How to reduce size of thumbnail images on product page (MOBILE) refresh theme

[Svds]

the thumbnail images on my website are too big, how do i reduce the size of them? 

STORE URL: https://facce-amsterdam.nl/

[Jack_Khan_Baba]

go to edits code search for the file section-main-product.css  Search

.product--small .thumbnail-list.slider--tablet-up .thumbnail-list__item.slider__slide {
width: calc(25% - .8rem);

}
reduce the value 25% according to your choice then save it.
if you only want to reduce the size on the mobile add the media query above it. 
if you feel any hardel feel free to ask

[Svds]

hey i am now working on the menu, but the font is not the same as the normal font as you can see in the picture, how can i match the menu font to the text font?

[Svds]

what is the media query?