/* ===================================================================
   CORTEX — AI & Machine Learning Engineering Roadmap
   Minimal, High-Density, Research-Lab Aesthetic
   Designed for Technical AI Literacy
   =================================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;

  /* Dark Theme Palette (Default) */
  --bg: #07090e;
  --surface: #0f131a;
  --surface-raised: #151a24;
  --surface-sunk: #0a0d13;
  --line: #1c2330;
  --line-strong: #283244;
  --line-focus: #3b82f6;

  --ink: #e6edf5;
  --ink-soft: #94a3b8;
  --ink-faint: #546478;

  /* Source Accents */
  --zachary: #f59e0b;
  --zachary-bg: color-mix(in srgb, var(--zachary) 10%, var(--surface-sunk));
  --tbb: #38bdf8;
  --tbb-bg: color-mix(in srgb, var(--tbb) 10%, var(--surface-sunk));
  --statquest: #10b981;
  --statquest-bg: color-mix(in srgb, var(--statquest) 10%, var(--surface-sunk));
  --karpathy: #a78bfa;
  --karpathy-bg: color-mix(in srgb, var(--karpathy) 10%, var(--surface-sunk));
  --reading: #f472b6;
  --reading-bg: color-mix(in srgb, var(--reading) 10%, var(--surface-sunk));

  --done: #22c55e;
  --done-bg: color-mix(in srgb, var(--done) 10%, var(--surface-sunk));

  --video-accent: #ef4444;
  --search-accent: #64748b;

  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 6px;
  --max-w: 1160px;
}

[data-theme="light"] {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-raised: #f1f5f9;
  --surface-sunk: #f8fafc;
  --line: #e2e8f0;
  --line-strong: #cbd5e1;
  --line-focus: #2563eb;

  --ink: #0f172a;
  --ink-soft: #475569;
  --ink-faint: #94a3b8;

  --zachary: #d97706;
  --zachary-bg: color-mix(in srgb, var(--zachary) 12%, #fff);
  --tbb: #0284c7;
  --tbb-bg: color-mix(in srgb, var(--tbb) 12%, #fff);
  --statquest: #059669;
  --statquest-bg: color-mix(in srgb, var(--statquest) 12%, #fff);
  --karpathy: #7c3aed;
  --karpathy-bg: color-mix(in srgb, var(--karpathy) 12%, #fff);
  --reading: #db2777;
  --reading-bg: color-mix(in srgb, var(--reading) 12%, #fff);

  --done: #16a34a;
  --done-bg: color-mix(in srgb, var(--done) 12%, #fff);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  padding-bottom: 90px; /* Space for floating HUD */
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  background: none;
  border: none;
}

/* -------------------------------------------------------------------
   TOPBAR NAVIGATION
   ------------------------------------------------------------------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.topbar-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-link {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink);
}

.brand-dot {
  color: var(--zachary);
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding: 2px 6px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.portal-switch {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-soft);
  padding: 4px 10px;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.portal-switch:hover {
  color: var(--ink);
  border-color: var(--zachary);
  background: var(--surface-raised);
}

.topnav {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.topnav a {
  transition: color 0.15s ease;
}

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

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn-pill {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 6px 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  color: var(--ink);
  background: var(--surface);
  transition: all 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.btn-pill:hover {
  background: var(--surface-raised);
  border-color: var(--ink-faint);
}

/* -------------------------------------------------------------------
   HERO THESIS SECTION
   ------------------------------------------------------------------- */
.hero {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 64px 24px 36px;
  border-bottom: 1px solid var(--line);
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--zachary);
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(2.1rem, 4.2vw, 3.4rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--ink);
  margin-bottom: 18px;
}

.hero-lede {
  max-width: 780px;
  font-size: 1.08rem;
  line-height: 1.65;
  color: var(--ink-soft);
  margin-bottom: 28px;
}

.hero-sources {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 14px;
  margin-bottom: 28px;
}

.source-card {
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: var(--surface-sunk);
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-left: 3px solid var(--card-accent, var(--line));
}

.source-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.source-card-name {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--ink);
}

