/* ============================================================
   IC · IA · COMPLEJIDAD — DESIGN SYSTEM v2
   Base + Interactive Components + Depth & Motion
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,opsz,wght@0,8..60,300;0,8..60,400;0,8..60,600;0,8..60,700;1,8..60,300;1,8..60,400&family=DM+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* === TOKENS === */
:root {
  --color-bg: #FAF8F4;
  --color-bg-alt: #F0EDE6;
  --color-bg-dark: #1B2332;
  --color-bg-darker: #0f172a;
  --color-bg-card: #FFFFFF;
  --color-text: #2C2C2C;
  --color-text-light: #6B6B6B;
  --color-text-inverse: #FAF8F4;
  --color-heading: #1B2332;
  --color-accent: #C4553A;
  --color-accent-glow: rgba(196, 85, 58, 0.4);
  --color-teal: #2A7B6F;
  --color-teal-light: #E8F4F1;
  --color-teal-glow: rgba(42, 123, 111, 0.3);
  --color-gold: #C49A2A;
  --color-gold-light: #FDF6E3;
  --color-border: #E0DCD4;
  --color-border-strong: #C8C2B6;
  --phase1-color: #C4553A;
  --phase1-bg: #FDF0ED;
  --phase2-color: #2A7B6F;
  --phase2-bg: #E8F4F1;
  --color-success: #2D6B2D;
  --color-success-bg: #E8F4E8;
  --font-serif: 'Source Serif 4', Georgia, serif;
  --font-sans: 'DM Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'JetBrains Mono', Consolas, monospace;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
  --max-width: 820px;
  --max-width-wide: 1100px;
  --nav-height: 64px;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* === RESET === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 17px; scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body { font-family: var(--font-serif); color: var(--color-text); background: var(--color-bg); line-height: 1.72; min-height: 100vh; }

/* === TYPOGRAPHY === */
h1, h2, h3, h4, h5, h6 { font-family: var(--font-sans); color: var(--color-heading); line-height: 1.2; letter-spacing: -0.015em; }
h1 { font-size: 2.8rem; font-weight: 700; margin-bottom: var(--space-lg); }
h2 { font-size: 1.9rem; font-weight: 600; margin-top: var(--space-2xl); margin-bottom: var(--space-lg); padding-bottom: var(--space-sm); border-bottom: 2px solid var(--color-border); }
h3 { font-size: 1.35rem; font-weight: 600; margin-top: var(--space-xl); margin-bottom: var(--space-md); }
h4 { font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; font-size: 0.85rem; color: var(--color-text-light); margin-top: var(--space-lg); margin-bottom: var(--space-sm); }
p { margin-bottom: var(--space-md); }
a { color: var(--color-accent); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color 0.2s; }
a:hover { border-bottom-color: var(--color-accent); }
strong { font-weight: 600; }
blockquote { border-left: 3px solid var(--color-accent); padding: var(--space-md) var(--space-lg); margin: var(--space-xl) 0; background: var(--color-bg-alt); font-style: italic; color: var(--color-text-light); }
blockquote p:last-child { margin-bottom: 0; }
code { font-family: var(--font-mono); font-size: 0.88em; background: var(--color-bg-alt); padding: 0.15em 0.4em; border-radius: 3px; }
hr { border: none; border-top: 1px solid var(--color-border); margin: var(--space-2xl) 0; }
ul, ol { margin-bottom: var(--space-md); padding-left: var(--space-xl); }
li { margin-bottom: var(--space-sm); }

/* === NAV === */
.nav { position: sticky; top: 0; z-index: 100; background: rgba(27, 35, 50, 0.95); backdrop-filter: blur(12px); height: var(--nav-height); display: flex; align-items: center; padding: 0 var(--space-xl); box-shadow: 0 1px 8px rgba(0,0,0,0.15); }
.nav__logo { font-family: var(--font-sans); font-weight: 700; font-size: 0.95rem; color: var(--color-text-inverse); text-decoration: none; border: none; letter-spacing: 0.02em; white-space: nowrap; }
.nav__logo:hover { border: none; opacity: 0.85; }
.nav__links { display: flex; gap: var(--space-lg); margin-left: auto; list-style: none; flex-wrap: wrap; }
.nav__links a { font-family: var(--font-sans); font-size: 0.82rem; font-weight: 500; color: rgba(250,248,244,0.55); text-decoration: none; border: none; letter-spacing: 0.02em; transition: color 0.3s; }
.nav__links a:hover, .nav__links a.active { color: var(--color-text-inverse); }
.nav__toggle { display: none; background: none; border: none; color: var(--color-text-inverse); font-size: 1.5rem; cursor: pointer; margin-left: auto; }

/* === LAYOUT === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-xl); }
.container--wide { max-width: var(--max-width-wide); margin: 0 auto; padding: 0 var(--space-xl); }
.container--full { max-width: 1320px; margin: 0 auto; padding: 0 var(--space-xl); }

