Enclose your code with the html and body tags. Size attribute does not correspond to font-size and it looks like its domain does not go beyond value 7. Furthermore font tag is not supported in HTML5. Consider this code for your case
From the matplotlib documentation, This sets the font of all items to the font specified by the kwargs object, font. Alternatively, you could also use the rcParams update method as suggested in this answer: or You can find a full list of available properties on the Customizing matplotlib page.
The font-size won’t respond like this when resizing the browser window. Instead they respond to the browser zoom/type size settings, such as if you press Ctrl and + together on the keyboard while in the browser. Media Queries You would have to look at using media queries to reduce the font-size at certain intervals where it starts breaking your design and creating scrollbars. … Read more