.source-card-tag {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.source-card-desc {
  font-size: 0.8rem;
  color: var(--ink-soft);
  line-height: 1.45;
}

.hero-meta-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
}

.hero-stat-val {
  font-weight: 600;
  color: var(--ink);
}

.hero-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.btn-primary {
  background: var(--zachary);
  color: #000;
  font-weight: 600;
  font-size: 0.82rem;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: opacity 0.15s ease;
}

.btn-primary:hover {
  opacity: 0.9;
}

.btn-secondary {
  background: var(--surface-raised);
  border: 1px solid var(--line-strong);
  color: var(--ink);
  font-size: 0.82rem;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.btn-secondary:hover {
  border-color: var(--ink-faint);
}

/* -------------------------------------------------------------------
   CONTROL BAR (VIEW TOGGLE & SOURCE FILTERS)
   ------------------------------------------------------------------- */
.control-bar {
  position: sticky;
  top: 57px;
  z-index: 90;
  background: color-mix(in srgb, var(--bg) 95%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  padding: 12px 0;
}

.control-bar-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.view-pills {
  display: inline-flex;
  padding: 3px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.view-btn {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  padding: 6px 14px;
  color: var(--ink-soft);
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.view-btn.is-active {
  background: var(--surface-raised);
  color: var(--ink);
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--ink-faint);
  text-transform: uppercase;
}

.filter-btn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
  background: var(--surface);
  transition: all 0.15s ease;
}

.filter-btn:hover {
  color: var(--ink);
  border-color: var(--line-strong);
}

.filter-btn.is-active {
  border-color: var(--filter-color, var(--ink));
  color: var(--ink);
  background: var(--surface-raised);
}

/* -------------------------------------------------------------------
   LAYOUT CONTAINER & SECTIONS
   ------------------------------------------------------------------- */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px;
}

.section-head {
  margin-bottom: 24px;
}

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 6px;
}

.section-title {
  font-size: 1.55rem;
  font-weight: 600;
  color: var(--ink);
}

.section-desc {
  font-size: 0.95rem;
  color: var(--ink-soft);
  max-width: 720px;
  margin-top: 4px;
}

/* -------------------------------------------------------------------
   PHASE MODULES (ROADMAP)
   ------------------------------------------------------------------- */
.phases-list {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.phase-module {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.phase-module:hover {
  border-color: var(--line-strong);
}

.phase-header {
  padding: 22px 24px;
  background: var(--surface-raised);
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 16px;
  align-items: baseline;
}

.phase-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--zachary);
  padding: 4px 8px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.phase-title-block h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
}

.phase-title-block p {
  font-size: 0.88rem;
  color: var(--ink-soft);
}

.phase-duration {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--ink-faint);
  white-space: nowrap;
}

.phase-meta-row {
  padding: 12px 24px;
  background: var(--surface-sunk);
  border-bottom: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  font-size: 0.82rem;
}

.meta-item {
  color: var(--ink-soft);
}

.meta-item strong {
  color: var(--ink);
  font-weight: 600;
}

/* Concept Checklist Chips */
.concepts-bar {
  padding: 14px 24px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.concepts-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-right: 6px;
}

.concept-chip {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 2px 7px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
}

/* Resource Items Table/List */
.resource-list {
  display: flex;
  flex-direction: column;
}

.resource-item {
  padding: 16px 24px;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 32px 1fr auto;
  gap: 16px;
  align-items: baseline;
  transition: background 0.15s ease;
}

.resource-item:last-child {
  border-bottom: none;
}

.resource-item:hover {
  background: var(--surface-raised);
}

.resource-item.is-completed {
  background: color-mix(in srgb, var(--done) 4%, var(--surface));
}

.item-check-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 2px;
}

.cortex-checkbox {
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--surface-sunk);
  cursor: pointer;
  position: relative;
  transition: all 0.15s ease;
}

.cortex-checkbox:checked {
  background: var(--done);
  border-color: var(--done);
}

.cortex-checkbox:checked::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 2px;
  width: 5px;
  height: 9px;
  border: solid #000;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.item-body {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.item-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.item-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink);
}

.resource-item.is-completed .item-title {
  text-decoration: line-through;
  color: var(--ink-faint);
}