/* === HERO (with canvas background) === */
.hero {
  position: relative;
  background: linear-gradient(135deg, #0f172a 0%, #1B2332 40%, #1a2a3a 100%);
  color: var(--color-text-inverse);
  padding: var(--space-3xl) var(--space-xl);
  overflow: hidden;
  min-height: 480px;
  display: flex;
  align-items: center;
}
.hero-canvas {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  opacity: 0.5;
  pointer-events: none;
}
.hero__content {
  max-width: var(--max-width);
  margin: 0 auto;
  position: relative;
  z-index: 2;
  width: 100%;
}
.hero__overline {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-accent);
  margin-bottom: var(--space-md);
  opacity: 0;
  animation: fadeSlideUp 0.8s 0.2s var(--ease-out-expo) forwards;
}
.hero h1 {
  color: var(--color-text-inverse);
  font-size: 3.2rem;
  max-width: 720px;
  margin-bottom: var(--space-lg);
  letter-spacing: -0.02em;
  opacity: 0;
  animation: fadeSlideUp 0.8s 0.4s var(--ease-out-expo) forwards;
}
.hero__subtitle {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  line-height: 1.7;
  color: rgba(250,248,244,0.65);
  max-width: 600px;
  opacity: 0;
  animation: fadeSlideUp 0.8s 0.6s var(--ease-out-expo) forwards;
}
.hero__actions {
  margin-top: var(--space-xl);
  display: flex;
  gap: var(--space-md);
  align-items: center;
  opacity: 0;
  animation: fadeSlideUp 0.8s 0.8s var(--ease-out-expo) forwards;
}
.hero--phase1 { background: linear-gradient(135deg, #0f172a 0%, #2D1A1A 100%); }
.hero--phase2 { background: linear-gradient(135deg, #0f172a 0%, #1A2D28 100%); }

/* === BADGES === */
.badge { display: inline-block; font-family: var(--font-sans); font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; padding: 0.3em 0.8em; border-radius: 3px; }
.badge--phase1 { background: var(--phase1-bg); color: var(--phase1-color); }
.badge--phase2 { background: var(--phase2-bg); color: var(--phase2-color); }
.badge--method { background: var(--color-gold-light); color: var(--color-gold); }
.badge--free { background: var(--color-success-bg); color: var(--color-success); }
.badge--buy { background: #FDF0ED; color: #C4553A; }
.badge--search { background: var(--color-gold-light); color: #8B6914; }

/* === MAIN === */
.main { padding: var(--space-2xl) 0; }

/* === META STRIP === */
.meta-strip { display: flex; gap: var(--space-xl); flex-wrap: wrap; padding: var(--space-lg) 0; border-bottom: 1px solid var(--color-border); margin-bottom: var(--space-2xl); font-family: var(--font-sans); font-size: 0.85rem; color: var(--color-text-light); }
.meta-strip__item { display: flex; flex-direction: column; gap: var(--space-xs); }
.meta-strip__label { font-weight: 600; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.08em; }
.meta-strip__value { color: var(--color-text); font-weight: 500; }

/* === PHASE HEADER === */
.phase-header {
  margin-top: var(--space-3xl);
  margin-bottom: var(--space-xl);
}
.phase-header h2 {
  margin-top: 0;
  font-size: 2rem;
}
.phase-header p {
  max-width: 640px;
  color: var(--color-text-light);
}

/* === BLOCK GRID (homepage) === */
.block-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-xl);
  margin: var(--space-lg) 0;
}

/* BLOCK CARD — glassmorphism + depth */
.block-card {
  position: relative;
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 12px;
  padding: var(--space-xl) var(--space-xl) var(--space-lg);
  display: flex;
  flex-direction: column;
  box-shadow:
    0 1px 3px rgba(0,0,0,0.04),
    0 8px 24px rgba(0,0,0,0.04);
  transition: transform 0.4s var(--ease-out-expo), box-shadow 0.4s var(--ease-out-expo);
  /* scroll reveal default */
  opacity: 0;
  transform: translateY(32px);
}
.block-card.is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.7s var(--ease-out-expo), transform 0.7s var(--ease-out-expo);
}
.block-card:hover {
  transform: translateY(-6px);
  box-shadow:
    0 4px 12px rgba(0,0,0,0.06),
    0 20px 48px rgba(0,0,0,0.08);
}
/* Accent top-border glow */
.block-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  border-radius: 12px 12px 0 0;
  background: var(--card-accent, var(--color-accent));
  opacity: 0.7;
  transition: opacity 0.3s;
}
.block-card:hover::before { opacity: 1; }
.block-card--phase1 { --card-accent: var(--phase1-color); }
.block-card--phase2 { --card-accent: var(--phase2-color); }

.block-card__phase {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xs);
}
.block-card__phase--1 { color: var(--phase1-color); }
.block-card__phase--2 { color: var(--phase2-color); }
.block-card__number {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
}
.block-card__title {
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: var(--space-sm);
  line-height: 1.3;
}
.block-card__meta {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-md);
}
.block-card__desc {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--color-text-light);
  flex: 1;
}

