/* ─── Lesson page shared styles ──────────────────────────────────────────────
   Shared across all 11 lesson pages. Each lesson links this after site.css.
   Lesson-specific token colors and unique component styles stay per-page.
   Lesson 01 dialogue styles live in lesson-01.css.
   ──────────────────────────────────────────────────────────────────────────── */

/* ─── Exploration reference callout ───────────────────────────────────────── */

.exploration-ref {
  background: var(--surface-2);
  border-left: 3px solid var(--accent);
  padding: 0.75rem 1rem;
  margin: 1rem 0 1.5rem;
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--ink-2);
}

.exploration-ref code {
  background: var(--surface-1);
  padding: 0.1rem 0.3rem;
  border-radius: 3px;
  font-size: 0.85em;
}

/* ─── Layout ──────────────────────────────────────────────────────────────── */

.layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: 100vh;
  max-width: 1200px;
  margin: 0 auto;
}

/* ─── Sidebar ─────────────────────────────────────────────────────────────── */

.sidebar {
  border-right: 1px solid var(--border);
  padding: 2.5rem 1.5rem;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.sidebar-label {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 1rem;
}

.sidebar-title {
  font-family: var(--serif);
  font-size: 1.05rem;
  line-height: 1.4;
  color: var(--ink);
  margin-bottom: 1.5rem;
  font-weight: 400;
}
.sidebar-title a {
  color: var(--ink);
  text-decoration: none;
  font-size: 2.05rem;
}
.sidebar-title a:hover {
  color: var(--accent);
}
.sidebar-title a span.before-you-ship {
  display: block;
  font-style: italic;
  color: var(--ink-3);
  font-weight: 300;
  font-size: 0.9rem;
  margin: 0 0 0 2rem;
  line-height: 0rem;
}

.sidebar nav { margin-bottom: 2rem; }

.sidebar nav a {
  display: block;
  font-size: 13px;
  font-weight: 300;
  color: var(--ink-3);
  text-decoration: none;
  padding: 5px 0;
  border-bottom: 1px solid transparent;
  line-height: 1.4;
}

.sidebar nav a:hover { color: var(--ink); }

.sidebar nav a.current {
  color: var(--accent);
  font-weight: 500;
}

.sidebar nav a.done { color: var(--ink-3); }

.sidebar nav a .num {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-3);
  margin-right: 6px;
}

.sidebar nav a.current .num { color: var(--accent); opacity: 0.7; }
.sidebar nav a.done .num { color: var(--ink-3); opacity: 0.5; }

/* ─── Main content ────────────────────────────────────────────────────────── */

.main {
  padding: 4rem 4.5rem 6rem;
  max-width: 960px;
}

/* ─── Breadcrumb ──────────────────────────────────────────────────────────── */

.breadcrumb {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-3);
  margin-bottom: 2.5rem;
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb a { color: var(--ink-3); text-decoration: none; }
.breadcrumb a:hover { color: var(--ink); }
.breadcrumb .sep { opacity: 0.4; }
.breadcrumb .current { color: var(--ink-2); }

/* ─── Lesson header ───────────────────────────────────────────────────────── */

.lesson-num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-3);
  margin-bottom: 0.5rem;
}

h1 {
  font-family: var(--serif);
  font-size: 2.6rem;
  font-weight: 400;
  line-height: 1.1;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
  font-variation-settings: 'opsz' 40;
}

.subtitle {
  font-size: 1.05rem;
  color: var(--ink-2);
  font-weight: 300;
  line-height: 1.6;
  margin-bottom: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--border);
}

/* ─── Prose ───────────────────────────────────────────────────────────────── */

.lesson p {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--ink-2);
  margin-bottom: 1.25rem;
  font-weight: 300;
}

.lesson p a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}
.lesson p a:hover {
  background: #a84908;
  color: #fff;
}


.lesson p strong {
  color: var(--ink);
  font-weight: 500;
}

.lesson h2 {
  font-family: var(--sans);
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--ink);
  margin: 2.5rem 0 0.75rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--border);
  letter-spacing: -0.01em;
}

.lesson h2:first-of-type {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
}

.lesson h3 {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 500;
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin: 1.75rem 0 0.5rem;
}

/* ─── Inline code ─────────────────────────────────────────────────────────── */

.lesson code:not(.block) {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--ink);
}

/* ─── Code blocks ─────────────────────────────────────────────────────────── */

.code-block {
  margin: 1.5rem 0;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid #eee8d5;
}

.code-header {
  background: #eee8d5;
  padding: 8px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.code-filename {
  font-family: var(--mono);
  font-size: 11px;
  color: #93a1a1;
}

.code-lang {
  font-family: var(--mono);
  font-size: 10px;
  color: #93a1a1;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

pre {
  background: var(--code-bg);
  padding: 0;
  overflow-x: auto;
  margin: 0;
  line-height: 1.7;
}

pre code {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--code-fg);
  display: block;
}

/* ─── Syntax token classes ────────────────────────────────────────────────── */

