Thumbnail alignment

Hi, I have a build a page where I input 10 thumbnails with caption. Two issues with this: 1. The size of the box border always depends on how much text is in the caption. So the longer the text, the higher the box. Is there a way I can make all boxes the same size? Meaning, that the boxes with shorter captions have some white space before the bottom border? 2. I have input 10 thumbnails behind each other, and depending on the screensize, you can usually see 3 to 5 per row. The issue here is that sometimes the first picture of a row doesn't start at the left side, but somehow gets stuck under a picture above with a long caption, and shows up on the 3rd or 4th spot in a row, and everything to the left is blank. How do I solve this? Cheers!