CSSボタン生成

.btn {
  background-color: #3b82f6;
  color: #ffffff;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.btn:hover {
  filter: brightness(0.9);
  transform: translateY(-1px);
}