/* =============================================
   Advanced eClinical Training — Brand System
   CCMA: Understanding Diseases & Disorders
   Brand Colors: Navy #0B1A35 | Teal #66C6BE
   Fonts: Oswald (headings) | Roboto (body)
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Oswald:wght@400;500;600;700&family=Roboto:wght@300;400;500;600&display=swap');

/* CSS Variables — Brand Guide */
:root {
  --navy:         #0B1A35;
  --navy-mid:     #1a2f56;
  --navy-light:   #2d4a7a;
  --teal:         #66C6BE;
  --teal-dark:    #3da89f;
  --teal-light:   #a8e4e0;
  --teal-soft:    #e8f8f7;
  --teal-xsoft:   #f0fafa;
  --white:        #ffffff;
  --gray-50:      #f8fafb;
  --gray-100:     #f1f5f7;
  --gray-200:     #e4eaef;
  --gray-300:     #c8d4dc;
  --gray-400:     #8fa3b1;
  --gray-500:     #637585;
  --gray-600:     #445566;
  --gray-700:     #2e3d4e;
  --gray-800:     #1a2633;
  --charcoal:     #2C3E50;
  --red:          #e53e3e;
  --red-light:    #fff5f5;
  --red-border:   #fc8181;
  --green:        #38a169;
  --green-light:  #f0fff4;
  --green-border: #68d391;
  --amber:        #d97706;
  --amber-light:  #fffbeb;
  --amber-border: #fbbf24;
  --blue:         #2b6cb0;
  --blue-light:   #ebf8ff;
  --purple:       #6b46c1;
  --purple-light: #faf5ff;

  --shadow-xs:  0 1px 2px rgba(11,26,53,0.06);
  --shadow-sm:  0 2px 6px rgba(11,26,53,0.08);
  --shadow:     0 4px 12px rgba(11,26,53,0.10);
  --shadow-md:  0 8px 24px rgba(11,26,53,0.12);
  --shadow-lg:  0 16px 40px rgba(11,26,53,0.14);

  --radius-xs:  6px;
  --radius-sm:  10px;
  --radius:     14px;
  --radius-lg:  18px;
  --radius-xl:  24px;
  --radius-full: 999px;

  --transition: all 0.22s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* =============================================
   RESET & BASE
   ============================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-weight: 300;
  background: var(--gray-50);
  color: var(--charcoal);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

h1, h2, h3, h4, h5 {
  font-family: 'Oswald', sans-serif;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.2;
  letter-spacing: 0.02em;
}

/* =============================================
   APP LAYOUT
   ============================================= */
#app { display: flex; flex-direction: column; min-height: 100vh; }

/* =============================================
   TOP NAVIGATION
   ============================================= */
.top-nav {
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  padding: 0 28px;
  height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-xs);
}

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

.nav-logo {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--navy), var(--navy-mid));
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.nav-logo svg { width: 20px; height: 20px; }

.nav-title {
  font-family: 'Oswald', sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  line-height: 1.2;
}
.nav-subtitle { font-size: 11px; color: var(--gray-400); font-weight: 400; margin-top: 1px; }

.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-progress-label { font-size: 12px; color: var(--gray-500); font-weight: 500; }

.nav-progress-track {
  width: 140px;
  height: 5px;
  background: var(--gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.nav-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--teal-dark), var(--teal));
  border-radius: var(--radius-full);
  transition: width 0.5s ease;
}

.screen-counter {
  font-size: 11px;
  color: var(--gray-500);
  font-weight: 500;
  background: var(--gray-100);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  letter-spacing: 0.04em;
}

/* =============================================
   SIDEBAR
   ============================================= */
.app-body { display: flex; flex: 1; }

.sidebar {
  width: 236px;
  background: var(--white);
  border-right: 1px solid var(--gray-200);
  padding: 16px 0 24px;
  position: sticky;
  top: 62px;
  height: calc(100vh - 62px);
  overflow-y: auto;
  flex-shrink: 0;
}

.sidebar-section-label {
  font-family: 'Oswald', sans-serif;
  font-size: 10px;
  font-weight: 500;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 0.10em;
  padding: 0 16px 6px;
  margin-top: 12px;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  cursor: pointer;
  transition: var(--transition);
  border-left: 3px solid transparent;
  position: relative;
}

.sidebar-item:hover { background: var(--gray-50); }

.sidebar-item.active {
  background: var(--teal-xsoft);
  border-left-color: var(--teal);
}

.sidebar-dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid var(--gray-300);
  background: var(--white);
  flex-shrink: 0;
  position: relative;
  transition: var(--transition);
}

.sidebar-item.active .sidebar-dot {
  border-color: var(--teal);
  background: var(--teal);
}

.sidebar-item.active .sidebar-dot::after {
  content: '';
  width: 6px;
  height: 6px;
  background: white;
  border-radius: 50%;
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
}

.sidebar-item.completed .sidebar-dot {
  background: var(--teal);
  border-color: var(--teal);
}

.sidebar-item.completed .sidebar-dot::after {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%) rotate(45deg);
  width: 4px;
  height: 7px;
  border-right: 2px solid white;
  border-bottom: 2px solid white;
  margin-top: -1px;
}

.sidebar-text {
  font-size: 12px;
  color: var(--gray-600);
  font-weight: 400;
  line-height: 1.3;
}

.sidebar-item.active .sidebar-text { color: var(--teal-dark); font-weight: 500; }
.sidebar-item.completed .sidebar-text { color: var(--gray-500); }

/* =============================================
   MAIN CONTENT
   ============================================= */
.main-content {
  flex: 1;
  padding: 36px 40px;
  max-width: 100%;
  overflow-y: auto;
}

/* =============================================
   SCREEN SYSTEM
   ============================================= */
.screen { display: none; animation: screenIn 0.35s ease both; }
.screen.active { display: block; }

@keyframes screenIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* =============================================
   TYPOGRAPHY
   ============================================= */
.screen-title {
  font-family: 'Oswald', sans-serif;
  font-size: 30px;
  font-weight: 700;
  color: var(--navy);
  letter-spacing: 0.02em;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.screen-title .title-icon {
  width: 40px;
  height: 40px;
  background: var(--teal-soft);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.screen-title .title-icon svg { width: 22px; height: 22px; color: var(--teal-dark); }

.screen-subtitle {
  font-size: 14px;
  color: var(--gray-500);
  font-weight: 400;
  line-height: 1.7;
  margin-bottom: 28px;
  max-width: 720px;
}

.section-title {
  font-family: 'Oswald', sans-serif;
  font-size: 18px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
  margin-bottom: 4px;
}

.section-subtitle {
  font-size: 13px;
  color: var(--gray-500);
  margin-bottom: 20px;
}

/* =============================================
   CARDS
   ============================================= */
.card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  transition: var(--transition);
  overflow: hidden;
}

.card:hover { box-shadow: var(--shadow); }
.card-body { padding: 24px; }
.card-footer {
  padding: 14px 24px;
  border-top: 1px solid var(--gray-100);
  background: var(--gray-50);
}

/* =============================================
   BUTTONS
   ============================================= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: var(--radius-sm);
  font-family: 'Oswald', sans-serif;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  transition: var(--transition);
  border: 2px solid transparent;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--teal);
  color: var(--navy);
  border-color: var(--teal);
}

.btn-primary:hover {
  background: var(--teal-dark);
  border-color: var(--teal-dark);
  color: var(--white);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(102,198,190,0.4);
}

.btn-secondary {
  background: var(--white);
  color: var(--navy);
  border-color: var(--navy);
}

.btn-secondary:hover {
  background: var(--navy);
  color: var(--white);
  transform: translateY(-1px);
}

.btn-navy {
  background: var(--navy);
  color: var(--white);
  border-color: var(--navy);
}

.btn-navy:hover { background: var(--navy-mid); border-color: var(--navy-mid); }

.btn-sm {
  padding: 8px 16px;
  font-size: 12px;
}

.btn-lg {
  padding: 14px 30px;
  font-size: 16px;
  border-radius: var(--radius);
}

.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none !important; box-shadow: none !important; }

.nav-buttons {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--gray-200);
}

/* =============================================
   BADGES & TAGS
   ============================================= */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 10px;
  font-weight: 500;
  font-family: 'Oswald', sans-serif;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.badge-teal   { background: var(--teal-soft); color: var(--teal-dark); border: 1px solid var(--teal-light); }
.badge-navy   { background: #e8eef7; color: var(--navy); border: 1px solid #c5d3e8; }
.badge-red    { background: var(--red-light); color: #c53030; border: 1px solid var(--red-border); }
.badge-green  { background: var(--green-light); color: #276749; border: 1px solid var(--green-border); }
.badge-amber  { background: var(--amber-light); color: #92400e; border: 1px solid var(--amber-border); }
.badge-purple { background: var(--purple-light); color: #553c9a; border: 1px solid #b794f4; }
.badge-orange { background: #fff7ed; color: #9a3412; border: 1px solid #fed7aa; }

