/* Learn Claude Code — shared shell for all 12 lesson pages.
   Kept minimal: just the frame, widgets, and typography. Each lesson
   inlines its own widget-specific rules if needed. */

:root {
  --bg: #ffffff;
  --bg-subtle: #f6f8fa;
  --border: #d0d7de;
  --border-muted: #d8dee4;
  --fg: #1f2328;
  --fg-muted: #59636e;
  --fg-subtle: #818b98;
  --accent: #0969da;
  --accent-muted: #ddf4ff;
  --success: #1a7f37;
  --success-muted: #dafbe1;
  --attention: #9a6700;
  --attention-muted: #fff8c5;
  --danger: #cf222e;
  --danger-muted: #ffebe9;
  --done: #8250df;
  --done-muted: #fbefff;
}
body { font-family: 'Inter', system-ui, sans-serif; color: var(--fg); background: var(--bg); letter-spacing: -0.005em; -webkit-font-smoothing: antialiased; margin: 0; }
.mono { font-family: 'JetBrains Mono', ui-monospace, 'SF Mono', monospace; }

/* Layout */
.learn-layout { display: grid; grid-template-columns: 280px minmax(0, 1fr); gap: 0; max-width: 1320px; margin: 0 auto; }
@media (max-width: 900px) { .learn-layout { grid-template-columns: 1fr; } .toc-sidebar { display: none; } }

/* Sidebar */
.toc-sidebar { border-right: 1px solid var(--border-muted); padding: 28px 20px 80px 28px; position: sticky; top: 56px; height: calc(100vh - 56px); overflow-y: auto; font-size: 13.5px; }
.toc-label { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: .08em; color: var(--fg-subtle); margin-bottom: 12px; }
.toc-list { list-style: none; margin: 0; padding: 0; }
.toc-list li { margin: 0; }
.toc-list a, .toc-list span { display: flex; align-items: center; gap: 10px; padding: 7px 10px; border-radius: 6px; color: var(--fg-muted); text-decoration: none; transition: background .12s; }
.toc-list a:hover { background: var(--bg-subtle); color: var(--fg); }
.toc-list .active a { background: var(--accent-muted); color: var(--accent); font-weight: 600; }
.toc-list .soon { color: var(--fg-subtle); cursor: not-allowed; }
.toc-num { font-size: 11px; font-weight: 600; width: 30px; opacity: .7; }
.soon-badge { margin-left: auto; font-size: 10px; color: var(--fg-subtle); border: 1px solid var(--border-muted); padding: 1px 6px; border-radius: 999px; }

/* Article */
.learn-article { padding: 40px 56px 120px; max-width: 820px; }
@media (max-width: 700px) { .learn-article { padding: 28px 20px 80px; } }
.breadcrumb { font-size: 12.5px; color: var(--fg-muted); margin-bottom: 16px; }
.breadcrumb a { color: var(--accent); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.eyebrow { display: inline-block; font-size: 11.5px; font-weight: 600; text-transform: uppercase; letter-spacing: .09em; color: var(--accent); padding: 4px 10px; background: var(--accent-muted); border-radius: 999px; }
h1.lesson-title { font-size: 42px; font-weight: 700; letter-spacing: -0.02em; line-height: 1.12; margin: 12px 0 14px; }
.subtitle { font-size: 18.5px; color: var(--fg-muted); line-height: 1.55; margin-bottom: 28px; }
.lesson-meta { display: flex; gap: 18px; align-items: center; font-size: 12.5px; color: var(--fg-subtle); padding: 14px 0; border-top: 1px solid var(--border-muted); border-bottom: 1px solid var(--border-muted); margin-bottom: 40px; flex-wrap: wrap; }
.lesson-meta a { color: var(--fg-muted); text-decoration: none; }
.lesson-meta a:hover { color: var(--accent); }

.prose h2 { font-size: 24px; font-weight: 700; letter-spacing: -0.015em; margin: 44px 0 14px; padding-top: 24px; border-top: 1px solid var(--border-muted); }
.prose h2:first-of-type { border-top: none; padding-top: 0; }
.prose h3 { font-size: 17px; font-weight: 600; margin: 28px 0 10px; color: var(--fg); }
.prose p { line-height: 1.75; font-size: 15.5px; margin: 12px 0; color: var(--fg); }
.prose p code, .prose li code { font-family: 'JetBrains Mono', ui-monospace, monospace; font-size: 13px; background: var(--accent-muted); color: var(--accent); padding: 1px 6px; border-radius: 4px; }
.prose ul, .prose ol { margin: 12px 0 12px 8px; padding-left: 20px; line-height: 1.75; font-size: 15.5px; }
.prose li { margin: 4px 0; }
.prose a { color: var(--accent); text-decoration: none; }
.prose a:hover { text-decoration: underline; }
.prose strong { color: var(--fg); font-weight: 600; }

