Given that Steam provides support for skins, it should be hardly surprising to discover that the default UI can be modified quite extensively, even without modding know-how. Quite a few options are buried within the resources, meaning you can make many changes by following these steps.
Open Windows Explorer, either by clicking “Computer” / “This PC” or by opening another window and going to this option.
Click the hard drive on which you have Steam installed. For many users, this drive will be identified as C:. From here, enter your “Program Files” folder. You may have a “Program Files (x86)” folder; if you do, then Steam should be installed there instead, so click that folder.
Find the “Steam” folder and enter it. There should be a long list of different folder names and files, though you should be searching for a folder named “resource”, for it contains the necessary “styles” folder.
If you would prefer to be taken there automatically, you can use this link by clicking the destination bar at the top of your Windows Explorer menu. Simply choose the version you need, depending on whether your operating system is 32-bit or 64-bit: or
Inside the “styles” folder, there will be only two different files, both of which end in the .styles file format. This format does not actually exist; simply open “steam.styles” in Notepad and it will appear properly. The steam.styles file contains a large amount of text, and it is not always clear to find what you want. When viewing the style file, use “Ctrl + F” to find the element you wish to change, in this case, “font.”
Once you have found the font string, change only the first line. The default font in Windows is Arial, though you can change this to anything else. Changing the font in this file will change it across the Steam UI, so it is wise to pick something readable. Restart Steam once you have made your changes, as they will not take effect without this step. Changing anything else is a matter of restarting the client again. Changing the font is not something everyone may wish to do, but for those who have wondered whether it is possible or not, there is a way, and it is surprisingly simple. Being able to change font sizes is also welcome, simply because it makes Steam easier to use for the visually impaired.