/* =============================================
   CALLOUT BOXES
   ============================================= */
.callout {
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  border-left: 4px solid;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin: 14px 0;
}

.callout-icon { font-size: 16px; flex-shrink: 0; margin-top: 1px; }
.callout-title {
  font-family: 'Oswald', sans-serif;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}
.callout-text { font-size: 13px; line-height: 1.65; font-weight: 400; }

.callout-teal   { background: var(--teal-soft); border-color: var(--teal); color: var(--teal-dark); }
.callout-teal .callout-title { color: var(--teal-dark); }

.callout-navy   { background: #eef2f9; border-color: var(--navy); color: var(--navy); }
.callout-navy .callout-title { color: var(--navy); }

.callout-yellow { background: var(--amber-light); border-color: var(--amber); color: #78350f; }
.callout-yellow .callout-title { color: #92400e; }

.callout-red    { background: var(--red-light); border-color: var(--red); color: #742a2a; }
.callout-red .callout-title { color: #c53030; }

.callout-green  { background: var(--green-light); border-color: var(--green); color: #22543d; }
.callout-green .callout-title { color: #276749; }

/* =============================================
   SCREEN 0 — WELCOME (BRAND REDESIGN)
   ============================================= */
.welcome-hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 55%, #1e4a6e 100%);
  border-radius: var(--radius-xl);
  padding: 56px 52px;
  color: white;
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 40px;
  align-items: center;
  margin-bottom: 36px;
  position: relative;
  overflow: hidden;
}

.welcome-hero::before {
  content: '';
  position: absolute;
  top: -80px; right: -80px;
  width: 300px; height: 300px;
  background: rgba(102,198,190,0.06);
  border-radius: 50%;
}

.welcome-hero::after {
  content: '';
  position: absolute;
  bottom: -60px; right: 140px;
  width: 200px; height: 200px;
  background: rgba(102,198,190,0.04);
  border-radius: 50%;
}

.welcome-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(102,198,190,0.15);
  border: 1px solid rgba(102,198,190,0.3);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 500;
  font-family: 'Oswald', sans-serif;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--teal-light);
  margin-bottom: 20px;
}

.welcome-h1 {
  font-family: 'Oswald', sans-serif;
  font-size: 42px;
  font-weight: 700;
  line-height: 1.08;
  margin-bottom: 18px;
  color: white;
  letter-spacing: 0.02em;
}

.welcome-h1 span { color: var(--teal); }

.welcome-desc {
  font-size: 14px;
  line-height: 1.75;
  color: rgba(255,255,255,0.72);
  margin-bottom: 28px;
  max-width: 480px;
  font-weight: 300;
}

.welcome-meta {
  display: flex;
  gap: 20px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.welcome-meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: rgba(255,255,255,0.65);
  font-weight: 400;
}

.welcome-meta-icon {
  width: 30px;
  height: 30px;
  background: rgba(102,198,190,0.15);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
}

.welcome-meta-icon svg { width: 16px; height: 16px; color: var(--teal); }

.welcome-graphic {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  z-index: 1;
}

.welcome-visual {
  width: 280px;
  height: 280px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.welcome-visual-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(102,198,190,0.2);
  animation: ringPulse 3s ease-in-out infinite;
}

.welcome-visual-ring:nth-child(1) { width: 100%; height: 100%; animation-delay: 0s; }
.welcome-visual-ring:nth-child(2) { width: 75%; height: 75%; animation-delay: 0.6s; border-color: rgba(102,198,190,0.3); }
.welcome-visual-ring:nth-child(3) { width: 50%; height: 50%; animation-delay: 1.2s; border-color: rgba(102,198,190,0.45); }

.welcome-visual-icon {
  position: relative;
  z-index: 2;
  width: 90px;
  height: 90px;
  background: rgba(102,198,190,0.15);
  border-radius: 50%;
  border: 2px solid rgba(102,198,190,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: float 4s ease-in-out infinite;
}

.welcome-visual-icon svg { width: 44px; height: 44px; color: var(--teal); }

@keyframes ringPulse {
  0%, 100% { opacity: 0.4; transform: scale(1); }
  50%       { opacity: 0.8; transform: scale(1.04); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-10px); }
}

/* Welcome Objective Cards */
.welcome-objectives { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }

.welcome-obj-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-xs);
  transition: var(--transition);
  border-top: 3px solid var(--teal);
}

.welcome-obj-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-top-color: var(--navy);
}

.welcome-obj-icon {
  width: 38px;
  height: 38px;
  background: var(--teal-soft);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}

.welcome-obj-icon svg { width: 20px; height: 20px; color: var(--teal-dark); }

.welcome-obj-title {
  font-family: 'Oswald', sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 5px;
  letter-spacing: 0.02em;
}

.welcome-obj-text { font-size: 12px; color: var(--gray-500); line-height: 1.55; font-weight: 400; }

/* =============================================
   SCREEN 1 — LEARNING OBJECTIVES
   ============================================= */
.objectives-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }

.obj-card {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 22px 24px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.obj-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--teal), var(--teal-light));
  opacity: 0;
  transition: var(--transition);
}

.obj-card:hover { border-color: var(--teal); transform: translateY(-1px); box-shadow: var(--shadow); }
.obj-card:hover::before { opacity: 1; }
.obj-card.expanded { border-color: var(--teal); box-shadow: var(--shadow); }
.obj-card.expanded::before { opacity: 1; }

.obj-card-header { display: flex; align-items: center; gap: 14px; margin-bottom: 10px; }

.obj-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.obj-icon svg { width: 22px; height: 22px; }

.obj-card-title {
  font-family: 'Oswald', sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}

.obj-card-tag { font-size: 11px; color: var(--gray-400); font-weight: 400; margin-top: 2px; }

.obj-expand-icon {
  margin-left: auto;
  font-size: 18px;
  color: var(--gray-400);
  transition: var(--transition);
  flex-shrink: 0;
  font-weight: 300;
}

.obj-card.expanded .obj-expand-icon { transform: rotate(180deg); color: var(--teal); }

.obj-card-body { display: none; animation: expandIn 0.3s ease both; }
.obj-card.expanded .obj-card-body { display: block; }

@keyframes expandIn {
  from { opacity: 0; transform: translateY(-6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.obj-card-body p {
  font-size: 13px;
  color: var(--gray-600);
  line-height: 1.7;
  margin-bottom: 12px;
  font-weight: 300;
}

.obj-key-points { list-style: none; display: flex; flex-direction: column; gap: 6px; }

.obj-key-points li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 12px;
  color: var(--gray-700);
  line-height: 1.5;
  font-weight: 400;
}

.obj-key-points li::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--teal);
  flex-shrink: 0;
  margin-top: 5px;
}

/* =============================================
   SCREEN 2 — DISEASE TYPES MAP
   ============================================= */
.disease-map-layout {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 24px;
  min-height: 480px;
}

.disease-categories { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; align-content: start; }

.disease-cat-btn {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 18px 16px;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
  display: flex;
  align-items: center;
  gap: 12px;
}

.disease-cat-btn:hover { border-color: var(--teal); transform: translateY(-1px); box-shadow: var(--shadow-sm); }
.disease-cat-btn.active { border-color: var(--teal); background: var(--teal-soft); box-shadow: var(--shadow); }

.disease-cat-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.disease-cat-icon svg { width: 22px; height: 22px; }

.disease-cat-name {
  font-family: 'Oswald', sans-serif;
  font-size: 13px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}

.disease-cat-sub { font-size: 11px; color: var(--gray-400); margin-top: 2px; font-weight: 300; }

.disease-panel {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1.5px solid var(--gray-200);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 80px;
  transition: var(--transition);
}

.disease-panel.has-content { border-color: var(--teal); }

.disease-panel-empty {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--gray-400);
  text-align: center;
  gap: 12px;
  padding: 40px 20px;
}

.disease-panel-empty-icon { opacity: 0.4; }
.disease-panel-empty-icon svg { width: 48px; height: 48px; color: var(--gray-300); }

.disease-panel-content { display: none; animation: screenIn 0.3s ease; }
.disease-panel-content.active { display: block; }

.disease-panel-icon { margin-bottom: 14px; }
.disease-panel-icon svg { width: 44px; height: 44px; color: var(--teal-dark); }

.disease-panel-title {
  font-family: 'Oswald', sans-serif;
  font-size: 22px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 3px;
  letter-spacing: 0.02em;
}

.disease-panel-type { font-size: 11px; color: var(--teal-dark); font-weight: 500; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 18px; }