.item-desc {
  font-size: 0.85rem;
  color: var(--ink-soft);
  line-height: 1.5;
}

/* Badges */
.badge {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.badge-source-zachary {
  background: var(--zachary-bg);
  color: var(--zachary);
  border: 1px solid color-mix(in srgb, var(--zachary) 30%, transparent);
}

.badge-source-tbb {
  background: var(--tbb-bg);
  color: var(--tbb);
  border: 1px solid color-mix(in srgb, var(--tbb) 30%, transparent);
}

.badge-source-karpathy {
  background: var(--karpathy-bg);
  color: var(--karpathy);
  border: 1px solid color-mix(in srgb, var(--karpathy) 30%, transparent);
}

.badge-source-reading {
  background: var(--reading-bg);
  color: var(--reading);
  border: 1px solid color-mix(in srgb, var(--reading) 30%, transparent);
}

.badge-source-statquest {
  background: var(--statquest-bg);
  color: var(--statquest);
  border: 1px solid color-mix(in srgb, var(--statquest) 30%, transparent);
}

.badge-core {
  background: var(--surface-raised);
  color: var(--ink);
  border: 1px solid var(--line-strong);
}

.badge-optional {
  background: transparent;
  color: var(--ink-faint);
  border: 1px dashed var(--line-strong);
}

.badge-link-video {
  background: color-mix(in srgb, var(--video-accent) 12%, var(--surface-sunk));
  color: var(--video-accent);
  border: 1px solid color-mix(in srgb, var(--video-accent) 30%, transparent);
}

.badge-link-search {
  background: color-mix(in srgb, var(--accent) 12%, var(--surface-sunk));
  color: var(--accent);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
}

/* Link Actions */
.item-action {
  white-space: nowrap;
}

.link-btn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 500;
  transition: all 0.15s ease;
}

.link-btn-video {
  background: color-mix(in srgb, var(--video-accent) 12%, var(--surface-raised));
  color: var(--ink);
  border: 1px solid color-mix(in srgb, var(--video-accent) 40%, transparent);
}

.link-btn-video:hover {
  background: var(--video-accent);
  color: #fff;
}

.link-btn-search {
  background: color-mix(in srgb, var(--accent) 12%, var(--surface-raised));
  color: var(--ink);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, transparent);
}

.link-btn-search:hover {
  background: var(--accent);
  color: #0a0c10;
  border-color: var(--accent);
}

/* Self-Check Accordion Box */
.self-check-box {
  background: var(--surface-sunk);
  border-top: 1px solid var(--line);
  padding: 16px 24px;
}

.self-check-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

.self-check-heading {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 8px;
}

.self-check-indicator {
  font-size: 0.7rem;
  color: var(--ink-faint);
  transition: transform 0.2s ease;
}

.self-check-box.is-open .self-check-indicator {
  transform: rotate(180deg);
}

.self-check-content {
  margin-top: 14px;
  display: none;
}

.self-check-box.is-open .self-check-content {
  display: block;
}

.self-check-intro {
  font-size: 0.82rem;
  color: var(--ink-soft);
  margin-bottom: 12px;
}

.self-check-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.self-check-item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 0.84rem;
  color: var(--ink-soft);
}

.self-check-item input {
  margin-top: 3px;
}

/* -------------------------------------------------------------------
   PHASE 8: PROJECT LAB CARDS
   ------------------------------------------------------------------- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 20px;
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: border-color 0.2s ease, transform 0.2s ease;
  border-top: 3px solid var(--proj-accent, var(--line-strong));
}

.project-card:hover {
  border-color: var(--line-strong);
}

.project-card.is-completed {
  border-color: var(--done);
  background: color-mix(in srgb, var(--done) 3%, var(--surface));
}

.project-head-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.project-num {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--proj-accent, var(--ink));
}

.project-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.3;
}

.project-stack {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
}

.project-desc {
  font-size: 0.86rem;
  color: var(--ink-soft);
  line-height: 1.55;
}

.project-mental-model {
  padding: 10px 12px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink);
  line-height: 1.5;
}

.project-mental-label {
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 4px;
}

