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

/* Base */
body {
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
  background: #f4f6f8;
  color: #333;
  padding: 20px;
}

/* Header */
header {
  text-align: center;
  background: #2c3e50;
  color: white;
  padding: 30px 20px;
  border-radius: 12px;
  margin-bottom: 20px;
}
header h1 {
  font-size: 2.5rem;
  margin-bottom: 8px;
}
header .subtitle {
  font-size: 1.2rem;
  color: #ecf0f1;
}

/* Sections */
main section {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  margin-bottom: 20px;
}
main h2 {
  font-size: 1.5rem;
  margin-bottom: 10px;
  border-bottom: 2px solid #3498db;
  padding-bottom: 5px;
  color: #2c3e50;
}
main ul {
  margin-left: 20px;
  list-style: disc;
}

/* Articles */
article h3 {
  font-size: 1.2rem;
  margin-bottom: 5px;
  color: #34495e;
}
article p {
  margin-bottom: 10px;
}
article ul {
  margin-bottom: 15px;
}

/* Two Columns */
.two-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.two-columns .column {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

/* Footer */
footer {
  text-align: center;
  margin-top: 20px;
  font-size: 0.9rem;
  color: #666;
}

/* Responsive */
@media (max-width: 800px) {
  .two-columns {
    grid-template-columns: 1fr;
  }
  header h1 {
    font-size: 2rem;
  }
}