.disease-info-row { margin-bottom: 14px; }
.disease-info-label { font-family: 'Oswald', sans-serif; font-size: 10px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--gray-400); margin-bottom: 4px; }
.disease-info-text { font-size: 13px; color: var(--gray-700); line-height: 1.65; font-weight: 300; }

/* =============================================
   SCREEN 3 — HOMEOSTASIS
   ============================================= */
.body-system-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-bottom: 24px; }

.body-system-card {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 22px;
  cursor: pointer;
  transition: var(--transition);
}

.body-system-card:hover { border-color: var(--teal); transform: translateY(-2px); box-shadow: var(--shadow); }
.body-system-card.active { border-color: var(--teal); box-shadow: var(--shadow); }

.body-system-header { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }

.body-system-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.body-system-icon svg { width: 26px; height: 26px; }

.body-system-name {
  font-family: 'Oswald', sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}

.body-system-organs { font-size: 11px; color: var(--gray-400); margin-top: 2px; font-weight: 300; }

.cause-effect-chain { display: flex; flex-direction: column; gap: 6px; }

.chain-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 9px 12px;
  border-radius: var(--radius-xs);
  background: var(--gray-50);
  font-size: 12px;
  color: var(--gray-700);
  border-left: 3px solid transparent;
  font-weight: 400;
  line-height: 1.4;
}

.chain-num {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Oswald', sans-serif;
  font-size: 10px;
  font-weight: 600;
  flex-shrink: 0;
  color: white;
  margin-top: 1px;
}

.chain-arrow { text-align: center; color: var(--teal); font-size: 14px; margin: -3px 0; font-weight: 300; }

.system-detail-panel {
  background: var(--white);
  border: 1.5px solid var(--teal);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-top: 8px;
  animation: screenIn 0.3s ease;
}

/* =============================================
   SCREEN 4 — ETIOLOGY
   ============================================= */
.etiology-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 24px; }

.etio-card {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 20px 16px;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.etio-card:hover { border-color: var(--teal); transform: translateY(-2px); box-shadow: var(--shadow); }
.etio-card.active { border-color: var(--teal); background: var(--teal-soft); box-shadow: var(--shadow); }

.etio-icon {
  width: 48px;
  height: 48px;
  background: var(--teal-soft);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 10px;
}

.etio-icon svg { width: 24px; height: 24px; color: var(--teal-dark); }
.etio-card.active .etio-icon { background: rgba(102,198,190,0.25); }

.etio-name {
  font-family: 'Oswald', sans-serif;
  font-size: 13px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 3px;
  letter-spacing: 0.02em;
}

.etio-hint { font-size: 11px; color: var(--gray-400); font-weight: 300; }

.etio-detail-panel {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1.5px solid var(--teal);
  padding: 28px;
  animation: screenIn 0.3s ease;
  margin-bottom: 24px;
}

/* Match Activity */
.match-activity {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.match-pairs { display: flex; flex-direction: column; gap: 10px; margin-top: 14px; }

.match-pair { display: grid; grid-template-columns: 1fr auto 1fr; gap: 12px; align-items: center; }

.match-cause, .match-disease {
  padding: 10px 14px;
  border-radius: var(--radius-xs);
  border: 1.5px solid var(--gray-200);
  font-size: 13px;
  font-weight: 400;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  background: var(--white);
  color: var(--charcoal);
}

.match-cause:hover, .match-disease:hover { border-color: var(--teal); background: var(--teal-soft); }
.match-cause.selected { border-color: var(--teal); background: var(--teal-soft); color: var(--teal-dark); }
.match-disease.selected { border-color: var(--navy); background: #eef2f9; color: var(--navy); }
.match-cause.correct, .match-disease.correct { border-color: var(--green); background: var(--green-light); color: #276749; }
.match-cause.incorrect, .match-disease.incorrect { border-color: var(--red); background: var(--red-light); color: #c53030; }

.match-arrow { color: var(--gray-300); font-size: 16px; text-align: center; }

/* =============================================
   SCREEN 5 — SIGNS VS SYMPTOMS
   ============================================= */
.sort-instruction {
  background: var(--navy);
  color: white;
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.sort-instruction-icon { flex-shrink: 0; }
.sort-instruction-icon svg { width: 28px; height: 28px; color: var(--teal); }
.sort-instruction-text { font-size: 14px; line-height: 1.65; color: rgba(255,255,255,0.85); font-weight: 300; }
.sort-instruction-text strong { font-family: 'Oswald', sans-serif; font-size: 15px; font-weight: 600; display: block; margin-bottom: 4px; color: white; letter-spacing: 0.02em; }

.sort-items-bank {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
  min-height: 60px;
  padding: 16px;
  border: 1.5px dashed var(--gray-300);
  border-radius: var(--radius);
  background: var(--gray-50);
}

.sort-item {
  padding: 9px 16px;
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-xs);
  font-size: 13px;
  font-weight: 500;
  color: var(--charcoal);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
  user-select: none;
}

.sort-item:hover { border-color: var(--teal); transform: translateY(-1px); box-shadow: var(--shadow-sm); }
.sort-item.used { opacity: 0.3; cursor: default; pointer-events: none; }

.sort-zones { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 24px; }

.sort-zone {
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 20px;
  min-height: 200px;
  background: var(--white);
}

.sort-zone.sign-zone { border-color: var(--blue); }
.sort-zone.symptom-zone { border-color: var(--purple); }

.sort-zone-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--gray-200);
}

.sort-zone-icon svg { width: 22px; height: 22px; }

.sort-zone-title {
  font-family: 'Oswald', sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}

.sort-zone-subtitle { font-size: 11px; color: var(--gray-400); margin-top: 1px; font-weight: 300; }

.sort-zone-items { display: flex; flex-direction: column; gap: 8px; min-height: 100px; }

.sorted-item {
  padding: 9px 12px;
  border-radius: var(--radius-xs);
  font-size: 12px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
  animation: screenIn 0.2s ease;
}

.sorted-item.correct  { background: var(--green-light); color: #276749; border: 1px solid var(--green-border); }
.sorted-item.incorrect { background: var(--red-light); color: #c53030; border: 1px solid var(--red-border); }
.sorted-item.neutral  { background: var(--gray-100); color: var(--gray-700); border: 1px solid var(--gray-200); }

.sort-feedback {
  display: none;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.65;
  animation: screenIn 0.3s ease;
  font-weight: 300;
}

.sort-feedback.show { display: block; }
.sort-feedback.correct-fb { background: var(--green-light); border: 1px solid var(--green-border); color: #22543d; }
.sort-feedback.incorrect-fb { background: var(--red-light); border: 1px solid var(--red-border); color: #742a2a; }

/* =============================================
   SCREEN 6 — CELL GROWTH
   ============================================= */
.cell-cards-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 24px; }

.cell-card {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 20px 16px;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cell-card::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--teal), var(--teal-light));
  opacity: 0;
  transition: var(--transition);
}

.cell-card:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: var(--teal); }
.cell-card:hover::after { opacity: 1; }
.cell-card.active { border-color: var(--teal); box-shadow: var(--shadow); }
.cell-card.active::after { opacity: 1; }

.cell-card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 10px;
}

.cell-card-icon svg { width: 22px; height: 22px; }

.cell-card-name {
  font-family: 'Oswald', sans-serif;
  font-size: 13px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 3px;
  letter-spacing: 0.02em;
}

.cell-card-prefix { font-size: 11px; color: var(--gray-400); font-weight: 300; }

.cell-detail {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1.5px solid var(--teal);
  padding: 28px;
  margin-bottom: 24px;
  animation: screenIn 0.3s ease;
}

/* Quiz Block */
.quiz-quick {
  background: var(--navy);
  border-radius: var(--radius-lg);
  padding: 28px;
  color: white;
}

.quiz-quick-q {
  font-family: 'Oswald', sans-serif;
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 20px;
  line-height: 1.4;
  letter-spacing: 0.01em;
}

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

.quiz-opt {
  padding: 12px 16px;
  border-radius: var(--radius-xs);
  background: rgba(255,255,255,0.07);
  border: 1.5px solid rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.8);
  font-size: 13px;
  font-weight: 400;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 12px;
}

.quiz-opt:hover { background: rgba(255,255,255,0.12); border-color: rgba(102,198,190,0.5); color: white; }
.quiz-opt.correct-opt { background: rgba(56,161,105,0.2); border-color: var(--green); color: #9ae6b4; }
.quiz-opt.incorrect-opt { background: rgba(229,62,62,0.2); border-color: var(--red); color: rgba(255,255,255,0.6); }
.quiz-opt.disabled { cursor: default; }

.quiz-opt-letter {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: rgba(255,255,255,0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Oswald', sans-serif;
  font-size: 12px;
  font-weight: 600;
  flex-shrink: 0;
}

