eugacc
You will need to customize css a bit here, you can use inspect element on your web browser. What I usually do is set Compress CSS in Template manager to No (in this case, you can temporarily disable jchOptimize extension), then hover on any HTML element (i.e. button, tag, text, ...) you want and right click on it and then click on inspect element, it will show you which CSS class it is using and which CSS file and the path to this element on the right side. then you can go to the file and replace it with new CSS you change.
Let me take a sample of login icon: https://prnt.sc/p4zuy4
You can use this css:
#jf_login .jf_l_modal_trigger {
height: 47px;
line-height: 47px;
text-align: center;
}
then put it into the file: /templates/ja_focus/css/custom.css (Create this file if it doesn't exist).
Do the same with other elements that you want to customize style.