:root {
  --bg-color: #ffffff;
  --surface-color: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --accent-color: #0284c7;
  --accent-hover: #0369a1;
  --border-color: #e2e8f0;
  --focus-ring: #38bdf8;
  --progress-bg: #cbd5e1;
  --transition-speed: 300ms;
}



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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  font-size: 16px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3 {
  font-family: Georgia, 'Times New Roman', Times, serif;
  font-weight: 400;
  line-height: 1.3;
}

.app-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

.app-header {
  text-align: center;
  margin-bottom: 2rem;
}

.app-header h1 {
  font-size: 1.75rem;
  color: var(--accent-color);
  margin-bottom: 0.5rem;
}

.app-header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.infographic {
  background-color: var(--surface-color);
  border-radius: 12px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* Progress bar */
.progress-nav {
  padding: 1.5rem;
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
}

.progress-steps {
  display: flex;
  justify-content: space-between;
  list-style: none;
  position: relative;
}

.progress-steps::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--progress-bg);
  transform: translateY(-50%);
  z-index: 0;
}

.step-btn {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background-color: var(--progress-bg);
  border: 2px solid var(--surface-color);
  color: transparent;
  cursor: pointer;
  position: relative;
  z-index: 1;
  transition: all var(--transition-speed) ease;
  padding: 0;
}

.step-btn:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
}

.step-btn[aria-current="true"] {
  background-color: var(--accent-color);
  transform: scale(1.3);
}

.step-btn.completed {
  background-color: var(--accent-color);
}

/* Panels */
.panels-container {
  position: relative;
  min-height: 400px;
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr;
}

.panel {
  grid-area: 1 / 1 / 2 / 2;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-speed) ease, visibility var(--transition-speed) ease;
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  pointer-events: none;
}

.panel.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  z-index: 10;
}

.panel-image {
  flex-shrink: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 1.5rem;
  color: var(--accent-color);
}

.panel-svg {
  width: 150px;
  height: 150px;
  max-width: 100%;
}

.panel-content {
  flex-grow: 1;
}

.panel-content h2 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.panel-content p {
  margin-bottom: 1.25rem;
  font-size: 1rem;
  color: var(--text-secondary);
}

.citation-details {
  background-color: var(--bg-color);
  border-radius: 6px;
  padding: 0.75rem;
  font-size: 0.85rem;
  border: 1px solid var(--border-color);
}

.citation-details summary {
  cursor: pointer;
  color: var(--accent-color);
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.citation-details summary:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
  border-radius: 4px;
}

.citation-text {
  margin-bottom: 0;
  color: var(--text-secondary);
}

/* Controls */
.controls-nav {
  display: flex;
  justify-content: space-between;
  padding: 1.5rem;
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-color);
}

.control-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background-color: transparent;
  color: var(--accent-color);
  border: 2px solid var(--accent-color);
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.control-btn:hover:not(:disabled) {
  background-color: var(--accent-color);
  color: #ffffff;
}

.control-btn:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
}

.control-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  border-color: var(--text-secondary);
  color: var(--text-secondary);
}



/* Tablet and desktop enhancements */
@media (min-width: 768px) {
  .app-container {
    padding: 3rem 1rem;
  }
  
  .app-header h1 {
    font-size: 2.25rem;
  }
  
  .app-header p {
    font-size: 1.1rem;
  }
  
  .panel {
    flex-direction: row;
    align-items: center;
    gap: 3rem;
    padding: 3rem;
  }
  
  .panel-image {
    margin-bottom: 0;
    flex-basis: 40%;
  }
  
  .panel-svg {
    width: 250px;
    height: 250px;
  }
  
  .panel-content {
    flex-basis: 60%;
  }
  
  .panel-content h2 {
    font-size: 1.75rem;
  }
  
  .panel-content p {
    font-size: 1.1rem;
  }
}

/* Styling for tech tabs in Stage 3 */
.tech-btn {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.95rem;
}
.tech-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}
.tech-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: #fff;
    box-shadow: 0 2px 8px rgba(2, 132, 199, 0.3);
}
.tech-desc {
    background: var(--bg-color);
    padding: 1rem;
    border-radius: 8px;
    border-left: 3px solid var(--accent-color);
    font-size: 0.95rem;
    animation: fadeIn 0.3s ease-out forwards;
    color: var(--text-primary);
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- CSS DE REFERÊNCIAS --- */
.references { margin-top: 2rem; padding: 1.5rem; background: rgba(15,23,42,0.05); border-radius: 8px; font-size: 0.9rem; text-align: left; }
.references h3 { margin-top: 0; font-size: 1rem; color: var(--text-primary, #17202a); margin-bottom: 0.5rem; }
.references p { margin-bottom: 1rem; color: var(--text-secondary, #475569); }
.references ol { padding-left: 1.5rem; margin-bottom: 1rem; }
.references li { margin-bottom: 0.5rem; color: var(--text-secondary, #475569); }
.references a { color: #0ea5e9; text-decoration: none; font-weight: bold; }
.references .disclaimer { margin-top: 1rem; font-style: italic; color: #64748b; font-size: 0.85rem; border-top: 1px solid rgba(0,0,0,0.1); padding-top: 0.8rem; }