.quiz-feedback-box {
  display: none;
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: var(--radius-xs);
  font-size: 13px;
  line-height: 1.65;
  animation: screenIn 0.3s ease;
  font-weight: 300;
}

.quiz-feedback-box.show { display: block; }
.quiz-feedback-box.correct-fb { background: rgba(56,161,105,0.15); border: 1px solid rgba(56,161,105,0.4); color: #9ae6b4; }
.quiz-feedback-box.incorrect-fb { background: rgba(229,62,62,0.15); border: 1px solid rgba(229,62,62,0.4); color: #feb2b2; }

/* =============================================
   CASE STUDY SCREENS
   ============================================= */
.case-header {
  background: linear-gradient(135deg, var(--navy), var(--navy-mid));
  color: white;
  border-radius: var(--radius-lg);
  padding: 26px 30px;
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 24px;
}

.case-avatar {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  background: rgba(102,198,190,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  border: 2px solid rgba(102,198,190,0.4);
}

.case-avatar svg { width: 36px; height: 36px; color: var(--teal); }

.case-patient-name {
  font-family: 'Oswald', sans-serif;
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 4px;
  letter-spacing: 0.02em;
}

.case-patient-info { font-size: 13px; color: rgba(255,255,255,0.7); font-weight: 300; }

.case-steps { display: flex; gap: 0; margin-bottom: 22px; overflow-x: auto; padding-bottom: 4px; }

.case-step-pill { display: flex; align-items: center; }

.case-step-btn {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 9px 14px;
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-full);
  font-family: 'Oswald', sans-serif;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--gray-400);
  cursor: default;
  white-space: nowrap;
}

.case-step-btn.completed { border-color: var(--teal); color: var(--teal-dark); background: var(--teal-soft); }
.case-step-btn.active    { border-color: var(--navy); color: white; background: var(--navy); }

.case-step-connector { width: 24px; height: 2px; background: var(--gray-200); flex-shrink: 0; }
.case-step-connector.done { background: var(--teal); }

.case-stage { display: none; animation: screenIn 0.3s ease; }
.case-stage.active { display: block; }

.case-stage-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  padding: 26px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 18px;
}

.case-question {
  font-family: 'Oswald', sans-serif;
  font-size: 17px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 16px;
  line-height: 1.4;
  letter-spacing: 0.01em;
}

.case-choices { display: flex; flex-direction: column; gap: 10px; }

.case-choice {
  padding: 13px 16px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-xs);
  font-size: 13px;
  font-weight: 400;
  color: var(--charcoal);
  cursor: pointer;
  transition: var(--transition);
  background: var(--white);
  text-align: left;
  display: flex;
  align-items: center;
  gap: 12px;
}

.case-choice:hover { border-color: var(--teal); background: var(--teal-soft); color: var(--teal-dark); }
.case-choice.correct-choice  { border-color: var(--green); background: var(--green-light); color: #276749; pointer-events: none; }
.case-choice.incorrect-choice { border-color: var(--red); background: var(--red-light); color: #c53030; pointer-events: none; }
.case-choice.disabled { pointer-events: none; opacity: 0.5; }

.case-choice-letter {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 1.5px solid currentColor;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Oswald', sans-serif;
  font-size: 12px;
  font-weight: 600;
  flex-shrink: 0;
}

.case-feedback {
  display: none;
  padding: 14px 18px;
  border-radius: var(--radius-xs);
  font-size: 13px;
  line-height: 1.7;
  animation: screenIn 0.3s ease;
  font-weight: 300;
}

.case-feedback.show     { display: block; }
.case-feedback.correct-fb  { background: var(--green-light); border-left: 4px solid var(--green); color: #22543d; }
.case-feedback.incorrect-fb { background: var(--red-light); border-left: 4px solid var(--red); color: #742a2a; }
.case-feedback.info-fb  { background: var(--teal-soft); border-left: 4px solid var(--teal); color: var(--teal-dark); }

/* =============================================
   SCREEN 8 — TIMELINE (CASE 2)
   ============================================= */
.timeline-layout { display: grid; grid-template-columns: 260px 1fr; gap: 24px; }

.timeline-nav { display: flex; flex-direction: column; gap: 0; }

.timeline-step-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: var(--white);
  border: none;
  border-left: 3px solid var(--gray-200);
  text-align: left;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.timeline-step-btn::before {
  content: '';
  position: absolute;
  left: -7px;
  top: 50%;
  transform: translateY(-50%);
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gray-300);
  border: 2px solid var(--white);
  box-shadow: var(--shadow-xs);
  transition: var(--transition);
}

.timeline-step-btn.completed { border-left-color: var(--teal); }
.timeline-step-btn.completed::before { background: var(--teal); }
.timeline-step-btn.active { border-left-color: var(--navy); background: var(--gray-50); }
.timeline-step-btn.active::before { background: var(--navy); width: 14px; height: 14px; left: -9px; }

.timeline-step-num { font-family: 'Oswald', sans-serif; font-size: 10px; font-weight: 500; color: var(--gray-400); text-transform: uppercase; letter-spacing: 0.08em; }
.timeline-step-title { font-family: 'Oswald', sans-serif; font-size: 13px; font-weight: 600; color: var(--navy); margin-top: 2px; letter-spacing: 0.02em; }

.timeline-content {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.timeline-stage { display: none; animation: screenIn 0.3s ease; }
.timeline-stage.active { display: block; }

.timeline-stage-icon { margin-bottom: 12px; }
.timeline-stage-icon svg { width: 44px; height: 44px; color: var(--teal-dark); }

.timeline-stage-title {
  font-family: 'Oswald', sans-serif;
  font-size: 22px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 8px;
  letter-spacing: 0.02em;
}

.timeline-stage-body { font-size: 14px; color: var(--gray-600); line-height: 1.75; margin-bottom: 20px; font-weight: 300; }

.timeline-questions { display: flex; flex-direction: column; gap: 16px; }

.timeline-q {
  background: var(--gray-50);
  border-radius: var(--radius-xs);
  padding: 16px 18px;
  border-left: 4px solid var(--teal);
}

.timeline-q-text {
  font-family: 'Oswald', sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 10px;
  letter-spacing: 0.01em;
}

.timeline-q-choices { display: flex; flex-direction: column; gap: 8px; }

.timeline-q-choice {
  padding: 10px 14px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-xs);
  font-size: 13px;
  background: var(--white);
  cursor: pointer;
  transition: var(--transition);
  font-weight: 400;
  color: var(--charcoal);
}

.timeline-q-choice:hover { border-color: var(--teal); background: var(--teal-soft); }
.timeline-q-choice.correct-choice  { border-color: var(--green); background: var(--green-light); color: #276749; pointer-events: none; }
.timeline-q-choice.incorrect-choice { border-color: var(--red); background: var(--red-light); color: #c53030; pointer-events: none; }
.timeline-q-choice.disabled { pointer-events: none; opacity: 0.5; }

/* =============================================
   SCREEN 9 — IMMUNITY
   ============================================= */
.immunity-cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-bottom: 24px; }

.immunity-card {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  min-height: 220px;
}

.immunity-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.immunity-card.flipped { border-color: var(--teal); box-shadow: var(--shadow-md); }

.immunity-card-front { }
.immunity-card-back  { display: none; animation: screenIn 0.3s ease; }
.immunity-card.flipped .immunity-card-front { display: none; }
.immunity-card.flipped .immunity-card-back  { display: block; }

.immunity-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}

.immunity-card-icon svg { width: 26px; height: 26px; }

.immunity-card-type {
  font-family: 'Oswald', sans-serif;
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.10em;
  color: var(--gray-400);
  margin-bottom: 4px;
}

.immunity-card-title {
  font-family: 'Oswald', sans-serif;
  font-size: 20px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 8px;
  letter-spacing: 0.02em;
}

.immunity-card-teaser { font-size: 13px; color: var(--gray-500); line-height: 1.6; font-weight: 300; }

.immunity-flip-hint {
  font-size: 11px;
  color: var(--teal-dark);
  font-weight: 500;
  margin-top: 14px;
  display: flex;
  align-items: center;
  gap: 5px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-family: 'Oswald', sans-serif;
}

.immunity-flip-hint svg { width: 14px; height: 14px; }

.immunity-card-back-title {
  font-family: 'Oswald', sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 8px;
  letter-spacing: 0.02em;
}

.immunity-card-back-def { font-size: 13px; color: var(--gray-600); line-height: 1.7; margin-bottom: 12px; font-weight: 300; }
.immunity-card-back-example {
  font-size: 12px;
  background: var(--teal-soft);
  padding: 10px 12px;
  border-radius: var(--radius-xs);
  color: var(--teal-dark);
  line-height: 1.6;
  border-left: 3px solid var(--teal);
  font-weight: 400;
}

