You'd need to apply your edits to:
app/themes/Peafowl/views/login.php
Put your updated file in; app/themes/Peafowl/overrides/views/login.php
Or ideally make a copy the Peafowl theme and put your edits in there.
Don't forget to switch to your new theme in: dashboard/settings/theme
Also, take into account that the page appears differently in mobile view, so check out the relevent classes and the corresponding CSS.