/* VV Claude Code Harness — teaching site
   Plain CSS, no build step. Tokens on :root, dark override in a media query. */

:root {
  --bg: #fbfbf9;
  --bg-raised: #ffffff;
  --bg-sunken: #f2f1ed;
  --ink: #1a1a17;
  --ink-soft: #55534c;
  --ink-faint: #8a877d;
  --line: #e2e0d9;
  --line-strong: #cbc8bd;

  --accent: #b8482a;
  --accent-soft: #f6e3dd;
  --green: #2f6b46;
  --green-soft: #e0efe5;
  --amber: #8a6410;
  --amber-soft: #f7ecd2;
  --blue: #2a5a8a;
  --blue-soft: #dfeaf4;

  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: ui-sans-serif, -apple-system, "Segoe UI", Inter, Helvetica, Arial, sans-serif;

  --radius: 10px;
  --shadow: 0 1px 2px rgba(20, 18, 12, 0.05), 0 6px 20px rgba(20, 18, 12, 0.05);
  --maxw: 76rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14140f;
    --bg-raised: #1c1c16;
    --bg-sunken: #100f0b;
    --ink: #ecebe4;
    --ink-soft: #b1aea3;
    --ink-faint: #7e7b71;
    --line: #2e2d25;
    --line-strong: #434136;

    --accent: #e8845f;
    --accent-soft: #3a1f16;
    --green: #74c295;
    --green-soft: #172e21;
    --amber: #d9ac52;
    --amber-soft: #322611;
    --blue: #7db2e0;
    --blue-soft: #14273a;

    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.3);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------- scroll progress ---------- */

#progress {
  position: fixed;
  inset: 0 auto auto 0;
  height: 3px;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: var(--accent);
  z-index: 60;
}

/* ---------- nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.7rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.4rem;
  flex-wrap: wrap;
}

.nav-brand {
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
  margin-right: auto;
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.98rem;
}

.nav-brand .dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  flex: none;
}

.nav a.nav-link {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
}

.nav a.nav-link:hover { color: var(--ink); }
.nav a.nav-link[aria-current="page"] {
  color: var(--ink);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

/* ---------- layout ---------- */

main { max-width: var(--maxw); margin: 0 auto; padding: 0 1.5rem 6rem; }

section { padding: 4rem 0 1rem; scroll-margin-top: 4.5rem; }
section + section { border-top: 1px solid var(--line); }

.prose { max-width: 46rem; }

h1 {
  font-size: clamp(2.1rem, 5vw, 3.2rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin: 0 0 1rem;
  font-weight: 800;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 0.9rem;
  font-weight: 700;
}

h3 {
  font-size: 1.13rem;
  margin: 2rem 0 0.6rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

p { margin: 0 0 1.05rem; color: var(--ink-soft); }
.prose p strong, li strong { color: var(--ink); }

a { color: var(--accent); text-underline-offset: 2px; }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 0.7rem;
}

.lede { font-size: 1.13rem; color: var(--ink-soft); }

ul, ol { color: var(--ink-soft); padding-left: 1.2rem; margin: 0 0 1.1rem; }
li { margin-bottom: 0.45rem; }

code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--bg-sunken);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 0.1em 0.35em;
  color: var(--ink);
}

pre {
  background: var(--bg-sunken);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  overflow-x: auto;
  margin: 0 0 1.2rem;
  line-height: 1.55;
}

pre code {
  background: none;
  border: 0;
  padding: 0;
  font-size: 0.85rem;
  white-space: pre;
}

.tok-c { color: var(--ink-faint); }
.tok-k { color: var(--accent); }
.tok-p { color: var(--green); }

/* ---------- tables ---------- */

.table-wrap { overflow-x: auto; margin: 0 0 1.4rem; }

table {
  border-collapse: collapse;
  width: 100%;
  min-width: 34rem;
  font-size: 0.92rem;
}

th, td {
  text-align: left;
  padding: 0.62rem 0.8rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  color: var(--ink-soft);
}

th {
  color: var(--ink);
  font-weight: 650;
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border-bottom-color: var(--line-strong);
}

td code { white-space: nowrap; }

/* ---------- cards ---------- */

.grid { display: grid; gap: 1rem; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(19rem, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }

.card {
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.15rem 1.25rem;
  box-shadow: var(--shadow);
}

.card h3 { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }

a.card { text-decoration: none; display: block; color: inherit; }
a.card:hover { border-color: var(--line-strong); }
a.card .go { color: var(--accent); font-weight: 600; font-size: 0.9rem; }

.callout {
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  background: var(--bg-raised);
  border-radius: var(--radius);
  padding: 0.95rem 1.15rem;
  margin: 0 0 1.4rem;
}

.callout p:last-child { margin-bottom: 0; }
.callout .label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amber);
  display: block;
  margin-bottom: 0.3rem;
}

.callout.wrong { border-left-color: var(--accent); }
.callout.wrong .label { color: var(--accent); }