pre.code-block { background: #0d1117; color: #c9d1d9; padding: 16px 18px; border-radius: 8px; overflow-x: auto; font-family: 'JetBrains Mono', ui-monospace, monospace; font-size: 13px; line-height: 1.65; margin: 14px 0; border: 1px solid #21262d; white-space: pre; }
pre.code-block .c-kw { color: #ff7b72; }
pre.code-block .c-fn { color: #d2a8ff; }
pre.code-block .c-str { color: #a5d6ff; }
pre.code-block .c-cmt { color: #8b949e; font-style: italic; }
pre.code-block .c-num { color: #79c0ff; }
pre.code-block .c-hl { background: rgba(56, 139, 253, .18); display: block; margin: 0 -18px; padding: 0 18px; }

blockquote.callout { border-left: 3px solid var(--accent); background: var(--accent-muted); padding: 12px 16px; border-radius: 0 6px 6px 0; margin: 20px 0; font-size: 14.5px; color: #054289; }
blockquote.callout strong { color: var(--accent); }

/* Widget shell */
.widget { border: 1px solid var(--border); border-radius: 10px; background: var(--bg); margin: 24px 0; overflow: hidden; }
.widget-head { padding: 14px 18px; border-bottom: 1px solid var(--border-muted); background: var(--bg-subtle); }
.widget-head .widget-tag { display: inline-block; font-size: 10.5px; font-weight: 600; text-transform: uppercase; letter-spacing: .08em; color: var(--done); background: var(--done-muted); padding: 2px 8px; border-radius: 999px; margin-right: 8px; }
.widget-head h3 { font-size: 16px; font-weight: 600; margin: 4px 0 0; color: var(--fg); }
.widget-head p { font-size: 13px; color: var(--fg-muted); margin: 4px 0 0; line-height: 1.55; }
.widget-body { padding: 18px; }

/* Buttons */
.btn { padding: 6px 14px; font-size: 13.5px; font-weight: 500; border-radius: 6px; border: 1px solid var(--border); background: var(--bg-subtle); color: var(--fg); cursor: pointer; transition: background .12s, border-color .12s; font-family: inherit; }
.btn:hover:not(:disabled) { background: #eef1f4; border-color: #afb8c1; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primary { background: var(--fg); color: white; border-color: var(--fg); }
.btn-primary:hover:not(:disabled) { background: #2e343b; }
.btn-danger { background: var(--danger); color: white; border-color: var(--danger); }
.btn-success { background: var(--success); color: white; border-color: var(--success); }
.btn-sm { padding: 4px 10px; font-size: 12px; }

/* Shared bubble styles (used across lessons) */
.msg-bubble { padding: 10px 12px; border-radius: 8px; margin: 8px 0; font-size: 13px; line-height: 1.55; border: 1px solid transparent; animation: fadein .25s ease-out; }
.msg-user   { background: var(--bg-subtle); border-color: var(--border-muted); }
.msg-assistant { background: #f0f7ff; border-color: rgba(9,105,218,.2); }
.msg-tool-use { background: var(--attention-muted); border-color: #d4a72c; font-family: 'JetBrains Mono', monospace; font-size: 12px; }
.msg-tool-result { background: var(--success-muted); border-color: #a7dfb5; font-family: 'JetBrains Mono', monospace; font-size: 12px; }
.msg-label { font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; margin-bottom: 4px; opacity: .75; }

/* Header */
header.site-header { position: sticky; top: 0; z-index: 40; background: rgba(255,255,255,.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border-muted); }
.header-inner { max-width: 1320px; margin: 0 auto; padding: 0 20px; height: 56px; display: flex; align-items: center; gap: 20px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 600; color: var(--fg); text-decoration: none; font-size: 15px; }
.logo-mark { width: 30px; height: 30px; border-radius: 8px; background: linear-gradient(135deg, var(--accent), var(--done)); color: white; display: inline-flex; align-items: center; justify-content: center; }
.header-nav { display: flex; align-items: center; gap: 2px; margin-left: 12px; }
.header-nav a { padding: 6px 12px; border-radius: 6px; color: var(--fg-muted); font-size: 13.5px; text-decoration: none; transition: all .12s; }
.header-nav a:hover { background: var(--bg-subtle); color: var(--fg); }
.header-nav a.active { color: var(--accent); }
.header-cta { margin-left: auto; }
.header-cta a { padding: 6px 14px; background: var(--fg); color: white; border-radius: 6px; font-size: 13.5px; text-decoration: none; font-weight: 500; }
.header-cta a:hover { background: #2e343b; }