.deliverables-box {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.deliverables-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.deliverables-list {
  padding-left: 18px;
  font-size: 0.82rem;
  color: var(--ink-soft);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.acceptance-box {
  padding: 10px 12px;
  border-left: 2px solid var(--done);
  background: var(--surface-sunk);
  font-size: 0.8rem;
  color: var(--ink-soft);
}

.acceptance-box strong {
  color: var(--ink);
}

.project-footer {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.project-toggle-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--ink-soft);
  cursor: pointer;
}

/* -------------------------------------------------------------------
   WEEKLY STUDY TIMELINE
   ------------------------------------------------------------------- */
.weekly-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.week-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 24px;
  align-items: baseline;
}

.week-badge-col {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.week-num {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--ink);
}

.week-phase {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--zachary);
  text-transform: uppercase;
}

.week-content {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.week-focus {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
}

.week-sessions {
  padding-left: 18px;
  font-size: 0.85rem;
  color: var(--ink-soft);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.week-sub-block {
  padding: 10px 14px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: var(--ink-soft);
}

.week-sub-block strong {
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  text-transform: uppercase;
  margin-right: 6px;
}

/* -------------------------------------------------------------------
   ARCHITECTURE MENTAL MODELS
   ------------------------------------------------------------------- */
.models-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 20px;
}

.model-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.model-card h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
}

.model-diagram {
  padding: 16px;
  background: var(--surface-sunk);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  line-height: 1.55;
  color: var(--tbb);
  overflow-x: auto;
  white-space: pre-wrap;
}

.framework-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-top: 24px;
}

.framework-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.framework-item {
  padding: 14px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  display: flex;
  gap: 12px;
  align-items: baseline;
}

.framework-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--zachary);
}

.framework-text h5 {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 2px;
}

.framework-text p {
  font-size: 0.78rem;
  color: var(--ink-soft);
}

/* -------------------------------------------------------------------
   GLOSSARY & SEARCH
   ------------------------------------------------------------------- */
.glossary-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

.glossary-search {
  flex: 1;
  min-width: 260px;
  padding: 10px 14px;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  color: var(--ink);
  font-size: 0.88rem;
}

.glossary-search:focus {
  outline: none;
  border-color: var(--line-focus);
}

.glossary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 14px;
}

.glossary-card {
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.glossary-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.glossary-term {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink);
}

.glossary-category {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--ink-faint);
  text-transform: uppercase;
}

.glossary-def {
  font-size: 0.84rem;
  color: var(--ink-soft);
  line-height: 1.5;
}

/* -------------------------------------------------------------------
   SCREENSHOT VIDEO INVENTORY TABLE
   ------------------------------------------------------------------- */
.inventory-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.inventory-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  text-align: left;
}

.inventory-table th {
  padding: 12px 18px;
  background: var(--surface-raised);
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.inventory-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
}

.inventory-table tr:last-child td {
  border-bottom: none;
}

.inventory-table tr:hover td {
  background: var(--surface-sunk);
}

.inventory-table strong {
  color: var(--ink);
}

/* -------------------------------------------------------------------
   FLOATING PROGRESS HUD
   ------------------------------------------------------------------- */
.cortex-hud {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid var(--line-strong);
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.35);
}

.cortex-hud-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.hud-left {
  display: flex;
  align-items: center;
  gap: 16px;
  flex: 1;
}

.hud-progress-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
  max-width: 440px;
}

.hud-progress-text {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.72rem;
}

.hud-progress-label {
  color: var(--ink-faint);
}

.hud-progress-val {
  color: var(--ink);
  font-weight: 600;
}

.hud-bar-bg {
  width: 100%;
  height: 6px;
  background: var(--surface-sunk);
  border-radius: 3px;
  overflow: hidden;
  border: 1px solid var(--line);
}

.hud-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--zachary), var(--tbb), var(--done));
  border-radius: 3px;
  transition: width 0.3s ease;
}

.hud-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* -------------------------------------------------------------------
   MODAL DIALOG (BACKUP / SYNC)
   ------------------------------------------------------------------- */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  z-index: 200;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.modal-backdrop.is-open {
  opacity: 1;
  pointer-events: auto;
}

