body, h1, h2, h3, p, ul {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
}

.flex-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.content-wrapper {
  flex: 1;
  width: 90%;
  max-width: 900px;
  margin: 20px auto;
}

.site-header {
  background-color: #333;
  color: white;
  padding: 20px;
}
.site-header a {
  color: white;
  text-decoration: none;
}
.site-header nav ul {
  list-style: none;
  display: flex; 
  gap: 15px;
  margin-top: 10px;
}
.site-footer {
  background-color: #f4f4f4;
  text-align: center;
  padding: 20px;
  margin-top: auto;
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr); 
  gap: 20px;
  margin-top: 20px;
}

.grid-item {
  border: 1px solid #ccc;
  padding: 15px;
  border-radius: 5px;
}

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

  .site-header nav ul {
    flex-direction: column;
    gap: 10px;
  }
}