body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #f9f9f9;
  color: #333;
}

header {
  background-color: #4a90e2;
  color: white;
  padding: 1rem;
  text-align: center;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.container {
  padding: 1.5rem;
}

.toolbar {
  margin: 1rem 0;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

button {
  padding: 10px 16px;
  background: #4a90e2;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 3px 5px rgba(0,0,0,0.1);
}

button:hover {
  background-color: #3f7ecb;
}

.thumbnail-container {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
}

.thumbnail {
  border: 2px solid #ccc;
  border-radius: 10px;
  overflow: hidden;
  padding: 8px;
  background: white;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  width: 150px;
  cursor: move;
  text-align: center;
}

.thumbnail.selected {
  border-color: #4a90e2;
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.4);
}

.thumbnail img {
  width: 100%;
  display: block;
}

.thumbnail label {
  font-size: 0.8rem;
  margin-top: 5px;
  display: block;
}