/* ── DESIGN TOKENS ─────────────────────── */
:root {
  --bg:        #0f0e17;
  --surface:   #1a1830;
  --card:      #221f38;
  --border:    #2e2b4a;
  --text:      #fffffe;
  --muted:     #a7a9be;
  --code-bg:   #13111f;

  /* Phase 4 accent — teal/automation green */
  --accent:    #06d6a0;
  --accent-dim: rgba(6, 214, 160, 0.12);
  --accent-glow: rgba(6, 214, 160, 0.35);

  --gold:   #ffd166;
  --blue:   #4db8ff;
  --coral:  #ff6b6b;
  --purple: #c77dff;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Nunito', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  display: flex;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── SIDEBAR ───────────────────────────── */
.sidebar {
  width: 280px;
  min-width: 280px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  height: 100vh;
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-header {
  padding: 24px 20px 16px;
  border-bottom: 1px solid var(--border);
}

.phase-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent-dim);
  border: 1px solid rgba(6,214,160,0.3);
  color: var(--accent);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 2px;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 10px;
}

.sidebar-title {
  font-family: 'Fredoka One', cursive;
  font-size: 1.15rem;
  line-height: 1.2;
  margin-bottom: 4px;
}

.sidebar-sub {
  font-size: 11px;
  color: var(--muted);
  font-family: 'Fira Code', monospace;
}

/* progress snake */
.progress-track {
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
}

.progress-label {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 10px;
}

.progress-dots {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.p-dot {
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--border);
  border: 2px solid var(--border);
  transition: all 0.3s;
  cursor: pointer;
  position: relative;
}

.p-dot.done {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 8px var(--accent-glow);
}

.p-dot.active {
  background: transparent;
  border-color: var(--accent);
  box-shadow: 0 0 10px var(--accent-glow);
}

.progress-bar-wrap {
  margin-top: 10px;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--blue));
  border-radius: 2px;
  transition: width 0.4s ease;
  width: 0%;
}

.progress-text {
  font-size: 11px;
  color: var(--muted);
  margin-top: 6px;
  font-family: 'Fira Code', monospace;
}

/* nav */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 10px 0;
}

.sidebar-nav::-webkit-scrollbar { width: 4px; }
.sidebar-nav::-webkit-scrollbar-track { background: transparent; }
.sidebar-nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px;
  cursor: pointer;
  transition: all 0.2s;
  border-left: 3px solid transparent;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--muted);
}

.nav-item:hover { background: var(--accent-dim); color: var(--text); }

.nav-item.active {
  background: var(--accent-dim);
  border-left-color: var(--accent);
  color: var(--accent);
}

.nav-item.completed {
  color: var(--accent);
  opacity: 0.7;
}

.nav-num {
  font-family: 'Fira Code', monospace;
  font-size: 10px;
  font-weight: 600;
  color: var(--muted);
  min-width: 22px;
}

.nav-item.active .nav-num,
.nav-item.completed .nav-num { color: var(--accent); }

.nav-check {
  margin-left: auto;
  font-size: 12px;
  opacity: 0;
  transition: opacity 0.2s;
}
.nav-item.completed .nav-check { opacity: 1; }

.sidebar-footer {
  padding: 16px 20px;
  border-top: 1px solid var(--border);
}

.phase-links {
  display: flex;
  gap: 8px;
}

.phase-link {
  flex: 1;
  padding: 8px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
  transition: all 0.2s;
  font-family: 'Nunito', sans-serif;
}
.phase-link:hover { border-color: var(--accent); color: var(--accent); }
.phase-link.next {
  background: var(--accent-dim);
  border-color: rgba(6,214,160,0.3);
  color: var(--accent);
}

/* ── MAIN CONTENT ──────────────────────── */
.main {
  flex: 1;
  overflow-y: auto;
  padding: 0;
}

.lesson { display: none; }
.lesson.active { display: block; }

/* lesson header */
.lesson-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 32px 48px 28px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.lesson-eyebrow {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
  font-family: 'Fira Code', monospace;
}

