Post overlap page template

Hi, I’m new to WP and I’m having this problem where my posts are overlapping the page template when they are viewed in tag search mode. I set the post template to default template without any sidebar. Its hard to explain but here are the links to my post :

original post

viewed in tag search mode

Another example

How do I ensure that the content does not overlap the sidebar widgets on the right hand side? If any additional detail is required, please let me know. Thank you