/* ai-learn — editorial minimal, one-page level system */
:root {
  --bg: #0a0d0a;
  --ink: #e8f5e8;
  --muted: #7a8a7a;
  --cream: #111a11;
  --card: #0f140f;
  --line: rgba(168, 230, 168, 0.14);
  --shadow: 0 1px 0 rgba(0,0,0,0.5);
  --serif: 'Instrument Serif', 'Times New Roman', serif;
  --sans: 'Inter Tight', system-ui, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, monospace;
  --accent: oklch(0.78 0.22 142);
  --easy: oklch(0.72 0.18 152);
  --medium: oklch(0.76 0.16 88);
  --hard: oklch(0.62 0.22 24);
  --font-scale: 1;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: calc(16px * var(--font-scale));
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background 0.4s ease, color 0.4s ease;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
code, .inline-mono {
  font-family: var(--mono);
  font-size: 13px;
  background: var(--card);
  padding: 1px 6px;
  border-radius: 2px;
  border: 1px solid var(--line);
  white-space: nowrap;
}
.mono-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ── HEADER ── */
.ai-header {
  padding: 14px 40px;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.ai-logo {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}
.ai-logo .dot { color: var(--accent); }
.header-left {
  display: flex;
  align-items: center;
  gap: 14px;
}
.back-link {
  font-family: var(--sans);
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s;
}
.back-link:hover { color: var(--accent); text-decoration: none; }

.progress-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 200px;
}
.progress-label { white-space: nowrap; }
.progress-bar {
  flex: 1;
  height: 4px;
  background: var(--line);
  border-radius: 2px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.5s ease;
}
.lang-control {
  display: flex;
  align-items: center;
  gap: 8px;
}
.lang-switch {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 2px;
  overflow: hidden;
}
.lang-btn {
  padding: 8px 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
  background: transparent;
  transition: color 150ms, background 150ms;
}
.lang-btn:hover { color: var(--ink); }
.lang-btn.active {
  background: var(--ink);
  color: var(--bg);
}

/* ── HERO ── */
.hero {
  text-align: center;
  padding: 80px 24px 60px;
  max-width: 720px;
  margin: 0 auto;
}
.hero-title {
  font-family: var(--serif);
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 400;
  font-style: italic;
  line-height: 1.1;
  margin: 0 0 16px;
  letter-spacing: -0.02em;
}
.hero-sub {
  font-size: 16px;
  color: var(--muted);
  margin: 0 0 32px;
}
.hero-cta {
  display: inline-block;
  padding: 12px 32px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: var(--accent);
  color: var(--bg);
  border-radius: 2px;
  transition: filter 150ms;
}
.hero-cta:hover { filter: brightness(1.15); }

.hero-img {
  display: block;
  width: 100%;
  max-width: 720px;
  height: auto;
  margin: 32px auto;
  border-radius: 3px;
  border: 1px solid var(--line);
  opacity: 0.88;
}

/* ── ROADMAP ── */
.roadmap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

/* ── LEVEL CARD ── */
.level-card {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 40px 36px;
  margin-bottom: 32px;
  transition: opacity 0.4s ease, filter 0.4s ease;
}

/* LOCKED STATE */
.level-card.locked {
  opacity: 0.4;
  filter: grayscale(0.6);
  pointer-events: none;
  cursor: default;
}
.level-card.locked .lock-overlay { display: flex; }
.level-card.locked .complete-btn { display: none; }
.level-card.locked .level-body { display: none; }
.level-card.locked .tldr { display: none; }

/* UNLOCKED STATE */
.level-card.unlocked { opacity: 1; filter: none; pointer-events: auto; }
.level-card.unlocked .lock-overlay { display: none; }
.level-card.unlocked .level-body { display: block; }

/* COMPLETED STATE */
.level-card.completed {
  opacity: 1;
  filter: none;
  pointer-events: auto;
  border-color: var(--accent);
}
.level-card.completed .lock-overlay { display: none; }
.level-card.completed .complete-btn { display: none; }
.level-card.completed .level-body { display: block; }
.level-card.completed .tldr { display: block; }

.lock-overlay {
  display: none;
  position: absolute;
  top: 16px;
  right: 20px;
  align-items: center;
  justify-content: center;
}
.lock-icon {
  font-size: 18px;
  color: var(--muted);
  opacity: 0.7;
  user-select: none;
  transform: rotate(180deg);
  display: inline-block;
}

/* ── LEVEL META ── */
.level-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}
.level-num { color: var(--accent); }

.difficulty-pill, .time-pill {
  font-size: 10px;
  padding: 2px 8px;
  border-radius: 2px;
  border: 1px solid var(--line);
}
.difficulty-pill.easy   { color: var(--easy);   border-color: var(--easy); }
.difficulty-pill.medium { color: var(--medium); border-color: var(--medium); }
.difficulty-pill.hard   { color: var(--hard);   border-color: var(--hard); }

