/* ------------------------------------------------------------------
   ml.css — dark theme for the Machine Learning section.
   Scoped to body[data-section="ml"] so tokens don't leak.
   Accent: electric indigo #7c7cff. Background: #0d0d1a.
   ------------------------------------------------------------------ */

/* ── Tokens ──────────────────────────────────────────────────────── */

body[data-section="ml"] {
  --bg:              #0d0d1a;
  --bg-card:         #13132a;
  --bg-card-alt:     #16163a;
  --border:          #1e1e3f;
  --border-hover:    #2a2a55;
  --text-primary:    #e8e6f5;
  --text-secondary:  #8880ac;
  --text-tertiary:   #4e4a6e;
  --accent:          #7c7cff;
  --accent-dim:      #3a3a8a;
  --accent-glow:     rgba(124, 124, 255, 0.12);
  --positive:        #6ec0a0;
  --tag-bg:          rgba(124, 124, 255, 0.10);
  --tag-text:        #a0a0ff;
  --font-mono:       "JetBrains Mono", "Fira Code", "Cascadia Code", ui-monospace, monospace;

  color-scheme: dark;

  /* Layered background: subtle radial accent bloom + dot grid */
  background-color: var(--bg);
  background-image:
    radial-gradient(900px 500px at 30% -5%, rgba(124,124,255,0.06), transparent 55%),
    radial-gradient(600px 400px at 80% 90%, rgba(124,124,255,0.04), transparent 55%),
    radial-gradient(circle, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: auto, auto, 28px 28px;
  background-attachment: fixed;
  color: var(--text-primary);
}

/* ── Chrome overrides ────────────────────────────────────────────── */

body[data-section="ml"] .site-header {
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  border-bottom-color: var(--border);
  backdrop-filter: blur(12px);
}

body[data-section="ml"] .site-nav__link[aria-current="page"] {
  color: var(--accent);
}

/* ── Page header ─────────────────────────────────────────────────── */

.ml-hero-header {
  padding: 2.5rem 1.5rem 1.5rem;
  max-width: 72rem;
  margin: 0 auto;
}

.ml-title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 0.4rem;
  color: var(--text-primary);
}

.ml-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  max-width: 60ch;
  line-height: 1.5;
  margin: 0;
}

/* ── Sections ────────────────────────────────────────────────────── */

.ml-section {
  padding: 0 1.5rem 2.5rem;
  max-width: 72rem;
  margin: 0 auto;
  position: relative;
}

.ml-section + .ml-section {
  border-top: 1px solid var(--border);
  padding-top: 2rem;
}

/* Accent tab on the left edge of each section divider */
.ml-section + .ml-section::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 1.5rem;
  width: 40px;
  height: 2px;
  background: var(--accent);
  border-radius: 0 0 2px 2px;
}

.ml-section__header {
  margin-bottom: 1.5rem;
}

.ml-section__title {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-secondary);
  margin: 0 0 0.2rem;
}

.ml-section__desc {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  margin: 0;
}

/* ── Reading list ────────────────────────────────────────────────── */

.ml-reading-group {
  margin-bottom: 2rem;
}

.ml-reading-group__theme,
.ml-concepts-group__theme {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin: 0 0 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.ml-reading-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.75rem;
}

.ml-reading-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition:
    border-color 200ms ease,
    transform 200ms ease,
    box-shadow 200ms ease;
}

.ml-reading-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.5);
}

.ml-reading-card__link {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 1rem;
  text-decoration: none;
  color: inherit;
  height: 100%;
}

a.ml-reading-card__link:hover .ml-reading-card__title {
  color: var(--accent);
}

.ml-reading-card__meta {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.15rem;
}

.ml-reading-card__title {
  font-size: 0.85rem;
  font-weight: 600;
  line-height: 1.35;
  color: var(--text-primary);
  transition: color 150ms ease;
}

.ml-reading-card__authors {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-tertiary);
  margin-top: 0.05rem;
}

.ml-reading-card__year {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-tertiary);
  margin-left: auto;
  flex-shrink: 0;
}

.ml-reading-card__note {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-top: 0.35rem;
}

