/* ==========================================================================
   POČÍTAČOVÁ CHEMIE - PŘÍRODOVĚDECKÁ FAKULTA UNIVERZITY PALACKÉHO V OLOMOUCI
   Jednotný vizuální styl a moderní responsivní design
   ========================================================================== */

:root {
  /* UPOL Brand Colors */
  --up-blue-dark: #002855;
  --up-blue: #004990;
  --up-blue-light: #0077b6;
  --up-cyan: #00b4d8;
  --up-cyan-light: #90e0ef;
  --up-accent: #06d6a0;
  --up-orange: #f77f00;
  --up-red: #e63946;

  /* Neutrals (Light Mode) */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-glass: rgba(255, 255, 255, 0.85);
  --border-color: #e2e8f0;
  --border-subtle: #edf2f7;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-subtle: #64748b;
  --text-inverse: #ffffff;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 25px -3px rgba(0, 73, 144, 0.1), 0 4px 10px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 35px -5px rgba(0, 73, 144, 0.15), 0 8px 16px -6px rgba(0, 0, 0, 0.08);

  /* Fonts */
  --font-heading: 'Outfit', 'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #0a0f1d;
  --bg-secondary: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #273549;
  --bg-glass: rgba(15, 23, 42, 0.85);
  --border-color: #334155;
  --border-subtle: #1e293b;
  
  --text-main: #f8fafc;
  --text-muted: #cbd5e1;
  --text-subtle: #94a3b8;
  --text-inverse: #0f172a;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 35px -5px rgba(0, 0, 0, 0.6);
}

/* Reset & Base Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

p {
  margin-bottom: 1.15rem;
  color: var(--text-muted);
}

a {
  color: var(--up-blue-light);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--up-cyan);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Utility Containers */
.container {
  width: 100%;
  max-width: 1240px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.container-narrow {
  max-width: 900px;
}

.section {
  padding: 5.5rem 0;
  position: relative;
}

.section-alt {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

/* Section Header */
.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  display: inline-block;
  padding: 0.35rem 1rem;
  background: rgba(0, 180, 216, 0.12);
  color: var(--up-blue-light);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.85rem;
  border: 1px solid rgba(0, 180, 216, 0.25);
}

[data-theme="dark"] .section-tag {
  color: var(--up-cyan);
  background: rgba(0, 180, 216, 0.18);
}

.section-title {
  font-size: 2.35rem;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--text-main) 30%, var(--up-blue-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="dark"] .section-title {
  background: linear-gradient(135deg, #ffffff 40%, var(--up-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
}

/* Navigation & Top Bar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
}

.nav-logo {
  height: 48px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.6rem;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  position: relative;
  padding: 0.4rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--up-blue);
}

[data-theme="dark"] .nav-link:hover, [data-theme="dark"] .nav-link.active {
  color: var(--up-cyan);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2.5px;
  background: var(--up-cyan);
  border-radius: var(--radius-full);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.5rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.theme-toggle:hover {
  background: var(--bg-card-hover);
  border-color: var(--up-cyan);
}

.mobile-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.45rem;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-heading);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  text-decoration: none;
  box-shadow: var(--shadow-sm);
}

.btn-primary {
  background: linear-gradient(135deg, var(--up-blue) 0%, var(--up-blue-light) 100%);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.1);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--up-blue-dark) 0%, var(--up-blue) 100%);
  color: #ffffff;
  box-shadow: var(--shadow-md), 0 0 16px rgba(0, 180, 216, 0.35);
  transform: translateY(-2px);
}

.btn-cyan {
  background: linear-gradient(135deg, var(--up-cyan) 0%, #0077b6 100%);
  color: #ffffff;
}

.btn-cyan:hover {
  background: linear-gradient(135deg, #0096c7 0%, #023e8a 100%);
  color: #ffffff;
  box-shadow: var(--shadow-md), 0 0 16px rgba(0, 180, 216, 0.4);
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-main);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--up-blue-light);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--up-blue-light);
  border-color: var(--up-blue-light);
}