/* Prev / Next */
.prev-next { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 56px; padding-top: 28px; border-top: 1px solid var(--border-muted); }
.pn-card { border: 1px solid var(--border); border-radius: 10px; padding: 16px 18px; text-decoration: none; color: var(--fg); display: block; transition: all .15s; }
.pn-card:hover { border-color: var(--accent); box-shadow: 0 2px 8px rgba(9,105,218,.08); }
.pn-card.disabled { opacity: .45; cursor: not-allowed; pointer-events: none; }
.pn-dir { font-size: 11px; color: var(--fg-subtle); text-transform: uppercase; letter-spacing: .08em; margin-bottom: 6px; }
.pn-title { font-size: 15px; font-weight: 600; color: var(--fg); }
.pn-sub { font-size: 13px; color: var(--fg-muted); margin-top: 2px; }

/* Quiz widget (used across multiple lessons) */
.quiz-item { border: 1px solid var(--border-muted); border-radius: 8px; padding: 14px; margin-bottom: 12px; background: var(--bg); transition: border-color .15s; }
.quiz-item.answered-ok { border-color: var(--success); background: #f0fff4; }
.quiz-item.answered-bad { border-color: var(--danger); background: #fff5f5; }
.quiz-json { font-family: 'JetBrains Mono', monospace; font-size: 12px; background: #0d1117; color: #c9d1d9; padding: 10px 12px; border-radius: 6px; margin-bottom: 10px; white-space: pre; overflow-x: auto; line-height: 1.6; }
.quiz-json .k { color: #79c0ff; }
.quiz-json .v { color: #a5d6ff; }
.quiz-json .n { color: #ffa657; }
.quiz-actions { display: flex; gap: 8px; margin-top: 8px; flex-wrap: wrap; }
.quiz-feedback { font-size: 13px; line-height: 1.55; margin-top: 10px; padding: 8px 10px; border-radius: 6px; display: none; }
.quiz-feedback.show { display: block; }
.quiz-feedback.ok { background: var(--success-muted); color: var(--success); }
.quiz-feedback.bad { background: var(--danger-muted); color: var(--danger); }
.quiz-summary { margin-top: 18px; padding: 14px 16px; border-radius: 8px; background: var(--bg-subtle); border: 1px solid var(--border-muted); font-size: 14px; display: flex; align-items: center; justify-content: space-between; }
.quiz-summary strong { font-size: 15px; color: var(--fg); }

/* Verdict banners */
.verdict { margin-top: 14px; padding: 10px 14px; border-radius: 6px; font-size: 13.5px; line-height: 1.55; }
.verdict-ok   { background: var(--success-muted); border: 1px solid #a7dfb5; color: var(--success); }
.verdict-bad  { background: var(--danger-muted); border: 1px solid #ffc1ba; color: var(--danger); }
.verdict-info { background: var(--accent-muted); border: 1px solid #a5d0ff; color: var(--accent); }

/* Tabs (used across lessons) */
.l-tabs { display: flex; border-bottom: 1px solid var(--border-muted); margin-bottom: 16px; }
.l-tab { padding: 10px 18px; font-size: 13.5px; font-weight: 500; color: var(--fg-muted); cursor: pointer; border-bottom: 2px solid transparent; transition: all .15s; background: none; border-top: 0; border-left: 0; border-right: 0; font-family: inherit; }
.l-tab:hover { color: var(--fg); }
.l-tab.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.l-panel { display: none; }
.l-panel.active { display: block; animation: fadein .2s ease-out; }

/* Animations */
@keyframes fadein { from { opacity: 0; transform: translateY(3px); } to { opacity: 1; transform: none; } }
@keyframes pulse-soft { 0%,100% { opacity: 1 } 50% { opacity: .6 } }

/* Mobile ToC */
.mobile-toc-btn { display: none; margin-bottom: 20px; padding: 8px 12px; border: 1px solid var(--border); border-radius: 6px; background: var(--bg-subtle); cursor: pointer; font-size: 13px; width: 100%; text-align: left; color: var(--fg); font-family: inherit; }
@media (max-width: 900px) { .mobile-toc-btn { display: block; } }
.mobile-toc { display: none; padding: 8px 12px; border: 1px solid var(--border-muted); border-top: 0; border-radius: 0 0 6px 6px; margin-top: -20px; margin-bottom: 20px; background: var(--bg); }
.mobile-toc.open { display: block; }

/* Utilities */
.flex { display: flex; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 720px) { .grid-2 { grid-template-columns: 1fr; } }
.pane { border: 1px solid var(--border-muted); border-radius: 8px; padding: 12px; min-height: 180px; background: var(--bg-subtle); font-size: 12.5px; font-family: 'JetBrains Mono', monospace; overflow-y: auto; max-height: 360px; }
.pane-label { font-size: 11px; color: var(--fg-subtle); text-transform: uppercase; letter-spacing: .08em; font-weight: 600; margin-bottom: 8px; font-family: 'Inter', sans-serif; }
.ctrl-row { display: flex; gap: 8px; align-items: center; margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--border-muted); flex-wrap: wrap; font-size: 12.5px; color: var(--fg-muted); }
.ctrl-row .spacer { flex: 1; }