.cortex-modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.96);
  z-index: 210;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-md);
  width: 90%;
  max-width: 500px;
  padding: 28px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
  opacity: 0;
  pointer-events: none;
  transition: all 0.2s ease;
}

.cortex-modal.is-open {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, -50%) scale(1);
}

.modal-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}

.modal-head h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--ink);
}

.modal-close {
  font-size: 1.4rem;
  color: var(--ink-faint);
  line-height: 1;
}

.modal-close:hover {
  color: var(--ink);
}

.modal-body p {
  font-size: 0.88rem;
  color: var(--ink-soft);
  margin-bottom: 18px;
}

.modal-action-block {
  padding: 16px;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  margin-bottom: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.modal-action-block h4 {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--ink);
}

.modal-action-block p {
  font-size: 0.8rem;
  color: var(--ink-soft);
  margin: 0;
}

/* -------------------------------------------------------------------
   SITE FOOTER
   ------------------------------------------------------------------- */
.site-footer {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 0.82rem;
  color: var(--ink-faint);
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a:hover {
  color: var(--ink);
}

/* -------------------------------------------------------------------
   RESPONSIVE QUERIES
   ------------------------------------------------------------------- */
@media (max-width: 860px) {
  .hero {
    padding: 40px 20px 24px;
  }
  .phase-header {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .resource-item {
    grid-template-columns: 28px 1fr;
  }
  .resource-item .item-action {
    grid-column: 2;
    margin-top: 8px;
  }
  .week-card {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .topnav {
    display: none; /* Mobile menu handles this */
  }
  .cortex-hud-inner {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    padding: 10px 16px;
  }
}


/* ===================================================================
   CALM LAYOUT LAYER: collapsible phases, quieter rows, compact chrome
   =================================================================== */

/* Hero source cards → compact legend chips */
.hero-sources { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.source-card { padding: 6px 12px; border-left-width: 3px; display: inline-flex; align-items: center; }
.source-card-head { margin: 0; gap: 8px; }
.source-card-name { font-size: 0.85rem; }
.source-card-tag { font-size: 0.6rem; }
.source-card-desc { display: none; }

/* Control bar */
.filter-sep { width: 1px; height: 16px; background: var(--line-strong); margin: 0 2px; }
.filter-label { text-transform: none; letter-spacing: 0; }

/* Section head controls */
.phase-controls { display: flex; gap: 14px; margin-top: 14px; }
.text-btn {
  background: none; border: 0; padding: 0; cursor: pointer;
  font: inherit; font-size: 0.82rem; color: var(--ink-soft);
  text-decoration: underline; text-underline-offset: 3px; text-decoration-color: var(--line-strong);
}
.text-btn:hover { color: var(--ink); }

/* Phase cards */
.phases-list { display: flex; flex-direction: column; gap: 10px; }
.phase-module { padding: 0; overflow: hidden; margin: 0; }
.phase-toggle {
  width: 100%; display: grid; grid-template-columns: auto 1fr auto auto; align-items: center; gap: 16px;
  padding: 16px 20px; background: none; border: 0; color: inherit; text-align: left; cursor: pointer; font: inherit;
}
.phase-toggle:hover { background: var(--surface-raised); }
.phase-toggle:focus-visible { outline: 2px solid var(--line-focus); outline-offset: -2px; }
.phase-num {
  font-family: var(--font-mono); font-size: 0.8rem; color: var(--ink-faint);
  width: 32px; height: 32px; display: grid; place-items: center;
  border: 1px solid var(--line-strong); border-radius: 50%;
}
.phase-module.is-done .phase-num { border-color: var(--done); color: var(--done); }
.phase-head-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.phase-title { font-size: 1.02rem; font-weight: 600; color: var(--ink); }
.phase-sub { font-size: 0.78rem; color: var(--ink-faint); }
.phase-progress { display: flex; align-items: center; gap: 10px; }
.phase-progress-text { font-family: var(--font-mono); font-size: 0.75rem; color: var(--ink-soft); min-width: 36px; text-align: right; }
.phase-progress-bar { width: 72px; height: 4px; background: var(--line); border-radius: 2px; overflow: hidden; }
.phase-progress-bar i { display: block; height: 100%; background: var(--done); transition: width 0.25s ease; }
.phase-chevron {
  width: 8px; height: 8px; border-right: 1.5px solid var(--ink-faint); border-bottom: 1.5px solid var(--ink-faint);
  transform: rotate(45deg); transition: transform 0.2s ease; margin: 0 4px 4px;
}
.phase-module.is-open .phase-chevron { transform: rotate(225deg); margin-bottom: -2px; }
.phase-body { display: none; border-top: 1px solid var(--line); padding: 4px 20px 18px; }
.phase-module.is-open .phase-body { display: block; }
.phase-objective { color: var(--ink-soft); font-size: 0.9rem; margin: 14px 0 6px; max-width: 70ch; }

