body {
  margin: 0;
  font-family: system-ui, sans-serif;
  background: #f9f9f9;
  color: #222;
}

header {
  background: #004080;
  color: white;
  text-align: center;
  padding: 1rem;
}

h1 {
  margin: 0.2rem 0;
  font-size: 1.8rem;
}

p {
  margin: 0.5rem 0;
}

.container {
  display: flex;
  max-width: 1400px;
  margin: 0 auto;
  flex-wrap: wrap;
}

.side-ad {
  flex: 0 0 150px;
  padding: 1rem 0.5rem;
  text-align: center;
}

.main-content {
  flex: 1;
  padding: 1rem;
  min-height: 600px;
  min-width: 300px;
}

iframe {
  width: 100%;
  height: 600px;
  border: 1px solid #ccc;
  border-radius: 8px;
}

footer {
  background: #eee;
  text-align: center;
  padding: 1rem;
  font-size: 0.9rem;
  color: #666;
  margin-top: 2rem;
}

.footer-ad {
  margin: 2rem auto;
  text-align: center;
}

a {
  color: #004080;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

@media (max-width: 768px) {
  .container {
    flex-direction: column;
  }
  .side-ad {
    display: none;
  }
}