/* Mini viz preview in card */
.block-card__viz {
  margin: var(--space-md) 0;
  height: 100px;
  border-radius: 6px;
  overflow: hidden;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
}
.block-card__viz svg {
  width: 100%;
  height: 100%;
}

.block-card__link {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  margin-top: var(--space-md);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
  transition: gap 0.3s var(--ease-out-expo);
}
.block-card__link:hover { gap: 0.7em; }

/* === WEEK CARDS === */
.week-card { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: 6px; padding: var(--space-lg) var(--space-xl); margin-bottom: var(--space-lg); transition: box-shadow 0.2s, border-color 0.2s; }
.week-card:hover { box-shadow: 0 2px 12px rgba(0,0,0,0.06); border-color: var(--color-border-strong); }
.week-card__number { font-family: var(--font-sans); font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-accent); margin-bottom: var(--space-xs); }
.week-card__title { font-family: var(--font-sans); font-size: 1.15rem; font-weight: 600; color: var(--color-heading); margin-bottom: var(--space-sm); }
.week-card__dates { font-family: var(--font-sans); font-size: 0.78rem; color: var(--color-text-light); margin-bottom: var(--space-md); }
.week-card__content { font-size: 0.95rem; line-height: 1.7; }
.week-card__readings { margin-top: var(--space-md); padding-top: var(--space-md); border-top: 1px solid var(--color-border); }
.week-card__readings h5 { font-family: var(--font-sans); font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-text-light); margin-bottom: var(--space-sm); }
.reading-item { display: flex; align-items: flex-start; gap: var(--space-sm); margin-bottom: var(--space-sm); font-size: 0.88rem; line-height: 1.55; }
.reading-item .badge { flex-shrink: 0; margin-top: 2px; }

/* === INFO BOXES === */
.info-box { border-radius: 8px; padding: var(--space-lg) var(--space-xl); margin: var(--space-xl) 0; }
.info-box--note { background: var(--color-gold-light); border-left: 3px solid var(--color-gold); }
.info-box--warning { background: var(--phase1-bg); border-left: 3px solid var(--color-accent); }
.info-box--tip { background: var(--color-teal-light); border-left: 3px solid var(--color-teal); }
.info-box__title { font-family: var(--font-sans); font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: var(--space-sm); }

/* === STRUCTURE GRID (how units work) === */
.structure-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-lg);
  margin: var(--space-xl) 0;
}
.structure-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: var(--space-xl);
  position: relative;
  overflow: hidden;
  transition: transform 0.4s var(--ease-out-expo), box-shadow 0.4s var(--ease-out-expo);
  /* scroll reveal */
  opacity: 0;
  transform: translateY(24px);
}
.structure-card.is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.6s var(--ease-out-expo), transform 0.6s var(--ease-out-expo);
}
.structure-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(0,0,0,0.07);
}
.structure-card__icon {
  font-size: 2rem;
  margin-bottom: var(--space-md);
  display: block;
}
.structure-card__block {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xs);
}
.structure-card__title {
  font-family: var(--font-sans);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: var(--space-sm);
}
.structure-card__meta {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
}
.structure-card__desc {
  font-size: 0.88rem;
  color: var(--color-text-light);
  line-height: 1.65;
}
.structure-card a {
  display: inline-block;
  margin-top: var(--space-sm);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
}

/* === MEDIA GRID === */
.media-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: var(--space-md); margin: var(--space-lg) 0; }
.media-item { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: 6px; padding: var(--space-md); font-family: var(--font-sans); font-size: 0.85rem; }
.media-item__type { font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-text-light); margin-bottom: var(--space-xs); }
.media-item__title { font-weight: 600; color: var(--color-heading); margin-bottom: var(--space-xs); }
.media-item__detail { font-size: 0.8rem; color: var(--color-text-light); line-height: 1.5; }

/* === DELIVERABLE === */
.deliverable { background: var(--color-bg-dark); color: var(--color-text-inverse); border-radius: 8px; padding: var(--space-xl); margin: var(--space-xl) 0; }
.deliverable__label { font-family: var(--font-sans); font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-accent); margin-bottom: var(--space-sm); }
.deliverable__title { font-family: var(--font-sans); font-size: 1.2rem; font-weight: 600; margin-bottom: var(--space-md); }
.deliverable__content { font-size: 0.92rem; line-height: 1.7; color: rgba(250,248,244,0.8); }

/* === FOOTER === */
.footer { background: var(--color-bg-dark); color: rgba(250,248,244,0.4); padding: var(--space-xl); text-align: center; font-family: var(--font-sans); font-size: 0.78rem; }
.footer a { color: rgba(250,248,244,0.6); border: none; }

/* === UTILITIES === */
.text-center { text-align: center; }
.text-light { color: var(--color-text-light); }
.text-small { font-size: 0.88rem; }
.text-sans { font-family: var(--font-sans); }

/* ============================================================
   INTERACTIVE COMPONENTS
   ============================================================ */