.lesson-title {
  font-family: 'Fredoka One', cursive;
  font-size: 2rem;
  line-height: 1.1;
  margin-bottom: 8px;
}

.lesson-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.meta-pill {
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 1px;
  padding: 3px 10px;
  border-radius: 20px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border);
  color: var(--muted);
}

.meta-pill.accent { background: var(--accent-dim); border-color: rgba(6,214,160,0.3); color: var(--accent); }

/* lesson body */
.lesson-body {
  padding: 40px 48px 60px;
  max-width: 860px;
}

.lesson-body h2 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.5rem;
  margin: 40px 0 14px;
  color: var(--text);
}

.lesson-body h2:first-child { margin-top: 0; }

.lesson-body h3 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.15rem;
  margin: 28px 0 10px;
  color: var(--accent);
}

.lesson-body p {
  color: #c8c8dc;
  margin-bottom: 16px;
  font-size: 0.97rem;
  line-height: 1.85;
}

.lesson-body p strong { color: var(--text); }

.lesson-body ul, .lesson-body ol {
  margin: 12px 0 20px 24px;
  color: #c8c8dc;
  font-size: 0.95rem;
  line-height: 2;
}

/* code blocks */
pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px 24px;
  overflow-x: auto;
  margin: 18px 0;
  position: relative;
}

pre code {
  font-family: 'Fira Code', monospace;
  font-size: 0.85rem;
  line-height: 1.9;
  color: #e0e0f0;
}

.code-label {
  position: absolute;
  top: 10px;
  right: 14px;
  font-family: 'Fira Code', monospace;
  font-size: 10px;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* syntax */
.kw  { color: #c77dff; }
.fn  { color: #06d6a0; }
.str { color: #ffaa6b; }
.cm  { color: #4a4870; font-style: italic; }
.num { color: #ff6b9d; }
.cls { color: #ffd166; }
.dec { color: #4db8ff; }
.op  { color: #ff6b6b; }
.out { color: #a7f3d0; }

/* callouts */
.callout {
  border-radius: 12px;
  padding: 18px 22px;
  margin: 20px 0;
  font-size: 0.93rem;
  line-height: 1.8;
  border-left: 4px solid;
}

.callout-tip   { background: rgba(6,214,160,0.08); border-color: var(--accent); }
.callout-warn  { background: rgba(255,209,102,0.08); border-color: var(--gold); }
.callout-info  { background: rgba(77,184,255,0.08); border-color: var(--blue); }
.callout-danger{ background: rgba(255,107,107,0.08); border-color: var(--coral); }

.callout strong { display: block; font-weight: 800; margin-bottom: 4px; font-size: 0.85rem; letter-spacing: 1px; text-transform: uppercase; }
.callout-tip   strong { color: var(--accent); }
.callout-warn  strong { color: var(--gold); }
.callout-info  strong { color: var(--blue); }
.callout-danger strong { color: var(--coral); }

/* compare grid */
.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 20px 0;
}

.compare-box {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.compare-label {
  padding: 8px 16px;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 2px;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border);
}

.compare-label.bad  { color: var(--coral); background: rgba(255,107,107,0.08); }
.compare-label.good { color: var(--accent); background: rgba(6,214,160,0.08); }
.compare-label.lang { color: var(--blue); background: rgba(77,184,255,0.08); }
.compare-label.py   { color: var(--gold); background: rgba(255,209,102,0.08); }

.compare-box pre {
  margin: 0;
  border: none;
  border-radius: 0;
  background: transparent;
}

/* table */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 0.88rem;
}

.data-table th {
  background: var(--card);
  color: var(--accent);
  font-weight: 800;
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  padding: 10px 14px;
  text-align: left;
  border-bottom: 2px solid var(--border);
}

.data-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: #c8c8dc;
  font-family: 'Fira Code', monospace;
  font-size: 0.82rem;
}

.data-table tr:hover td { background: var(--accent-dim); }

/* quiz */
.quiz-block {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  margin: 28px 0;
}

.quiz-q {
  font-family: 'Fredoka One', cursive;
  font-size: 1.15rem;
  margin-bottom: 18px;
}

