CSS Help with Magento Product Description

I have a Magento and eBay store, I’m using M2E to synchronize data between magento and eBay. When I list an item in Magento, it will automatically list the item to my eBay store. Now the issue comes with the product description. I created a nice looking style for my items and I copy the html codes in my products description box, but when the product is displayed in my magento site, some CSS codes are missing but in eBay it looks perfect. It looks like somehow, magento is not reading the codes correctly like eBay. See sample below eBay Store Item Number 1343 [login to view URL]:MESCX:IT Magento Store Same item number [login to view URL] Please fine attached the html codes that I’m using, it may need some changes in order to be compatible with magento Thank you