CSS not working after refreshing page? HELP!

Hello, I am using a css padding code on my first page and it seems to work normally, but after I refresh the page the style does not apply to the block. 

After long hours here, I noticed that the DIV ID seems to change everytime I refresh the page. 

Does anyone knows how to solve this? I would be so thankful!

I am on Version 7.0– Galapagos family 

Thanks!