.quiz-options { display: flex; flex-direction: column; gap: 10px; }

.quiz-option {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 18px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 700;
  transition: all 0.2s;
  font-family: 'Fira Code', monospace;
  text-align: left;
  color: var(--text);
}

.quiz-option:hover { border-color: var(--accent); background: var(--accent-dim); }
.quiz-option.correct { border-color: var(--accent); background: rgba(6,214,160,0.15); color: var(--accent); }
.quiz-option.wrong   { border-color: var(--coral); background: rgba(255,107,107,0.1); color: var(--coral); }

.quiz-explain {
  margin-top: 14px;
  padding: 12px 16px;
  border-radius: 8px;
  font-size: 0.88rem;
  display: none;
  line-height: 1.7;
}
.quiz-explain.show { display: block; }
.quiz-explain.correct-exp { background: rgba(6,214,160,0.1); color: var(--accent); border: 1px solid rgba(6,214,160,0.2); }
.quiz-explain.wrong-exp   { background: rgba(255,107,107,0.1); color: var(--coral); border: 1px solid rgba(255,107,107,0.2); }

/* project card */
.project-card {
  background: linear-gradient(135deg, #1a2535, #1a1f35);
  border: 1px solid rgba(6,214,160,0.25);
  border-radius: 20px;
  padding: 32px;
  margin: 32px 0;
}

.project-eyebrow {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

.project-title {
  font-family: 'Fredoka One', cursive;
  font-size: 1.6rem;
  margin-bottom: 12px;
}

.project-desc {
  color: #c8c8dc;
  font-size: 0.95rem;
  line-height: 1.85;
  margin-bottom: 20px;
}

.project-requirements {
  list-style: none;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.project-requirements li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.9rem;
  color: #c8c8dc;
}

.project-requirements li::before {
  content: '→';
  color: var(--accent);
  font-weight: 800;
  flex-shrink: 0;
  margin-top: 2px;
}

/* complete btn */
.complete-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 40px;
  background: linear-gradient(135deg, var(--accent), #04b888);
  color: #0f0e17;
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 0.95rem;
  padding: 14px 28px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
}
.complete-btn:hover { transform: translateY(-2px); box-shadow: 0 10px 28px var(--accent-glow); }
.complete-btn.done { background: var(--surface); color: var(--accent); border: 1px solid rgba(6,214,160,0.3); cursor: default; transform: none; box-shadow: none; }

/* next lesson bar */
.next-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 22px;
  margin-top: 24px;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.next-bar:hover { border-color: var(--accent); background: var(--accent-dim); }

.next-bar-label { font-size: 10px; font-weight: 800; letter-spacing: 2px; text-transform: uppercase; color: var(--muted); margin-bottom: 3px; }
.next-bar-title { font-weight: 800; color: var(--text); }
.next-bar-arrow { font-size: 1.4rem; color: var(--accent); }

/* section divider */
.divider {
  height: 1px;
  background: var(--border);
  margin: 32px 0;
}

/* highlight inline */
.hl       { color: var(--accent); font-weight: 700; }
.hl-gold  { color: var(--gold); font-weight: 700; }
.hl-blue  { color: var(--blue); font-weight: 700; }
.hl-coral { color: var(--coral); font-weight: 700; }
.hl-purple{ color: var(--purple); font-weight: 700; }

/* tag chips */
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0; }
.tag {
  font-size: 11px;
  font-weight: 800;
  padding: 4px 12px;
  border-radius: 20px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border);
  color: var(--muted);
  font-family: 'Fira Code', monospace;
}

/* recipe card */
.recipe {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 24px;
  margin: 18px 0;
}

.recipe-title {
  font-family: 'Fredoka One', cursive;
  font-size: 1rem;
  color: var(--accent);
  margin-bottom: 10px;
}

/* mobile */
@media (max-width: 800px) {
  .sidebar { display: none; }
  .lesson-header, .lesson-body { padding: 24px 20px; }
  .compare { grid-template-columns: 1fr; }
}