This is the window size best for my page.
This is PaleMoon with the Moonscape Theme in the searchbar "about:addons" in addons search for Moonscape
Preferences can be opened in the 'pale moon' drop menu.
Here is a look at said Preference Menu.
From here a proxy can be set on the browser.
About
"Pale Moon is an Open Source, Goanna-based web browser available for various operating systems including Microsoft Windows, Mac OS and Linux (with contributed other operating system support), focusing on efficiency and customization. Make sure to get the most out of your browser!
Pale Moon offers you a browsing experience in a browser completely built from its own, independently developed source that has been forked off from Firefox/Mozilla code a number of years ago, with carefully selected features and optimizations to improve the browser's stability and user experience, while offering full customization and a growing collection of extensions and themes to make the browser truly your own." - PaleMoon Download.
"Themes allow you to change the look and feel of the user interface and personalize it to your tastes. A theme can simply change the colors of the UI or it can change every aspect of its appearance."