body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #111;
  color: #eee;
}

header {
  background: #222;
  padding: 1em;
  text-align: center;
}

nav a {
  margin: 0 1em;
  color: #eee;
  text-decoration: none;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1em;
  padding: 1em;
}

.video-card {
  background: #333;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 6px rgba(0,0,0,0.5);
  padding: 0.5em;
}