:root {
  --primary-color: #4f46e5;
  --primary-hover: #4338ca;
  --secondary-color: #6b7280;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --bg-color: #ffffff;
  --surface-color: #f9fafb;
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --border-color: #e5e7eb;
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] {
  --bg-color: #111827;
  --surface-color: #1f2937;
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --border-color: #374151;
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-color);
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.navbar {
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
}

.nav-menu {
  display: flex;
  gap: 1rem;
}

.nav-item {
  background: none;
  border: none;
  padding: 8px 16px;
  border-radius: 6px;
  cursor: pointer;
  color: var(--text-secondary);
  font-weight: 500;
  transition: all 0.3s ease;
}

.nav-item:hover {
  background-color: var(--border-color);
  color: var(--text-primary);
}

.nav-item.active {
  background-color: var(--primary-color);
  color: white;
}

.theme-toggle {
  background: none;
  border: 2px solid var(--border-color);
  border-radius: 50px;
  padding: 8px 16px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  border-color: var(--primary-color);
}

[data-theme="dark"] .sun-icon {
  opacity: 0.5;
}

[data-theme="light"] .moon-icon,
:root .moon-icon {
  opacity: 0.5;
}

/* Page System */
.page {
  display: none;
  min-height: calc(100vh - 120px);
}

.page.active {
  display: block;
}

.content-section {
  padding: 4rem 0;
}

/* Home Page Sections */
.home-section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.home-section:last-child {
  border-bottom: none;
}

.home-section.alternate {
  background-color: var(--surface-color);
}

.section-content {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 400px;
}

.section-text {
  text-align: center;
  max-width: 800px;
}

.section-text h2 {
  font-size: 2.2rem;
  margin-bottom: 1rem; /* Adjusted spacing */
  color: var(--text-primary);
}

.section-btn {
  font-size: 1.1rem;
  padding: 14px 28px;
  margin-bottom: 2rem; /* Adjusted spacing */
}

.section-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 2rem;
}

/* Hero Section */
.hero {
  padding: 4rem 0;
  text-align: center;
  background: linear-gradient(135deg, var(--surface-color) 0%, var(--bg-color) 100%);
}

.hero h2 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.focus-stats {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  margin: 2rem 0;
  flex-wrap: wrap;
}

.stat-card {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
  min-width: 200px;
}

.stat-card.declining {
  border-color: var(--error-color);
  background: rgba(239, 68, 68, 0.05);
}

.stat-number {
  font-size: 3rem;
  font-weight: bold;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.declining .stat-number {
  color: var(--error-color);
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.arrow {
  font-size: 2rem;
  color: var(--text-secondary);
}

.hero-text {
  max-width: 800px;
  margin: 2rem auto 0;
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* Impact Cards */
.impact-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.impact-card {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow);
}

.impact-card h3 {
  margin-bottom: 1rem;
  color: var(--text-primary);
  font-size: 1.2rem;
}

.impact-card p {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Success Case */
.success-case {
  background: var(--surface-color);
  padding: 3rem;
  border-radius: 12px;
  text-align: center;
  margin: 3rem 0;
  border: 1px solid var(--border-color);
}

.success-stat {
  font-size: 4rem;
  font-weight: bold;
  color: var(--success-color);
  margin-bottom: 1rem;
}

.success-case p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Test Section */
.test-container {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.test-controls {
  margin-bottom: 2rem;
  display: flex;
  gap: 1rem;
  justify-content: center;
}

/* Test Preview */
.test-preview {
  margin: 2rem 0;
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(2, 40px);
  grid-template-rows: repeat(2, 40px);
  gap: 4px;
  justify-content: center;
  margin-bottom: 1rem;
}

.mini-cell {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: bold;
  color: var(--text-primary);
}

.test-instruction {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-style: italic;
}

.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  display: inline-block;
}

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

.btn-primary:hover {
  background-color: var(--primary-hover);
}

.btn-secondary {
  background-color: var(--surface-color);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

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

.back-btn {
  background: none;
  border: none;
  color: var(--primary-color);
  font-size: 1rem;
  cursor: pointer;
  margin-bottom: 1rem;
  padding: 8px 0;
}

.back-btn:hover {
  text-decoration: underline;
}

/* Page Navigation Buttons */
.page-nav-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem; /* Adjusted spacing */
  flex-wrap: wrap;
}

.page-description-text {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 3rem; /* Adjusted spacing */
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Schulte Grid Introduction Popup */
.schulte-intro-popup {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  margin-top: 2rem; /* Adjusted spacing */
  margin-bottom: 2rem; /* Adjusted spacing */
  text-align: left;
}

.intro-content h3 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.intro-content p {
  margin-bottom: 1.5rem;
  color: var(--text-secondary);
}

.instructions {
  background: var(--bg-color);
  padding: 1.5rem;
  border-radius: 8px;
  margin-bottom: 2rem;
}

.instructions h4 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.instruction-steps {
  display: grid;
  gap: 1rem;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.step-number {
  background: var(--primary-color);
  color: white;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  flex-shrink: 0;
  font-size: 0.9rem;
}

.step-content {
  flex: 1;
}

.step-content strong {
  color: var(--text-primary);
}

.timer-display {
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.grid-container {
  display: flex;
  justify-content: center;
  margin-bottom: 2rem;
}

.schulte-grid {
  display: grid;
  gap: 4px;
  background-color: var(--border-color);
  padding: 4px;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
}