.bonus-badge {
  display: inline-block;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 2px;
  border: 1px solid var(--accent);
  color: var(--accent);
  vertical-align: middle;
  margin-left: 8px;
}

.bonus-note {
  font-family: var(--sans);
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 16px;
  line-height: 1.5;
}

.level-title {
  font-family: var(--serif);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 400;
  font-style: italic;
  margin: 8px 0 0;
  letter-spacing: -0.01em;
}

.level-divider {
  height: 1px;
  background: var(--line);
  margin: 20px 0 24px;
}

/* ── LEVEL IMAGE ── */
.level-img {
  display: block;
  width: 100%;
  max-width: 640px;
  height: auto;
  margin: 0 auto 24px;
  border-radius: 3px;
  border: 1px solid var(--line);
  opacity: 0.92;
  background: var(--card);
}
.level-card.locked .level-img { display: none; }
.level-card.completed .level-img,
.level-card.unlocked .level-img { display: block; }

.level-img-secondary {
  display: block;
  width: 100%;
  max-width: 560px;
  height: auto;
  margin: 8px auto 6px;
  border-radius: 3px;
  border: 1px solid var(--line);
  opacity: 0.92;
  background: var(--card);
}
.level-card.locked .level-img-secondary { display: none; }
.img-caption {
  text-align: center;
  color: var(--muted);
  font-size: 0.78rem;
  margin: 0 0 24px;
}
.level-card.locked .img-caption { display: none; }

/* ── SECTIONS ── */
.section-label {
  display: block;
  margin-bottom: 10px;
}
.outcome, .steps {
  margin-bottom: 24px;
}
.outcome ul, .steps ol, .warnings ul {
  margin: 0;
  padding-left: 20px;
}
.outcome li, .steps li, .warnings li {
  margin-bottom: 8px;
  line-height: 1.55;
}
.steps code { font-size: 12px; padding: 2px 8px; }
.step-intro {
  margin: 4px 0 12px;
  color: var(--text-dim, #aaa);
  font-size: 14px;
  line-height: 1.5;
}
.steps h3.section-label { margin-top: 20px; }
.steps h3.section-label:first-of-type { margin-top: 0; }
.warnings {
  background: rgba(168, 230, 168, 0.05);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 16px 20px;
  margin-bottom: 24px;
}
.warnings .section-label { color: var(--medium); }
.warnings li { margin-bottom: 6px; }
.warnings li:last-child { margin-bottom: 0; }

/* ── CONCEPT BOX ── */
.concept-box {
  background: rgba(168, 230, 168, 0.04);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 20px 24px;
  margin-bottom: 24px;
}
.concept-box .section-label {
  margin-bottom: 16px;
  color: var(--accent);
}
.concept-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.concept-label {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 8px;
  color: var(--ink);
}
.concept-col p {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink);
}
.concept-col p:last-child { margin-bottom: 0; }
.concept-col p strong { color: var(--ink); font-weight: 700; }
.concept-col p em { color: var(--accent); font-style: normal; font-weight: 600; }
.concept-hint {
  font-size: 12px;
  color: var(--muted);
  font-style: italic;
  margin-top: auto;
  padding-top: 8px;
}
.concept-examples {
  font-size: 12px;
  color: var(--muted);
  margin: 4px 0 10px;
  line-height: 1.5;
}
.concept-examples .mono-label { margin-right: 4px; }
.concept-col { display: flex; flex-direction: column; }
.concept-img {
  display: block;
  width: 100%;
  max-width: 320px;
  height: auto;
  margin: 12px 0;
  border-radius: 3px;
  border: 1px solid var(--line);
  opacity: 0.9;
}
.concept-cmp-img {
  max-width: 640px;
  margin: 24px auto 0;
}
.concept-caption {
  font-size: 11px;
  color: var(--muted);
  margin: 4px 0 12px;
  line-height: 1.5;
}

/* ── WALKTHROUGH (click-by-click, beginner-safe) ── */
/* Built for Level 3's "install Claude Code in VS Code" — heavy on whitespace and
   color cues so beginners don't drown in prose. Each step is its own card. */
.walkthrough {
  margin: 8px 0 28px;
}
.walkthrough-intro {
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink);
  margin: 0 0 20px;
  padding: 14px 18px;
  background: rgba(120, 180, 255, 0.06);     /* cool blue tint = "info", calmer than the green warnings */
  border-left: 3px solid oklch(0.72 0.13 240);
  border-radius: 3px;
}
.walkthrough-intro strong { color: var(--ink); }
/* The MCP / jargon decoder — the one term a beginner must not be scared of */
.jargon {
  font-size: 13px;
  line-height: 1.55;
  color: var(--muted);
  margin: 0 0 24px;
  padding: 12px 16px;
  background: var(--cream);
  border: 1px dashed var(--line);
  border-radius: 3px;
}
.jargon b { color: var(--accent); font-weight: 600; }