/* === SPLIT LAYOUT (Seeing Theory–inspired: text guides, viz dominates) === */
.split {
  display: grid;
  grid-template-columns: minmax(280px, 38%) 1fr;
  gap: var(--space-2xl);
  align-items: start;
  min-height: 70vh;
  padding: var(--space-xl) 0;
}
.split-text {
  font-size: 0.95rem;
  line-height: 1.72;
}
.split-viz {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-xl));
  min-height: 480px;
  display: flex;
  align-items: stretch;
}

/* === BREADCRUMB === */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.4em;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--color-text-light);
  padding: var(--space-sm) var(--space-xl);
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
}
.breadcrumb a {
  color: var(--color-text-light);
  border: none;
  transition: color 0.2s;
}
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb__sep { opacity: 0.4; font-size: 0.7em; }
.breadcrumb__current { color: var(--color-heading); font-weight: 600; }

/* === BLOCK PROGRESS (thin bar under breadcrumb) === */
.block-progress {
  height: 3px;
  background: var(--color-bg-alt);
  position: relative;
}
.block-progress__fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent), var(--color-teal));
  border-radius: 0 2px 2px 0;
  transition: width 0.8s var(--ease-out-expo);
}

/* === SESSION DOTS (intra-unit navigation) === */
.session-dots {
  position: fixed;
  right: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  list-style: none;
  padding: 0;
  margin: 0;
}
.session-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(44, 44, 44, 0.15);
  border: 1.5px solid rgba(44, 44, 44, 0.3);
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
}
.session-dot:hover {
  background: rgba(44, 44, 44, 0.35);
  transform: scale(1.3);
}
.session-dot.active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  transform: scale(1.3);
}
.session-dot::before {
  content: attr(data-label);
  position: absolute;
  right: 100%;
  top: 50%;
  transform: translateY(-50%);
  margin-right: 0.8rem;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--color-text-light);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
  background: var(--color-bg-dark);
  color: var(--color-text-inverse);
  padding: 0.3em 0.7em;
  border-radius: 4px;
}
.session-dot:hover::before { opacity: 1; }

/* === SECTION SEPARATOR === */
.section-break {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin: var(--space-3xl) 0 var(--space-xl);
  color: var(--color-text-light);
}
.section-break::before,
.section-break::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}
.section-break__label {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

/* === PANEL TRIGGERS === */
.panel-triggers {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
}
.panel-trigger {
  position: relative;
  background: var(--color-gold-light);
  color: var(--color-gold);
  border: 1px solid rgba(196, 154, 42, 0.3);
  padding: 0.45em 1em;
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s var(--ease-out-expo);
  overflow: hidden;
}
.panel-trigger::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--color-gold);
  opacity: 0;
  transition: opacity 0.3s;
  z-index: 0;
}
.panel-trigger:hover::before { opacity: 1; }
.panel-trigger:hover { color: white; border-color: var(--color-gold); }
.panel-trigger span { position: relative; z-index: 1; }
.panel-trigger--teal { background: var(--color-teal-light); color: var(--color-teal); border-color: rgba(42, 123, 111, 0.3); }
.panel-trigger--teal::before { background: var(--color-teal); }
.panel-trigger--teal:hover { border-color: var(--color-teal); }
.panel-trigger--accent { background: var(--phase1-bg); color: var(--color-accent); border-color: rgba(196, 85, 58, 0.3); }
.panel-trigger--accent::before { background: var(--color-accent); }
.panel-trigger--accent:hover { border-color: var(--color-accent); }

/* === SLIDE PANELS === */
.slide-panel {
  position: fixed;
  right: -620px;
  top: 0;
  width: 600px;
  height: 100vh;
  background: var(--color-bg-card);
  box-shadow: -8px 0 40px rgba(0,0,0,0.12);
  z-index: 200;
  transition: right 0.4s var(--ease-out-expo);
  overflow-y: auto;
  overscroll-behavior: contain;
}
.slide-panel.open { right: 0; }
.slide-panel__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-lg) var(--space-xl);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  z-index: 10;
}
.slide-panel__header h3 { margin: 0; font-size: 1.1rem; }
.slide-panel__close {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text-light);
  transition: color 0.2s, transform 0.2s;
  padding: 0.25em;
  line-height: 1;
}
.slide-panel__close:hover { color: var(--color-text); transform: scale(1.15); }
.slide-panel__content {
  padding: var(--space-xl);
  font-size: 0.9rem;
  line-height: 1.78;
}
.slide-panel__content h4 { font-size: 0.95rem; text-transform: none; letter-spacing: normal; color: var(--color-heading); margin-top: var(--space-xl); margin-bottom: var(--space-sm); }
.slide-panel__content h4:first-child { margin-top: 0; }
.slide-panel__content p { margin-bottom: var(--space-md); }
.slide-panel__content blockquote { font-size: 0.88rem; margin: var(--space-lg) 0; }
.slide-panel__content ul, .slide-panel__content ol { font-size: 0.88rem; margin-bottom: var(--space-md); }