/* ---------- misc bits ---------- */

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--mono);
  font-size: 0.76rem;
  padding: 0.25rem 0.6rem;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: var(--bg-raised);
  color: var(--ink-soft);
}

.chip.ok { border-color: var(--green); color: var(--green); background: var(--green-soft); }
.chip.no { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }

.btn-row { display: flex; gap: 0.7rem; flex-wrap: wrap; margin: 1.6rem 0 0; }

.btn {
  display: inline-block;
  padding: 0.6rem 1.1rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.94rem;
  border: 1px solid var(--line-strong);
  color: var(--ink);
  background: var(--bg-raised);
}

.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }

.stats { display: flex; gap: 0.55rem; flex-wrap: wrap; margin: 1.6rem 0 0; }

.stat {
  border: 1px solid var(--line);
  background: var(--bg-raised);
  border-radius: var(--radius);
  padding: 0.65rem 0.9rem;
  min-width: 8.5rem;
}

.stat b { display: block; font-size: 1.3rem; letter-spacing: -0.02em; }
.stat span { font-size: 0.76rem; color: var(--ink-faint); font-family: var(--mono); }

.steps { counter-reset: step; list-style: none; padding: 0; }

.steps > li {
  counter-increment: step;
  position: relative;
  padding-left: 2.6rem;
  margin-bottom: 1.5rem;
}

.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.05rem;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--bg-sunken);
  border: 1px solid var(--line-strong);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.8rem;
  display: grid;
  place-items: center;
  font-weight: 700;
}

.steps > li h3 { margin: 0 0 0.35rem; }

/* ---------- figures ---------- */

figure {
  margin: 0 0 1.6rem;
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.3rem;
  box-shadow: var(--shadow);
  overflow: hidden;
}

figcaption {
  font-size: 0.85rem;
  color: var(--ink-faint);
  margin-top: 1rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--line);
}

.replay {
  font-family: var(--mono);
  font-size: 0.74rem;
  background: none;
  border: 1px solid var(--line-strong);
  color: var(--ink-soft);
  border-radius: 999px;
  padding: 0.2rem 0.7rem;
  cursor: pointer;
  float: right;
}

.replay:hover { color: var(--ink); border-color: var(--ink-faint); }

/* A2 — memory across the session boundary */

.shift { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 1.2rem; }
.shift-col { border: 1px solid var(--line); border-radius: var(--radius); padding: 0.9rem; }
.shift-col h4 { margin: 0 0 0.15rem; font-size: 0.95rem; }
.shift-col .sub { font-size: 0.78rem; color: var(--ink-faint); margin: 0 0 0.9rem; font-family: var(--mono); }
.session-band { display: flex; align-items: flex-end; gap: 0.35rem; height: 5.5rem; }

.mem {
  flex: 1;
  background: var(--blue-soft);
  border: 1px solid var(--blue);
  border-radius: 5px;
  height: 6px;
  transform-origin: 50% 100%;
}

.boundary {
  margin: 0.7rem 0;
  border-top: 2px dashed var(--line-strong);
  text-align: center;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-faint);
}

.boundary span { background: var(--bg-raised); padding: 0 0.5rem; position: relative; top: -0.65rem; }
.persist { font-family: var(--mono); font-size: 0.75rem; color: var(--green); }
.lost { font-family: var(--mono); font-size: 0.75rem; color: var(--accent); }

/* A3 / A11 — file trees */

.tree { font-family: var(--mono); font-size: 0.8rem; line-height: 1.85; color: var(--ink-soft); overflow-x: auto; }
.tree .row { white-space: pre; }
.tree .row b { color: var(--ink); font-weight: 600; }
.tree .row i { color: var(--ink-faint); font-style: normal; }

/* A4 — session loop */

.loop-wrap { display: grid; grid-template-columns: minmax(0, 20rem) minmax(0, 1fr); gap: 1.4rem; align-items: center; }
@media (max-width: 44rem) { .loop-wrap { grid-template-columns: 1fr; } }

.loop-steps { list-style: none; padding: 0; margin: 0; }

.loop-steps li {
  padding: 0.42rem 0.7rem;
  border-radius: 7px;
  border: 1px solid transparent;
  font-size: 0.9rem;
  color: var(--ink-faint);
  display: flex;
  gap: 0.6rem;
  margin: 0;
}

.loop-steps li b { color: inherit; font-weight: 600; }
.loop-steps li.on { color: var(--ink); background: var(--accent-soft); border-color: var(--accent); }

.loop-canvas { position: relative; }
.loop-canvas svg { display: block; width: 100%; height: auto; overflow: visible; }
.loop-canvas #loop-path { fill: none; stroke: var(--line-strong); stroke-width: 1.5; stroke-dasharray: 5 7; }

.loop-canvas .marker {
  position: absolute;
  top: 0;
  left: 0;
  width: 14px;
  height: 14px;
  margin: -7px 0 0 -7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 5px color-mix(in srgb, var(--accent) 22%, transparent);
}