/* Immunity Matching */
.immunity-match {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.immunity-match-questions { display: flex; flex-direction: column; gap: 14px; margin-top: 16px; }

.immunity-match-q {
  background: var(--gray-50);
  border-radius: var(--radius-xs);
  padding: 16px;
  border-left: 4px solid var(--teal);
}

.immunity-match-q-text {
  font-family: 'Oswald', sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 10px;
  letter-spacing: 0.01em;
}

.immunity-match-options { display: flex; flex-wrap: wrap; gap: 8px; }

.immunity-match-opt {
  padding: 8px 14px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-xs);
  font-size: 12px;
  font-weight: 400;
  background: var(--white);
  cursor: pointer;
  transition: var(--transition);
  color: var(--charcoal);
}

.immunity-match-opt:hover { border-color: var(--teal); background: var(--teal-soft); }
.immunity-match-opt.correct-opt  { border-color: var(--green); background: var(--green-light); color: #276749; pointer-events: none; }
.immunity-match-opt.incorrect-opt { border-color: var(--red); background: var(--red-light); color: #c53030; pointer-events: none; }
.immunity-match-opt.disabled { pointer-events: none; opacity: 0.4; }

/* =============================================
   SCREEN 10 — PATHOLOGY WORKFLOW
   ============================================= */
.path-workflow { display: flex; align-items: stretch; gap: 0; margin-bottom: 28px; overflow-x: auto; }

.path-step {
  flex: 1;
  min-width: 150px;
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 22px 16px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  margin-right: 24px;
}

.path-step:last-child { margin-right: 0; }

.path-step:not(:last-child)::after {
  content: '';
  position: absolute;
  right: -20px;
  top: 50%;
  transform: translateY(-50%);
  width: 0;
  height: 0;
  border-top: 8px solid transparent;
  border-bottom: 8px solid transparent;
  border-left: 12px solid var(--teal);
  z-index: 1;
}

.path-step:hover { border-color: var(--teal); transform: translateY(-2px); box-shadow: var(--shadow); }
.path-step.active { border-color: var(--teal); background: var(--teal-soft); box-shadow: var(--shadow); }

.path-step-num {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--teal);
  color: var(--navy);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Oswald', sans-serif;
  font-size: 13px;
  font-weight: 700;
  margin: 0 auto 10px;
}

.path-step.active .path-step-num { background: var(--navy); color: white; }

.path-step-icon { margin-bottom: 8px; }
.path-step-icon svg { width: 28px; height: 28px; color: var(--teal-dark); }

.path-step-name {
  font-family: 'Oswald', sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}

.path-step-sub { font-size: 11px; color: var(--gray-400); margin-top: 2px; font-weight: 300; }

.path-detail {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1.5px solid var(--teal);
  padding: 28px;
  margin-bottom: 24px;
  animation: screenIn 0.3s ease;
}

/* =============================================
   SCREEN 11 — TREATMENT
   ============================================= */
.treatment-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }

.treatment-cats { display: flex; flex-direction: column; gap: 10px; }

.treatment-cat-btn {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 16px 18px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 14px;
  text-align: left;
}

.treatment-cat-btn:hover { border-color: var(--teal); transform: translateX(2px); box-shadow: var(--shadow-sm); }
.treatment-cat-btn.active { border-color: var(--teal); background: var(--teal-soft); }

.treatment-cat-icon {
  width: 44px;
  height: 44px;
  background: var(--gray-100);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.treatment-cat-icon svg { width: 22px; height: 22px; color: var(--teal-dark); }
.treatment-cat-btn.active .treatment-cat-icon { background: rgba(102,198,190,0.2); }

.treatment-cat-name {
  font-family: 'Oswald', sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}

.treatment-cat-sub { font-size: 12px; color: var(--gray-400); margin-top: 2px; font-weight: 300; }

.treatment-detail {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  min-height: 300px;
}

.disease-selector-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }

.disease-pill {
  padding: 7px 14px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 400;
  cursor: pointer;
  transition: var(--transition);
  background: var(--white);
  color: var(--charcoal);
}

.disease-pill:hover { border-color: var(--teal); background: var(--teal-soft); }
.disease-pill.active { border-color: var(--navy); background: var(--navy); color: white; }

/* =============================================
   SCREEN 12 — PREVENTION
   ============================================= */
.prevention-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 24px; }

.prevention-card {
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 20px 16px;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.prevention-card:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: var(--teal); }
.prevention-card.active { border-color: var(--teal); background: var(--teal-soft); }

.prevention-card-icon {
  width: 44px;
  height: 44px;
  background: var(--teal-soft);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 10px;
}

.prevention-card-icon svg { width: 22px; height: 22px; color: var(--teal-dark); }
.prevention-card.active .prevention-card-icon { background: rgba(102,198,190,0.25); }

.prevention-card-name {
  font-family: 'Oswald', sans-serif;
  font-size: 13px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 3px;
  letter-spacing: 0.02em;
}

.prevention-card-sub { font-size: 11px; color: var(--gray-400); font-weight: 300; }

.prevention-detail {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1.5px solid var(--teal);
  padding: 24px;
  margin-bottom: 24px;
  animation: screenIn 0.3s ease;
}

.outbreak-scenario {
  background: var(--navy);
  color: white;
  border-radius: var(--radius-lg);
  padding: 28px;
}

.outbreak-scenario h3 {
  font-family: 'Oswald', sans-serif;
  color: white;
  font-size: 20px;
  margin-bottom: 10px;
  letter-spacing: 0.02em;
}

/* =============================================
   SCREEN 13 — ASSESSMENT
   ============================================= */
.quiz-progress-bar {
  background: var(--gray-200);
  height: 6px;
  border-radius: var(--radius-full);
  margin-bottom: 24px;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--teal-dark), var(--teal));
  border-radius: var(--radius-full);
  transition: width 0.5s ease;
}

.quiz-q-counter { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; }
.quiz-q-num { font-family: 'Oswald', sans-serif; font-size: 13px; font-weight: 600; color: var(--teal-dark); text-transform: uppercase; letter-spacing: 0.08em; }
.quiz-score-live { font-size: 13px; color: var(--gray-500); font-weight: 400; }

.quiz-question-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 18px;
}

.quiz-category-tag { font-family: 'Oswald', sans-serif; font-size: 10px; font-weight: 600; text-transform: uppercase; color: var(--teal-dark); letter-spacing: 0.10em; margin-bottom: 10px; }

.quiz-q-text { font-family: 'Oswald', sans-serif; font-size: 19px; font-weight: 600; color: var(--navy); line-height: 1.4; margin-bottom: 20px; letter-spacing: 0.01em; }

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

.quiz-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 16px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: var(--transition);
  background: var(--white);
  font-size: 13px;
  font-weight: 400;
  color: var(--charcoal);
}

.quiz-option:hover  { border-color: var(--teal); background: var(--teal-soft); color: var(--teal-dark); }
.quiz-option.selected { border-color: var(--teal); background: var(--teal-soft); color: var(--teal-dark); }
.quiz-option.correct  { border-color: var(--green); background: var(--green-light); color: #276749; pointer-events: none; }
.quiz-option.incorrect { border-color: var(--red); background: var(--red-light); color: #c53030; pointer-events: none; }
.quiz-option.disabled { pointer-events: none; opacity: 0.5; }

.quiz-opt-key {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1.5px solid currentColor;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Oswald', sans-serif;
  font-size: 12px;
  font-weight: 600;
  flex-shrink: 0;
}

.quiz-rationale {
  display: none;
  background: var(--gray-50);
  border-radius: var(--radius-xs);
  padding: 14px 16px;
  border-left: 4px solid var(--teal);
  font-size: 13px;
  color: var(--gray-700);
  line-height: 1.7;
  animation: screenIn 0.3s ease;
  font-weight: 300;
  margin-top: 14px;
}

.quiz-rationale.show { display: block; }

/* =============================================
   SCREEN 14 — COMPLETION
   ============================================= */
.completion-hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 50%, #1a4a6e 100%);
  border-radius: var(--radius-xl);
  padding: 56px 40px;
  text-align: center;
  color: white;
  margin-bottom: 32px;
  position: relative;
  overflow: hidden;
}

.completion-badge {
  width: 96px;
  height: 96px;
  background: rgba(102,198,190,0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  border: 3px solid rgba(102,198,190,0.4);
  animation: badgePop 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) both;
}

.completion-badge svg { width: 48px; height: 48px; color: var(--teal); }

@keyframes badgePop {
  from { transform: scale(0) rotate(-20deg); opacity: 0; }
  to   { transform: scale(1) rotate(0); opacity: 1; }
}

