Problems viewing the website in Firefox

Today I have been working on the recipe page and adding images next to the recipes to show the user what the finished product is meant to look like and also to make the page look more interesting. I viewed the page in Internet Explorer and everything displayed as it should but then when I went to view it in Firefox, although the images I had been working on were ok, I noticed that the carrot image down the side of the page and the links had all moved down and there was no border around the links. I then went on Google to try find a way to fix this and after trying different things I finally got it to display the website in Firefox the same as it does in Internet Explorer. To get the carrot back in the right place I had to float it to the left. To get the border to show around the links I had to change the border width from 'thin' to '2px'.