.panel-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.4);
  z-index: 190;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s;
  backdrop-filter: blur(2px);
}
.panel-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

/* === QUIZ === */
.quiz-box {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: var(--space-xl);
  margin: var(--space-xl) 0;
  box-shadow: 0 2px 12px rgba(0,0,0,0.03);
}
.quiz-box__header { display: flex; justify-content: space-between; align-items: center; margin-bottom: var(--space-lg); font-family: var(--font-sans); }
.quiz-box__title { font-size: 1rem; font-weight: 600; color: var(--color-heading); }
.quiz-box__progress { font-size: 0.78rem; color: var(--color-text-light); font-weight: 500; }
.quiz-question { margin-bottom: var(--space-xl); padding-bottom: var(--space-lg); border-bottom: 1px solid var(--color-border); }
.quiz-question:last-of-type { border-bottom: none; }
.quiz-question__number { font-family: var(--font-sans); font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-accent); margin-bottom: var(--space-sm); }
.quiz-question__text { font-weight: 600; font-family: var(--font-sans); margin-bottom: var(--space-lg); font-size: 0.95rem; line-height: 1.5; }
.quiz-option {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-sm);
  border: 1.5px solid var(--color-border);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.25s var(--ease-out-expo);
  font-family: var(--font-sans);
  font-size: 0.88rem;
  line-height: 1.5;
}
.quiz-option:hover:not(.quiz-option--locked) {
  border-color: var(--color-accent);
  background: var(--phase1-bg);
  transform: translateX(4px);
}
.quiz-option input[type="radio"] { flex-shrink: 0; margin-top: 0.2em; accent-color: var(--color-accent); }
.quiz-option--correct { border-color: var(--color-success); background: var(--color-success-bg); }
.quiz-option--incorrect { border-color: var(--color-accent); background: var(--phase1-bg); }
.quiz-option--locked { cursor: default; opacity: 0.85; }
.quiz-option--locked.quiz-option--correct { opacity: 1; }
.quiz-feedback {
  padding: var(--space-md) var(--space-lg);
  margin-top: var(--space-sm);
  border-radius: 6px;
  font-size: 0.85rem;
  line-height: 1.6;
  font-family: var(--font-sans);
}
.quiz-feedback--correct { background: var(--color-success-bg); border-left: 3px solid var(--color-success); color: #1a3a1a; }
.quiz-feedback--incorrect { background: var(--phase1-bg); border-left: 3px solid var(--color-accent); color: #5a2a20; }
.quiz-score {
  font-family: var(--font-sans);
  font-weight: 600;
  margin-top: var(--space-lg);
  padding: var(--space-lg);
  border-radius: 8px;
  text-align: center;
  font-size: 1.1rem;
}
.quiz-score--pass { background: var(--color-success-bg); color: var(--color-success); border: 1px solid var(--color-success); }
.quiz-score--fail { background: var(--phase1-bg); color: var(--color-accent); border: 1px solid var(--color-accent); }
.quiz-retry {
  display: inline-block;
  margin-top: var(--space-md);
  padding: 0.5em 1.5em;
  background: var(--color-accent);
  color: white;
  border: none;
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.15s;
}
.quiz-retry:hover { background: #a8432d; transform: translateY(-1px); }

/* === CHECKLIST === */
.checklist {
  background: var(--color-teal-light);
  border: 1px solid rgba(42, 123, 111, 0.25);
  border-radius: 10px;
  padding: var(--space-xl);
  margin: var(--space-xl) 0;
}
.checklist__title { font-family: var(--font-sans); font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-teal); margin-bottom: var(--space-lg); }
.checklist-item { display: flex; gap: var(--space-md); padding: var(--space-md) 0; border-bottom: 1px solid rgba(42, 123, 111, 0.1); }
.checklist-item:last-child { border-bottom: none; }
.checklist-item input[type="checkbox"] { flex-shrink: 0; width: 20px; height: 20px; margin-top: 0.2em; cursor: pointer; accent-color: var(--color-teal); }
.checklist-item label { cursor: pointer; font-size: 0.9rem; line-height: 1.5; color: var(--color-text); transition: color 0.3s; }
.checklist-item input[type="checkbox"]:checked + label { color: var(--color-text-light); text-decoration: line-through; }
.checklist__verdict { margin-top: var(--space-lg); padding: var(--space-lg); background: rgba(255,255,255,0.5); border-radius: 6px; text-align: center; font-family: var(--font-sans); font-weight: 600; font-size: 0.9rem; color: var(--color-teal); }
.checklist__verdict--complete { background: var(--color-success-bg); color: var(--color-success); border: 1px solid var(--color-success); }
.checklist__next {
  display: inline-block;
  margin-top: var(--space-md);
  padding: 0.5em 1.5em;
  background: var(--color-teal);
  color: white;
  border: none;
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
}
.checklist__next:hover { background: #1f5f55; color: white; border-bottom: none; transform: translateY(-1px); }