/* ── Pills ───────────────────────────────────────────────────────── */

.ml-pill {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 2px 5px;
  border-radius: 3px;
  line-height: 1;
}

.ml-pill--paper {
  background: rgba(124, 124, 255, 0.12);
  color: var(--accent);
  border: 1px solid rgba(124, 124, 255, 0.22);
}

.ml-pill--book {
  background: rgba(110, 192, 160, 0.1);
  color: var(--positive);
  border: 1px solid rgba(110, 192, 160, 0.22);
}

/* ── Concepts ────────────────────────────────────────────────────── */

.ml-concepts-group {
  margin-bottom: 2rem;
}

.ml-concepts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 0.75rem;
}

.ml-concept-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.1rem 1rem 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transition:
    border-color 200ms ease,
    box-shadow 200ms ease;
}

.ml-concept-card:hover {
  border-color: var(--border-hover);
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
}

.ml-concept-card__header {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.ml-concept-card__abbr {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
}

.ml-concept-card__name {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
}

.ml-concept-card__intuition {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

.ml-concept-card__gotcha {
  background: rgba(124, 124, 255, 0.05);
  border: 1px solid rgba(124, 124, 255, 0.12);
  border-radius: 5px;
  padding: 0.55rem 0.65rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.ml-concept-card__gotcha-label {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  opacity: 0.75;
}

.ml-concept-card__gotcha-text {
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0;
}

.ml-concept-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.1rem;
}

.ml-tag {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--tag-text);
  background: var(--tag-bg);
  padding: 2px 6px;
  border-radius: 3px;
}

/* ── Queue ───────────────────────────────────────────────────────── */

.ml-queue-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.ml-queue-item {
  display: flex;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  align-items: flex-start;
}

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

.ml-queue-item--active {
  border-left: 2px solid var(--accent);
  padding-left: 0.75rem;
}

.ml-queue-item__rank {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--text-tertiary);
  min-width: 1.5rem;
  padding-top: 0.1rem;
  text-align: right;
  flex-shrink: 0;
}

.ml-queue-item__body {
  flex: 1;
  min-width: 0;
}

.ml-queue-item__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.3rem;
}

.ml-queue-item__topic {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
}

.ml-queue-item__note {
  font-size: 0.77rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0;
}

.ml-queue-badge {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 2px 6px;
  border-radius: 3px;
  flex-shrink: 0;
  line-height: 1.6;
}

.ml-queue-badge--active {
  background: rgba(124, 124, 255, 0.14);
  color: var(--accent);
  border: 1px solid rgba(124, 124, 255, 0.28);
}

.ml-queue-badge--next {
  background: rgba(110, 192, 160, 0.1);
  color: var(--positive);
  border: 1px solid rgba(110, 192, 160, 0.22);
}

.ml-queue-badge--queued {
  background: transparent;
  color: var(--text-tertiary);
  border: 1px solid var(--border-hover);
}

/* ── Formulas ────────────────────────────────────────────────────── */

.ml-formula-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 0.75rem;
}

.ml-formula-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.1rem 1rem 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  min-width: 0;
}

.ml-formula-card__name {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
}

/* KaTeX display containers */
.ml-formula-card__eq {
  overflow-x: auto;
  padding: 0.5rem 0;
}

/* KaTeX display math centering */
.ml-formula-card__eq .katex-display {
  margin: 0;
}

.ml-formula-card__eq .katex {
  font-size: 0.95em;
  color: var(--text-primary);
}

.ml-formula-card__note {
  font-size: 0.76rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

/* ── Mobile ──────────────────────────────────────────────────────── */

@media (max-width: 560px) {
  .ml-hero-header {
    padding: 1.75rem 1rem 1.25rem;
  }

  .ml-section {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .ml-section + .ml-section::before {
    left: 1rem;
  }

  .ml-reading-list {
    grid-template-columns: 1fr;
  }

  .ml-concepts-grid {
    grid-template-columns: 1fr;
  }

  .ml-formula-grid {
    grid-template-columns: 1fr;
  }

  .ml-queue-item__header {
    flex-direction: column;
    gap: 0.35rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .ml-reading-card,
  .ml-concept-card,
  .ml-formula-card {
    transition: none;
  }
}