.completion-title { font-family: 'Oswald', sans-serif; font-size: 36px; font-weight: 700; margin-bottom: 8px; letter-spacing: 0.02em; }
.completion-subtitle { font-size: 15px; color: rgba(255,255,255,0.7); margin-bottom: 28px; font-weight: 300; }
.score-display { font-family: 'Oswald', sans-serif; font-size: 64px; font-weight: 700; color: var(--teal); margin-bottom: 6px; line-height: 1; }
.score-label { font-size: 13px; color: rgba(255,255,255,0.6); letter-spacing: 0.06em; text-transform: uppercase; font-family: 'Oswald', sans-serif; font-weight: 500; }

.completion-stats { display: flex; justify-content: center; gap: 48px; margin-top: 28px; }
.completion-stat { text-align: center; }
.completion-stat-num { font-family: 'Oswald', sans-serif; font-size: 28px; font-weight: 700; color: white; }
.completion-stat-label { font-size: 11px; color: rgba(255,255,255,0.55); margin-top: 2px; text-transform: uppercase; letter-spacing: 0.08em; font-family: 'Oswald', sans-serif; font-weight: 500; }

.takeaways-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-bottom: 28px; }

.takeaway-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 20px;
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-xs);
  border-top: 3px solid var(--teal);
}

.takeaway-icon {
  width: 36px;
  height: 36px;
  background: var(--teal-soft);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
}

.takeaway-icon svg { width: 18px; height: 18px; color: var(--teal-dark); }
.takeaway-title { font-family: 'Oswald', sans-serif; font-size: 14px; font-weight: 600; color: var(--navy); margin-bottom: 4px; letter-spacing: 0.02em; }
.takeaway-text { font-size: 12px; color: var(--gray-500); line-height: 1.55; font-weight: 300; }

/* =============================================
   UTILITY
   ============================================= */
.hidden { display: none !important; }
.text-teal  { color: var(--teal-dark); }
.text-navy  { color: var(--navy); }
.text-gray  { color: var(--gray-600); }
.font-oswald { font-family: 'Oswald', sans-serif; }
.mb-4 { margin-bottom: 16px; }
.mb-6 { margin-bottom: 24px; }

/* =============================================
   SCROLLBAR
   ============================================= */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: var(--gray-100); }
::-webkit-scrollbar-thumb { background: var(--gray-300); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--teal); }

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 1024px) {
  .main-content { padding: 28px 24px; }
  .disease-map-layout { grid-template-columns: 1fr; }
  .welcome-hero { grid-template-columns: 1fr; }
  .welcome-graphic { display: none; }
}

/* =============================================
   SCREEN 0 v2 — WELCOME REDESIGN  (w2-*)
   ============================================= */

/* Hero Banner */
.w2-hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 52%, #1e4a6e 100%);
  border-radius: var(--radius-xl);
  padding: 56px 52px;
  color: white;
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 48px;
  align-items: center;
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}
.w2-hero::before {
  content:''; position:absolute; top:-90px; right:-90px;
  width:320px; height:320px; background:rgba(102,198,190,0.05);
  border-radius:50%;
}
.w2-hero::after {
  content:''; position:absolute; bottom:-60px; left:30%;
  width:180px; height:180px; background:rgba(102,198,190,0.04);
  border-radius:50%;
}

/* Badge pill */
.w2-badge {
  display:inline-flex; align-items:center; gap:7px;
  background:rgba(102,198,190,0.14); border:1px solid rgba(102,198,190,0.30);
  padding:5px 13px; border-radius:var(--radius-full);
  font-size:11px; font-weight:500; font-family:'Oswald',sans-serif;
  letter-spacing:0.08em; text-transform:uppercase; color:var(--teal-light);
  margin-bottom:22px;
}

/* Heading */
.w2-h1 {
  font-family:'Oswald',sans-serif; font-size:44px; font-weight:700;
  line-height:1.06; margin-bottom:18px; color:#fff; letter-spacing:0.02em;
}
.w2-h1-accent { color:var(--teal); }

/* Description */
.w2-desc {
  font-size:14px; line-height:1.78; color:rgba(255,255,255,0.70);
  margin-bottom:28px; max-width:490px; font-weight:300;
}

/* Stats strip */
.w2-stats {
  display:flex; align-items:center; gap:0;
  background:rgba(255,255,255,0.06); border:1px solid rgba(255,255,255,0.10);
  border-radius:var(--radius-sm); padding:14px 20px;
  margin-bottom:30px; flex-wrap:wrap;
}
.w2-stat { display:flex; align-items:center; gap:10px; padding:0 18px; flex:1; min-width:100px; }
.w2-stat:first-child { padding-left:0; }
.w2-stat:last-child  { padding-right:0; }
.w2-stat-divider { width:1px; height:36px; background:rgba(255,255,255,0.14); flex-shrink:0; }
.w2-stat-icon {
  width:32px; height:32px; background:rgba(102,198,190,0.16);
  border-radius:var(--radius-xs); display:flex; align-items:center; justify-content:center; flex-shrink:0;
}
.w2-stat-icon svg { width:16px; height:16px; color:var(--teal); }
.w2-stat-val { font-family:'Oswald',sans-serif; font-size:16px; font-weight:700; color:#fff; line-height:1.2; }
.w2-stat-lbl { font-size:10px; color:rgba(255,255,255,0.50); text-transform:uppercase; letter-spacing:0.06em; font-weight:400; }

/* CTA row */
.w2-cta-row { display:flex; align-items:center; gap:18px; flex-wrap:wrap; }
.w2-start-btn {
  padding:14px 32px !important; font-size:15px !important;
  border-radius:var(--radius-full) !important; letter-spacing:0.04em;
}
.w2-cta-note {
  display:flex; align-items:center; gap:6px;
  font-size:12px; color:rgba(255,255,255,0.52); font-weight:300;
}
.w2-cta-note svg { color:var(--teal-light); }

/* Hero Visual (right panel) */
.w2-hero-visual {
  position:relative; width:100%; height:300px;
  display:flex; align-items:center; justify-content:center;
  z-index:1;
}
.w2-ring {
  position:absolute; border-radius:50%;
  border:1px solid rgba(102,198,190,0.20);
  animation:ringPulse 3s ease-in-out infinite;
}
.w2-ring-1 { width:270px; height:270px; animation-delay:0s; }
.w2-ring-2 { width:200px; height:200px; animation-delay:0.7s; border-color:rgba(102,198,190,0.30); }
.w2-ring-3 { width:130px; height:130px; animation-delay:1.4s; border-color:rgba(102,198,190,0.45); }
.w2-center-icon {
  position:relative; z-index:2;
  width:88px; height:88px;
  background:rgba(102,198,190,0.14); border-radius:50%;
  border:2px solid rgba(102,198,190,0.38);
  display:flex; align-items:center; justify-content:center;
  animation:float 4s ease-in-out infinite;
  color:var(--teal);
}

/* Floating chips */
.w2-chip {
  position:absolute; display:flex; align-items:center; gap:5px;
  background:rgba(255,255,255,0.08); border:1px solid rgba(255,255,255,0.14);
  padding:5px 11px; border-radius:var(--radius-full);
  font-size:11px; font-weight:500; color:rgba(255,255,255,0.75);
  font-family:'Oswald',sans-serif; letter-spacing:0.04em;
  text-transform:uppercase; backdrop-filter:blur(4px);
  animation:float 4s ease-in-out infinite;
}
.w2-chip svg { color:var(--teal-light); flex-shrink:0; }
.w2-chip-1 { top:18px;  left:10px;  animation-delay:0s; }
.w2-chip-2 { top:18px;  right:10px; animation-delay:0.8s; }
.w2-chip-3 { bottom:40px; left:4px;  animation-delay:1.6s; }
.w2-chip-4 { bottom:40px; right:4px; animation-delay:2.4s; }

/* Section heading */
.w2-section-head { margin-bottom:20px; }
.w2-section-eyebrow {
  font-family:'Oswald',sans-serif; font-size:11px; font-weight:500;
  letter-spacing:0.10em; text-transform:uppercase; color:var(--teal-dark);
  margin-bottom:4px;
}
.w2-section-title {
  font-family:'Oswald',sans-serif; font-size:22px; font-weight:700;
  color:var(--navy); letter-spacing:0.01em; margin-bottom:4px;
}
.w2-section-sub { font-size:13px; color:var(--gray-500); font-weight:300; }

/* Objectives Grid */
.w2-obj-grid {
  display:grid; grid-template-columns:repeat(3, 1fr); gap:14px; margin-bottom:28px;
}
.w2-obj-card {
  background:var(--white); border:1.5px solid var(--gray-200);
  border-radius:var(--radius); padding:20px 18px;
  box-shadow:var(--shadow-xs); transition:var(--transition);
  cursor:pointer; position:relative; overflow:hidden;
}
.w2-obj-card::before {
  content:''; position:absolute; top:0; left:0; right:0; height:3px;
  background:var(--teal); border-radius:var(--radius) var(--radius) 0 0;
  transition:var(--transition);
}
.w2-obj-card:hover { transform:translateY(-3px); box-shadow:var(--shadow-md); }
.w2-obj-card:hover::before { background:var(--navy); }