/* === VIZ CONTAINER (immersive — no border, no frame) === */
.viz-container {
  width: 100%;
  min-height: 480px;
  background: transparent;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  flex: 1;
}
/* Dark variant for labs/simulations */
.viz-container--dark {
  background: var(--color-bg-dark);
  border-radius: 12px;
}
.viz-container svg { width: 100%; height: 100%; }
.viz-container--short { min-height: 320px; }
.viz-container--tall { min-height: 560px; }
/* Framed variant (opt-in for when border is needed) */
.viz-container--framed {
  border: 1px solid var(--color-border);
  background: var(--color-bg-card);
}
.viz-controls {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: var(--space-md) var(--space-lg);
  background: linear-gradient(transparent, rgba(255,255,255,0.97));
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  font-family: var(--font-sans);
  font-size: 0.8rem;
}
.viz-controls label { font-weight: 600; color: var(--color-text-light); white-space: nowrap; }
.viz-controls input[type="range"] { flex: 1; accent-color: var(--color-accent); }
.viz-controls .viz-value { font-family: var(--font-mono); font-size: 0.82rem; color: var(--color-heading); min-width: 3em; text-align: right; }
.viz-btn { padding: 0.35em 0.9em; background: var(--color-bg-dark); color: var(--color-text-inverse); border: none; border-radius: 6px; font-family: var(--font-sans); font-size: 0.78rem; font-weight: 600; cursor: pointer; transition: background 0.2s, transform 0.15s; }
.viz-btn:hover { background: #2d3a4d; transform: translateY(-1px); }
.viz-btn--accent { background: var(--color-accent); }
.viz-btn--accent:hover { background: #a8432d; }
.viz-btn--teal { background: var(--color-teal); }
.viz-btn--teal:hover { background: #1f5f55; }
.viz-tooltip {
  position: absolute;
  background: var(--color-bg-dark);
  color: var(--color-text-inverse);
  padding: 0.6em 1em;
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  line-height: 1.4;
  pointer-events: none;
  z-index: 50;
  max-width: 240px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.25);
  opacity: 0;
  transition: opacity 0.15s;
}
.viz-tooltip.visible { opacity: 1; }

/* === SECTIONS === */
.section { margin-bottom: var(--space-2xl); padding-bottom: var(--space-xl); border-bottom: 1px solid var(--color-border); }
.section:last-child { border-bottom: none; }

/* === UNIT NAV === */
.unit-nav { display: flex; justify-content: space-between; align-items: center; padding: var(--space-xl) 0; margin-top: var(--space-2xl); border-top: 1px solid var(--color-border); font-family: var(--font-sans); font-size: 0.9rem; }
.unit-nav span { color: var(--color-text-light); }
.unit-nav a { font-weight: 600; }

/* === CTA BUTTON === */
.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  padding: 0.75em 2em;
  background: var(--color-accent);
  color: white;
  border: none;
  border-radius: 8px;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s, transform 0.15s, gap 0.3s var(--ease-out-expo);
  box-shadow: 0 2px 8px var(--color-accent-glow);
}
.cta:hover {
  background: #a8432d;
  color: white;
  border-bottom: none;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--color-accent-glow);
  gap: 0.7em;
}
.cta--teal { background: var(--color-teal); box-shadow: 0 2px 8px var(--color-teal-glow); }
.cta--teal:hover { background: #1f5f55; box-shadow: 0 6px 20px var(--color-teal-glow); }
.cta--ghost {
  background: transparent;
  color: rgba(250,248,244,0.7);
  border: 1px solid rgba(250,248,244,0.25);
  box-shadow: none;
}
.cta--ghost:hover {
  color: white;
  border-color: rgba(250,248,244,0.5);
  background: rgba(250,248,244,0.08);
  box-shadow: none;
}

/* === PROGRESS BAR === */
.progress-bar { width: 100%; height: 5px; background: var(--color-bg-alt); border-radius: 3px; overflow: hidden; margin: var(--space-sm) 0; }
.progress-bar__fill { height: 100%; background: linear-gradient(90deg, var(--color-teal), #3da895); border-radius: 3px; transition: width 0.6s var(--ease-out-expo); }

/* ============================================================
   ANIMATIONS
   ============================================================ */

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 0.8; }
}

/* Scroll-triggered reveal */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s var(--ease-out-expo), transform 0.7s var(--ease-out-expo);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}
/* Stagger children */
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s var(--ease-out-expo), transform 0.6s var(--ease-out-expo);
}
.reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0s; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 0.1s; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 0.2s; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 0.3s; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(5) { transition-delay: 0.4s; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(6) { transition-delay: 0.5s; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(7) { transition-delay: 0.6s; opacity: 1; transform: translateY(0); }

