MX's Default Look tool makes it simple to quickly adjust panel orientation and desktop themes, with a light and dark theme (default) available. The default Panel orientation is vertical. Other theme options are provided in Appearance and Windows Manager settings.
Default MX-16 desktop (Dark Theme)
After a few minutes adjusting icon and clock font sizes, wallpaper and panel background to use a transparent *.gif (enabling compositing in Settings Manager-Windows Manager Tweaks-Compositor), adding a light background opacity to the Whisker Menu in Properties (ie. application/start menu), I settled upon a light theme to match my current wallpaper:
My personalized desktop layout