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

:root {
  --primary: #2c3e50;
  --secondary: #3498db;
  --accent: #e74c3c;
  --light: #ecf0f1;
  --dark: #34495e;
  --success: #27ae60;
  --warning: #f39c12;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  min-height: 100vh;
}

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

header {
  background: var(--primary);
  color: white;
  padding: 2rem 0;
  text-align: center;
  border-radius: 10px;
  margin-bottom: 2rem;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
}

.nav-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 2rem;
}

.tab-btn {
  padding: 12px 24px;
  background: white;
  border: none;
  border-radius: 25px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s ease;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.tab-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.tab-btn.active {
  background: var(--secondary);
  color: white;
}

.content-section {
  background: white;
  border-radius: 10px;
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  display: none;
}

.content-section.active {
  display: block;
  animation: fadeIn 0.5s ease;
}

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

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

h2 {
  color: var(--primary);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--light);
}

h3 {
  color: var(--secondary);
  margin: 1.5rem 0 0.5rem;
}

.code-block {
  background: var(--dark);
  color: var(--light);
  padding: 1rem;
  border-radius: 5px;
  margin: 1rem 0;
  overflow-x: auto;
  font-family: "Courier New", monospace;
}

.example-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 1.5rem 0;
}

.example-box {
  background: var(--light);
  padding: 1rem;
  border-radius: 5px;
  border-left: 4px solid var(--secondary);
}

.visualization {
  background: #f8f9fa;
  border: 1px solid #dee2e6;
  border-radius: 5px;
  padding: 1rem;
  margin: 1rem 0;
}

.stack-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 1rem 0;
}

.stack-item {
  width: 200px;
  padding: 10px;
  background: var(--secondary);
  color: white;
  text-align: center;
  margin: 2px 0;
  border-radius: 3px;
}

.stack-item.current {
  background: var(--accent);
  font-weight: bold;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
}

.comparison-table th,
.comparison-table td {
  border: 1px solid #ddd;
  padding: 12px;
  text-align: left;
}

.comparison-table th {
  background: var(--primary);
  color: white;
}

.comparison-table tr:nth-child(even) {
  background: #f2f2f2;
}

.interactive-demo {
  background: #f0f8ff;
  border: 1px dashed var(--secondary);
  border-radius: 5px;
  padding: 1.5rem;
  margin: 1.5rem 0;
}

button.demo-btn {
  background: var(--success);
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 4px;
  cursor: pointer;
  margin: 5px;
}

footer {
  text-align: center;
  margin-top: 2rem;
  padding: 1rem;
  color: var(--dark);
}

@media (max-width: 768px) {
  .example-container {
    grid-template-columns: 1fr;
  }

  .nav-tabs {
    flex-direction: column;
    align-items: center;
  }

  .tab-btn {
    width: 100%;
    max-width: 300px;
  }
}