Container div for the fontawesome icon is inheriting background and color from its parent. The issue is you're not using a flat color, but strictly changing the alpha value of black. This causes 2 black colors with alpha of 0.2 to stack on top of one another and causes it to look like they've separate backgrounds. The button background CSS can be found below.
IN: templates/joomspirit_113/css/template.css
ON: Line 4123
You can either change it to a solid color or make the below edit to fit your usage
IN: components/com_comprofiler/plugin/templates/default/bootstrap.css?v=7304d3e307dc10eb
ON: Line 7446
FROM:
Code:
.cb_template {
background-color: inherit;
color: inherit;
}
TO:
Code:
.cb_template {
background-color: transparent;
color: inherit;
}
If you don't want the button display at all then edit your CB Login module and under "Login and Logout Options" adjust "Login and Logout Buttons" as needed.