/* ────────────────────────────────────────────────────────────
   topic-template.css — shared styles for the interview-prep
   sections rendered by js/topic-renderer.js. Uses existing CSS
   variables so themes work without changes.
   ──────────────────────────────────────────────────────────── */

/* ── Topic header (Section 1) ────────────────────────────── */
.topic-header-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 12px 0 20px;
  font-size: 13px;
  color: var(--text-secondary);
}
.topic-header-meta .meta-item {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.topic-header-meta .meta-label {
  font-weight: 600;
  color: var(--text-primary);
}

/* ── Interview Cheat Sheet (Section 3) ────────────────────── */
.cheat-sheet-card {
  border: 1px solid var(--border-color);
  border-radius: 10px;
  overflow: hidden;
  background: var(--bg-card);
  margin: 16px 0 24px;
}
.cheat-sheet-head {
  padding: 10px 14px;
  font-weight: 600;
  background: linear-gradient(135deg, var(--accent-primary, #6366f1), var(--accent-secondary, #818cf8));
  color: white;
  font-size: 14px;
}
.cheat-sheet-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 14px;
}
.cs-box {
  padding: 10px 12px;
  border-radius: 8px;
}
.cs-box-ops      { background: rgba(99, 102, 241, 0.08); }
.cs-box-use      { background: rgba(34, 197, 94, 0.08); }
.cs-box-avoid    { background: rgba(239, 68, 68, 0.06); }
.cs-box-pitfall  { background: rgba(245, 158, 11, 0.08); }
.cs-box .cs-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 8px;
}
.cs-box .cs-row {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-size: 13px;
  margin-bottom: 4px;
  line-height: 1.4;
}
.cs-box .cs-op-name {
  font-family: var(--font-mono, monospace);
  font-size: 12px;
  color: var(--text-primary);
}
.cs-box .cs-O {
  font-family: var(--font-mono, monospace);
  font-weight: 700;
  font-size: 12px;
  white-space: nowrap;
}
.cs-O-good { color: #16a34a; }
.cs-O-bad  { color: #dc2626; }

@media (max-width: 640px) {
  .cheat-sheet-grid { grid-template-columns: 1fr; }
}

/* ── Patterns that use this (Section 7) ──────────────────── */
.patterns-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
  margin: 16px 0 24px;
}
.pattern-card {
  display: block;
  padding: 14px;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  background: var(--bg-card);
  text-decoration: none;
  color: inherit;
  transition: transform 0.15s, border-color 0.15s;
}
.pattern-card:hover {
  border-color: var(--accent-primary, #6366f1);
  transform: translateY(-2px);
}
.pattern-card .pattern-title {
  font-weight: 600;
  font-size: 15px;
  margin-bottom: 6px;
  color: var(--accent-primary, #6366f1);
}
.pattern-card .pattern-one-liner {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ── Ask before coding (Section 8) ───────────────────────── */
.ask-callout {
  border-left: 4px solid var(--accent-primary, #6366f1);
  background: rgba(99, 102, 241, 0.05);
  padding: 14px 18px;
  border-radius: 6px;
  margin: 16px 0 24px;
}
.ask-callout h4 {
  margin: 0 0 10px 0;
  font-size: 14px;
  color: var(--text-primary);
}
.ask-callout ul {
  margin: 0;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.6;
}
.ask-callout li { margin-bottom: 4px; }

/* ── Curated problems (Section 9) ────────────────────────── */
.problems-section {
  margin: 16px 0 24px;
}
.problem-group-title {
  font-weight: 600;
  font-size: 14px;
  margin: 18px 0 6px;
  padding-bottom: 4px;
  border-bottom: 2px solid var(--border-color);
  color: var(--text-secondary);
}
.problem-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 6px;
  margin-bottom: 3px;
  font-size: 14px;
  flex-wrap: wrap;
}
.problem-row:hover { background: var(--bg-card); }
.problem-row .problem-title {
  font-weight: 500;
  flex: 1 1 200px;
}
.problem-row .problem-title a {
  color: var(--accent-primary, #6366f1);
  text-decoration: none;
}
.problem-row .problem-title a:hover { text-decoration: underline; }
.pill {
  padding: 2px 9px;
  border-radius: 10px;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.pill-easy { background: rgba(34, 197, 94, 0.15); color: #166534; }
.pill-medium { background: rgba(245, 158, 11, 0.15); color: #92400e; }
.pill-hard { background: rgba(239, 68, 68, 0.15); color: #991b1b; }
.pill-pattern { background: rgba(99, 102, 241, 0.15); color: #3730a3; }
.pill-blind-75 { background: rgba(250, 204, 21, 0.15); color: #854d0e; }
.pill-neetcode-150 { background: rgba(168, 85, 247, 0.15); color: #6b21a8; }
.pill-faang-common { background: rgba(244, 114, 182, 0.15); color: #9d174d; }