[data-theme="dark"] .btn-outline {
  color: var(--up-cyan);
  border-color: var(--up-cyan);
}

.btn-outline:hover {
  background: rgba(0, 180, 216, 0.1);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 0.5rem 0.95rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 0.95rem 1.95rem;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

/* Hero Section */
.hero {
  padding: 5rem 0 5.5rem 0;
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at 80% 20%, rgba(0, 180, 216, 0.12) 0%, transparent 60%),
              radial-gradient(circle at 10% 80%, rgba(0, 73, 144, 0.1) 0%, transparent 50%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-content {
  max-width: 650px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.1rem;
  background: rgba(0, 73, 144, 0.08);
  border: 1px solid rgba(0, 73, 144, 0.18);
  color: var(--up-blue);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}

[data-theme="dark"] .hero-badge {
  background: rgba(0, 180, 216, 0.15);
  border-color: rgba(0, 180, 216, 0.3);
  color: var(--up-cyan);
}

.hero-title {
  font-size: 3.35rem;
  line-height: 1.12;
  margin-bottom: 1.25rem;
  font-weight: 800;
}

.hero-title .gradient-text {
  background: linear-gradient(135deg, var(--up-blue) 0%, var(--up-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="dark"] .hero-title .gradient-text {
  background: linear-gradient(135deg, #38bdf8 0%, #a5f3fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: 1.2rem;
  line-height: 1.7;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  padding-top: 1.8rem;
  border-top: 1px solid var(--border-color);
}

.stat-item h3 {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--up-blue-light);
  margin-bottom: 0.2rem;
}

[data-theme="dark"] .stat-item h3 {
  color: var(--up-cyan);
}

.stat-item p {
  font-size: 0.88rem;
  color: var(--text-subtle);
  margin-bottom: 0;
}

/* Hero Visual / Interactive Card */
.hero-visual {
  position: relative;
}

.hero-card {
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-xl);
  backdrop-filter: blur(16px);
  position: relative;
  overflow: hidden;
}

.hero-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--up-blue), var(--up-cyan), var(--up-accent));
}

.hero-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.hero-canvas-wrap {
  position: relative;
  width: 100%;
  height: 280px;
  background: #0b1329;
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-canvas-overlay {
  position: absolute;
  bottom: 12px;
  left: 12px;
  right: 12px;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.85rem;
  font-size: 0.8rem;
  color: #e2e8f0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.1);
  z-index: 10;
}

/* Grotthuss Explainer Popover & Bubble */
.grotthuss-bubble-wrapper {
  display: inline-flex;
  align-items: center;
}

.grotthuss-info-btn {
  background: linear-gradient(135deg, rgba(0, 180, 216, 0.25), rgba(0, 73, 144, 0.4));
  border: 1px solid var(--up-cyan);
  color: #38bdf8;
  font-family: var(--font-heading);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: var(--transition);
  box-shadow: 0 0 10px rgba(0, 180, 216, 0.2);
}

.grotthuss-info-btn:hover {
  background: var(--up-cyan);
  color: #0f172a;
  box-shadow: 0 0 16px rgba(0, 180, 216, 0.5);
  transform: translateY(-1px);
}

.grotthuss-popover {
  position: absolute;
  top: 8px;
  left: 8px;
  right: 8px;
  bottom: 8px;
  background: rgba(11, 19, 41, 0.96);
  border: 1.5px solid var(--up-cyan);
  border-radius: var(--radius-md);
  padding: 1rem 1.15rem;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.8), 0 0 24px rgba(0, 180, 216, 0.3);
  backdrop-filter: blur(16px);
  color: #f8fafc;
  font-size: 0.83rem;
  line-height: 1.5;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transform: scale(0.96);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  overflow-y: auto;
  pointer-events: none;
}

.grotthuss-popover.active {
  opacity: 1;
  visibility: visible;
  transform: scale(1);
  pointer-events: auto;
}

