}
.ix-pivot-arrow { color: var(--dim); }
.ix-pivot-result { margin: 0.8rem 0 0; max-width: 60ch; }
.ix-pivot-ok { color: var(--green); font-weight: 600; }
.ix-pivot-bad { color: var(--red); font-weight: 600; }

.ix-find-form {
  display: grid;
  gap: 0.55rem;
  margin: 0 0 0.8rem;
  max-width: 40rem;
}
.ix-find-field {
  display: grid;
  gap: 0.25rem;
  font-weight: 600;
}
.ix-find-field select {
  font: inherit;
  font-weight: 400;
  padding: 0.4rem 0.5rem;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--fg);
  border-radius: 0;
}
.ix-find-field select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.ix-find-out { margin: 0; max-width: 65ch; font-weight: 600; }

.ix-rr-exchange {
  list-style: none;
  margin: 0 0 0.8rem;
  padding: 0;
  border: 1px solid var(--line);
  background: var(--card);
}
.ix-rr-line {
  margin: 0;
  padding: 0.4rem 0.7rem;
  cursor: pointer;
  border-bottom: 1px solid var(--line);
}
.ix-rr-line:last-child { border-bottom: 0; }
.ix-rr-line.is-active { background: var(--hi-soft); }
.ix-rr-line:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}
.ix-rr-req code { color: var(--fg); }
.ix-rr-res code { color: var(--green); }
.ix-rr-note { margin: 0.6rem 0 0; color: var(--dim); max-width: 60ch; }

@media (prefers-reduced-motion: reduce) {
  .ix-cw-slot,
  .ix-buf-cell,
  .ix-rr-line,
  .ix-find-field select {
    transition: none !important;
  }
}

@media print {
  .ix-cw-panel[hidden],
  .ix-buf-panel[hidden],
  .ix-rr-panel[hidden],
  .ix-acl-notes [hidden],
  [data-pivot-result][hidden] { display: block !important; }
}


@media (prefers-reduced-motion: reduce) {
  .ix-chip,
  .ix-choice,
  .tool-cat-card a { transition: none !important; }
}

/* ---------- print (E6) ---------- */
@media print {
  .site-header,
  .site-footer,
  .skip-link,
  .hub-controls,
  .picture-controls,
  .q-choices,
  .ix-toolbar,
  .ix-reset,
  .article-pager,
  [data-hub-export],
  .hub-import-label { display: none !important; }
  body { background: #fff; color: #000; }
  a { color: #000; text-decoration: underline; }
  .lesson, .learn-main { max-width: none; }
  .ix, .callout, .picture, .artifact, .quiz { break-inside: avoid; }
  .ix-fallback, .q-nojs { display: block !important; }
  .ix-results [hidden],
  .ix-ethics-step[hidden],
  .ix-enc-panel[hidden],
  .ix-cw-panel[hidden],
  .ix-buf-panel[hidden],
  .ix-rr-panel[hidden],
  .ix-acl-notes [hidden],
  [data-pivot-result][hidden] { display: block !important; }
  .table-scroll { overflow: visible; }
}

/* ---------- mobile 375 pass (E4) ---------- */
@media (max-width: 400px) {
  .learn-main { width: min(100% - 1.25rem, 52rem); }
  .hub-hero h1 { font-size: clamp(1.85rem, 9vw, 2.6rem); }
  .hub-cta { max-width: 100%; }
  .hub-cta-continue { white-space: normal; }
  .hub-cta-continue b { overflow-wrap: anywhere; }
  .path-meta { white-space: normal; grid-column: 2; }
  .path-unit-link { grid-template-columns: 2rem 1fr; gap: 0.15rem 0.45rem; }
  .unit-lessons { margin-left: 1.6rem; }
  .lesson-body pre,
  .ix-enc-sample,
  .artifact pre { max-width: 100%; overflow-x: auto; }
  .q-choices { grid-template-columns: 1fr; }
  .site-header,
  .site-footer { width: min(100% - 1.25rem, 90rem); }
  .site-header nav { gap: 0.45rem 0.8rem; }
}