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 768px) {
  .nav__toggle { display: block; }
  .nav__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0; right: 0;
    background: rgba(27, 35, 50, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: var(--space-lg) var(--space-xl);
    gap: var(--space-md);
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
  }
  .nav__links.open { display: flex; }
  h1 { font-size: 2rem; }
  .hero { min-height: 400px; padding: var(--space-2xl) var(--space-xl); }
  .hero h1 { font-size: 2.2rem; }
  .split { grid-template-columns: 1fr; gap: var(--space-lg); min-height: auto; }
  .split-viz { position: static; min-height: 320px; }
  .slide-panel { width: 100%; right: -100%; }
  .block-grid { grid-template-columns: 1fr; }
  .viz-controls { flex-wrap: wrap; }
  .session-dots { display: none; }
  .breadcrumb { font-size: 0.72rem; padding: var(--space-xs) var(--space-md); overflow-x: auto; white-space: nowrap; }
}

@media (min-width: 1441px) {
  :root { --max-width: 880px; --max-width-wide: 1200px; }
}

/* === LAB COMPONENTS (standardized dark-themed interactive visualizations) === */
.lab-header {
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.lab-header h3 {
  color: #ffffff;
  margin: 0 0 0.25rem 0;
  font-size: 1.1rem;
  font-family: var(--font-sans);
}
.lab-header p {
  margin: 0;
  color: rgba(255,255,255,0.6);
  font-size: 0.85rem;
}

.lab-controls {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1rem;
  background: rgba(0,0,0,0.2);
  padding: 1rem;
  border-radius: 8px;
}

.lab-slider-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.lab-slider-group label {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  color: rgba(255,255,255,0.8);
  font-family: var(--font-sans);
}

.lab-slider-group input[type="range"] {
  width: 100%;
  accent-color: var(--color-accent);
}

.lab-canvas {
  flex-grow: 1;
  width: 100%;
  min-height: 250px;
  position: relative;
  background: #0f0f0f;
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.lab-canvas canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.lab-readout {
  background: rgba(0,0,0,0.5);
  padding: 0.75rem;
  text-align: center;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-weight: 600;
  font-size: 0.95rem;
  color: rgba(255,255,255,0.9);
  font-family: var(--font-sans);
}

/* Legacy support: keep wildcard selectors for existing HTML */
[class*="-lab-header"] { margin-bottom: 1rem; padding-bottom: 0.75rem; border-bottom: 1px solid rgba(255,255,255,0.1); }
[class*="-lab-header"] h3 { color: #ffffff; margin: 0 0 0.25rem 0; font-size: 1.1rem; }
[class*="-lab-header"] p { margin: 0; color: rgba(255,255,255,0.6); }
[class*="-controls"]:not(.lab-controls):not(.viz-controls) { display: flex; flex-direction: column; gap: 1rem; margin-bottom: 1rem; background: rgba(0,0,0,0.2); padding: 1rem; border-radius: 8px; }
[class*="-slider-group"]:not(.lab-slider-group) { display: flex; flex-direction: column; gap: 0.5rem; }
[class*="-slider-group"]:not(.lab-slider-group) label { display: flex; justify-content: space-between; font-size: 0.9rem; color: rgba(255,255,255,0.8); }
[class*="-slider-group"]:not(.lab-slider-group) input[type="range"] { width: 100%; accent-color: var(--phase1-color, #C4553A); }
[class*="-canvas-container"] { flex-grow: 1; width: 100%; min-height: 250px; position: relative; background: #0f0f0f; border-radius: 8px; border: 1px solid rgba(255,255,255,0.1); overflow: hidden; display: flex; flex-direction: column; }
[class*="-canvas-container"] canvas { width: 100%; height: 100%; display: block; }
[class*="-dynamic-text"] { background: rgba(0,0,0,0.5); padding: 0.75rem; text-align: center; border-top: 1px solid rgba(255,255,255,0.1); font-weight: 600; font-size: 0.95rem; color: rgba(255,255,255,0.9); }

/* === CASCADE SIMULATOR SPECIFIC === */
[class*="-btn-group"] {
  display: flex;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

[class*="-btn"] {
  flex: 1;
  padding: 0.6rem 0.75rem;
  background: var(--phase1-color, #C4553A);
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  transition: background 0.2s;
}

[class*="-btn"]:hover:not(:disabled) {
  background: rgba(196, 85, 58, 0.8);
}

[class*="-btn"]:disabled {
  background: rgba(196, 85, 58, 0.4);
  cursor: not-allowed;
}

[class*="-sim-arena"] {
  padding: 1rem;
  background: rgba(0,0,0,0.3);
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.1);
}

[class*="-agents-container"] {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 0.6rem;
  margin-bottom: 1rem;
}

[class*="-agent-node"] {
  width: 100%;
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(196, 85, 58, 0.2);
  border: 2px solid rgba(196, 85, 58, 0.5);
  border-radius: 6px;
  color: rgba(255,255,255,0.8);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
}

[class*="-agent-node"].decided-a {
  background: rgba(46, 125, 50, 0.3);
  border-color: #2e7d32;
  color: #81c784;
}