.grotthuss-popover-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.65rem;
  padding-bottom: 0.45rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.grotthuss-popover-header h5 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #38bdf8;
  margin-bottom: 0;
}

.grotthuss-close-btn {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: #f8fafc;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 0.2rem 0.55rem;
  transition: var(--transition);
}

.grotthuss-close-btn:hover {
  background: #ef4444;
  border-color: #ef4444;
  color: #ffffff;
}

.grotthuss-formula {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--up-accent);
  background: rgba(0, 0, 0, 0.45);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  text-align: center;
  margin-bottom: 0.65rem;
  border: 1px solid rgba(6, 214, 160, 0.25);
}

.grotthuss-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 0.65rem 0;
  font-size: 0.76rem;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: #cbd5e1;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.grotthuss-note {
  font-size: 0.76rem;
  color: #94a3b8;
  margin-bottom: 0;
  border-top: 1px dashed rgba(255, 255, 255, 0.15);
  padding-top: 0.5rem;
}

/* Feature Grid (Co je počítačová chemie) */
.pillars-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.pillar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.85rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  position: relative;
  display: flex;
  flex-direction: column;
}

.pillar-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--up-cyan);
}

.pillar-icon {
  width: 58px;
  height: 58px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 1.35rem;
  background: rgba(0, 180, 216, 0.12);
  color: var(--up-blue-light);
  border: 1px solid rgba(0, 180, 216, 0.25);
}

[data-theme="dark"] .pillar-icon {
  color: var(--up-cyan);
}

.pillar-card h3 {
  font-size: 1.35rem;
  margin-bottom: 0.85rem;
}

.pillar-card p {
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.pillar-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: auto;
}

.pillar-tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-full);
  background: var(--bg-primary);
  color: var(--text-subtle);
  border: 1px solid var(--border-color);
}

/* Why Study at UPOL Section */
.reasons-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.reason-card {
  display: flex;
  gap: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: var(--transition);
}

.reason-card:hover {
  border-color: var(--up-blue-light);
  box-shadow: var(--shadow-lg);
}

.reason-icon-wrap {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(0, 73, 144, 0.1), rgba(0, 180, 216, 0.15));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: var(--up-blue-light);
}

/* Study Programs (Bc. & Mgr.) */
.program-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.tab-btn {
  padding: 0.85rem 1.85rem;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-muted);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn:hover {
  border-color: var(--up-blue-light);
  color: var(--up-blue-light);
}

.tab-btn.active {
  background: var(--up-blue);
  color: #ffffff;
  border-color: var(--up-blue);
  box-shadow: var(--shadow-md), 0 0 14px rgba(0, 73, 144, 0.3);
}

[data-theme="dark"] .tab-btn.active {
  background: var(--up-blue-light);
  border-color: var(--up-blue-light);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.35s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.curriculum-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.85rem;
}

.year-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
}

.year-card-header {
  background: linear-gradient(135deg, var(--up-blue-dark), var(--up-blue));
  color: #ffffff;
  padding: 1.25rem 1.5rem;
}

.year-card-header h3 {
  color: #ffffff;
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.year-card-header span {
  font-size: 0.85rem;
  color: var(--up-cyan-light);
}

.courses-list {
  list-style: none;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  flex-grow: 1;
}

.course-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  font-size: 0.92rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px dashed var(--border-color);
}

.course-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.course-code {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--up-blue-light);
  background: rgba(0, 180, 216, 0.1);
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-sm);
  margin-left: 0.5rem;
  white-space: nowrap;
}

[data-theme="dark"] .course-code {
  color: var(--up-cyan);
}

/* Master Program Highlight Box */
.mgr-highlight {
  background: linear-gradient(135deg, rgba(0, 73, 144, 0.08) 0%, rgba(0, 180, 216, 0.08) 100%);
  border: 2px solid var(--up-blue-light);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  margin-bottom: 2.5rem;
}

.mgr-highlight-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.mgr-badge {
  background: var(--up-blue);
  color: #ffffff;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
}