.w2-obj-num {
  font-family:'Oswald',sans-serif; font-size:11px; font-weight:700;
  color:var(--gray-300); letter-spacing:0.08em; margin-bottom:10px;
}
.w2-obj-icon-wrap {
  width:40px; height:40px; border-radius:var(--radius-xs);
  display:flex; align-items:center; justify-content:center; margin-bottom:12px;
}
.w2-obj-icon-wrap svg { width:22px; height:22px; }
.w2-obj-teal   { background:var(--teal-soft);   color:var(--teal-dark); }
.w2-obj-navy   { background:#e8edf5;             color:var(--navy); }
.w2-obj-amber  { background:var(--amber-light);  color:var(--amber); }
.w2-obj-green  { background:var(--green-light);  color:var(--green); }
.w2-obj-purple { background:var(--purple-light); color:var(--purple); }
.w2-obj-name {
  font-family:'Oswald',sans-serif; font-size:14px; font-weight:700;
  color:var(--navy); margin-bottom:5px; letter-spacing:0.01em;
}
.w2-obj-desc { font-size:12px; color:var(--gray-500); line-height:1.55; font-weight:300; margin-bottom:10px; }
.w2-obj-pill {
  display:inline-block; padding:3px 8px;
  background:var(--teal-soft); border-radius:var(--radius-full);
  font-size:10px; font-weight:500; color:var(--teal-dark);
  font-family:'Oswald',sans-serif; letter-spacing:0.06em; text-transform:uppercase;
}

/* Tip/Why-this-matters strip */
.w2-tip-strip {
  display:flex; align-items:flex-start; gap:16px;
  background:linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 100%);
  border-radius:var(--radius); padding:22px 24px; color:#fff;
}
.w2-tip-icon {
  width:44px; height:44px; background:rgba(102,198,190,0.18); border-radius:var(--radius-xs);
  display:flex; align-items:center; justify-content:center; flex-shrink:0; color:var(--teal-light);
}
.w2-tip-label {
  font-family:'Oswald',sans-serif; font-size:13px; font-weight:700;
  letter-spacing:0.06em; text-transform:uppercase; color:var(--teal);
  margin-bottom:6px;
}
.w2-tip-text { font-size:13px; color:rgba(255,255,255,0.75); line-height:1.7; font-weight:300; }

/* =============================================
   SCREEN 9 v2 — IMMUNITY REDESIGN  (imm2-*)
   ============================================= */

/* Header Block */
.imm2-header {
  display:flex; align-items:flex-start; gap:18px; margin-bottom:24px;
  padding:24px; background:var(--white); border-radius:var(--radius-lg);
  border:1.5px solid var(--gray-200); box-shadow:var(--shadow-sm);
}
.imm2-header-icon {
  width:52px; height:52px; background:var(--teal-soft); border-radius:var(--radius-sm);
  display:flex; align-items:center; justify-content:center; flex-shrink:0; color:var(--teal-dark);
}
.imm2-header-icon svg { width:28px; height:28px; }
.imm2-eyebrow {
  font-family:'Oswald',sans-serif; font-size:11px; font-weight:500;
  text-transform:uppercase; letter-spacing:0.08em; color:var(--teal-dark); margin-bottom:4px;
}
.imm2-title {
  font-family:'Oswald',sans-serif; font-size:26px; font-weight:700;
  color:var(--navy); margin-bottom:6px; letter-spacing:0.01em;
}
.imm2-subtitle { font-size:13px; color:var(--gray-500); line-height:1.65; font-weight:300; }
.imm2-badge-group { display:flex; flex-direction:column; gap:6px; margin-left:auto; flex-shrink:0; }
.imm2-badge {
  display:inline-flex; align-items:center; justify-content:center;
  padding:5px 12px; border-radius:var(--radius-full);
  font-family:'Oswald',sans-serif; font-size:11px; font-weight:600;
  letter-spacing:0.06em; text-transform:uppercase; white-space:nowrap;
}
.imm2-badge-teal { background:var(--teal-soft); color:var(--teal-dark); }
.imm2-badge-navy { background:#e8edf5; color:var(--navy); }

/* Card Progress Tracker */
.imm2-tracker {
  display:flex; align-items:center; gap:14px; margin-bottom:20px;
  padding:12px 18px; background:var(--gray-50); border-radius:var(--radius-sm);
  border:1px solid var(--gray-200);
}
.imm2-tracker-label {
  font-family:'Oswald',sans-serif; font-size:12px; font-weight:600;
  text-transform:uppercase; letter-spacing:0.06em; color:var(--navy); flex-shrink:0;
}
.imm2-tracker-dots { display:flex; gap:8px; }
.imm2-dot {
  width:14px; height:14px; border-radius:50%;
  background:var(--gray-200); border:2px solid var(--gray-300);
  transition:var(--transition);
}
.imm2-dot.done {
  background:var(--teal); border-color:var(--teal-dark);
  box-shadow:0 0 0 3px rgba(102,198,190,0.25);
}
.imm2-tracker-hint { font-size:11px; color:var(--gray-400); font-weight:300; margin-left:auto; }

/* Flip Cards Grid */
.imm2-grid {
  display:grid; grid-template-columns:repeat(2, 1fr); gap:16px; margin-bottom:24px;
}
.imm2-card {
  background:var(--white); border:1.5px solid var(--gray-200);
  border-radius:var(--radius-lg); cursor:pointer;
  transition:var(--transition); overflow:hidden; position:relative;
  border-top:4px solid var(--imm-accent, var(--teal));
}
.imm2-card:hover { transform:translateY(-3px); box-shadow:var(--shadow-md); }
.imm2-card.imm2-flipped { border-color:var(--imm-accent, var(--teal)); box-shadow:var(--shadow-md); }
.imm2-card.imm2-flipped .imm2-card-front { display:none; }
.imm2-card.imm2-flipped .imm2-card-back  { display:block; animation:screenIn 0.28s ease; }
.imm2-card-front { padding:22px 22px 18px; }
.imm2-card-back  { display:none; padding:22px 22px 18px; }

.imm2-card-stripe {
  height:4px; width:100%; margin:-22px -22px 16px;
  width:calc(100% + 44px); background:var(--imm-accent, var(--teal)); opacity:0.12;
}
.imm2-card-type-badge {
  font-family:'Oswald',sans-serif; font-size:10px; font-weight:600;
  text-transform:uppercase; letter-spacing:0.10em; color:var(--gray-400); margin-bottom:12px;
}
.imm2-card-icon-wrap {
  width:52px; height:52px; border-radius:var(--radius-sm);
  background:var(--imm-soft, var(--teal-soft)); color:var(--imm-accent, var(--teal-dark));
  display:flex; align-items:center; justify-content:center; margin-bottom:14px;
}
.imm2-card-name {
  font-family:'Oswald',sans-serif; font-size:19px; font-weight:700;
  color:var(--navy); letter-spacing:0.01em; line-height:1.2; margin-bottom:8px;
}
.imm2-card-teaser { font-size:12px; color:var(--gray-500); line-height:1.6; font-weight:300; margin-bottom:12px; }
.imm2-card-keywords { display:flex; flex-wrap:wrap; gap:5px; margin-bottom:14px; }
.imm2-card-keywords span {
  padding:3px 9px; border-radius:var(--radius-full); font-size:10px; font-weight:500;
  background:var(--imm-soft, var(--teal-soft)); color:var(--imm-accent, var(--teal-dark));
  font-family:'Oswald',sans-serif; letter-spacing:0.04em; text-transform:uppercase;
}
.imm2-flip-cue {
  display:flex; align-items:center; gap:5px;
  font-size:11px; color:var(--imm-accent, var(--teal-dark)); font-weight:500;
  font-family:'Oswald',sans-serif; letter-spacing:0.06em; text-transform:uppercase;
}

/* Back side */
.imm2-back-title {
  font-family:'Oswald',sans-serif; font-size:16px; font-weight:700;
  color:var(--navy); margin-bottom:8px; letter-spacing:0.01em;
}
.imm2-back-def { font-size:12.5px; color:var(--gray-600); line-height:1.72; font-weight:300; margin-bottom:10px; }
.imm2-back-example {
  font-size:12px; background:var(--imm-soft, var(--teal-soft));
  padding:10px 12px; border-radius:var(--radius-xs); line-height:1.65;
  border-left:3px solid var(--imm-accent, var(--teal));
  color:var(--gray-700); margin-bottom:8px;
}
.imm2-example-label {
  display:flex; align-items:center; gap:5px;
  font-family:'Oswald',sans-serif; font-size:10px; font-weight:600;
  text-transform:uppercase; letter-spacing:0.08em;
  color:var(--imm-accent, var(--teal-dark)); margin-bottom:5px;
}
.imm2-back-tip {
  display:flex; align-items:flex-start; gap:6px; font-size:11.5px;
  color:var(--navy); font-weight:400; line-height:1.6;
  padding:8px 10px; background:#e8edf5; border-radius:var(--radius-xs);
}
.imm2-back-tip svg { color:var(--navy); flex-shrink:0; margin-top:2px; }