.walkthrough-badge {
  font-size: 14px;
  margin-left: auto;
}

/* ── Problem progress chips (per-problem page) ─────────────── */
.problem-progress-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
  flex-wrap: wrap;
}
.problem-progress-label {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}
.progress-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  color: var(--text-primary);
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
  user-select: none;
}
.progress-chip:hover { border-color: var(--accent-primary); }
.progress-chip.active {
  border-color: transparent;
  font-weight: 600;
}
.progress-chip[data-status="unattempted"].active {
  background: rgba(148, 163, 184, 0.18);
  color: #475569;
}
.progress-chip[data-status="attempted"].active {
  background: rgba(245, 158, 11, 0.18);
  color: #92400e;
}
.progress-chip[data-status="solved"].active {
  background: rgba(34, 197, 94, 0.18);
  color: #166534;
}
.progress-chip__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}
.dot-unattempted { background: #cbd5e1; }
.dot-attempted   { background: #f59e0b; }
.dot-solved      { background: #22c55e; }

/* ── Problem status indicator (on row lists) ───────────────── */
.problem-status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
  background: #e2e8f0;
}
.problem-status-dot.solved   { background: #22c55e; }
.problem-status-dot.attempted { background: #f59e0b; }

/* ── Solution walkthroughs (Section 10) ──────────────────── */
.walkthrough-card {
  border: 1px solid var(--border-color);
  border-radius: 10px;
  overflow: hidden;
  background: var(--bg-card);
  margin: 12px 0;
}
.walkthrough-head {
  padding: 12px 14px;
  background: rgba(99, 102, 241, 0.06);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}
.walkthrough-head .walkthrough-title {
  font-weight: 600;
  font-size: 15px;
  flex: 1;
}
.walkthrough-summary {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-color);
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
}
.approach-block {
  border-top: 1px solid var(--border-color);
}
.approach-block:first-of-type { border-top: none; }
.approach-summary {
  padding: 10px 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  list-style: none;
  user-select: none;
}
.approach-summary::-webkit-details-marker { display: none; }
.approach-summary::before {
  content: '▶';
  font-size: 10px;
  color: var(--text-secondary);
  transition: transform 0.15s;
}
details[open] .approach-summary::before { transform: rotate(90deg); }
.approach-name { font-weight: 600; flex: 1; }
.approach-O-time, .approach-O-space {
  font-family: var(--font-mono, monospace);
  font-size: 11px;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
}
.approach-O-good { background: rgba(34, 197, 94, 0.15); color: #166534; }
.approach-O-bad  { background: rgba(239, 68, 68, 0.15); color: #991b1b; }
.approach-body {
  padding: 0 14px 12px;
}
.approach-body pre {
  background: #1e293b;
  color: #e2e8f0;
  padding: 12px;
  border-radius: 6px;
  font-family: var(--font-mono, monospace);
  font-size: 13px;
  line-height: 1.5;
  overflow-x: auto;
}
.approach-body .approach-why {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  font-style: italic;
}

/* ── Reasoned next steps (Section 13) ────────────────────── */
.next-steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
  margin: 16px 0 24px;
}
.next-step-card {
  padding: 14px;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  background: var(--bg-card);
  text-decoration: none;
  color: inherit;
  transition: transform 0.15s, border-color 0.15s;
}
.next-step-card:hover {
  border-color: var(--accent-primary, #6366f1);
  transform: translateY(-2px);
}
.next-step-card .next-step-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 6px;
}
.next-step-card .next-step-title {
  font-weight: 600;
  font-size: 15px;
  color: var(--accent-primary, #6366f1);
  margin-bottom: 6px;
}
.next-step-card .next-step-why {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}