/* Career / Uplatnění */
.career-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.career-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem 1.4rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.career-card:hover {
  transform: translateY(-5px);
  border-color: var(--up-cyan);
  box-shadow: var(--shadow-lg);
}

.career-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: rgba(0, 180, 216, 0.12);
  color: var(--up-blue-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin: 0 auto 1.25rem auto;
}

[data-theme="dark"] .career-icon {
  color: var(--up-cyan);
}

/* Instructors / Vyučující */
.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.team-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.team-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--up-blue-light);
}

.team-card-top {
  padding: 1.75rem 1.5rem 1rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.team-avatar {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--up-blue), var(--up-cyan));
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  font-weight: 800;
  flex-shrink: 0;
  border: 3px solid var(--bg-secondary);
  box-shadow: var(--shadow-md);
}

.team-info h4 {
  font-size: 1.15rem;
  margin-bottom: 0.2rem;
}

.team-info .role {
  font-size: 0.82rem;
  color: var(--up-blue-light);
  font-weight: 600;
}

[data-theme="dark"] .team-info .role {
  color: var(--up-cyan);
}

.team-card-body {
  padding: 0 1.5rem 1.5rem 1.5rem;
  flex-grow: 1;
}

.team-card-body p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.team-research-tag {
  display: inline-block;
  font-size: 0.75rem;
  background: var(--bg-primary);
  color: var(--text-subtle);
  border: 1px solid var(--border-color);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  margin-right: 0.35rem;
  margin-bottom: 0.35rem;
}

/* Textbook Teaser Section */
.textbook-teaser {
  background: linear-gradient(135deg, var(--up-blue-dark) 0%, #032b5f 100%);
  color: #ffffff;
  border-radius: var(--radius-lg);
  padding: 3.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.textbook-teaser::after {
  content: '';
  position: absolute;
  top: -50px;
  right: -50px;
  width: 250px;
  height: 250px;
  background: radial-gradient(circle, rgba(0, 180, 216, 0.3) 0%, transparent 70%);
  border-radius: 50%;
}

.textbook-teaser-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.textbook-teaser h2 {
  color: #ffffff;
  font-size: 2.35rem;
  margin-bottom: 1rem;
}

.textbook-teaser p {
  color: #cbd5e1;
  font-size: 1.05rem;
  margin-bottom: 1.75rem;
}

.chapter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 2rem;
}

.chapter-pill {
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(6px);
  color: #ffffff;
  padding: 0.4rem 0.95rem;
  border-radius: var(--radius-full);
  font-size: 0.86rem;
  font-weight: 500;
  border: 1px solid rgba(255, 255, 255, 0.22);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
}

a.chapter-pill:hover {
  background: rgba(0, 180, 216, 0.35);
  border-color: var(--up-cyan);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 4px 14px rgba(0, 180, 216, 0.35);
}

/* Sidebar & Info box (Inspirace bioinformatikou) */
.info-sidebar-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.65fr;
  gap: 2.5rem;
}

.info-sidebar-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 1.75rem;
}

.info-box-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 1.2rem;
  padding-bottom: 0.85rem;
  border-bottom: 2px solid var(--up-blue-light);
  margin-bottom: 1.25rem;
}

.download-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: var(--transition);
  text-decoration: none;
  margin-bottom: 0.85rem;
}

.download-card:hover {
  border-color: var(--up-cyan);
  background: var(--bg-card-hover);
  transform: translateX(4px);
}

.download-icon {
  font-size: 1.75rem;
  color: var(--up-red);
}

.download-info h5 {
  font-size: 0.95rem;
  color: var(--text-main);
  margin-bottom: 0.2rem;
}

.download-info span {
  font-size: 0.78rem;
  color: var(--text-subtle);
}

/* Contact cards */
.contact-person {
  margin-bottom: 1.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

.contact-person:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.contact-person h5 {
  font-size: 1.05rem;
  margin-bottom: 0.15rem;
}

.contact-person .title {
  font-size: 0.82rem;
  color: var(--up-blue-light);
  margin-bottom: 0.5rem;
}

