All websites are made by hand using a combination of html and Javascript. Creating the websites by hand (instead of using a popular website editor like on Wordpress or WIX) means that your website will run as fast as possible. This actually gives a slight boost to search engine results and will also give a better experience for anyone looking at your page.
Your website will be created with mobile, tablet, and desktop sizes in mind. The user experience will be very similar for anyone viewing your website, regardless of what device they are using to view it on.
Websites use what are referred to as "break points." These break points are when the size of a screen changes the layout of your website. For example, when shrinking a desktop website there should be a certain point where the menu changes to the mobile version.
Your website will be carefully crafted and tested to ensure these break points make sense. Regardless of the screen used to view your website, great care will be taken to ensure that your website looks great!