/* Comparison Table */
.imm2-compare {
  background:var(--white); border:1.5px solid var(--gray-200);
  border-radius:var(--radius-lg); padding:24px; margin-bottom:24px;
  box-shadow:var(--shadow-sm);
}
.imm2-compare-head { display:flex; align-items:flex-start; gap:14px; margin-bottom:18px; }
.imm2-compare-icon {
  width:40px; height:40px; background:var(--teal-soft); border-radius:var(--radius-xs);
  display:flex; align-items:center; justify-content:center; color:var(--teal-dark); flex-shrink:0;
}
.imm2-compare-title {
  font-family:'Oswald',sans-serif; font-size:16px; font-weight:700;
  color:var(--navy); letter-spacing:0.01em;
}
.imm2-compare-sub { font-size:12px; color:var(--gray-500); font-weight:300; }
.imm2-table { border-radius:var(--radius-xs); overflow:hidden; border:1px solid var(--gray-200); }
.imm2-table-header {
  display:grid; grid-template-columns:1.4fr 1.2fr 1.4fr 1.4fr;
  background:var(--navy); color:#fff; padding:10px 14px;
  font-family:'Oswald',sans-serif; font-size:11px; font-weight:600;
  letter-spacing:0.06em; text-transform:uppercase; gap:10px;
}
.imm2-table-row {
  display:grid; grid-template-columns:1.4fr 1.2fr 1.4fr 1.4fr;
  padding:10px 14px; gap:10px; font-size:12.5px; font-weight:400;
  border-bottom:1px solid var(--gray-100);
}
.imm2-table-row:last-child { border-bottom:none; }
.imm2-row-green  { background:#fafffe; }
.imm2-row-blue   { background:#fafcff; }
.imm2-row-amber  { background:#fffdf5; }
.imm2-row-purple { background:#fdf9ff; }

/* Matching Activity */
.imm2-match {
  background:var(--white); border:1.5px solid var(--gray-200);
  border-radius:var(--radius-lg); padding:24px; margin-bottom:24px;
  box-shadow:var(--shadow-sm);
}
.imm2-match-header {
  display:flex; align-items:flex-start; gap:14px; margin-bottom:20px; flex-wrap:wrap;
}
.imm2-match-icon {
  width:40px; height:40px; background:var(--teal-soft); border-radius:var(--radius-xs);
  display:flex; align-items:center; justify-content:center; color:var(--teal-dark); flex-shrink:0;
}
.imm2-match-title {
  font-family:'Oswald',sans-serif; font-size:16px; font-weight:700;
  color:var(--navy); letter-spacing:0.01em;
}
.imm2-match-sub { font-size:12px; color:var(--gray-500); font-weight:300; }
.imm2-score-badge {
  display:flex; align-items:center; gap:6px; margin-left:auto;
  background:var(--teal-soft); border-radius:var(--radius-full);
  padding:6px 14px; font-family:'Oswald',sans-serif;
  font-size:13px; font-weight:700; color:var(--teal-dark); flex-shrink:0;
}

.imm2-questions { display:flex; flex-direction:column; gap:14px; }
.imm2-q-block {
  background:var(--gray-50); border-radius:var(--radius-sm);
  padding:16px 18px; border-left:4px solid var(--teal);
}
.imm2-q-num {
  display:inline-block; font-family:'Oswald',sans-serif; font-size:11px; font-weight:700;
  letter-spacing:0.08em; text-transform:uppercase; color:var(--teal-dark);
  background:var(--teal-soft); padding:2px 9px; border-radius:var(--radius-full);
  margin-bottom:8px;
}
.imm2-q-text {
  font-family:'Oswald',sans-serif; font-size:14px; font-weight:600;
  color:var(--navy); margin-bottom:10px; line-height:1.4;
}
.imm2-opts { display:flex; flex-wrap:wrap; gap:8px; }
.imm2-opt {
  padding:8px 16px; border:1.5px solid var(--gray-200); border-radius:var(--radius-full);
  font-size:12.5px; font-weight:400; background:var(--white); cursor:pointer;
  transition:var(--transition); color:var(--charcoal);
}
.imm2-opt:hover { border-color:var(--teal); background:var(--teal-soft); color:var(--teal-dark); }
.imm2-opt.correct-opt  { border-color:var(--green); background:var(--green-light); color:#276749; pointer-events:none; font-weight:500; }
.imm2-opt.incorrect-opt { border-color:var(--red); background:var(--red-light); color:#c53030; pointer-events:none; }
.imm2-opt.disabled { pointer-events:none; opacity:0.38; }

.imm2-feedback {
  font-size:12.5px; margin-top:8px; padding:8px 12px;
  border-radius:var(--radius-xs); font-weight:400; line-height:1.5;
  display:none;
}
.imm2-feedback.show { display:block; animation:screenIn 0.25s ease; }
.imm2-feedback.correct  { background:var(--green-light); color:#276749; border-left:3px solid var(--green); }
.imm2-feedback.incorrect { background:var(--red-light);   color:#c53030; border-left:3px solid var(--red); }

/* Key Takeaway */
.imm2-takeaway {
  display:flex; align-items:flex-start; gap:16px;
  background:linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 100%);
  border-radius:var(--radius); padding:22px 24px; color:#fff;
  margin-bottom:8px;
}
.imm2-takeaway-icon {
  width:44px; height:44px; background:rgba(102,198,190,0.18); border-radius:var(--radius-xs);
  display:flex; align-items:center; justify-content:center; flex-shrink:0; color:var(--teal-light);
}
.imm2-takeaway-label {
  font-family:'Oswald',sans-serif; font-size:13px; font-weight:700;
  letter-spacing:0.06em; text-transform:uppercase; color:var(--teal); margin-bottom:6px;
}
.imm2-takeaway-text { font-size:13px; color:rgba(255,255,255,0.75); line-height:1.72; font-weight:300; }

/* =============================================
   RESPONSIVE — updated for new screens
   ============================================= */
@media (max-width: 900px) {
  .sidebar { display: none; }
  .main-content { padding: 20px 16px; }
  .welcome-objectives { grid-template-columns: 1fr 1fr; }
  .w2-hero { grid-template-columns: 1fr; padding: 40px 32px; }
  .w2-hero-visual { display: none; }
  .w2-obj-grid { grid-template-columns: repeat(2, 1fr); }
  .imm2-grid { grid-template-columns: 1fr; }
  .imm2-table-header,
  .imm2-table-row { grid-template-columns: 1fr 1fr; }
  .imm2-table-header div:nth-child(n+3),
  .imm2-table-row  div:nth-child(n+3) { display: none; }
  .objectives-grid { grid-template-columns: 1fr; }
  .cell-cards-grid { grid-template-columns: repeat(2, 1fr); }
  .timeline-layout { grid-template-columns: 1fr; }
  .treatment-layout { grid-template-columns: 1fr; }
  .etiology-grid { grid-template-columns: repeat(2, 1fr); }
  .prevention-grid { grid-template-columns: repeat(2, 1fr); }
  .path-workflow { flex-direction: column; }
  .path-step { margin-right: 0; margin-bottom: 8px; }
  .path-step::after { display: none; }
  .takeaways-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 600px) {
  .welcome-objectives { grid-template-columns: 1fr; }
  .w2-obj-grid { grid-template-columns: 1fr; }
  .w2-stats { gap: 10px; }
  .w2-stat { padding: 0 8px; min-width: 80px; }
  .w2-h1 { font-size: 32px; }
  .imm2-header { flex-wrap: wrap; }
  .imm2-badge-group { flex-direction: row; }
  .imm2-grid { grid-template-columns: 1fr; }
  .disease-categories { grid-template-columns: 1fr; }
  .immunity-cards { grid-template-columns: 1fr; }
  .sort-zones { grid-template-columns: 1fr; }
  .body-system-grid { grid-template-columns: 1fr; }
  .cell-cards-grid { grid-template-columns: 1fr 1fr; }
  .prevention-grid { grid-template-columns: 1fr 1fr; }
  .nav-progress-track { display: none; }
  .welcome-h1 { font-size: 30px; }
  .screen-title { font-size: 22px; }
  .completion-stats { gap: 20px; }
}