.contact-person a {
  display: block;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}

.contact-person a:hover {
  color: var(--up-blue);
}

/* Footer */
.footer {
  background: var(--up-blue-dark);
  color: #cbd5e1;
  padding: 4.5rem 0 2rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer h4 {
  color: #ffffff;
  font-size: 1.15rem;
  margin-bottom: 1.25rem;
}

.footer p, .footer a {
  color: #94a3b8;
  font-size: 0.9rem;
}

.footer a:hover {
  color: var(--up-cyan);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

/* ==========================================================================
   INTERACTIVE EXERCISES & TEXTBOOK STYLES
   ========================================================================== */

.ucebnice-container {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 2.5rem;
  padding: 3rem 0;
}

.ucebnice-sidebar {
  position: sticky;
  top: 96px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.toc-item a {
  display: block;
  padding: 0.55rem 0.85rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
}

.toc-item a:hover, .toc-item a.active {
  background: rgba(0, 180, 216, 0.12);
  color: var(--up-blue);
  font-weight: 700;
}

[data-theme="dark"] .toc-item a:hover, [data-theme="dark"] .toc-item a.active {
  color: var(--up-cyan);
}

.chapter-article {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 2.5rem;
}

.chapter-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 2px solid var(--border-color);
}

.chapter-number {
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--up-blue-light);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}

[data-theme="dark"] .chapter-number {
  color: var(--up-cyan);
}

.chapter-title {
  font-size: 2.2rem;
}

.interactive-box {
  background: var(--bg-primary);
  border: 2px solid var(--up-blue-light);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  margin: 2rem 0;
  box-shadow: var(--shadow-lg);
}

.interactive-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.interactive-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--up-blue);
  color: #ffffff;
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
}

.callout-remember {
  background: rgba(6, 214, 160, 0.1);
  border-left: 4px solid var(--up-accent);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.75rem 0;
}

.callout-remember h5 {
  color: #059669;
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

[data-theme="dark"] .callout-remember h5 {
  color: var(--up-accent);
}

/* Interactive Canvas / Simulation Controls */
.sim-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1rem;
  background: var(--bg-card);
  padding: 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.sim-slider-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-grow: 1;
}

.sim-slider-group label {
  font-size: 0.88rem;
  font-weight: 600;
  white-space: nowrap;
}

.sim-slider-group input[type="range"] {
  flex-grow: 1;
  accent-color: var(--up-blue-light);
}

.sim-canvas {
  width: 100%;
  height: 380px;
  background: #090d16;
  border-radius: var(--radius-md);
  display: block;
}

/* Responsive Media Queries */
@media (max-width: 1024px) {
  .hero-grid, .textbook-teaser-grid, .info-sidebar-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  
  .pillars-grid, .curriculum-grid, .team-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .career-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .ucebnice-container {
    grid-template-columns: 1fr;
  }

  .ucebnice-sidebar {
    position: static;
    max-height: none;
  }
}

@media (max-width: 768px) {
  .nav-links, .nav-actions .btn {
    display: none;
  }
  
  .mobile-toggle {
    display: block;
  }

  .hero-title {
    font-size: 2.4rem;
  }

  .hero-stats {
    grid-template-columns: 1fr;
  }

  .pillars-grid, .reasons-grid, .curriculum-grid, .team-grid, .career-grid, .footer-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 3.5rem 0;
  }

  .chapter-article {
    padding: 1.75rem;
  }
}

/* Ketcher Molecular Editor Styles */
.ketcher-tool-btn, .ketcher-atom-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.2rem 0.45rem;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  color: var(--text-main);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  height: 26px;
}

.ketcher-tool-btn:hover, .ketcher-atom-btn:hover {
  background: var(--bg-surface);
  border-color: var(--up-cyan);
  color: var(--up-cyan);
}

.ketcher-tool-btn.active, .ketcher-atom-btn.active {
  background: var(--up-blue-light);
  border-color: var(--up-cyan);
  color: #040915 !important;
}