body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f5f5f5;
}

header {
  background: #333;
  color: white;
  padding: 20px;
  text-align: center;
}

#gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 10px;
  padding: 10px;
}

.thumb {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-radius: 6px;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.thumb:hover {
  transform: scale(1.03);
}

.viewer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0,0,0,0.9);
  display: flex;
  align-items: center;
  justify-content: center;
}

.viewer img,
.viewer video {
  max-width: 90%;
  max-height: 90%;
}

.viewer-close {
  position: absolute;
  top: 20px;
  right: 30px;
  font-size: 40px;
  color: white;
  cursor: pointer;
}