.t-comment { color: var(--code-comment); font-style: italic; }
.t-keyword { color: var(--code-keyword); }
.t-type { color: var(--code-type); }
.t-string { color: var(--code-string); }
.t-number { color: var(--code-number); }
.t-prop { color: var(--code-prop); }
.t-fn { color: var(--code-fn); }
.t-op { color: var(--code-op); }
.t-plain { color: var(--code-fg); }
.t-dim { color: #93a1a1; }
.t-shell-prompt { color: var(--code-comment); user-select: none; }
.t-shell-out { color: #859900; }
.t-shell-cmd { color: var(--code-fg); }

/* ─── Shell block ─────────────────────────────────────────────────────────── */

.shell-block {
  border-radius: 8px;
  margin: 0 0 30px 0;
  overflow: hidden;
}

.shell-block pre { padding: 0; }

/* ─── File tree ───────────────────────────────────────────────────────────── */

.file-tree {
  margin: 1.5rem 0;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid #eee8d5;
}

.file-tree pre {
  background: none;
  padding: 1.25rem 1.5rem;
}

.file-tree code {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--code-fg);
  display: block;
  line-height: 1.9;
}

.ft-dir { color: var(--code-type); }
.ft-new { color: var(--code-string); }
.ft-dim { color: #93a1a1; }

/* ─── Callout ─────────────────────────────────────────────────────────────── */

.callout {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  background: var(--accent-bg);
  margin: 1.5rem 0;
}

.callout .callout-label {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 6px;
}

.callout p {
  font-size: 18px;
  color: var(--ink-2);
  margin: 0 !important;
  line-height: 1.65;
}

.callout p + p { margin-top: 0.5rem !important; }

/* ─── Warning ─────────────────────────────────────────────────────────────── */

.warn {
  border: 1px solid var(--warn-border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  background: var(--warn-bg);
  margin: 1.5rem 0;
}

.warn .warn-label {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--amber);
  margin-bottom: 6px;
}

.warn p {
  font-size: 14px;
  color: var(--ink-2);
  margin: 0 !important;
  line-height: 1.65;
}

/* ─── Checkpoint ──────────────────────────────────────────────────────────── */

.checkpoint {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  background: var(--surface);
  margin: 2rem 0;
}

.checkpoint .checkpoint-label {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.checkpoint ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.checkpoint li {
  font-size: 18px;
  color: var(--ink-2);
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.5;
}

.checkpoint li::before {
  content: '✓';
  color: #639922;
  font-family: var(--mono);
  font-size: 18px;
  flex-shrink: 0;
  margin-top: 1px;
}

/* ─── Next lesson nav ─────────────────────────────────────────────────────── */

.next-lesson {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.next-lesson .next-label {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}

.next-lesson a {
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--ink);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.next-lesson a:hover { color: var(--accent); }
.next-lesson a .arrow { font-size: 1.1rem; }

/* ─── Sidebar signup ──────────────────────────────────────────────────────── */

.sidebar-signup {
  margin-top: 1.5rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
}

.sidebar-signup .ss-label {
  font-family: var(--mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 8px;
}

.sidebar-signup .ss-text {
  font-size: 14px;
  color: var(--ink-2);
  line-height: 1.55;
  margin-bottom: 10px;
}

.sidebar-signup form {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.sidebar-signup input[type="email"] {
  font-family: var(--sans);
  font-size: 14px;
  padding: 7px 9px;
  border: 1px solid var(--border);
  border-radius: 3px;
  background: var(--bg);
  color: var(--ink);
  outline: none;
  width: 100%;
  transition: border-color 0.15s;
}

.sidebar-signup input:focus { border-color: var(--accent); }

.sidebar-signup .sidebar-input-button {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  padding: 7px 9px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 3px;
  cursor: pointer;
  transition: background 0.15s;
}

.sidebar-signup .sidebar-input-button:hover { background: #a84908; }

/* ─── Companion box (dead — elements removed, CSS harmless) ───────────────── */

.companion-box {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem;
  background: var(--surface);
}

.companion-box .companion-label {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.companion-box p {
  font-size: 14px;
  color: var(--ink-2);
  line-height: 1.6;
  margin-bottom: 8px;
}

.companion-box .skill-file {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-3);
}

/* ─── Copy button ─────────────────────────────────────────────────────────── */

.copy-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: #93a1a1;
  padding: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 3px;
  transition: color 0.15s, background 0.15s;
  flex-shrink: 0;
}

.copy-btn:hover { color: var(--ink-2); background: rgba(0,0,0,0.06); }
.copy-btn--copied { color: #639922 !important; }

.copy-btn--overlay {
  position: absolute;
  top: 8px;
  right: 8px;
}

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

@media (max-width: 960px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .main { padding: 2rem 1.5rem 4rem; }
  h1 { font-size: 2rem; }
}

/* ─── Updating Unordered lists──────────────────────────────────────────────────────────── */
.lesson ul.open-spec-example,
.lesson ol.formatted,
.lesson ul.formatted  {
  margin: 0 0 1.25rem 1.5rem;
}
.lesson ul.open-spec-example li,
.lesson ol.formatted li,
.lesson ul.formatted li {
  /* font-family: var(--mono); */
  /* font-size: 18px; */
  color: var(--ink-2);
  margin-bottom: 0.5rem;
  line-height: 1.5;
}