{"id":"electricity-cost","engine":"core","category":"math","name":"用電費用計算","fields":[{"key":"watts","label":"功率 (W)","type":"number","default":1500,"required":true,"min":0},{"key":"hours","label":"小時數 (h/d)","type":"number","default":2,"required":true,"min":0,"max":24},{"key":"days","label":"天數","type":"number","default":30,"required":true,"min":0},{"key":"rate","label":"價格 / kWh","type":"number","default":0.2,"required":true,"min":0}],"sample":{"watts":1500,"hours":2,"days":30,"rate":0.2}}