add these
Code:
remove_attributes = ['height','width']
masthead_url = 'https://static.scientificamerican.com/sciam/assets/Image/newsletter/salogo.png'
extra_css = '''
.image-captioned{font-size:small;}
.feature-article__byline-authors{font-size:small;}
.article-header__inner__category{font-size:small; color:gray;}
.t_caption{font-size:small; text-align:center;}
.author-bio{font-size:small;}
.opinion-article__byline-authors{font-size:small;}
.article-author{font-size:small;}
[role="presentation"]{font-size:small;}
'''
and add '
medium-up-hide' to remove tags classes