/* Numbered step cards — big gaps between them so each click feels separate */
.wt-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 18px;                                  /* the breathing room the user asked for */
  counter-reset: wt;
}
.wt-step {
  position: relative;
  counter-increment: wt;
  padding: 16px 18px 16px 56px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 6px;
  line-height: 1.55;
  font-size: 14.5px;
}
.wt-step::before {
  content: counter(wt);
  position: absolute;
  left: 14px;
  top: 14px;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--bg);
  background: var(--accent);
  border-radius: 50%;
}
.wt-step strong { color: var(--ink); font-weight: 600; }
.wt-step .wt-head {
  display: block;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
}
.wt-step .wt-note {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  color: var(--muted);
}
/* "type this / click this" chips — a visual cue distinct from inline code */
.click-chip {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12px;
  padding: 2px 8px;
  margin: 0 1px;
  border-radius: 3px;
  background: rgba(168, 230, 168, 0.12);
  border: 1px solid var(--accent);
  color: var(--accent);
  white-space: nowrap;
}
/* a couple of steps are "this is the confusing part" — flag them warmly, not with alarm */
.wt-step.key {
  border-color: var(--accent);
  background: rgba(168, 230, 168, 0.05);
}
.wt-step.key::before { background: var(--easy); }

/* ── TL;DR ── */
.tldr {
  display: none;
  border-top: 1px solid var(--line);
  margin-top: 24px;
  padding-top: 20px;
}
.level-card.completed .tldr { display: block; }
.tldr-icon {
  display: inline-block;
  margin-bottom: 6px;
  color: var(--accent);
}
.tldr-text {
  margin: 0;
  font-family: var(--sans);
  font-style: normal;
  font-size: 15px;
  color: var(--ink);
  line-height: 1.6;
}
.tldr-text em { color: var(--accent); font-style: normal; font-weight: 600; }
.tldr-text strong { color: var(--ink); font-weight: 700; }

/* ── COMPLETE BUTTON ── */
.complete-btn {
  display: inline-block;
  margin-top: 24px;
  padding: 10px 28px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 2px;
  transition: background 150ms, color 150ms;
}
.complete-btn:hover {
  background: var(--accent);
  color: var(--bg);
}

/* ── OUTRO ── */
.outro {
  text-align: center;
  padding: 60px 24px 80px;
  max-width: 600px;
  margin: 0 auto;
}
.outro-title {
  font-family: var(--serif);
  font-size: 40px;
  font-style: italic;
  font-weight: 400;
  margin: 0 0 12px;
}
.outro-text {
  color: var(--muted);
  margin: 0 0 28px;
  line-height: 1.6;
}
.outro-cta {
  display: inline-block;
  padding: 12px 32px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: var(--accent);
  color: var(--bg);
  border-radius: 2px;
  text-decoration: none;
  transition: filter 150ms;
}
.outro-cta:hover { filter: brightness(1.15); text-decoration: none; }

/* ── FOOTER ── */
.ai-footer {
  text-align: center;
  padding: 0 24px 40px;
}
.reset-btn {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  opacity: 0.5;
  transition: opacity 150ms;
}
.reset-btn:hover { opacity: 1; }
.version {
  margin-top: 8px;
  opacity: 0.35;
}
.made-by {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  opacity: 0.6;
}
.made-by-link {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  transition: border-color 150ms;
}
.made-by-link:hover { border-bottom-color: var(--accent); }

/* ── FADE-IN ON UNLOCK ── */
.level-card.fade-in {
  animation: aiFadeIn 0.5s ease both;
}
@keyframes aiFadeIn {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── RESPONSIVE ── */
@media (max-width: 640px) {
  .ai-header { padding: 12px 20px; }
  .progress-wrap { width: 100%; order: 3; }
  .lang-control { margin-left: auto; }
  .lang-label { display: none; }
  .hero { padding: 48px 20px 40px; }
  .level-card { padding: 28px 22px; }
  .roadmap { padding: 0 16px 60px; }
  .concept-cols { grid-template-columns: 1fr; gap: 16px; }
  .wt-step { padding: 14px 14px 14px 48px; }
  .wt-step::before { left: 12px; top: 12px; width: 24px; height: 24px; font-size: 12px; }
}

/* ── PRINT ── */
@media print {
  body { background: #fff; color: #111; }
  .ai-header, .hero-cta, .complete-btn, .reset-btn, .lang-control,
  .lock-overlay, .progress-wrap { display: none !important; }
  .level-card.locked {
    opacity: 1 !important;
    filter: none !important;
    pointer-events: auto !important;
    border-color: #ccc !important;
  }
  .level-card.locked .lock-overlay { display: none !important; }
  .level-card.locked .level-body { display: block !important; }
  .level-card.locked .tldr { display: block !important; }
  .level-card { break-inside: avoid; page-break-inside: avoid; }
  .tldr { display: block !important; }
  a { color: #111; text-decoration: underline; }
  .outro { display: block !important; }
  .hero { padding: 20px 0; }
  .hero-title { font-size: 28px; color: #111; }
}