/* Resource rows */
.resource-list { display: flex; flex-direction: column; border: 0; gap: 0; }
.resource-item {
  display: grid; grid-template-columns: auto 1fr auto; align-items: start; gap: 14px;
  padding: 12px 4px; border: 0; border-bottom: 1px solid var(--line); background: none;
}
.resource-item:last-child { border-bottom: 0; }
.resource-item .cortex-checkbox { margin-top: 3px; }
.item-body { min-width: 0; }
.item-title { display: inline; font-size: 0.95rem; font-weight: 500; color: var(--ink); text-decoration: none; line-height: 1.4; }
.item-title:hover { text-decoration: underline; text-underline-offset: 3px; }
.item-meta { display: flex; align-items: center; gap: 6px; margin-top: 3px; font-size: 0.75rem; color: var(--ink-faint); }
.src-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--dot); flex: none; }
.item-desc { margin-top: 4px; font-size: 0.84rem; color: var(--ink-soft); line-height: 1.5; max-width: 72ch; }
.item-open {
  font-size: 0.78rem; color: var(--ink-soft); text-decoration: none; white-space: nowrap;
  padding: 4px 10px; border: 1px solid var(--line-strong); border-radius: 999px; margin-top: 1px;
}
.item-open:hover { color: var(--ink); border-color: var(--ink-faint); }
.resource-item.is-completed .item-title { color: var(--ink-faint); text-decoration: line-through; text-decoration-color: var(--line-strong); }
.resource-item.is-completed .item-desc { display: none; }

/* Disclosure groups inside a phase */
.optional-group, .phase-about { margin-top: 12px; border: 1px solid var(--line); border-radius: var(--radius-lg); }
.optional-group > summary, .phase-about > summary {
  cursor: pointer; padding: 10px 14px; font-size: 0.84rem; color: var(--ink-soft); list-style: none;
  display: flex; align-items: center; gap: 8px;
}
.optional-group > summary::-webkit-details-marker, .phase-about > summary::-webkit-details-marker { display: none; }
.optional-group > summary::before, .phase-about > summary::before {
  content: ""; width: 6px; height: 6px; border-right: 1.5px solid currentColor; border-bottom: 1.5px solid currentColor;
  transform: rotate(-45deg); transition: transform 0.2s ease;
}
.optional-group[open] > summary::before, .phase-about[open] > summary::before { transform: rotate(45deg); }
.optional-group > summary:hover, .phase-about > summary:hover { color: var(--ink); }
.optional-group .count { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint); }
.optional-group > .resource-list { padding: 0 14px 4px; }
.phase-about > :not(summary) { margin: 0 14px 12px; font-size: 0.86rem; color: var(--ink-soft); }
.phase-about .concepts-bar { display: flex; flex-wrap: wrap; gap: 6px; padding: 0; border: 0; background: none; }
.phase-about .self-check-list { display: flex; flex-direction: column; gap: 8px; }
.empty-note { padding: 18px 0; color: var(--ink-faint); font-size: 0.86rem; }

@media (max-width: 640px) {
  .phase-toggle { gap: 12px; padding: 14px 16px; }
  .phase-progress-bar { display: none; }
  .phase-body { padding: 4px 16px 16px; }
  .resource-item { grid-template-columns: auto 1fr; }
  .item-open { grid-column: 2; justify-self: start; }
}