.grid-4x4 {
  grid-template-columns: repeat(4, min(80px, 18vw));
  grid-template-rows: repeat(4, min(80px, 18vw));
}

.grid-3x3 {
  grid-template-columns: repeat(3, min(80px, 25vw));
  grid-template-rows: repeat(3, min(80px, 25vw));
}

.grid-5x5 {
  grid-template-columns: repeat(5, min(70px, 15vw));
  grid-template-rows: repeat(5, min(70px, 15vw));
}

.grid-cell {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--text-primary);
}

.grid-cell:hover {
  background-color: var(--primary-color);
  color: white;
  transform: scale(1.05);
}

.grid-cell.completed {
  font-weight: bold;
  color: var(--text-primary);
  background-color: var(--surface-color);
}

.grid-cell.error {
  background-color: var(--error-color);
  color: white;
  animation: shake 0.5s ease-in-out;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-5px);
  }
  75% {
    transform: translateX(5px);
  }
}

.current-number {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.test-result {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  margin-top: 2rem;
}

.test-result h3 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.result-time {
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.result-grade {
  font-size: 1.3rem;
  font-weight: bold;
  margin-bottom: 1rem;
}

.grade-excellent {
  color: var(--success-color);
}
.grade-good {
  color: var(--primary-color);
}
.grade-fair {
  color: var(--warning-color);
}
.grade-poor {
  color: var(--error-color);
}

.result-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

.mt-4 {
  margin-top: 1rem;
}

/* Training Plans */
.training-plans {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

/* Training Preview */
.training-preview {
  margin: 2rem 0;
}

.preview-plans {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.preview-plan {
  background: var(--surface-color);
  padding: 1rem;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  text-align: center;
  min-width: 120px;
}

.preview-plan h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.preview-plan p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin: 0.2rem 0;
}

.success-case-mini {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin: 2rem 0;
  padding: 1rem;
  background: var(--surface-color);
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.success-stat-mini {
  font-size: 2rem;
  font-weight: bold;
  color: var(--success-color);
}

.success-case-mini span:last-child {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.plan-card {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow);
  text-align: center;
}

.plan-card h3 {
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  font-size: 1.3rem;
}

.plan-details {
  background: var(--bg-color);
  padding: 1rem;
  border-radius: 8px;
  margin-bottom: 1rem;
  text-align: left;
}

.plan-details p {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.plan-details strong {
  color: var(--text-primary);
}

.plan-description {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

/* Training Area */
.training-header {
  margin-bottom: 2rem;
}

.training-area {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  text-align: center;
  margin-top: 2rem; /* Adjusted spacing */
}

.training-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
  text-align: center;
}

.stat {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 0.5rem;
  background: var(--bg-color);
  border-radius: 6px;
  border: 1px solid var(--border-color);
}

.stat-highlight {
  color: var(--primary-color);
  font-weight: bold;
}

.training-controls {
  margin-bottom: 2rem;
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Instructions Modal */
.instructions-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.instructions-modal-content {
  background: var(--bg-color);
  padding: 2rem;
  border-radius: 12px;
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  position: relative;
}

.close-modal {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
}

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

/* Footer */
footer {
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  padding: 2rem 0;
  text-align: center;
  color: var(--text-secondary);
}

/* Utility Classes */
.hidden {
  display: none !important;
}

/* Responsive Design */
@media (max-width: 768px) {
  .section-text h2 {
    font-size: 1.8rem;
  }

  .preview-plans {
    flex-direction: column;
    align-items: center;
  }

  .success-case-mini {
    flex-direction: column;
    gap: 0.5rem;
  }

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

  .nav-menu {
    flex-direction: column;
    gap: 0.5rem;
  }

  .nav-item {
    padding: 6px 12px;
    font-size: 0.9rem;
  }

  .hero h2 {
    font-size: 2rem;
  }

  .focus-stats {
    flex-direction: column;
    gap: 1rem;
  }

  .arrow {
    transform: rotate(90deg);
  }

  .grid-4x4 {
    grid-template-columns: repeat(4, min(60px, 22vw));
    grid-template-rows: repeat(4, min(60px, 22vw));
  }

  .grid-3x3 {
    grid-template-columns: repeat(3, min(60px, 30vw));
    grid-template-rows: repeat(3, min(60px, 30vw));
  }

  .grid-5x5 {
    grid-template-columns: repeat(5, min(50px, 18vw));
    grid-template-rows: repeat(5, min(50px, 18vw));
  }

  .grid-cell {
    font-size: 1.2rem;
  }

  .training-plans {
    grid-template-columns: 1fr;
  }

  .training-stats {
    flex-direction: column;
    gap: 1rem;
  }

  .test-controls,
  .training-controls,
  .page-nav-buttons {
    flex-direction: column;
    align-items: center;
  }

  .impact-cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

  .content-section {
    padding: 2rem 0;
  }

  .grid-4x4 {
    grid-template-columns: repeat(4, min(50px, 20vw));
    grid-template-rows: repeat(4, min(50px, 20vw));
  }

  .grid-3x3 {
    grid-template-columns: repeat(3, min(50px, 28vw));
    grid-template-rows: repeat(3, min(50px, 28vw));
  }

  .grid-5x5 {
    grid-template-columns: repeat(5, min(45px, 17vw));
    grid-template-rows: repeat(5, min(45px, 17vw));
  }

  .grid-cell {
    font-size: 1rem;
  }

  .success-stat {
    font-size: 3rem;
  }
}