What did Holy Roman Empire become?

OK I looked up a map and the Holy Roman Empire was where Germany is today (but over more countries) and I also read that it became the German Empire which became modern day Germany. But, my dad says that it became Italy and that it's capital was Rome, like Italy's today. The internet says it became part of Germany, Austria, Belgium, Croatia, Czech Republic, France, Italy, Liechtenstein, Luxembourg, Monaco, The Netherlands, Poland, San Marino, Slovenia, and Switzerland. No details on how it was destroyed(I am a crybaby about this stuff thx to Hetalia), just what it became.