[class*="-agent-node"].decided-b {
  background: rgba(198, 40, 40, 0.3);
  border-color: #c62828;
  color: #e57373;
}

[class*="-agent-node"].cascade {
  border-style: dashed;
}

[class*="-agent-node"].pending {
  background: rgba(100, 100, 100, 0.2);
  border-color: rgba(255,255,255,0.3);
}

[class*="-sim-status"],
[class*="-sim-summary"] {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.8);
  padding: 0.75rem;
  background: rgba(0,0,0,0.3);
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

[class*="-sim-summary"] {
  margin-bottom: 0;
  display: none;
}

/* === ARCHITECTURE SIMULATOR SPECIFIC === */
[class*="-arch-container"] {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin-bottom: 1rem;
}

[class*="-arch-col"] {
  padding: 1rem;
  background: rgba(0,0,0,0.3);
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.1);
}

[class*="-arch-title"] {
  font-size: 0.95rem;
  font-weight: 600;
  color: rgba(255,255,255,0.9);
  margin-bottom: 0.75rem;
  text-align: center;
}

[class*="-nodes-grid"] {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(28px, 1fr));
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  min-height: 80px;
  place-items: center;
}

[class*="-node"] {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 600;
  border: 1px solid rgba(255,255,255,0.2);
}

[class*="-node"].vote-a {
  background: rgba(74, 144, 217, 0.3);
  border-color: #4A90D9;
  color: #4A90D9;
}

[class*="-node"].vote-b {
  background: rgba(245, 166, 35, 0.3);
  border-color: #F5A623;
  color: #F5A623;
}

[class*="-node"]:hover {
  opacity: 0.8;
}

[class*="-arch-result"] {
  font-size: 0.85rem;
  padding: 0.6rem;
  background: rgba(100, 100, 100, 0.2);
  border-radius: 4px;
  text-align: center;
  color: rgba(255,255,255,0.8);
  font-weight: 600;
}

[class*="-tradeoffs-section"] {
  margin-top: 1rem;
  padding: 1rem;
  background: rgba(0,0,0,0.3);
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.1);
}

[class*="-metrics-container"] {
  margin-top: 1rem;
}

[class*="-metric-row"] {
  margin-bottom: 0.75rem;
}

[class*="-metric-label"] {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.8);
  margin-bottom: 0.25rem;
}

[class*="-metric-bg"] {
  width: 100%;
  height: 16px;
  background: rgba(0,0,0,0.3);
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.1);
}

[class*="-metric-fill"] {
  height: 100%;
  background: linear-gradient(90deg, var(--phase1-color, #C4553A) 0%, rgba(196, 85, 58, 0.5) 100%);
  transition: width 0.3s ease;
}

/* === CONCEPT CROSSLINK === */
.crosslink {
  display: inline-flex;
  align-items: center;
  gap: 0.3em;
  padding: 0.2em 0.6em;
  background: var(--color-teal-light);
  border: 1px solid rgba(42, 123, 111, 0.2);
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-teal);
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}
.crosslink:hover {
  background: var(--color-teal);
  color: white;
  border-color: var(--color-teal);
  border-bottom-color: var(--color-teal);
}
.crosslink::before { content: '↗'; font-size: 0.7em; opacity: 0.7; }

/* === COMING SOON (Bloques 4-8) === */
.coming-soon {
  position: relative;
  opacity: 0.55;
  pointer-events: none;
}
.coming-soon::after {
  content: 'Próximamente';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-text-light);
  background: var(--color-bg);
  padding: 0.5em 1.5em;
  border: 1.5px solid var(--color-border-strong);
  border-radius: 6px;
  pointer-events: auto;
  z-index: 5;
}

/* === UNIT HEADER (enhanced, consistent with ST homepage) === */
.unit-header {
  position: relative;
  min-height: 400px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--color-text-inverse);
}
.unit-header__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.unit-header__content {
  position: relative;
  z-index: 2;
  max-width: 640px;
  padding: var(--space-3xl) var(--space-xl);
}
.unit-header__number {
  position: absolute;
  right: 8vw;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-sans);
  font-size: clamp(5rem, 10vw, 8rem);
  font-weight: 800;
  opacity: 0.1;
  pointer-events: none;
  z-index: 1;
  color: #fff;
}
.unit-header__overline {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  opacity: 0.6;
  margin-bottom: var(--space-md);
}
.unit-header h1 {
  color: #fff;
  font-size: clamp(2rem, 4vw, 3rem);
  max-width: 600px;
  margin-bottom: var(--space-md);
}
.unit-header__subtitle {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.7;
  opacity: 0.7;
  max-width: 520px;
}

/* === PRINT === */
@media print {
  .nav, .footer, .panel-triggers, .slide-panel, .panel-overlay, .quiz-retry, .checklist__next, .hero-canvas { display: none; }
  .hero { background: white !important; color: black !important; }
  .split { grid-template-columns: 1fr; }
  body { font-size: 11pt; }
  .block-card, .structure-card, .reveal { opacity: 1 !important; transform: none !important; }
}