/* A5 — compaction */

.ctx-bar { height: 16px; border-radius: 999px; background: var(--bg-sunken); border: 1px solid var(--line); overflow: hidden; }
.ctx-fill { height: 100%; width: 4%; background: var(--blue); }
.reinject { display: flex; gap: 0.5rem; margin-top: 1rem; flex-wrap: wrap; }


/* A6 — the gate */

.track {
  position: relative;
  height: 5.5rem;
  min-width: 32rem;
  max-width: 46rem;
  margin: 0 auto;
  border-radius: var(--radius);
  background: var(--bg-sunken);
  border: 1px solid var(--line);
  overflow: hidden;
}

.token {
  position: absolute;
  top: 50%;
  left: 14%;
  transform: translateX(-50%);
  margin-top: -0.95rem;
  padding: 0.32rem 0.7rem;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 0.78rem;
  background: var(--bg-raised);
  border: 1px solid var(--line-strong);
  color: var(--ink);
  white-space: nowrap;
}

.gate-bar { position: absolute; top: 0; bottom: 0; left: 58%; width: 6px; background: var(--line-strong); }
.gate-label { position: absolute; top: 0.5rem; left: calc(58% + 14px); font-family: var(--mono); font-size: 0.72rem; color: var(--ink-faint); }
.main-label { position: absolute; bottom: 0.5rem; right: 0.8rem; font-family: var(--mono); font-size: 0.72rem; color: var(--ink-faint); }

/* A7 — tiers */

.tier { margin-bottom: 0.9rem; }
.tier .top { display: flex; justify-content: space-between; font-size: 0.86rem; margin-bottom: 0.3rem; }
.tier .top b { font-weight: 650; color: var(--ink); }
.tier .top span { font-family: var(--mono); font-size: 0.76rem; color: var(--ink-faint); }
.tier .rail { height: 10px; background: var(--bg-sunken); border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.tier .bar { height: 100%; border-radius: 999px; background: var(--green); }
.tier[data-tier="prompted"] .bar { background: var(--blue); }
.tier[data-tier="structural"] .bar { background: var(--blue); }
.tier[data-tier="instructional"] .bar { background: var(--amber); }

/* A8 — task gate lanes */

.lanes { display: grid; gap: 0.6rem; }

.lane {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.6rem 0.9rem;
  background: var(--bg-raised);
  font-size: 0.9rem;
  color: var(--ink-soft);
}

.lane .mark { font-family: var(--mono); width: 1.2rem; text-align: center; }
.lane .name { font-family: var(--mono); font-size: 0.82rem; color: var(--ink); min-width: 8.5rem; }
.lane.muted { opacity: 0.55; border-style: dashed; }
.lane.pass .mark { color: var(--green); }

/* A9 — fan out */

/* Diagrams whose geometry only reads at their design width scroll rather than distort. */
.diagram-scroll { overflow-x: auto; }

.fan { position: relative; aspect-ratio: 600 / 260; min-width: 34rem; }
.node {
  position: absolute;
  border: 1px solid var(--line-strong);
  background: var(--bg-raised);
  border-radius: 8px;
  padding: 0.4rem 0.7rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink);
  white-space: nowrap;
  transform: translate(-50%, -50%);
}
.node.lead { border-color: var(--accent); color: var(--accent); font-weight: 600; }

.node .role { display: block; font-size: 0.68rem; color: var(--ink-faint); }
.fan svg { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.fan path { fill: none; stroke: var(--line-strong); stroke-width: 1.5; }

/* A10 — scope collision */

.scopes { position: relative; height: 8rem; border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg-sunken); overflow: hidden; }
.scope-box {
  position: absolute;
  top: 50%;
  height: 3.4rem;
  margin-top: -1.7rem;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 0.78rem;
  border: 1.5px solid var(--blue);
  background: var(--blue-soft);
  color: var(--ink);
}
.verdict { text-align: center; font-family: var(--mono); font-size: 0.82rem; margin-top: 0.8rem; color: var(--ink-faint); }

/* A11 — terminal */

.term {
  background: var(--bg-sunken);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.9rem 1.1rem;
  font-family: var(--mono);
  font-size: 0.84rem;
  line-height: 1.75;
}

.term .line { white-space: pre-wrap; }
.term .line .ps { color: var(--accent); }
.term .line.out { color: var(--ink-faint); }

/* ---------- footer ---------- */

footer {
  border-top: 1px solid var(--line);
  padding: 2rem 1.5rem 3rem;
  color: var(--ink-faint);
  font-size: 0.87rem;
}

footer .inner { max-width: var(--maxw); margin: 0 auto; display: flex; gap: 1.5rem; flex-wrap: wrap; justify-content: space-between; }
footer a { color: var(--ink-soft); }

.pager { display: flex; justify-content: space-between; gap: 1rem; margin-top: 3rem; flex-wrap: wrap; }
.pager a { text-decoration: none; font-weight: 600; }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}